news SRK’s 45th Anniversary

1974 - 2019

No. 60 SRK Consulting’s International Newsletter

Over 45 years, we’ve grown into an independent, international consultancy with 45 offices, 1,400 staff, and more than 20,000 earth and water resource projects under our belt. This newsletter features key services provided for some of these projects.

Our business activities continue to be guided international regulations, and facilitate project by a spirit of entrepreneurialism and discovery. advancement. “Whether our clients are facing new mining Our guiding principles are largely owed to our challenges or seeking more efficient and cost- “spiritual leader”, Dr Oskar Steffen, who sadly effective solutions to old ones, we have always passed away in 2018. Not only was Oskar a aspired to be the consultancy of choice,” said first-rate engineer, but his personal values SRK Group Chairman and Corporate Consultant greatly influenced the evolution of SRK’s Jeff Parshley. “Many of our people have culture of belonging and responsibility, and become world-class experts in their fields reputation as a premium industry brand. and strive to add significant value to clients’ projects by meeting their unique needs.” We added to our service offerings by combining with subsurface ventilation experts Recognising the importance of accountability Mine Ventilation Services and dynamic process to our stakeholders, we support development simulation specialists Labrecque Technologies that can be sustained environmentally, socially, Inc. Our multidisciplinary expertise, global and economically. We help clients assess knowledge, and operational experience are their technical, financial, and social risks and illustrated on the following pages. devise cost-effective, technically sound solutions that respect local communities, comply with LEFT EDGE LEFT EDGE OF SIDEBAR BLOCK OF PHOTO AND COLUMN

Africa

Mandena mineral sands mine, Madagascar SRK initiated an investigation to evaluate the geotechnical properties of the orebody sands, aimed at defining the distribution and geotechnical properties of cemented strata within the orebody, to generate a site-specific geotechnical model for the deposit. The final outcomes of the investigation included a 3D geotechnical model showing the distribution and extent of the cemented strata and the geotechnical parameter ranges associated with defined geotechnical units. The model was incorporated into the mine and production planning to optimise operational planning and control.

International airport Marula tailings dam 2 Kipushi mine Cape Town International airport, one Marula Platinum Mine is in the process Kipushi is a past-producing, high-grade of three international airports in South of constructing a new tailings dam underground zinc–copper mine located Africa, currently comprises two active abutting their existing tailings dam. in the Central African Copperbelt. In runways. Airports Company South SRK completed the detail design of the 2016, Ivanhoe mines appointed SRK to Africa appointed SRK to manage the new tailings dam and assisted with the complete a pre-feasibility level mining Environmental Impact Assessment Water Use Licence Application (WULA) geotechnical investigation and design. for the re-alignment of the primary process for the project, during 2017 The project is currently focused on two runway and construction of associated and 2018. SRK is currently undertaking high-grade zinc orebodies, which will be infrastructure. Re-alignment of the construction monitoring and project mined by longhole stoping with post- the runway, built to international management of the construction phase. filling. Using geotechnical and structural specifications, will allow larger aircraft Construction completion is expected borehole logs, scanline mapping, and to land, enable airport expansion and by mid-2020. ATV data, SRK produced a geotechnical increase airport capacity. Impacts on block model and a structural model. surrounding communities included Geotechnical design parameters, based increased emissions and aircraft noise, on risk management strategies, were potentially affecting property values, derived and include backfill strength future land use planning and community and support requirements. SRK is now health and wellbeing. carrying out the feasibility level work.

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Chris Hani District Municipality This Municipality in the Eastern Cape has a Water Service Authority responsible for the provision of water and sanitation services. SRK was appointed to assist with emergency drought intervention programmes in 2016 and 2019. This included the drilling and testing of boreholes for rural water supply. In 2016, 36 villages formed part of the programme. Forty two boreholes were constructed for abstraction purposes at a combined yield of up to 53.55 L/s (4,626 m3/day). Thirteen villages formed part of the 2019 programme and 10 production boreholes were established to deliver a combined yield of 12 L/s (1,036 m3/day).

2 newly defined corridors containing high-grade N copper zones Kamoa North 0 5 10 Western Foreland kilometres exploration licences Kamoa (Ivanhoe Mines 100%) Kansoko Mine Total Copper (%) (2.0% cut-off) Kakula Mine 0 Kamoa Kakula 1 Mining Licence 2 (397.4km2) 3 Kakula West 4 5 Kamoa-Kakula Copper Project 6 Exploration Targets 7 Drill tested area 2% Total Copper grade contours >7

Environmental compliance Platreef 4 Mtpa feasibility study Kakula mine South Africa has a comprehensive In 2015, Ivanplats (Pty) Ltd investigated The Kamoa-Kakula Copper project has governance framework informing the feasibility to develop a new 4 Mtpa been independently ranked as the world’s environmental management compliance underground PGM mine known as the largest, undeveloped, high-grade copper in the mining sector. Legislation requires Platreef project, located on the Northern discovery and comprises a near-surface, mines to acquire relevant environmental Limb of South Africa’s Bushveld relatively flat-lying copper deposit located authorisations for projects. Over the Complex. The orebody would be mined within the Central African Copperbelt. SRK past two decades, SRK environmental by longhole stoping with post-filling. has assisted Kamoa since 2016 with the practitioners have provided independent SRK undertook the feasibility level geotechnical work required to develop technical assistance to major and mining geotechnical investigation and Kakula mine, which will be extracted by minor mining groups and undertaken design. The geotechnical investigation the drift and fill mining method. SRK’s numerous environmental, waste and was based on rock mass characterisation involvement with the project includes water authorisations, including specialist and a detailed structural analysis, to geotechnical investigations at the scoping studies and reviews for their South create a geotechnical block model. and pre-feasibility levels, whereby African operations. Geotechnical parameters were outlined rock mass characterisation has been for the mine design and include backfill undertaken and geotechnical mine design requirements, support requirements parameters and support requirements and strategies to manage potential provided. SRK is currently carrying out the geotechnical risks the mine may face. feasibility geotechnical investigation and design for this project.

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… Africa

Stakeholder mapping A mine’s ability to maintain good stakeholder relations has become essential in managing community expectations and proactively addressing legacy issues. In 2015, SRK was appointed by a major mining company to conduct stakeholder mapping of three of its mines in South Africa. The purpose of the assignment was to identify key external and internal stakeholders, ascertain their perceptions and behaviours, and identify measures to strengthen relationships - with the findings informing responsive stakeholder engagement plans. Understanding stakeholder dynamics is key to maintaining a mine’s social license to operate.

National Resettlement Framework Hydropower plant South African Power Pool (SAPP) The expansion of projects in Guinea In 2016, SRK was appointed to act SAPP coordinates power utilities to is encroaching on communities, as the Environmental, Health and support development and identify necessitating resettlement. Careful Safety Manager for a 9 megawatt priority power projects. Many of these management is required to guide hydropower plant. The plant is located projects are not currently bankable these processes and ensure positive on the Nkusi River on the border of because they have not adequately and sustainable outcomes for affected Hoima and Kibaale Districts, Western identified and assessed environmental peoples. Suitable legislation or a clearly Uganda. The key project structures are and social issues. SRK developed an defined and enforced framework is comprised of a concrete gravity weir, Environmental and Social Management not in place, so resettlement happens intake structure leading to a penstock Framework which the World Bank in an ad hoc fashion. In 2018, SRK (pipeline) and, subsequently, the power approved in 2018. It includes a set of was commissioned to develop a station. The penstock is located in a 905 tools to assist personnel, including National Resettlement Framework. It is m long tunnel constructed through an checklists; management plan examples; intended that a government decree be escarpment adjacent to Lake Albert. and lists of accepted environmental developed and signed into law, making SRK was responsible to ensure that and social requirements to guide the framework legally binding and the project ran in accordance to the utilities and independents to screen enforceable. International Finance Corporation key power projects that meet lenders’ Performance Standards, and to uplift requirements to ensure bankability and local HSE team skills. support implementation.

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Bisha mine Bisha is a polymetal operating mine in Eritrea, in the Horn of Africa. SRK’s team participated in multiple projects and provided operational assistance to this mine from 2014 to 2019. The work included annual reserve updates, strategic mine planning studies, pit optimisation, production schedules, equipment selection, detailed mine design, targeted short training modules for local National Mining Engineers, Geologists and Metallurgists, structural geology studies, mineral processing reviews and assistance for a highly complex mineralogy. SRK’s team assisted Bisha to overcome challenging technical issues over this period.

Sasol South Africa Limited Solar energy development Maputo harbour Sasol appointed SRK as the independent In the last decade, the South African An engineering geological study of the Environmental Assessment Practitioner government recognised that a stable entire seafront of the Maputo harbour, (EAP) to facilitate the environmental electrical grid would require sustainable in Mozambique was conducted between authorisation processes associated with energy generation and made the 2013 and 2014. The investigation the construction and operation of the decision to promote the renewable consisted of 132 rotary core boreholes Sasol Secunda Fine Ash Dam (FAD) 6 energy sector. In 2011, SRK was to average depths of about 25 m; project. The FAD 6 project plays a crucial appointed by Sato Energy Holdings 8 piezo cone penetrometer tests (CPTu) part in the life extension of the Sasol to undertake the environmental were also conducted and 104 boreholes Secunda operations facilities until 2050. authorisation process of a large-scale were drilled in 4 parallel transects on Sasol Secunda Synfuels Operations 500MW solar energy development in land and over water at existing berths awarded the 2017 Excellence Award for the Northern Cape province of South while 28 boreholes and CPTu testing stakeholder/customer focus team of the Africa, covering approximately 900 were conducted over water, at potential year to the Project Phase 1 project team. hectares. Through careful alignment new berths. In soft material, continuous The award recognises the contributions of the photovoltaic array and detailed down-hole standard penetration tests made by the multi-disciplinary project project management measures, impacts (SPT) were performed. The Maputo team which enabled the construction of on sensitive ecological habitats were Port Authority used the results of the the FAD 6 to proceed. either avoided or minimised. This project investigation to inform engineering has since been developed. design of new berths and for the upgrade of existing infrastructure.

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… Africa

Strategic planning Panda Hill feasibility study Koumbia mineral resource In Uganda, economic growth has had SRK was retained by Cradle Resources SRK prepared Mineral Resource a negative impact on the environment, to undertake the mining and estimates and models for 11 bauxite to the extent that environmental geotechnical components of the pre- deposits in Alliance Mining degradation has resulted in a decline feasibility and feasibility studies for the Commodities’ Koumbia Mining in economic growth. The cause of this Panda Hill Niobium project in south Concession area in Guinea to support degradation is inadequate environmental west Tanzania. SRK undertook mine a definitive feasibility study. The governance. While Uganda does have planning, including pit slope design and study focused on the extraction of strong environmental institutions in geotechnical characterisation for open export quality bauxite from selected place, insufficient funding to implement pit and mine infrastructure, open pit deposits and transportation to a river policies and laws has compromised optimisation, mine design, production port facility. Upon completion of the environmental governance. SRK and scheduling and cost estimation. Plant resource modelling study, SRK was a Ugandan partner were appointed site foundation analysis and design were commissioned to design and manage by the United Nations Development also completed for the feasibility study. an exploration programme aimed at Programme to compile a Strategic the collection and characterisation of Environmental Plan for the Ugandan material suitable for the preparation of government to guide environment marketing and metallurgical samples. management for the next decade.

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Mbombela: development of a Climate Change Response Policy, Strategy and Implementation Plan In response to the pressures and threats which they should level out until 2035 and The process involved extensive of climate change, it is essential that then start dropping. engagement with sectoral stakeholders all levels of government, nationally and in the municipality, province and national In 2015, SRK was appointed by the globally, develop a policy, strategy and ministeries. Mbombela local municipality to assist with implementation plan. South Africa’s the development of these documents This approach ensured the identification climate change policy framework has been to enable and guide the municipality’s of key issues that needed to be taken in development since the early 2000s. transition to a green economy and to account of and addressed in the Climate South Africa ranks high among the world’s mitigate and manage climate change Change Policy and Strategy. most significant carbon emitters per risks. The project is comprised of 3 capita; it is therefore appropriate that the The team worked closely with officials phases, namely a Climate Change country signed up to the Paris Agreement from the Mbombela Local Municipality in Response Policy, Climate Change on climate change and agreed to a peak, developing an implementation plan that Mitigation and Adaptation Strategy and plateau and decline trajectory that will see could be effectively implemented through an Implementation Plan for the Climate carbon emissions from fossil fuels (mainly municipal structures and processes. Change Mitigation strategy. coal) continue rising until 2030 – after

Genmin exploration support Tasiast coarse beneficiation Port Loko bauxite Since 2014, SRK has supported SRK has been working with mining SRK has provided technical assistance to Genmin’s exploration of iron ore companies to assess the potential to SierraMin Bauxite Holdings Ltd for their properties in Gabon and the Republic upgrade or pre-concentrate feed ahead Port Loko bauxite project in Sierra Leone of Congo. SRK’s involvement has of the process plant. This can be done since 2008. The project has grown included structural mapping, geological through a combination of screening, from an early-stage exploration project interpretation of ground and airborne bulk sorting and particle sorting. At the through to trial beneficiation and mining geophysical data, drilling assistance, Kinross Tasiast operation in Mauritania, in 2019, with full-scale mining expected development of sampling programs and SRK conducted bulk screening trials to commence in 2020. SRK has provided resource estimation assistance. SRK has to determine the upgrade potential of multi-disciplinary input to technical also provided independent valuations low to medium-grade stockpiles. The studies, as well as guiding exploration, of Genmin’s assets to the company fine fraction would be sent to the plant undertaking mineral resource estimates and their private equity partners. SRK while the coarse fraction could be heap and providing training to Company staff. continues to support Genmin’s staff leached. In addition, SRK has developed in the field with training, technical lab protocols on drillcore samples to assistance and as a French-speaking estimate where the valuable metal liaison to the Government and Gabonese will report to: coarse, medium or fine stakeholders. fractions.

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… Africa

Meya mine, Sierra Leone SRK has been involved in the project since 2016, assisting in geology development and bulk sampling. The Meya project is a field of significantly diamondiferous, steeply dipping kimberlite dykes and is geologically associated with the Koidu Mine. One of the features of the Meya dyke is the presence of high-quality diamonds, including large, rare Type IIa diamonds. These diamonds are only recovered from three other primary diamond deposits globally. SRK and the Meya team are working to better understand the morphology of the dykes as well as the diamond grade and value for resource estimation and mining.

Letšeng, Lesotho Rwanda Mines Lucara’s Karowe diamond mine The Letšeng Diamond Mine is the SRK was contracted by the Rwanda Lucara is a leading independent lowest grade primary diamond deposit Mines, Petroleum and Gas Board (RMB) producer of large, exceptional quality presently being mined globally and it to carry out exploration and evaluation of Type IIa diamonds from its 100% contains some of the world’s largest seven selected targets across Rwanda owned Karowe mine in Botswana, the and highest value diamonds. Due to the for multiple commodities. SRK led the only diamond mine in recorded history very low grade of the various rock types exploration in Rwanda, shadowed and to have produced two +1000 carat being mined, resource development supported by RMB staff who received diamonds. A positive feasibility study is challenging. Traditional evaluation training in geochemical sampling, for a potential underground operation methods are often not feasible. Resource mapping and trenching. Gold, tantalum- was completed in Q4 of 2019. SRK was development and extrapolation of grade tin-lithium and sapphire projects were retained to undertake data collection and value requires an understanding of advanced to the drilling or bulk sampling and interpretation for an extensive the volcanic history which is developed stage and RMB were supported during geotechnical drilling program and through petrography and geological marketing events in London. to complete further updates to the mapping. SRK has been involved in geological model and mineral resource geology development and training at based on the new drilling.

Letšeng for the last 5 years and is Photo caption: 1109 ct Lesedi La Rona, recovered in Nov 2015, on a sample of its presently involved in updating the current kimberlite host: EM/PK(S) 3D geology models and mineral resource in support of mine planning activities.

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Asia

Drone photogrammetry In 2019, SRK was retained by a and automated imaging at variable limestone mining company in India to camera angles. review the mine geotechnics, assess The resulting photogrammetry model opportunities for slope steepening was used to develop a comprehensive and to develop a slope management 3D structural model. A kinematic programme. The deposit occurs in a analysis helped to develop an optimal structurally complex terrain with varied bench-berm configuration to result in orientation of strata and joint systems improved economics. typical of a folded sequence, warranting detailed structural assessment for A slope management scheme was bench-berm optimisation. A drone-based also proposed to consider the specific photogrammetry mapping programme structural conditions. was adopted using predefined flight

Fuli Peridot Industry Co. Ltd. Red Bull copper project Grand T G Gold Holdings In 2017, SRK was retained by Fuli Peridot In 2015, SRK was commissioned by In 2016, SRK was commissioned by Industry Co. Ltd. to provide technical Goldstone Investment Co. Ltd. to Grand T G Gold Holdings Ltd. to provide services on its Yiqisong peridot project review a copper project in Shangri-la, an independent technical review on in Yanbian, Jilin province, China, contains Yunnan province, China as a potential the Haochayu-Ganxiewa-Xipo Gold more than one billion carats of gem investment. The Hongniu (Red Bull) mine. The gold mineralisation consists quality peridot, occurring in peridot sand copper project was under construction of a series of quartz-sulphide and inclusions in basalt. Since 2017, SRK at the time. Once commissioned, sulphide veins, veinlets, stringers, and conducted QA/QC on its exploration, underground mining methods will be disseminations in a structurally complex estimated JORC Resources, and used to supply 4,000 t/day of feed to assemblage of Archaean gneisses and prepared a technical report. Fuli is now a processing plant in order to produce amphibolites that have been intruded preparing to list the project in the Stock copper concentrates bearing silver. by granitic bodies. SRK conducted Exchange of Hong Kong Limited. SRK reported its Mineral Resources data verification, geological modelling according to JORC code, converted Ore and Mineral Resource/Ore Reserve Reserves, and carried out economic estimation according to the JORC analysis. SRK’s report supported Code, and prepared a technical report. Goldstone’s subsequent acquisition of The report was used by Grand T G in the project. the resumption of trading on the Stock Exchange of Hong Kong Ltd in 2016.

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Ciemas gold project Hindustan Zinc Ltd. Bunda Kandung From September 2017 to October SRK has provided consulting assistance In 2017, Agritrade, a Singapore-based 2018, SRK led a feasibility study to Hindustan Zinc Limited for their company, appointed SRK to conduct a gap and collaborated with China Nerin multiple operating mines and projects analysis for the Bunda Kandung open pit Engineering Co. Ltd. on the Indonesian located in India since 2005. The coal project, located in the jungle areas Ciemas Gold Project owned by P.T. commissions initially commenced of Central Kalimantan. SRK assessed Wilton Wahana Indonesia, a company from a London Stock Exchange Listing the project’s available technical data listed on the Singapore Stock Exchange. Competent Person’s Report and compliance against the JORC Code 2012. The project has four mineralised since then has comprised the annual A site visit was conducted and a number sections. SRK proposed to develop two auditing of the Mineral Resources and of gaps were identified. SRK prepared a underground mining systems to mine Ore Reserves, providing training and Gap Analysis Memo including technical 300 t/day and 1,200 t/day, respectively. mentoring and undertaking technical measures of infill drilling, topographic A back-filling mining method was used studies. Vedanta, the parent company, survey, etc. and recommended in the study. The ore will be processed expanded SRK’s role in 2018 to include subsequent measures for the company to by flotation to produce gold concentrate, its global assets in India, South Africa, close those gaps. SRK was also engaged which can be exported in initial operating Zambia and Namibia. to conduct technical due diligence reviews years, and thereafter will be further on several Agritrade projects located in roasted and milled, and then undergo a Indonesia and China. carbon-in-leach cyanidation process to produce gold doré.

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Oman mining strategy In 2017, SRK was appointed by the Public • Developing national assets and exploration targets, mineral deposits, Authority for Mining as lead consultant capabilities to ensure long-term development projects, and operations. of a consortium with Wood Mackenzie sustainability These were influenced by economic factors, including logistical and Limited and Mayer Brown LLP to deliver • Maximising the contribution of the downstream constraints/opportunities a multi-disciplinary review of the Oman mining sector to the quality of life in and the international supply and mining sector and develop a strategy to Oman support the sector’s development over demand process. the next decade, laying the foundation for Oman possess a diverse range of The strategy highlighted the its long-term sustainable growth. geological terranes and therefore the commission needed to consider both opportunities to create a more attractive The strategy considered: metalliferous and industrial mineral commercial environment for developers opportunities. and operators, whilst also identifying • Maximising the economic value of the a range of opportunities in a variety of Oman mining sector Each commodity was assessed in commodity value chains, that would • Managing the sustainable development terms of the technical considerations significantly increase the mining sector’s and utilisation of mineral resources when defining and assessing potential contribution to the Oman economy.

Sepon closure planning Caculo Cabaça Hydropower Bukit Besi SGX listing SRK assisted with the development In June 2016, SRK was appointed to SRK completed a Qualified Person’s of pre-feasibility level closure plans conduct pre-financial close due diligence Report and Independent Valuation of for Sepon, a large open-pit copper and a series of regular independent the Bukit Besi iron project in Malaysia. mine in central southern Laos. The compliance reviews, and thereafter The work was done in support of mine site included more than 40 pits, every six months to assess project Fortress Mining’s successful listing on some backfilled, and 13 waste rock performance against Equator Principles the Catalist, the secondary board of dumps. SRK reviewed the main risks, (EPs) during the construction phases. the Singapore Stock Exchange (SGX). evaluated closure options and developed This is the first major EPs compliance The Independent Valuation Report recommendations for each area. project in Chinese history, with was prepared under the Rulebook of Conceptual closure designs for waste challenges including establishment of the Catalist Board and the guidelines rock dumps and pits were developed the EPs concept for upper management, of the 2015 Edition of the VALMIN incorporating both passive and active preparation of environmental and Code. On 27 March 2019, Fortress water management infrastructure. The social management systems, and Minerals Limited commenced trading required closure works were described implementation of environmental and on the Catalist of Singapore Exchange for each mine area, on a catchment by social measures and fulfillment of Securities Trading Limited under the catchment basis. community development. After the most ticker symbol SGX.OAJ. recent audit in July 2019, the project is back on track in compliance with EPs.

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Australasia

Mount Isa closure designs SRK developed final landform designs for all Mount Isa Mines’ major landforms, including tailings storage facilities, waste rock dumps, major residual stockpiles and infrastructure areas in accordance with the closure goals and availability of rehabilitation materials and water management. SRK developed waste rock dump landform designs by undertaking stability, erosion and cover infiltration modelling and provides on-site support for grade control of the cover at the Handlebar Hill Waste Rock Dump.

Meekatharra BLUEBIRD GOLD MAJOR BLUEBIRD HISTORICAL PLANT 2.2 Mt p/a GOLD MINE 1.0 Moz

CALEDONIAN GABANINTHA FIELD 1.0 Moz BURNAKURA TENEMENTS TENEMENTS REEDYS 1.0 Moz TUCKANARRA TENEMENTS BURNAKURA GOLD PLANT 330 Kt p/a BIG BELL FIELD 3.9 Moz CUDDINGWARRA 0.8 Moz

PRIVATE GOLD PLANT Cue TUCKABIANA 1.0 Moz

DAY DAWN 1.6 Moz TUCKABIANA GOLD PLANT 1.2 Mt p/a

Century Zinc water quality studies Woodlawn u/g mining study Burnakura SRK completed a series of technical SRK completed the underground mining SRK prepared an Independent Technical studies to support closure planning at engineering components of a Feasibility Report in accordance with Canadian the Century Zinc mine, a large open Study for Heron Resources’ Woodlawn National Instrument 43-101 and an cut zinc, lead and silver mine located in Project. Woodlawn is a volcanogenic update of the Mineral Resources for North West Queensland. The objectives massive-sulphide (VMS) copper-zinc Monument Mining’s Burnakura project were to improve the understanding of deposit comprising two significant in Western Australia. SRK reviewed all the water quality that may develop in resource-based assets, the Woodlawn available data over the project’s 20- the pit lake post closure, and to assess Underground Project (WUP) and the year history and undertook additional potential post closure impacts on the Woodlawn Tailings Retreatment Project geological interpretations to inform the local and regional surface water and (WRP). SRK prepared mine designs, updated Mineral Resource Estimates, groundwater receiving environments. developed ventilation plans, outlined which will allow for refined targeting of power demand and water requirements, proposed drilling programs to extend produced personnel and mining and infill the mineralisation and achieve a equipment schedules and prepared a higher confidence and enlarged Mineral Mineral Reserves estimate. Resource. The review of the data and its relationship with the mineralisation has allowed for improved targeting of future drilling resources and refining data collection practices.

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Freida River integrated storage SRK undertook a multi-disciplinary design of an integrated hydroelectric power, mine waste rock and tailings storage facility. The design features a 190.5 m high asphalt core rockfill dam, two diversion dams, a 35.5 m high cofferdam, two diversion tunnels, and hydropower intake and conveyance system linked to a turbine facility, and a side-hill spillway. Designing for this unique setting presented challenges including the remote location, 8 m of rainfall per annum, high seismicity and steep terrain. SRK undertook complex 3D limnological modelling to characterise the behaviour of the waste rock and tailings planned for sub-aqueous disposal into the reservoir.

Capricorn Copper Structural modelling Croydon SRK provided Capricorn Copper SRK was first engaged in 1999 to review SRK prepared an Independent Specialist’s with independent reviews of the an underground coal mine’s structural Report, consisting of a technical development and reporting of resource interpretation, following a series of assessment and valuation of Crater estimates under guidelines for best complex unexpected faulting which had a Gold Mining’s base metal, graphite and practice and the JORC Code for serious impact on panel development. SRK gold exploration assets comprising the orebodies at its Capricorn Copper Mine developed an alternative structural model Croydon Project in Queensland, Australia. in North Queensland. The mine is one of and has since provided ongoing review and The report was prepared under the the largest copper development projects recalibration of the model. The modelling guidelines of the VALMIN Code (2015), in Australia. The reviews cover several approach has also been extended to other which includes the JORC Code (2012). groups of technical criteria as Capricorn project areas in the Western Coalfield. SRK conducted a high-level review of the Copper reaches milestones in the re- In recent years, the client is using the available technical information, including development and operation of the mine. structural models, along with on-site historical estimates of quantities and This ongoing review process allows geotechnical and surface and groundwater grades. SRK also assessed the project’s any issues to be highlighted early in the monitoring systems and a customised geology, Mineral Resources, exploration process and improved upon rather than spatial and temporal data analysis tool and project risks to determine the validity at the end of the resource estimation. to evaluate and better understand the of such information from a valuation interactions of groundwater behaviour perspective. and mine subsidence.

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Europe

Cukaru Peki, Serbia SRK was engaged to undertake studies on the Cukaru Peki upper zone. Prior to the PEA in 2017, SRK undertook an access and haulage study followed by a mining method assessment study and was responsible for the geology, geotechnical engineering, mine planning, cost estimation, closure planning, technical economics, risk assessment facilitation, and study management of the 2017 PEA and NI 43-101 report. After the PEA, the mining team undertook optimisation studies and the eventual mine planning and costing in the PFS. SRK was also engaged during the FS mine engineering and geotechnical work until the project was sold in early 2019.

mzn_code Ni MPO 5 MPO_base 4 MPO_bottom 3 MPOV rich_ore 2 VO 1 0

Plunge +05 Azimuth 033 0,00 125,00 250,00 375,00 500,00

Underground mine, Kazakhstan Almalyk Norilsk SRK completed a trade-off study of ore SRK undertook a maiden JORC compliant Norilsk’s Oktyabrskoe and Talnakh transport options between an operating MRE and PFS for the Almalyk mining and deposits are the largest Ni-Cu-PGE mine and an external processing facility metallurgical complex in Uzbekistan. This deposits in the world. The deposits have (road, rail, overland and aerial conveyor state owned mine is one of the largest been operated by five underground conveying/ropeway) to assess technical copper porphyry deposits in the world, mines for more than 30 years. In that feasibility and to estimate capital/ currently processing 35 Mtpa of ore time, a large volume of resource and operating costs. The objective was to from two open pits. SRK designed and grade-control data for multiple elements determine the best option to replace supervised a verification drilling program, was collected. SRK prepared geological the current complex, high-cost logistics and a multidisciplinary PFS that justified models for all five mines within seven system. An economic evaluation showed a production increase to 100 Mtpa. The months using Leapfrog software. The the road haulage or overland conveyor MRE presented a resource of 17 billion task involved creating litho-structural options would provide significant tonnes containing 44 million tonnes of models, reviewing the approach for savings compared to maintaining the contained copper and 184 million ounces delineating the higher-grade and existing system for the remaining of gold, making the United Mine one of lower-grade ores and reassessing the 14 year mine life. the largest gold deposits in the world. SRK correlation of the principal minerals. The also undertook an exploration program result was a detailed model which can that identified 25 targets in the vicinity. be used for mine planning.

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Woodsmith mine SRK has worked with Sirius Minerals on its polyhalite project in North Yorkshire, UK since 2010. Sirius is currently constructing a deep shaft mine, to around 1500 m below ground level to produce some 10 million tonnes of polyhalite per year in its first phase.

SRK has been involved during exploration, feasibility studies and construction, and most recently providing Competent Persons’ Report in support of the company’s listing in London and fund raising. SRK developed the geological model and worked with the Company to design the mining method.

DNK mine Phase 2 Gold mines of Wales Since 2011 SRK has been involved SRK completed geochemical soil of regularly spaced soil samples across with the DNK mine which exploits a sampling on behalf of Alba Mineral nine kilometers of strike length and world class chromite deposit located Resources plc (Alba) in the historic providing targets for further exploration in north-west Kazakhstan, operated Clogau-St David’s gold mine located near work. Since completing this commission, by the European Resource Group. In Dolgellau in North Wales, UK. The mine Alba has also rehabilitated the historical 2014, SRK undertook a technical study is in the Dolgellau Gold Belt, which has underground workings at Clogau on implementing the inclined caving been mined since Roman times and is and conducted a preliminary drilling method. In 2017, SRK was part of a team famed for producing the gold used in the programme investigating near-mine to determine growth opportunities at wedding rings of the British royal family. targets, yielding positive results ahead of DNK and ERG. Since 2018, SRK has further exploration work in 2020. SRK has worked with Alba on several been part of the ERG owner’s team, studies over the last five years and working on the preliminary feasibility provided field services during 2018 and study of mechanised caving methods 2019. The study included the collection and undertaking hydrogeology studies.

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… Europe

Blagodatnoye gold mine The Blagodatnoye gold mine is a large to determine suitable slope designs and operation in central Russia operated by water management strategies. SRK also Polyus Gold. The deposit is characterised evaluated the impact of blasting on the by strong bedding and structural wall rock strength and then determined features. Slope stability is further the risk of failure for each part of the pit, complicated by the presence of a stream considering local variability of rock mass and groundwater which creates high properties. We developed a series of pore pressure in the rock mass and slope and water control strategies based weakens some rock types. on the consequences and probability of failure estimation. Teams from SRK’s offices in Russia and Chile jointly collected geotechnical As a result of these studies, the client and hydrogeological data and prepared has been able to achieve more stable, a series of geotechnical block, optimised slopes. structural and hydrogeological models

Gypsum mine Curraghinalt mine SUEK Gyproc in Ireland, part of the French The Curraghinalt mine will be the SRK has, in 2019, once more undertaken company Saint-Gobain, extract first underground mine permitted in Coal Resource and Reserve audits on gypsum from shallow underground many years in Northern Ireland. The behalf of SUEK in Russia. This included room and pillar mines and an open proposed mine will produce gold, silver mobilising teams of experienced coal cut located in County Monaghan, and copper. It is expected to have a specialists for visits to SUEK’s 40 Ireland. SRK have been involved in mine life of at least 20 years. SRK have open pits, underground mines and providing underground geotechnical worked on the project for over 8 years, processing plants. SUEK is a coal, heat services at the mine since 1998. initially on the provision of studies and power company and a supplier to The work has included geotechnical for baseline and scoping work and the international coal market, producing characterisation and assessment of susequently on the mineral resource more than 100 Mtpa, with headquarters room and pillar stability, geotechnical estimation, dewatering assessment in Moscow and operations across hazard and risk assessments, annual and waste management. SRK have also Siberia and east Russia. Underground regulatory geotechnical audits of mining managed the Environmental and Social operations, mostly in the Kuzbass operations, assessment and analysis Impact Assessment and authored the Coal Basin, and many open pits supply of surface subsidence potential and Environmental Statement, involving hard coal for both internal and export numerical modelling to assess the collaboration with the engineering markets. Brown coal operations, mostly impact of undermining below 3rd party team, the planning advisors and legal in the Krasnoyarsk region, supply nearby surface infrastructure. review teams. power plants.

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Sakatti project Significant technological design challenges have been overcome to advance this world-class polymetallic VMS project in an area of protected biodiversity in Finland. SRK technical teams provided pre-feasibility study design solutions for mine access, ore extraction and waste management that won’t disturb the overlying Natura 2000 protected wetlands which host wild fauna and flora in an arctic habitat. The mine is designed to have no subsidence. Operations will use electric equipment to limit emissions. To manage waste, cemented paste backfill/waste- rock will be placed in underground voids, and benign tailings will be dry stacked on the surface.

Bystrinskoye Kazatomprom Norge Mining From 2006 to 2008, in cooperation On November 13, 2018, Kazatomprom Norway’s Bjerkreim-Sokndal layered with Russian design institutes in made its stock market debut in London intrusion is the largest in Europe at St Petersburg, SRK prepared a and Astana with an implied valuation 230 km2 and hosts important Ti-P-V Metallurgical/Processing Technical of US$3bn on initial trading. In support deposits. It is covered by Norge Mining Study for the 10 Mtpa Bystrinskoye of the listing process, SRK authored PLC’s exploration licences. Norge copper concentrator in Siberia. This a Competent Persons’ Report on the Mining engaged SRK ES in 2018 to study included laboratory and pilot uranium Mineral Assets of Kazatomprom develop the project. Our exploration testing, flowsheeting, equipment and authored simultaneous Competent has validated and expanded on definition, layouts and calculation of Person’s Report in English, Russian and historical interpretations and discovered capital and operating costs. In 2017, SRK Kazakh languages as part of a detailed extensions of mineralisation and new reviewed the project status during plant multidisciplinary due diligence process. zones. Geophysical surveys in 2019 commissioning. The concentrator was By measure of attributable production suggest a deep sulphide target. We very similar to the original SRK study from its 26 producing properties, have also completed an ESG review and and has since come online successfully, Kazatomprom was the largest producer advised on stakeholder engagement. We producing gold, copper and magnetite of natural uranium globally in 2018 will continue our excellent relationship concentrates. as well as being the second lowest with Norge Mining in 2020, and cost producer. anticipate an exciting expansion of operations.

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North America

Long Canyon mine, Nevada Hermosa SRK was selected by Newmont pit lake models and assisted with the SRK remains heavily involved in Mining Company to conduct baseline construction of a pilot Rapid Infiltration the South 32 Hermosa project in hydrogeologic studies to support basin (RIB) to predict RIB performance southern Arizona. This work focused on dewatering plans and predict impacts and to help evaluate candidate locations. developing a robust geological model, from dewatering associated with a The results of the field programs scalable to support regional exploration planned mine expansion. SRK assisted produced a body of work that led to as well as detailed feasibility study Newmont with numerous field the development of a regional-scale, work for resource estimation purposes, activities, including the installation of multi-basin 3D numerical groundwater geometallurgy, and rock mechanics. SRK a monitoring network in an adjacent flow model. Once calibrated, the model also played an integral part in developing large springs-and-wetland complex, provided dewatering estimates during the complex structural model, which and conducting pumping tests. The the LoM and estimates of impacts will underpin the current PFS effort. hydrogeologic investigations focused to groundwater which included the For almost three years, SRK has on obtaining a better understanding wetlands, and a municipal water supply been an instrumental member of the of a carbonate aquifer, the degree well field. SRK worked with Newmont development team for this Tier 1 base of hydrologic connection between during technical discussions in meetings metal project. the carbonate aquifer and abutting with the regulatory agencies which have basin-fill aquifer, and the interaction accepted the groundwater flow and pit of both aquifers with the wetlands. lake models as baseline studies to the SRK also developed geochemical and EIS that is in preparation.

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Copper Mountain mine This open pit copper mine near Since the reopening, SRK has annually requirement to be removed. The Princeton, British Columbia, resumed helped interpret monitoring data government approved this provided production in 2011 after the mine’s 1996 collected as part of waste rock and an enhanced monitoring program was suspension. tailings management plans. Samples of designed with alert levels specified for non-PAG rock confirmed its non-acid- segregation resumption. A permit condition of resumption generating characteristics, and samples was the segregation and separate Increasing waste rock placement of PAG waste rock indicated low ARD management of waste rock with options and decreasing re-handling potential. potential for acid rock drainage even have reduced operation costs. though ARD had not been seen at the Through a statistically-designed site during a century of mining. Any sampling program, SRK confirmed its potentially acid-generating (PAG) rock observation that while bulk rock could remaining after mining was to be re- be PAG, blast fines were consistently handled, used as backfill, and covered non-PAG. Based on this, our client with water to prevent oxidisation. asked for its permit segregation

Gahcho Kué Centerra Gold, BC Closure projects SRK was the Independent Engineer SRK developed a production simulation SRK has been involved in the closure for the Lenders $370M debt financing of the mine design for the extraction and Asset Retirement Obligation (ARO) for Mountain Province. Gahcho Kué, level of the Kemess Underground block cost estimation for a client with seven located in the Northwest Territories, cave mine. The model scope included mines located in four different states is a joint venture between Mountain production LHDs, secondary breaking in Mexico. The ARO costs are currently Province Diamonds and De Beers, 49% equipment, rockbreakers and crushers. being updated every two years, and 51% respectively. SRK’s multi- The simulation was used to predict involving a continuous collaboration disciplinary team completed the desktop future material handling performance with the client. SRK has identified new review and site visit, and identified risks based on various PC-BC production opportunities to optimise the closure including the logistical access to the schedules, perform routing sensitivity strategy and decrease closure costs site. All construction materials and fuel analysis, predict quarterly fleet based on site specific information had to be transported by ice road from requirements, and quantify the effects of generated by scientific and engineering Yellowknife, which only operates during design parameters on traffic interactions studies. SRK has also provided training February and March. After a successful and fleet efficiency. The model was also to the project staff, helping them to season the Lenders and Mountain used to test and optimise the location of understand the closure process as a Province closed the deal. At the end the crushers. multidisciplinary effort. of construction monitoring, SRK will conduct completion testing.

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Caving In the past three decades, modern mechanised cave mining has proven to be a successful mining method for the exploitation of large low-grade deposits that could not otherwise be economically extracted. In this decade, cave mining projects are moving to new frontiers with higher desired production rates, stronger rock masses, high caving lifts and greater depth than in the past.

The increasing speed of computing and the sophistication of numerical modelling codes enable experts to model more complex mining problems.

Robinson copper mine, Nevada Faro mine, Yukon Territory SRK assisted with management of The Faro mine was once one of the hydrology, and revegetation) and the new tailings storage facility (TSF) world’s largest lead and zinc mines. The engineering disciplines (such as civil, in 1996, and has provided a wide mine closed in 1998, when the operator geotechnical, hydrotechnical, water variety of engineering, permitting and became insolvent, leaving behind a resources, and water treatment). This closure services. From engineer-of- legacy of 320 million tonnes of acid- expert team must consider the long-term record through the 20-year life of the generating waste rock and 57 million future of the site, including the challenges original cycloned-sand TSF design, to tonnes of acid-generating tailings. posed by a changing climate and thawing design/permitting and phased annual At that time, the federal government permafrost. Our primary role is to develop construction of a 60-foot vertical assumed responsibility for the site, the engineering designs necessary to TSF expansion (with 4 miles of including managing the site to limit off- advance the Faro Mine Remediation new compacted-alluvium perimeter site impacts until a closure plan can be Plan through regulatory and early embankments), to development/ designed and implemented. implementation phases and to prepare for implementation of closure plans for the full-scale remedial works necessary SRK’s involvement in closure planning leach pads/dumps/seeps, to design/ to mitigate long-term environmental risks. began during the mine operations in construction of 5 evaporation cells, to We also provide expert support to site the 1980s. Today, SRK leads an expert pumping/piping designs, reclamation management in areas of geochemical team that brings together both scientific planning/costing, SRK has had two characterisation, water management, and disciplines (such as geochemistry, decades of challenging and rewarding design of interim remedial works. work through four mine operators.

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Dr Dennis Laubscher and Jarek Jakubec However, sophisticated visualisation is of new experience. Dr Dennis Laubscher ahead of predictive reliability for many was instrumental in the development of numerical models. The challenge is not only such techniques. He recently celebrated the complexity, but the need for accurate his 90th birthday and his appetite for input information, which is typically only news from the cave mining world has not available after the cave is operating. The diminished. We would like to wish him all success of predictive models without the best for the next decade. comprehensive calibration, especially for Although cave mining was very greenfield projects, is not very high and successful in the past two decades in does not necessarily increase confidence safety improvements, the increasing in the design compared to other empirical awareness of environmental legacy tools and benchmarking. Basic cave mining to future generations will also require principles have been postulated and reconsiderations for responsible mine proven. Moving to a new frontier requires decommissioning and closure. an update of those basic principles in light

Waste isolation pilot plant Twin Metals, Minnesota Mount Wright In 2014, a radioactive release occurred Beginning in 2015, SRK has been SRK’s open pit teams completed two at the Waste Isolation Pilot Plant providing environmental consulting and major projects on ArcelorMittal’s biggest (WIPP), an underground nuclear waste permitting expertise to Twin Metals, a iron ore operation in the world, Mount repository near Carlsbad, New Mexico, subsidiary of Antofagasta plc, for the Wright and Fire Lake in eastern Canada, contaminating parts of the facility. SRK’s development of an underground copper, from 2018 to 2019. The initial work ventilation engineers were brought in to nickel, platinum, palladium, gold and included an in-depth review of resource help with recovery efforts by developing silver mine in northern Minnesota. SRK models, mine designs and production ventilation schemes for operation with is also supporting the hydrogeological schedules. It was followed by strategic limited airflow, strategies for recovery, investigation efforts for the project, mine planning and detailed mine designs and the design and modelling of a and leading development of the site- for two major pits. SRK conducted pit new interim ventilation system. SRK wide water balance – a critical issue for optimisation for two major deposits, engineers also designed the long-term construction of a sulfide-bearing mineral selected the final pit considering the ventilation system, specifying the airflow project near the pristine Boundary company’s strategies, developed needs for the future of the facility. Waters Canoe Area Wilderness. detailed mine designs, sequenced mine In 2017, WIPP resumed its mission development and developed a detailed of nuclear waste emplacement, the production schedule for the life of primary goal of nearly three years of mine. SRK also assisted ArcelorMittal recovery efforts. in technical reports and long term mine planning.

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N Elev (Z) Kennady North SRK has provided geology development, SRK has worked with Aurora Geosciences 400.00 evaluation and resource estimation and Kennady Diamonds on the geological Present Surface for the Kennady North project, owned development and evaluation of these by Kennady Diamonds, a subsidiary kimberlites since 2013.

SOUTH 250.00 of Mountain Province Diamonds. It is LIMB Due to the unique shapes displayed by 200.00 located north of the Gahcho Kue diamond the kimberlites, new exploration and 150.00 mine that is operated by De Beers evaluation approaches were implemented 100.00 Canada in a joint venture with Mountain to develop the geology and understand 50.00 Province Diamonds. the grade distribution. NORTH 0.00 LIMB The Kennady North project includes -50.00 Resources have been classified for several significantly diamondiferous pipes the Kelvin, Faraday 1−3, and Faraday 2 -100.00 and dykes. The known pipes display LEGEND -150.00 kimberlites. Further exploration and KIMB1 -167.67 unique external morphology that has not KIMB2A KIMB2B evaluation work is warranted. KIMB3A+KIMB5 previously been documented. KIMB3B KIMB3C KIMB6 0 100m KIMB4+KIMB7 XENOLITH

Hope Bay, Nunavut Galore Creek mine Teck saturated rock fill projects

Since 2002, SRK has worked at the SRK hydrogeologists completed field Since 2008, SRK has worked with Doris North mine on the 80 km Hope studies in cooperation with the SRK Teck to develop technology for using Bay Greenstone Belt in Nunavut, and has rock mechanics and tailings teams to saturated rock fills (SRFs) for treatment helped advance this gold project from support design of an expanded mine of selenium and nitrate in waters at Teck’s the initial scoping study, through the design for the Galore Creek project, Elk Valley metallurgical coal operations. detailed engineering and construction British Columbia. The project area, In 2017, SRK and other specialists quality assurance phases. SRK provided a remote location in mountainous defined design parameters and layouts geotechnical (rock and permafrost soil), terrain with proximity to mountain for a pilot wellfield and technical and hydrotechnical, waste management glaciers, presents numerous water regulatory support during a pilot trial. As engineering, geochemistry, hydrogeology management challenges, including the of December 2019, the SRF has been and overall regulatory guidance. The potential for significant inflows to the removing nearly all nitrate and selenium tailings impoundment area designs pit and complex slope stability issues. from up to 10,000 m3/d of mine- include a precedent setting frozen core This work expanded on previous field impacted water. The technology may dam (north), and a frozen foundation investigations, slope design inputs reduce water treatment costs by millions dam (south). SRK continues consulting considering compartmentalisation, of dollars. SRK now supports Teck with towards developing and constructing dewatering system definition and mine expansion of the initial system, design more deposits and infrastructure. design trade-offs, including diversion and construction of a second, and initial of significant surface flow around or characterisation of a third. through the pits.

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South America

Chuquicamata pit closure Courtesy of Division Chuquicamata, SRK assisted in providing information for Codelco – Chile decisions on the best slope steepening alternative for closure of the pit. The methodology included three main tasks: Evaluation of the probability of failure (PF) representative of the stability conditions of pit slopes; Evaluation of economic losses derived from impact on production and costs; and generation of risk maps to compare the four closure alternatives. The results provided valuable information for decisions on the closure plan in accordance with the mine’s reference criteria for economic risk.

L‐F Contreras, E Hormazabal, R Ledezma, M Arellano. (2019). Geotechnical risk analysis for the closure alternatives of the Chuquicamata open pit.

100% Gravel Very coarse sand Coarse sand 80% Medium sand Fine sand 60% Very fine sand Silt 48% 21% Clay 40% 24% 20%

0% 2017 2018 2019

Cerro Moro Grainsize distribution monitoring Candelas lithium brine This project is located in the region SRK has been involved in various Candelas is located in the Antofagasta known as Macizo del Deseado, a gold studies relating to river dynamics for a de las Sierras District, Catamarca and silver district from low sulfidation confidential client to inform decisions Province, Argentina. In 2019, SRK’s epithermal deposits in the province on the reclamation of watercourses personnel supervised sample logging of Santa Cruz, Argentina. In 2017, SRK impacted by mining activities. One and contribution to the definition of was contracted by Estelar Resources study involves the evaluation of riverbed hydrogeological parameters of the S.A. for the development of the initial sediment grain size distributions and strata, as well as the taking of brine geochemical characterisation, acid rock the change in these with time. The samples, and reviewed and interpreted drainage/metal leaching assessment approach is to develop a database of geophysical studies carried out in the and a conceptual management plan sediment grain size distributions over area. SRK continues working on this for waste rock dumps based on the the years for statistical analyses to project, contributing to the construction potential for the production of acid identify parameters that could be used of the geological model of the deposit drainage and leaching of metals and as reliable indicators of river stability. as well as providing technical advice for metalloids. This study was developed the development of a Quality Assurance by means of static tests, optical Plan in order to update the results in the mineralogical studies, short-term metal different stages of exploration. leaching and kinetic testing.

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Pascua-Lama Since 2014, SRK has worked on the closure of the Pascua-Lama gold project on the border of Chile and Argentina, owned by Barrick Gold. The pre-feasibility level closure plan was developed for the mine pit, rock dumps, water management system, road infrastructure and cut- off wall considering the geotechnical, geochemical, hydrological and seismic issues. SRK developed the detail design and QA/QC plan of key infrastructure components of the mine closure, such as the design of the plug in the bi- national tunnel connecting Argentina and Chile.

Subfluvial tunnel and risers San Rafael geomechanical model TecPlata SRK assisted the client in the Additional resources have been In 2013, SRK designed the excavation construction of a tunnel and risers on found 1400 m below the surface sequence for the placement of rockfill the Matanza-Riachuelo project. The at San Rafael mine, but deepening protection under the dock at La Plata, project consists of a tunnel that is underground operations has become Argentina. Numerical models and 4.9 m in diameter and 12 km in length challenging. Engineers will have to analytical verifications of the background that will flush treated water into the work with high levels of rock mass stability and the stability of the sheet River La Plata. The excavation works stresses in unfavourable geomechanical piling of the lateral closing coffer were are located 40 m in the bed of the conditions. The project undertaken carried out. The anchoring system was river using double-shielded TBM. This by SRK considered the structural designed and the displacements of the tunnel will be one of the longest of its geological understanding, the rock mass containment wall were calculated. SRK kind in the world. Since January 2018, characterisation and measurements of staff made periodic visits to the site over several numerical analyses have been in-situ stresses to obtain modelling input two years to observe the progress of completed to check the geotechnical parameters and calibration. The results the work. Modifications and adjustments designs, complemented with analysis include the stope design, rib, sill and were made to the designs as the project of monitoring data and CPTu campaigns crown pillars, the assessment of the proceeded. to advise the client in the early mining sequence and recommended construction stages. support systems for maintaining a safe and profitable operation during the LOM.

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Cerro Vanguardia SRK worked for the Cerro Vanguardia of design, storage capacity assessment, mine, located in Santa Cruz, Argentina, review of geotechnical and stability from 2012-2018, validating and optimising assessment, water balance, tentative the design of several open pits. The construction procedure, operational project team analysed the geological, aspects, closure recommendations, structural and geotechnical data, material take-offs and cost estimates. determined the main geotechnical SRK has undertaken the detailed domains and characterised them for their design engineering of the embankment resistance, weathering and fracturing. and arcillary elements, including the Stability assessments at bench-berm, development of a tailings deposition inter-ramp and global scales were plan, the QMS manual, and construction undertaken for the designs proposed by procedure to allow ongoing production Cerro Vanguardia. to be deposited into the TSF while the embankment raise is undertaken. SRK completed a feasibility-level design on the TSF expansion, including the bases

x -3 SSR=1.00 SSR=1.10 [ 10 ] 150,00 137,50 125,00 112,50 SSR=1.20 SSR=1.30 100,00 87,50 75,00 62,50 50,00 SSR=1.40 SSR=1.45 37,50 25,00 12,50 0,00

Orosur Mining Salar del Rincon Computational geomechanics A deep open pit that was flooded for During 2015-18, SRK worked on the SRK has positioned itselt as a regional eleven years in Uruguay, was dewatered Rincon project in Salta, undertaking leader in the application of numerical in 2015 to carry out underground mining. a geotechnical investigation for the methods for geotechnical design and The exposed pit walls showed a large process plant and spent brine disposal analysis. This is the result of more wedge failure, leaving a 25-ton block ponds, and developed the feasibility than 10 years of practice in several hanging high above a projected mine and detailed engineering studies for the challenging projects throughout portal. SRK was called in to assess spent brine disposal facility (SBDF). The Argentina and other Latin American the risk of leaving the block in place geotechnical investigation included a countries. The numerical team also has and concluded that the chances of a site geotechnical campaign, laboratory been involved in projects located in fall could not be overlooked. The most testing and geotechnical interpretation. Central and North America, Australia, probable landing zone was located some The feasibility level study included West Asia and South Africa. One of 30 m away from the portal with a +50% the definitive location of the SBDF, the key experiences of the last 5 years chance of being hit. At the portal, the capacity assessment, water balance, is the analysis of tailings. SRK uses probability of impact was estimated as embankment design, surface water commercial and advanced material 0.35%, a low and tolerable value. management and material take-offs and models and in-house development to cost estimate. The detailed engineering predict realistic pore pressures under updated the analyses from the feasibility static and cyclic loading conditions and level study. evaluate how these impact the safety and performance of the dams.

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Chinchillas Chinchillas is a high-altitude silver, lead, and zinc deposit in northern Argentina. SRK worked on this project from 2015 to 2019 encompassing different levels of studies including preliminary economic assessments, pre-feasibility and feasibility. SRK provided mine operating cost estimates, detailed monthly plans, dilution models, waste dump designs, stockpile designs and access roads, site layout, cut-off grade, and pit optimisation. In summary, SRK engaged in detailed mine design and production planning suitable for construction and development that led to a positive construction decision for the open pit mine by 2018.

Salar de Uyuni brine deposit Geomechanical design Doce River, Brazil In 2017, the Government of Bolivia The Chuquicamata underground mine SRK has created a hydrological and appointed SRK to prepare a resource in the Atacama Desert in northern Chile hydraulic model that simulates extreme estimate of the Salar de Uyuni brine is one of the largest planned mining hydrological events that could cause a deposit. Uyuni is known as the largest projects in the world to use the method significant impact due to rising water lithium resource in the world, though no of block caving with a macro-blocks levels within the river channel. This official estimate has been published. The option to mine copper ore. CODELCO is was used to provide more accurate team then conducted hydrogeological currently finishing the detail engineering information regarding the population exploration to validate pumping stage and the construction of the impacted with the unexpected/unnatural scenarios and the geological model. main infrastructure for the project. The rise in water river level caused by the The team then developed a complex underground mine is expected to begin Fundão dam failure. This approach used numerical hydrogeological model for operations in 2019, with a 7-year ramp- a conservative scenario to simulate the both the resource estimate and the up period and a nominal production potential river flood. The model will be mine plan. SRK also provided training of 140,000 tonnes per day. The rock updated when more accurate surveying to the project staff to run their own mechanics team of SRK has been topobathimetry along the river is simulation scenarios throughout the life providing technical support to the project available. of the mine. during the last 8 years, including the prefeasibility, value, feasibility, liaison and detailed engineering stages.

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Cerro Lindo, Peru SRK was commissioned by Minera Milpo S.A.A. (Nexa Resources) to prepare an environmental study for the expansion of the processing plant to 22.5 Ktpd. The study included technical improvements of processing systems and ancillary facilities, and modifications to the desalination plant. The impacts associated with the proposed activities were identified and assessed. Occupation of new areas and dust emission due to ore transport were determined as the critical impacts. Two irrigation systems were recommended as an environmental mitigation measure; 90% of the water use would be recirculated.

Santander feasibility Inmaculada mine San Rafael mine, Peru Trevali operates the Santander Hochschild Mining operates the This mine is a deep and narrow hard rock Mining Unit in the province of Inmaculada Mining Mine Unit, a gold mine with frequent rock bursts problems Huaral, department of Lima, Peru. and silver operation in the province of due to large, open stopes left without SRK developed a study of location Páucar del Sara Sara, Peru. SRK’s work backfill. SRK provided a geotechnical rock alternatives and tailings disposal consisted of establishing exploratory mechanics study consisting of logging, methods for the project. Based on drilling plans to increase the level of mapping of underground workings, this study, the engineering design confidence in their economic viability to classifying rock mass quality to input was established at feasibility level categorise the resources as indicated, parameters for stopes design, mining for the most favourable alternative, allowing possible consideration as sequence and control strategies for corresponding to the growth of the reserves for further mining exploitation. over-excavation. By applying numerical Santander tailings dam pond at the In addition, the study considered 3D modelling of rock masses, strategies elevations for Stage 1 and Stage 2 of developing new veins for mining for mitigation of rock bursts were the facility. engineering at conceptual level. developed. One approach was to change the mining method to bench and fill or to transverse stopes in specific orebodies, optimise the mine sequence, evaluate of the paste backfill strength and design support to dynamic loading in burst- prone areas.

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MEIA expansion Atacocha Mining Company proposed the expansion of the Glory Hole open pit in Pasco, Peru and the development of new components. These involved the development of three pits, Glory Hole, GH West Satellite, and GH East Satellite; the development of the Atacocha waste dumps and two internal low grade pit fields. The objective was to identify and evaluate the environmental and social impacts that could occur due to the activities proposed during the construction, operation and closure stages; and establish environmental management strategies.

Veladero mine Tucush Buenos Aires Metro The Veladero mine is located in Argentina, The Tucush tailings deposit detailed In 2015, SRK developed the conceptual-to- in the west of the San Juan Province, engineering consisted of pulp and construction design for extending Line H, 5 km from the Chilean border. The current filtered tailings for the Contonga of the Buenos Aires Metro. SRK assumed mine plan includes mining operations mine located in Peru. Studies and full responsibility, leading the geological, continuing through 2024 with residual designs were developed at a detailed geotechnical, structural, waterproofing gold leaching continuing through 2029. engineering level to raise capacity, and procedural aspects of constructing In 2018/19, SRK updated the closure plan beginning with a pulp arrangement and five underground caverns, one cut-and- at the pre-feasibility level, evaluating the a filtering process for the final stage. cover station,1.2 km of warehouses and geochemical, geotechnical, seismic and The designs considered the harsh underground parking and 3.2 km of inter- hydrological aspects. The facilities included topographic conditions and geological, station tunnels. One landmark achievement three open pits, the heap leach valley, the geotechnical and hydrological aspects was the first head-bench excavation of an process plant, three waste rock dumps for technical and environmental viability. underground cavern. SRK’s underground and the camp and hotel facilities. expertise in Argentina spans 20 years.

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