Sustainability aspects of the Beverley Uranium Mines by Peter Woods MAusIMM(CP), Environment, Safety and Health Manager, Heathgate Resources Pty Ltd
Introduction
eathgate Resources Pty Ltd (Heathgate) operates the Htechnologically advanced in situ recovery (ISR) Beverley and Beverley North uranium mines, located about 550 km north of Adelaide, South Australia, on the arid plains between the northern Flinders Ranges and Lake Frome.
The original Beverley Uranium Mine has operated since 2000 under close environmental scrutiny (Jeuken et al, 2008; Märten et al, in press). Since the discovery (see Curtis, Brunt and Binks, 1990) and mining of the original Beverley uranium resources, additional uranium deposits have been found in the area and mining is extending over a larger area. In 2009 Heathgate’s exploration group discovered the first of several new deposits to the north of Beverley. The Pepegoona and Pannikan deposits are the first ISR uranium satellite mines in Australia and form the nuclei of the Beverley North Project.
Sustainability of the Beverley operations is achieved through an environmental management strategy, Figure 1. Location of Beverley Mines. developed in partnership with regulatory authorities. This strategy focuses on monitoring activities which of solution mining. This has been without the physical removal of ore and are undertaken to ensure that the mine described in detail in the original EIS overburden. It requires multiple close– complies with regulatory requirements and recent Public Environment Reports spaced wells into the ore, pipelines and has an acceptable impact on the and in several conference papers (eg to and from the wells and a surface environment. The ‘social licence to Jeuken et al, 2008). ISR mines have processing plant, but does not require operate’ aspect is also important, many advantages when compared with either underground mine workings or and extends to relationships with traditional mines since they have: open cut pits, or waste rock dumps and our stakeholders, including the State tailings management facilities. The and Federal governments, the local • Minimal surface disturbance; mine’s location is shown in Figure 1 traditional owners and landholders, • No ore surface exposure; and the general arrangement of ISR our employees and contractors and to • No waste rock dumps; facilities at Beverley and Beverley the wider community beyond. • No tailings dams; and North are shown in Figures 2 and 3 • Greatly reduced radiation exposure to respectively. Mining method workers and the community at large. ISR mining is feasible where the Heathgate undertakes mining by the ISR mining removes economic geological and hydrological in situ recovery (ISR) process, a form mineralisation from the host ore characteristics of the orebody are
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rich solution is pumped back to the surface via multiple extraction wells to a uranium processing plant; either the main plant at Beverley or a smaller satellite plant at Beverley North.
At the Beverley processing plant, uranium is stripped from the solution onto resin beads and held for later precipitation, drying and packaging. At Beverley North uranium–loaded resin is trucked to the main plant at Beverley; at Beverley the whole process takes place in the main plant. The barren mining solution is refortified to replace used reagents and recycled back to the injection wells. Within any given area, this cycle continues until the uranium remaining Figure 2. Schematic of mining at Beverley. in the ore is depleted to uneconomic levels. Typically mining solution is circulated 50 to 100 times through a given patch of mined ore.
The design and operation of the wellfield controls the flow of mining solution through the mineralisation. Operations are generally limited to only parts of wellfields at any one time, although the whole of each wellfield will eventually be mined during the life of the mine.
Injection and extraction wells are closely spaced, at present between 12 – 40 m apart. Within the active mining area at Beverley North, the volume of solutions extracted is slightly more than the volume injected. This ‘bleed’ ensures a slight continuous inflow from the surrounding formation into the active mining area and minimises leakage of Figure 3. Schematic of satellite mining at Beverley North. mining solutions away from the active mining area (excursions). At Beverley, ‘bleed’ is small and an essentially favourable. This is the case with reagents are commonly oxygen or neutral water balance is maintained the Beverley and Beverley North hydrogen peroxide, though other due to the very limited extent of the uranium deposits, where the uranium alternatives may be used. Complexing ore–bearing aquifer material at that is easily mobilised. The mineralised reagents may be acidic or alkaline. location, and its lack of connection to zone occurs in highly permeable Our present operations are an acidic regional groundwater systems. sediments that are confined by largely leach, using dilute sulfuric acid with impermeable strata above and below added hydrogen peroxide. Water is reused wherever possible. In the ore body and the mineralised zone the end, a small volume of saline water is saturated with groundwater. The mining solution (lixiviant) is passed cannot be reused. This is disposed of via multiple injection wells into a to the mining aquifer at Beverley, which In the ISR process, natural permeable orebody where it mobilises is an isolated sand body not connected groundwater from the mineralised the uranium contained in the ore. In to the flowing regional groundwater zone requires the addition of oxidising this process, some of the reagents systems. Originally considered by and complexing reagents. Oxidising are consumed. The resulting uranium– some to be controversial, because of
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the effective isolation of this saline water, the injection of waste water into the mined–out aquifer at Beverley has been confirmed as best practice by government reviews (CSIRO Land and Water, 2004; Geoscience Australian and Chief Scientist as quoted by the Minister for the Environment, Heritage and the Arts when announcing the approval of the Beverley extension,
20081.)
In contrast, at Beverley North where the uranium is located in a more regional aquifer, saline water disposal is not part of current approvals and additional measures for the protection of groundwater after mining must be Figure 4. Wellfield at Beverley (undisturbed desert at far left). undertaken (Heathgate 2010a, 2011; Kalka, Märten, and Woods, 2011).
Regulation and reporting Beverley’s annual environment report For the past few years Heathgate has The operations at Beverley are subject (since 2008 called the Mining and met its target of 20 per cent indigenous to stringent environmental regulations. Rehabilitation Compliance Report employment at Beverley; this is a The mines operate in accordance (MARCR) to meet local regulator goal we will continue try to maintain with the environmental standards guidelines (PIRSA, 2007)) has been in the future. At Beverley there is a and procedures initiated through available to the public since mining visitor’s centre that displays cultural a comprehensive environmental commenced (eg, Heathgate, 2010b). information, photographs and facts impact assessment process which The South Australian Environment about the Adnyamathanha people. incorporates input from State and Protection Authority is expected to Commonwealth governments as make the radiation reports public in Ongoing public well as from the broader community the near future. consultation and through consultation. This process interaction is ongoing as continual improvement Native title and is sought by all parties. As well indigenous relations as the original Beverley EIS Heathgate’s community engagement (Heathgate, 1998), thorough reviews Heathgate enjoys a strong working plans are part of the published and updating of environmental and relationship with the Adnyamathanha MARPs (Heathgate, 2008; 2011) and radiation protection aspects, and people, who are the traditional owners were subject to review and approval public consultation arrangements, and Native Title holders for the area by both state and commonwealth were undertaken as part of the where Beverley is located. Mining regulators. Formal meetings are held Public Environmental Report (PER) agreements have been in place for the with state regulators on a quarterly processes for the extension of mining life of the mines. basis and with combined state and at Beverley (Heathgate, 2007) and commonwealth regulators twice a Beverley North (Heathgate, 2010a). A new Beverley mining agreement year, together with many informal At the same time, significant review including Beverley North was meetings. Informal meetings are held and associated updates to its approved by Heathgate and the with local stakeholders in addition Radiation and Radioactive Waste Adnyamathanha community in May to the Adnyamathanha people, Management Plans was undertaken 2010. This ensures the continuance notably neighbouring pastoralists (Kutty et al, 2010). The current of royalty payments, community and the nearby Arkaroola Wilderness Mining and Rehabilitation Programs payments and employment Sanctuary. (MARP) for the Beverley and Beverley opportunities for Adnyamathanha North mines are public documents people. As a minimum Heathgate Heathgate is also a regular participant (Heathgate, 2008; 2011) and the meets quarterly with the in industry conferences (see reference South Australian Environment Adnyamathanha people, and several list for a selection) and hosts many site Protection Authority is expected to heritage clearances are undertaken visits each year from industry groups, make the radiation plans public in the in most years, depending on the level miners and explorers from Australia near future. of exploration and development. and other countries, regulators from
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Figure 5. Workers in a Beverley wellfield. Figure 6. Progressive rehabilitation of former exploration camp site (in a naturally patchy landscape).
Australian states, the commonwealth Beverley situation; they state ‘… there studies are also registered on the and overseas, regional development is considered to be no potential relevant government databases and boards and non–government for mining–affected water from the are thus available to researchers and organisations, including the Friends of Beverley project to enter the GAB’, investigators world–wide. Heathgate the Earth. page 23). The GAB is not present at also co–operates with other regional the location of the current Beverley environmental studies such as the Groundwater protection North operations; there, fractured rock distribution of the Lake Eyre Dragon and monitoring (bedrock) constitutes the underlying (Pedler and Neilly, 2010). aquifer which is monitored. Sustainable operation of the mine Post mining rehabilitation includes maintaining acceptable Other environmental impacts on the environment during protection and Wellfields are rehabilitated through operations and following mine closure. pressure grouting of old wells with Because of the nature of mining, monitoring sulphate resistant cement such that with low surface impact, much of penetrations into the mined aquifer the environmental protection effort • Management plans and monitoring are effectively sealed to prevent is groundwater related. The mined are undertaken of several other migration of groundwater to overlying aquifers at Beverley are recognised environmental and cultural aspects: or underlying aquifers. On the surface, as having low environmental value. In • Soils and creek sediments; obsolete infrastructure such as their natural state they are brackish • Vegetation; wellhouses, wellheads and surface to salty and too radioactive for any • Fauna; piping are recovered for re–use potable, agricultural or environmental • Surface water; elsewhere in the mines or for disposal. use, and also contain naturally high • Air quality; The surface is rehabilitated, which concentrations of fluoride. • Heritage; may include re–spreading of soil and • Third party issues (infrastructure etc). scarification, or the encouragement of Confirmation of proper control of volunteer vegetation which has been mining solution and waste water Since the PERs, programs have been effective in many areas. within the active regions of the mined based on a risk assessment approach aquifers is accomplished through (Woods et al, 2009; Heathgate; 2008, In the long term, the plant and other regular groundwater monitoring using 2010a). Results of these programs, in infrastructure that is not passed onto a comprehensive network of monitor common with groundwater monitoring, future responsible parties (eg water wells completed in lateral extensions are reported on publically in the Annual supply wells will be handed over to of the mined and adjacent aquifers. Environmental Report/MARCR. pastoral interests) will also be either Additional monitoring is undertaken relocated, such as the camp buildings, in underlying and overlying aquifers, Observations of routine monitoring or demolished for appropriate recycling although the risk to the underlying programs are sometimes of external or disposal and the area returned to aquifers including, at Beverley, the interest, such as an extension of the pastoral land use. Great Artesian Basin (GAB), has been known range of the Dusky Hopping assessed as not a credible risk (see Mouse (Waudby and How, 2008). Some progressive rehabilitation has CSIRO Land and Water, 2004 for the The results of fauna and vegetation been undertaken to date (Woods et
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al, 2010), but with the winding down states and countries. The thorough Heathgate, 2010b Beverley Uranium Mine ML 6321 of mining at the original Beverley process for the Beverley extension, and associated EMLs 6048-6052 inclusive deposits the focus on progressive Mining and Rehabilitation Compliance Report approved in 2008, was the basis for 2009. Bev-Report [online], 131, 31 March 2010. rehabilitation will increase from 2011. the later commonwealth best practice Available from:
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