LBMA RSG Rev. 02 Independent Reasonable Assurance Report September For third-party audits based on ISAE 3000 2020

Independent Reasonable Assurance Report to PORTOVESME SRL on its Refiner’s Compliance Report 2019 for the London Bullion Market Association’s Responsible Silver Guidance

To the Board of Directors of PORTOVESME SRL

We were engaged by Refiner to provide reasonable assurance on its Refiner’s Compliance Report for the year ended 31 December 2019. The assurance scope consists of the Refiner’s Compliance Report.

Management’s Responsibilities

The Management of PORTOVESME SRL is responsible for the preparation and presentation of the Refiner’s Compliance Report in accordance with the LBMA Responsible Silver Guidance (v.1) (the “Guidance”). This responsibility includes establishing appropriate risk management and internal controls from which the reported information is derived. The criteria identified by the Management as relevant for demonstrating compliance with the Guidance are the activities described within the Refiner’s Compliance Report.

Auditor’s Responsibilities

Our responsibility is to carry out a reasonable assurance engagement in order to express a conclusion based on the work performed. We conducted our assurance engagement in accordance with International Standard on Assurance Engagements ISAE 3000 Assurance Engagements other than Audits or Reviews of Historical Financial Information issued by the International Auditing and Assurance Standards Board and the guidance set out in the LBMA Responsible Silver Programme - Third Party Audit Guidance for ISAE 3000 Auditors (the “Audit Guidance”). This report has been prepared for Refiner for the purpose of assisting the Management in determining whether PORTOVESME SRL has complied with the Guidance and for no other purpose. Our assurance report is made solely to PORTOVESME SRL in accordance with the terms of our engagement. We do not accept or assume responsibility to anyone other than PORTOVESME SRL for our work, or for the conclusions we have reached in the assurance report.

Inherent limitations

Non-financial information, such as that included in the Refiner’s Compliance Report, is subject to more inherent limitations than financial information, given the more qualitative characteristics of the subject matter and the methods used for determining such information. The methods used by Refiners to comply with the Guidance may differ. It is important to read the PORTOVESME SRL’s silver supply chain policy available on PORTOVESME SRL’s website: https://www.portovesme.it/en/about-us/Pages/Supply-Chain-Policy.aspx.

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LBMA RSG Rev. 02 Independent Reasonable Assurance Report September For third-party audits based on ISAE 3000 2020

Independence and competency statement

In conducting our engagement, we have complied with the applicable requirements of the Code of Ethics for Professional Accountants issued by the International Ethics Standards Board for Accountants, which is founded on fundamental principles of integrity, objectivity, professional competence and due care, confidentiality and professional behaviour. We confirm that we satisfy the criteria for assurance providers as set out in out in the Audit Guidance to carry out the assurance engagement.

Conclusion

In our opinion, the PORTOVESME SRL’s Refiner’s Compliance Report for the year ended 31 December 2019, in all material respects, describes fairly the activities undertaken during the year to demonstrate compliance, and management’s overall conclusion contained therein, is in accordance with the requirements of the LBMA Responsible Silver Guidance (v.1).

Bureau Veritas September 16, 2020 Milan, Italy

2 Portovesme s.r.l.

Table1: Refiner’s details

Company Name: Portovesme s.r.l.

Entities and Location:  Portovesme s.r.l. SP n. 2 Carbonia - km 16,5 – 09010 Portoscuso (Italy);  Portovesme s.r.l. Località Pixina Linu – 09037 (Italy); Reporting year-end: 31/12/2019 Date of Report 31/05/2020 Senior management responsible for this report Davide Garofalo Responsible Sourcing Officer Maria Vittoria Asara History Portovesme s.r.l. was established on 2nd July 1999 by the acquisition by Glencore International AG from ENI of both the production site in Portoscuso - started up in 1970 - and the site in San Gavino, started up in 1929. Portovesme s.r.l. is totally owned as subsidiary of Glencore International AG, European leader in the trading of commodities and non ferrous metals in particular. Portovesme s.r.l. is the only Italian primary producer of Zinc, Lead and Silver from raw minerals, with size aligned to the highest international producers. At the moment Portovesme s.r.l. employs 655 direct workers and about 700 external contractors people, belonging to companies which permanently work in the plant. Portovesme s.r.l. in owns and operates two production sites and a landfill: • one site is located in Portoscuso (Carbonia-Iglesias) and produces Lead, Zinc and sulphuric acid as byproduct from raw materials and the recovery of metallurgical wastes; • the other site is located in San Gavino Monreale and is committed to the Lead refining and production of Silver and Gold; • Genna Luas landfill is located in the municipality of Iglesias – Carbonia and is devoted to the disposal of the process wastes from both sites. The following are the main production areas of the 2 manufacturing sites:

WAELZ ZINC LINE ROTATORY KILNS • The rotatory Waelz kilns treat EAF dusts and residues from other PV process (water treatment sludges) • The process is a reduction of the zinc by addition of anthracite and CaO: the final product is a Waelz Oxide with 60-62 % of Zn • This oxide is sent to the SX plant without a washing step or to the L.O.W. washing plant for a further delivery to the Roaster. SX SOLVENT EXTRACTION Consists of three main sections: • Leaching section: the waelz oxide (Zn 60 %) and KSS oxide (Zn 38%) are leached to produce a ZnSO4 solution (PLS) • Solvent extraction section: the organic solvent (D2EHPA + kerosene) extracts the zinc from PLS and then exchanges metal/acidity with the solution going to the cells house; • Bleed Treatment: Cd and Cu are extracted from the inorganic circuit like cement while the SO4-- like Gypsum . LURGI ROASTER AND ACID PLANT • The traditional Electrolytic process consists in various sections: Roaster; Leaching; Cells room; Casting; • Zinc concs and washed waelz oxide are roasted in the fluid bed furnace, obtaining calcine and sulphuric gas; • SO2 gas is mixed with the gas stream from the KSS lead furnace and treated in a double catalysis plant which produces sulphuric acid ZINC LINE – CELL HOUSE • In the leaching plant the calcine (with 55-60 % of Zn) is leached through several process stages; • zinc solution is purified and sent to the cell room, and added with the stream from SX: here the Zn is extracted in cathodes via an electrolitical process; • cathodes are casted in form of SHG Zinc ingots; • Pb and Ag are recovered in the sludge residues, sent to treatment in the KSS plant LEAD LINE - KIVCET PLANT • The plant treats Lead concentrates, Pb/Ag Sulphates and battery paste in a flash smelting process; • Final production consists in decopperized Lead (95% of lead content), which is refined in San Gavino. • Copper is recovered in by products (copper matte, copper drosses) available for sale. LEAD LINE - SAN GAVINO • San Gavino refines the decopperised Lead from KSS • The refining process is a thermic liquation-alligation that produces saleable refined Lead and Lead alloys. • Silver and gold are extracted from the thermic refinery in form of rich alloys; • In the precious metal section (Leferrer and TBRC) silver is concentrated in different stages and then it is refined in electrolytic process; • Silver is casted in ingots available for sale. Portovesme has a tolling contract with Glencore. Raw materials are owned by Glencore and received by Portovesme to treat them and produce base metals, including silver. Glencore collect from raw materials suppliers all informations needed to perform the due diligence in Compliance with LBMA and OECD guidance and pass the info to Portovesme. Methodological notes Portovesme s.r.l. receives feed materials for its plants - which naturally bear precious metals – from various producers from all over the world. The purpose of the company productive process is to produce nonferrous metals such as Lead, Zinc, Silver and Gold in the highest environmental

Compliance report 2019 Portovesme s.r.l. 1 Portovesme s.r.l.

respect and with the highest possible extraction yields. Precious metals produced in this way are sent back to Glencore that sell them to main precious metals manufactures.

Compliance report 2019 Portovesme s.r.l. 2 Portovesme s.r.l.

Portovesme s.r.l. EVALUATION

Table 2: Summary of activities undertaken to demonstrate. Compliance

Step 1: Establish strong company management systems

Compliance Statement with Requirement: We have fully complied with Step 1: Establish strong company management systems

1. Has the refiner adopted a company policy regarding due diligence for supply chains of Silver? Portovesme s.r.l. has adopted a policy and procedures regarding due diligence for the supply chain of Silver.

Comments and Demonstration of Compliance: In 2019, we started formalizing our supply chain policy for Silver responsible sourced metal which is based on our Code of Conduct and ethics and compliance policy. During the reporting year, we further continued to formalize our supply chain policy for Silver which is consistent with the model set out in the Annex II of the OECD due diligence guidance. This sets out our responsibility for conducting risk based due diligence, screening and monitoring of all transactions and governance structures in place. The latest policy on responsibly – sourced metals can be found on our web site.

2. Has the refiner set up an internal management structure to support supply chain due diligence? Portovesme s.r.l. has set up an internal management structure to support supply chain due diligence: the activity analysis are compliant with the policy and procedures regarding due diligence for the supply chain of Silver.

Comments and Demonstration of Compliance: An internal management system has been set up to define the governance, roles and responsibilities, internal audits, communication and senior management review according to the adopted policy. The Responsible sourcing Officer has been assigned to design, supervise and review the overall process, and has a direct line of reporting to the executive committee. The management system has been updated in compliance with the Version 1 of the Responsible Silver Guidance. The due diligence process in place includes the documentation and information collection in order to ensure suppliers compliance with the local environmental regulation and all legal provisions regarding protection of the environment and sustainable development. Indeed, in 2020 Portovesme s.r.l. will enforce his supply chain due diligence policy and system, by integrating the supplier’s assessment with a deeper evaluation on environmental and social aspects according to Glencore policy and procedures.

3. Has the refiner established a strong internal system of due diligence, controls and transparency over Silver supply chain, including traceability an identification of other supply chain actors?

Comments and Demonstration of Compliance: We have a very flexible process with many receipts, and specific documents must be received and transactional details entered before we process any silver – bearing and other potential conflict materials. Each lot received is accurately registered in our transactional system and ensures complete traceability within our production streams. Specific controls regarding received materials (evaluation of quality through laboratory analysis, transportation documents, weight) are carried out before processing incoming material as outlined in our internal guidelines. Regular training of our employees ensures that our guidelines are followed through; any form of nonconformance is unacceptable and reported to the compliance officer and senior management.

4. Has the refiner strengthened company engagement with silver supplying counterparties, and where possible, assist Silver supplying counterparties in building due diligence capabilities?

Comments and Demonstration of Compliance: During the reporting period, Portovesme s.r.l. has strengthened company engagement with silver supplying counterparts, as well as other suppliers of potentially conflict minerals. In 2018, we started the process to further modify our supplier agreements so that they make reference to the OECD guidelines. According to the Business Policy assumed by the Board of Directors, Portovesme s.r.l. doesn’t deal with a small scale artisanal miners, and the risk to come in contact with raw materials, containing Precious Metals, supplied by counterparts who use mercury in his extractive processes, is absolutely nothing, considering also the fact that every ingoing raw or semi – finished product material is preliminary subject to a specific laboratory analysis aimed to detect the presence of any kind of deleterious element.

Compliance report 2019 Portovesme s.r.l. 3 Portovesme s.r.l.

5. Has the refiner established a company – wide communication mechanism to promote broad based employee participation and risk identification to management?

Comments and Demonstration of Compliance: Portovesme s.r.l. has developed a mechanism allowing employees to raise concerns over the silver supply chain or other identified risks regarding conflict minerals or other compliance issues. A functional mailbox has been established which is reviewed by the Responsible Sourcing Officer of Portovesme s.r.l. Step 2: Identify and assess risks in the supply chain

Compliance Statement with Requirement: We have fully complied with Step 2: Identify and assess risks in the supply chain.

1. Does the refiner has a process to identify risks in the supply chain? Portovesme s.r.l. has processes in place to identify the risks in the supply chain.

Comments and Demonstration of Compliance: We identify and assess risks in the supply chain: for every supplier we have established a client database and allocated a risk profile according to our risk profile criteria. This process is now a formal requirement before entering any business relationship with any Precious Metal counterpart, including but not limited to Silver. Our due diligence process is carried out on a risk – based approach. This process includes the request and review of the suppliers’ compliance with the local environmental regulation and the legal provisions of the environment and sustainable development; furthermore, Portovesme s.r.l. will integrate its supplier assessment with a very detailed evaluation on environmental and social aspects.

2 Does the refiner assess risks in light of the standards of their due diligence system? Portovesme s.r.l. assesses the risk in light of the standards of its due diligence system

Comments and Demonstration of Compliance: Supply chain due diligence comprising all measures required by LBMA is performed before entering into a business relationship with any silver or other conflict minerals supplying counterpart. We perform enhanced due diligence for higher risks categories, which includes all silver-bearing mining material and where silver potentially originates from or transits via conflict affected areas and areas with human rights abuse, child labour or other high risk factors including the presence of small-scale artisanal miners that could use mercury in extractive process or the presence of World Heritage Sites. In addition, we conduct appropriate scrutiny and monitoring of transactions undertaken through the course of the relationship following a risk based approach. If our due diligence assessment leaves doubts, we refuse to enter into a new business based on our risk criteria. The Risk Assessment procedure together with the Due Diligence system has been integrated with the documentation put in place for the Responsible Sourcing.

3 Does the refine report risk assessment to the designated manager?

Comments and Demonstration of Compliance: The Responsible Sourcing Officer and his team assess the potential risks in-line with Portovesme s.r.l. internal guidelines as well as the OECD due diligence guidance as set out in the Annex II. If risks are identified with new or existing business partners he will deny acceptance of new business partner or cancel business with existing partners. Only if the business disagrees with the assessment of the Responsible Sourcing Officer, the issue will be escalated to the CEO or CFO for final decision; no such escalation was necessary during the reporting period. Senior management retains the ultimate control and responsibility.

4 Does the refiner assess the risk in the light of the Country Risk, Company Risk and Commodity Risk before enter into business with new counterparty and/or during the regular transactions Portovesme s.r.l. assess the risk in the light of the Country Risk, Company Risk and Commodity Risk before enter into business with new counterparty and/or during the regular transactions Comments and Demonstration of Compliance: Portovesme s.r.l. has implemented his risk assessment procedure basing the Investigation and Due Diligence process on the information acquired by primary worldwide business information providers (such as D&B, CERVED, World-Check by Thomson Reuters, and recently by List of Reference issued by the Bank of Italy) which help and support the activities concerning the supervision and monitoring of Country Risk, Company Risk and Commodity Risk which potentially could affect the new counterpart and/or the regular transactions carried out. Portovesme s.r.l. continuously conduct a monitoring of the above mentioned Risks also collecting any kind of news which could be useful in order to re-assess the global/potential risk in the supply chain.

Compliance report 2019 Portovesme s.r.l. 4 Portovesme s.r.l.

Step 3: Design and implement a management system to respond to identified risks

Compliance Statement with Requirement: We have fully complied with Step 3: Design and implement a management system to respond to identified risks.

1 Has the refiner devised a strategy for risk management of an identified risk by either (i) mitigation of the risk while continuing to trade; (ii) mitigation of the risk while suspending trade or (iii) disengagement from the risk? Portovesme s.r.l. has designed a strategy for risk management of an identified risk by either mitigation of the risk while continuing to trade; mitigation of the risk while suspending trade or disengagement from the risk.

Comments and Demonstration of Compliance: Portovesme s.r.l. has set-up an automated and ongoing screening of all business partners for identifying risks. In addition and based on the risk assessment a regular assessment of all business partners and transactions is established. In addition any ad-hoc identified risk brought up by any stakeholder will be carefully assessed by the Compliance officer and his team and necessary actions/ measures decided.

2 Where a management strategy of risk mitigation is undertaken, it should include measureable steps to be taken and achieved, monitoring of performance, periodic reassessment of risk, and regular reporting to designated senior management.

Comments and Demonstration of Compliance: Corresponding procedures are in place and are, when necessary, applied accordingly.

Step 4: Arrange for an independent third party audit of the supply chain due diligence

Compliance Statements with Requirements: We have fully complied with Step 4: Arrange for an independent third-party audit of the supply chain due diligence.

Comments and Demonstration of Compliance: Portovesme s.r.l. has engaged Bureau Veritas Italia (listed in the LBMA’s Approved Service Providers List) to perform a reasonable level of independent external assurance on compliance against the LBMA Responsible Silver Guidance, version 1, for the period 1 January 2019 to 31 December 2019. Auditors will verify that there aren’t any problems related to the performance of our system, policies, procedures, processes and practices; they have suggested us to implement some actions to improve our management system.

Step 5: Report on supply chain due diligence and on implementation of Risk Assessment procedures: Management Review for the period 1 January 2019 to 31 December 2019.

Compliance Statement with Requirement: We have fully complied with Step 5: Report on supply chain due diligence and on implementation of Risk Assessment procedures.

Comments Further information’s and details of how Portovesme s.r.l. systems, procedures, processes and controls have been implemented to align to the specific requirements in the LBMA Responsible Silver Guidance have been set out in our responsible silver policy which is available on our company website. Portovesme s.r.l. has issued a Management Review, as for the LBMA Responsible Guidance Management System, which provide full explanations and clarifications on the following matters: 1) Details on the Responsibly-sourced Metals Policy; 2) New Business relationship arisen in 2019; 3) Examination and Investigation on the monitoring documents provided by all the information sources utilized for the aim (e.g. Liste di riferimento – Banca d’Italia, World Check One – Thomson Reuters, Cerved, Dun & Bradstreet, Certificate of Incorporation) finalized to judge and evaluate the real Risk profile of the Business Counterparts; 4) Organization, Management and Control Model as for 231/2001 Regulation: presentation of the Final Report by the Supervisory Board.

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