Williamson

The Williamson kimberlite was discovered in 1940. At 146 hectares it is one of the largest economic kimberlites in the world with a major resource of 37.2 million carats.

Williamson is renowned for its ‘bubblegum’ pink diamonds, including the Williamson Pink, discovered in 1947, which is considered one of the world’s finest pink diamonds. The mine also produces beautifully rounded, high-quality white diamonds.

Current Mine Plan

To  2030

Potential mine life

0  years +

Resources

0 Mcts

Contribution to portfolio

0 % of revenues
(FY 2024)

Mining Method

Open Pit
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Delivering reliable production

Williamson is one of the world’s most reliable sources of high-value pink diamonds. Despite the mine’s age, the pit is only 120 metres at its deepest point due to the deposit’s large size. The low grade of the deposit is countered by the high value of its diamonds and lends itself well to high volume, bulk mining methods.

Petra’s expansion plan at Williamson has involved major pit reshaping and plant rehabilitation work.

Williamson Unit FY 2024FY 2023FY 2022FY 2021FY 2020FY 2019
Sales
RevenueUS$m5749.175.94.652.593.0
Diamonds SoldCarats297,915175,124197,75630,339297,245402,329
Average Price Per CaratUS$191280384150177231
Production
Tonnes TreatedTonnes4.731,829,3763,591,09904,283,0055,495,470
Diamonds ProducedCarats323, 434140,516228,0700298,130399,615
Grade
ROMCpht7.76.4010.210.9
TailingsCphtN/AN/AN/AN/AN/A
Segment resultUS$m22.2(14.3)19.339.94
Costs and capex
On-mine cash cost per total tonne treatedZAR/t1313.9010.211.1
Total capexUS$m1019.33.30.38.08.6
  1. Negatively impacted by the 71,654 carat parcel blocked for export.
  2. Total depreciation of US$128.0 million included in the segmental result comprises depreciation incurred at Finsch US$41.7 million, Cullinan US$66.1 million, Koffiefontein US$9.1 million, Williamson US$9.5 million, Helam US$0.7 million, Exploration US$0.1 million and Corporate administration US$0.8 million
  3. Total depreciation of US$78.3 million included in the segmental result comprises depreciation incurred at Finsch of US$25.8 million, Cullinan of US$40.4 million, Koffiefontein of US$2.5 million, Williamson of US$9.0 million, Exploration of US$0.1 million and Corporate administration of US$0.5 million.
  4. Total depreciation of US$106.7 million included in the segmental result comprises depreciation incurred at Finsch of US$32.7 million, Cullinan of US$56.1 million, Koffiefontein of US$6.9 million, Williamson of US$10.2 million, Exploration of US$0.1 million and Corporate administration of US$0.7 million.

FY 2024 key statistics

0m

ROM Tonnes

cpht

ROM GRADE

$0/ct

Average Price

$0m

Revenue

0

Gross Resources
(MCTS)

Current production and future potential

Williamson Resource Potential

Operations at Williamson were suspended in November 2022 for 7 months after a TSF failure. In July 2023 operations were resumed, ahead of schedule, with the focus of FY24 being to get the mine back to full ramp up. Once at steady state, the mine is expected to produce 400kcts per annum.

The Company’s current mine plan for Williamson is to 2030, however given the Mwadui kimberlite hosts a major resource of 37.5 Mcts, there is potential to substantially extend this.

Mine crossection

Optimise

Operations restarted July 2023

Current Production
Mine plan defined by special mining licence (ends
2030)
• 33Mt containing 2.3Mcts in reserves

Develop

Williamson presents further open-pit mining opportunity of up to 112 Mt to the top of Granite Breccia beyond 2030

  • Additional crushing will be required to cater for increased granite in the ore as mining gets deeperSome 400Mt identified below the granite breccia
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Valuing our people

Williamson employs c.988 employees and contractors. Given the generally accepted x10 multiplier effect, this means c.9,800 people in the surrounding community are dependent on the mine.

Let’s Do No Harm:

In FY 2024 Williamson achieved a total 0.0 Lost Time Injury Frequency Rate.

Health and wellbeing:

Williamson Mine manages an active community health programme in Tanzania, including health infrastructure, monitoring health indicators and providing training for healthcare professionals, a malaria control programme, education initiatives around TB control, alcohol and drugs, diabetes and hypertension, and sexual and reproductive health.

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Icon Globe

Respecting our planet

Responsible consumption and production are at the forefront of our operational planning at Williamson, with a dedicated focus on improved energy and water consumption, responsible waste management and biodiversity protection and rehabilitation.

0

FY24 Carbon Emissions
(tCO2-e/ct)

0

FY24 Water effeciency
(m3/t)

0

Area of protected land
(ha)

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Shared value partnerships

Our ambition is to foster meaningful relationships with all our stakeholders in a manner that builds trust, ensures transparent communication and creates shared value opportunities.

We partner with the Government of Tanzania at Williamson and continually engage with all our stakeholders, including, the Ministry of Mines Tanzania, local government, communities, business forums, NGOs, NPOs and organised labour.

Ownership
Williamson Diamonds Ltd75%
Government of Tanzania25%

Local Procurement

Ca. 93% of procurement spend at Williamson is with local suppliers.

Community and social investment

Williamson contributes directly towards community development through the advancement of social, commercial, industrial, educational, medical and administrative infrastructure for the benefit of local communities.

US$0m

Social Expenditure, Group wide in
FY 2024

0

Full time bursary students, Group wide in
FY 2024

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Background information

On 7 November 2022, Petra announced the failure of the Tailings Storage Facility (TSF) wall at Williamson which resulted in flooding away from the pit and extended into certain areas outside of the mine lease area.

Significant work has been undertaken to contain the failure, determine the extent of the social and environmental impact and carry out remediation. An investigation into the root cause of the incident is also underway.

Local Community

Whilst no fatalities or serious injuries were reported, the livelihoods of a number of community members were affected. A variety of short-term measures were initially taken, followed by an assessment of the impact on the surrounding communities and longer-term remediation measures. An Entitlement Framework has been developed that enables community members impacted by the TSF failure to be appropriately compensated, with Phase 1 and 2 compensation payments having been made.

Environment

Environmental work to date confirms the tailings material which flowed out of the TSF is inert. WDL has taken significant steps to carry out international best practice Environmental Assessments and continues to engage with Tanzania’s environmental regulator in this regard.

Technical and Production

A new TSF has been constructed, which received the required permits and complies with the GISTM standards. Production resumed at WDL in July 2023, with a steady ramp-up currently underway.

An investigation is being conducted to determine the root cause of the TSF failure, with the final report anticipated at the end of CY 2023.

Financial

Remediation costs relating to the incident were incurred during FY 2023 and additional costs will be incurred going forward. In FY 2023, US$8.3 million of costs have been incurred and a further US$2.4 million of costs, comprising management’s best estimate based on the current information available, have been provided for ongoing remediation costs. In addition, US$5.2 million of accelerated depreciation was recognised in the Year to fully write down assets damaged resulting from the TSF failure.

The remediation costs comprise establishing the root cause of the failure, humanitarian relief to the affected community, livelihood and environmental restoration and costs to repair.

Further information

Please refer to the Company’s FY 2023 Annual and Sustainability reports for more detailed information on the TSF failure and remediation process:

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Petra’s Tailings Management and its commitment to the Global International Standard on Tailings Management can be found here:

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For more information please see our updates below:

In May 2020, Leigh Day notified the Boards of Petra Diamonds Limited (“PDL”) and Williamson Diamonds Limited (“WDL”) that it had issued claim forms in the High Court of England and Wales on behalf of 32 anonymous individuals in relation to alleged breaches of human rights, personal injuries and deaths suffered at and surrounding the Mine, arising from the security operations. Additionally, in November 2020 RAID published a report outlining similar allegations, during the same period. Leigh Day subsequently expanded the number of anonymous claimants to 72 while RAID expanded the scope of their own allegations.

WDL and Petra have taken the human rights allegations mentioned above extremely seriously. They have sought to gain a full understanding of the allegations through an independent investigation, with the aim of supporting the provision of balanced and fair remedy, in the interest of all parties, and to put in place preventative measures. Petra formed an independent Board Sub-Committee comprised entirely of independent Non-executive Directors to oversee the matters and undertake an investigation into the allegations. The Sub-Committee was supported in its investigation by the specialist external investigator Control Risks, in conjunction with lawyers Freshfields Bruckhaus Deringer LLP.

On 12 May 2021 Petra announced that it had reached a settlement, on a no admission of liability basis, in relation to claims brought in London by Leigh Day, on behalf of the anonymous claimants, in relation to alleged breaches of human rights, associated with third-party security operations, within the SML.

Please see below Petra’s public disclosures regarding the allegations detailed above.

Please see below the responses Petra has sent to RAID regarding the allegations.

Additional Documents

This page provides further information about the parcel of 71,654.54 carats from the Williamson mine in Tanzania, which is currently blocked from export.

On 13 December 2021, Petra announced that it had reached agreement on a Framework Agreement in principle with the Government of Tanzania relating to the operations of the Williamson mine. As part of the Framework Agreement, the Government of Tanzania has agreed to provide financial support to Williamson Diamonds Limited through the allocation of the proceeds of the sale of the blocked diamond parcel towards the restart of operations at the Williamson Mine.

This certificate was issued for the Williamson parcel by the Ministry of Energy and Minerals (Diamond and Gemstone Valuation Unit-TANSORT) in Tanzania. Note that the certificate refers to a ‘Provisional Value’ for the Williamson parcel, rather than a ‘Final Value’.

rther to the sealing of the parcel by the MEM (Ministry of Energy and Minerals) and the TMAA (Tanzania Minerals Audit Agency), a Kimberley Process certificate was issued on behalf of the United Republic of Tanzania by the Commissioner for Minerals at the Central Western Zone Office in Tanzania.

This is Petra’s consignment invoice which accompanies the parcel and confirms the conflict-free source of the diamonds. Note that the ‘Provisional Value’ and volume for the parcel matches those listed on the Diamond Valuation and Kimberley Process certificates. The invoice refers to seals by the TRA (Tanzania Revenue Authority) and the Government of the United Republic of Tanzania, as well as the Company’s own seals.

Receipts confirming the Company’s payment of the provisional royalty and associated fees relating to the diamond parcel.

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