Tailings and waste management

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  • At 15:44pm, 21 Jan 2025

The global spotlight on tailings management in recent years underscores the broader impact of mining activity. We proactively mitigate the associated risks of TSFs to communities and the environment, and we reduce our environmental impact through responsible and effective waste management and mitigate associated liabilities.

In FY24:

  • The total volume of all recycled waste was 6 066kt (FY23: 6 617kt)
  • In South Africa, we recycled1 221 tonnes (FY23: 1 500 tonnes) of hazardous waste and 2 463kt (FY23: 3 527kt) of recycled waste
  • In Papua New Guinea, we recycled 39 tonnes (FY23: 0 tonne) of hazardous waste and 3 603kt (FY23: 3 090kt) of recycled waste

Our approach

Harmony manages 84 TSFs in South Africa and one in Papua New Guinea as part of the mining process, which includes deposition of waste material in TSFs. To maintain the integrity and stability of our TSFs, our tailings management approach encompasses:

  • Robust engineering and dam design
  • Continuous risk management
  • Tailings retreatment and reclamation
  • Layered assurance, oversight and compliance.

Aspects of the Global Industry Standard on Tailings Management (GISTM) augment our protocols for optimal stabilisation of TSFs. In South Africa, we also apply ISO 14001:2015 environmental standards to our TSF management. In Australasia, we adhere to the Australian National Committee on Large Dams (ANCOLD) guidelines.

Through monthly freeboard surveillance and regular inspections and audits, we maintain vigilant oversight of our facilities. This is complemented by comprehensive emergency preparedness plans and detailed risk registers for each facility. Areas of concern are addressed and resolved by management, the appointed experienced deposition contractor and specialist consulting engineers.

Waste management

Our mining and extractive processes generate both mineral waste (tailings and overburden) and non-mineral waste (hazardous and non-hazardous materials). Our waste management strategy focuses on minimising our environmental impact through recycling, reuse and proper disposal methods. We’ve set a five-year goal to reclaim 10% of our mineral waste footprint, though success depends on market conditions and infrastructure capacity. In FY24, we increased our non-hazardous waste recycled by 6% compared to FY23.

In our South African operations, we repurpose mineral waste as grinding media and backfill material, while at Hidden Valley, waste rock is used in TSF construction. In FY24, while total waste rock recycling across the group decreased by 8.3% due to plant modifications at Kusasalethu, slimes recycling increased by 1.4%. Hidden Valley experienced a 9% increase in waste rock deposits and a 23.4% increase in TSF construction usage.

Regional performance

South Africa

In South Africa, we actively manage a portfolio of 18 operational facilities, 11 remining facilities and 55 inactive facilities. We have achieved significant success with projects such as the Kareerand TSF, where we have implemented innovative buttressing programmes and enhanced drainage systems. Our focus on structural integrity and environmental protection has delivered strong results across our operations.

Papua New Guinea

At Hidden Valley, TSF 1 is the first large facility of its kind to operate successfully in Papua New Guinea. The facility employs downstream build methodology and maintains effective early warning systems. Construction of Hidden Valley TSF 2 started during FY24.

Australia

Environmental assessments at Eva Copper guide project design to minimise impacts, with comprehensive TSF and waste rock management plans in place. While 99% of waste rock is non-acid forming and will be used in construction and rehabilitation, the project faces challenges with non-mineral waste disposal due to limited facilities in North West Queensland. This has made us diligent in our assessment for the most appropriate non-mineral waste management strategies.

FUTURE FOCUS AREAS

We remain focused on managing safety factors to ensure compliance requirements are met. In South Africa, we are looking for opportunities to beneficiate TSF dams as part of our recycling initiatives, which remains top of our agenda. Part of our intention is to consolidate these dams for ease of management and risk mitigation. Additionally, land becomes available for social development opportunities.

Case studies

External assurance

Through the assistance of appointed external engineering and environmental consultants, Harmony strives to ensure compliance to local and international guidelines by employing known best practices in this field.

PNG, Hamata Tailings Storage Facility