Mining

Tailings are proving lucrative in Gauteng.

Credit: Harmony

Gauteng is home to many old mines which means that the province has to guard against many of the aftereffects of deep mining such as acid mine water and subsidence. The Council for Geoscience is actively engaged in research projects into such issues but the high prices that gold is attracting globally means that another byproduct of mining, tailings, has become more lucrative.

Mine Waste Solutions, a tailings retreatment operation bought by Harmony from AngloGold Ashanti in 2020 and operated by subsidiary Chemwes, has performed well for the group. Production of 2 057kg (66 133oz) of gold in the nine months to June 2021 reflected high productivity at a healthy average gold price of R729 882/kg.

Harmony Gold’s acquisition strategy, including the purchase from AngloGold of Moab Khotsong, will result in it being the country’s biggest gold producer. With 350 000 new ounces coming from Mponeng, it could produce an annual total of 1.7-million ounces.

A new company, Shallow Reefs Gold, has been created to pursue projects in the shallow reefs of the Witwatersrand Gold Basin. The company believes that the grade of the deposits makes for a good economic proposition, especially as the infrastructure required for shallow mining is much cheaper than for the deep mining that has characterised the sector in the past.

Cullinan diamond mine is engaged in an expansion programme called the C-Cut Phase 1 project. Cullinan is famous for its rare blue diamonds. The University of Witwatersrand started life as the South African School of Mines. The School of Mining Engineering at Wits is the highest-ranked school at the university in terms of the QS World University Rankings.

Gauteng is home to most of the research and training bodies associated with mining. SibanyeStillwater supports the Wits Mining Institute’s Digital Mining Laboratory (Digimine). AECI, the explosives and chemicals company, sponsors the Virtual Reality Mine Design Centre at the University of Pretoria.

The Mandela Mining Precinct is a joint venture between three government departments and the Minerals Council South Africa which aims to develop research into mining and showcase the country’s manufacturing abilities.

Mintek is an autonomous body based in Randburg which receives about 30% of its budget from the Department of Mineral Resources. The balance comes from joint ventures with private sector partners, or is earned in research and development income, the sale of services or products and from technology licensing agreements.

Pretoria University has a Department of Mining Engineering, the University of South Africa offers three national diplomas in minerelated fields, the University of Johannesburg has mine-surveying courses and the Vaal and Tshwane Universities of Technology have engineering faculties. ■

ONLINE RESOURCES

Council for Geoscience: www.geoscience.org.za Minerals Council South Africa: www.mineralscouncil.org.za National Department of Mineral Resources: www.dmr.gov.za SECTOR INSIGHT Harmony’s purchase of Mine Waste Solutions is paying off.

Cullinan Diamond Mine produces rare and exceptional “specials”

The General Manager of the Cullinan Diamond Mine, Jaison Rajan, explains how infrastructure investment is extending the life of one of the world’s great mines.

Jaison Rajan, General Manager

BIOGRAPHY

Jaison Rajan is a mining engineer with post-graduate Master’s qualifications in both mineral economics and business administration. He has over 20 years industry experience, having worked in various mineral commodities including heavy minerals, manganese, coal and diamonds. He is an accredited Professional Engineer with a Mine Manager’s certificate of competency (South Africa). Why is Cullinan Diamond Mine often referred to as an “iconic” diamond mine? Cullinan Diamond Mine has earned its status as a result of it being probably the world’s most consistent supplier of exceptional stones. One of the first, and arguably the bestknown, was the Cullinan Diamond found at the mine in 1905. This stone, at 3 106ct, is still the largest diamond ever found, and jewels cut from it adorn the Royal Crown and Sceptre of the United Kingdom.

Are there are other stones from the mine that could lay similar claims? Indeed! Cullinan Diamond Mine is also the source of most of the gem-quality Type II blue diamonds recovered and put to market. These diamonds are extremely rare, which is vouched for by the high prices per carat achieved when they are presented to the market. A recently recovered 39.34ct Type IIb blue stone sold for more than $40-million, which was the highest price that Petra has achieved for a single stone. Apart from this stone, there have been quite a number of other “specials”, both blue and white stones of exceptional quality with regards to both colour and clarity, many of which had been recovered by Petra since it took ownership of the mine in 2008. This includes the Blue Moon of Josephine, the Cullinan Dream and the Letlapa Tala Collection.

It was already an old mine when Petra took over; how much life is left in it, and what is Petra doing to ensure its future? The mine is still an exceptional resource with prospects of a long life into the future. From what we currently know, the resource still has a potential life upwards of 50 years, subject to market and economic conditions. Realising the value and potential, Petra embarked on an intensive capital investment programme soon after acquiring it, including the further development of underground resources (the so-called “C-Cut”) and replacement of the old processing plant with a new, cutting-edge treatment facility that will serve the mine well into the future.

How does the mine’s location within a metropole affect your planning? It is a rather unique situation and does impact on our approach. We accept and believe that the operations of any mine, including ours, should first and foremost benefit its most immediate stakeholders, which are the communities in which we operate. Giving effect to this has many facets, which includes ensuring that we recruit locally, providing local households with a stable income, focussing on procurement of local supply to boost local business, especially SMMEs, while contributing to their development, social investment programmes that are aimed at effectively addressing the needs of our communities and more. Our core operations also have impacts on the community, such as environmental impacts (the potential of dust, noise and vibration) as well as the naturally occurring scaling of the pit. All of these are closely monitored, mitigating actions are taken and we maintain open communication with the community around these issues.

Apart from the mine, the town of Cullinan is also somewhat of a tourism destination. What is the mine’s involvement in that? Cullinan is indeed a little town with a colourful history, much of which relates to the mine, and it is rightly a tourist favourite. From Cullinan Diamond Mine’s side, we believe that tourism will become an increasingly important contributor to the local economy and we are therefore supporting the private tourism industry in various ways, not least of which is by being the only underground mine allowing underground tours as part of its tourism offering. This support further extends to financial and promotional contributions, and we are excited to see the effect that these initiatives are having on the growth of tourism in the town.

The Covid-19 pandemic has had a profound impact on everything we do. How did it impact Cullinan Diamond Mine? When the news broke, Petra proactively put controls in place to implement a Mandatory Code of Practice for the prevention, mitigation and management of Covid-19. This included various controls for screening, social distancing, sanitising and wearing of masks, which allowed us to continue our operations at sustainable levels soon after the initial lockdown. Realising the impact of the pandemic on our communities, much of our focus also went into distress relief within our communities, in conjunction with partners such as the City of Tshwane, through the employee-funded Petra Hardship Fund that contributed foodstuffs and other relief materials. This included the distribution of more than 700 food hampers and 500 cloth masks to the community, assistance to health workers, schools and the Tshwane Metro Police with supplies such as surgical masks, sanitiser, disinfectant and sterile gloves, all to the value of more than R500 000. ■