Modern Mining January 2019

TOP PROJECTS

AFRICA’S TOP MINING PROJECTS In our regular Top Mining Projects feature we look at projects distinguished by their size, innovation or pioneering spirit. This year we have selected five that meet these criteria, four of them in South Africa and one in Ghana. The commodities covered are diamonds, zinc, fluorspar and gold.

T he first of our diamond projects is the new processing plant at Petra’s Cullinan Diamond Mine near Pre- toria, commissioned in October 2017. The plant, which features autogenous milling and the use of XRL sorters for primary recovery, re-concentration and fi- nal treatment of diamond-bearing ore, is a vast improvement on its predecessor, which was originally built in the late 1940s and sprawled over 27 ha. The new facility has a very com- pact footprint, requires far fewer items of equipment (for example, the number of electri- cal motors has been reduced from 589 to just 84) and is both energy and water efficient. Modern Mining covered this project a year ago and is now ‘revisiting’ it in the light of more than a full year of operations having been com- pleted. According to the mine’s management, the R1,65 billion plant is performing to expec- tations and is part of an overall transformation of Cullinan which has also seen the implemen- tation of the C-Cut life extension project. Our second diamond project is the Venetia Underground Project (VUP) of De Beers in Limpopo Province, which is costing US$2 bil- lion to develop and which will extend the life of this Tier 1 asset into the mid-2040s. Here again, this is a project we have covered in the past but with the implementation phase extending over the best part of a decade there is always some- thing new to report. The VUP has a new Head with Sailesh Sahu having taken over in 2018 from Christoff Kühn, who has moved on to the Quellaveco copper project in Peru. Sahu recently told Modern Mining that the project was progress- ing well, with a major focus currently being on developing the shaft stations and loading box within the production shaft to allow the equip- ping of the shaft to begin. He added that first ore from the VUP should be delivered in 2021 from the K2 ore body. Our third ‘top project’ is the Gamsberg zinc mine of Vedanta Zinc International (VZI) near Aggeneys in the Northern Cape, which is now in production and in the process of ramping up to its steady-state production target of 250 000 t/a of zinc in concentrate. As we explain in our

article, the project is something of a pacesetter, featuring an innovative concentrator design, a high-tech control room and an automated assay laboratory. The mining is also on a large scale with mining contractor Moolmans having deployed a mining fleet on site consisting of 66 items of primary equipment, including two 530-tonne face shovels. The current Phase I project is likely to be expanded in further phases of development, which could see Gamsberg ultimately produc- ing as much as 600 000 tonnes of zinc a year. Fluorspar comes under the spotlight in our fourth top project, the R1,7 billion Nokeng opencast mine of SepFluor at Rust de Winter, north-east of Pretoria. Now nearing completion, Nokeng has a 12 Mt reserve and an estimated 19-year life-of-mine. Some 630 000 tonnes of ore containing approximately 27 % calcium will be mined annually from surface and near- surface, initially from two deposits. From the mine’s state-of-the art concentrator, around 180 000 tonnes a year of acid grade flu- orspar and 30 000 tonnes a year of metallurgical grade fluorspar will be produced. Production costs are expected to be in the bottom quartile of producers internationally, largely because of the high grade and easy accessibility of the orebodies. We round out our Top Projects feature with an article on Project 5 Million (P5M) at the Asanko Gold Mine (AGM) of Asanko Gold and its joint venture partner Gold Fields. P5M has taken the nominal capacity of AGM’s processing plant from 3 Mt/a to 5 Mt/a for a modest capex of just US$29 million. The project recently won the ‘Best Performer in Innovation’ award at the 2018 Ghana Mining Awards organised by the Ghana Chamber of Mines. Although P5M was commissioned by the end of 2017, it subsequently proved difficult to consistently achieve the required mill feed rate. To optimise the performance of the SAG, ball mill and crusher (SABC) circuit, a focused com- minution initiative was launched by Asanko Gold. The measures implemented – including the installation of mill feed monitoring equip- ment – have allowed current milling rates (when annualised) to reach 5,8 Mt/a. „

The current Phase I project is likely to be expanded in further phases of development, which could see Gamsberg ultimately producing as much as 600 000 tonnes of zinc a year.

Top projects

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