Exco Mining

Venmyn Deloitte discusses smelting trends at Mineral Beneficiation summit

smelting

Venmyn Deloitte’s Munyar Chirisa spoke at a Mineral Beneficiation summit in Sandton, South Africa, on “The Upgrade of Minerals Through Smelting”. The summit, which was attended by a Member of Parliament as well as several finance, human resources and technical role players from the industry, focused on mineral beneficiation in South Africa.

Chirisa’s presentation discussed the various smelting techniques used, the necessity of smelting and the various pre-treatment steps used. The presentation also brought to the fore the fact that smelting is indispensable to metal extraction industries, with no viable alternative extraction method.

Chirisa’s presentation also made it clear to the attending delegates that, although smelting is a means of extracting metal, it is the also a process in which most of the value is unlocked in the mineral processing chain and that mineral companies with smelters in their portfolios trade at much higher unit values as compared to the companies with no smelters.

Processes such as pelletising are also turning previously untreatable fines into feed for submerged arc furnaces. Whilst irreplaceable for the foreseeable future, major factors that weigh against smelters are the extremely high capital outlays (~ZAR1bn) as well as the high power inputs required to run these plants.

The trend going forward certainly favours bigger plants that can capture the economies of scale. However, the limited availability of electrical power in South Africa makes this trend unfavourable as bigger smelters require even more power to operate. This also means that smelter operators have to find ways of saving on power, which can contribute to as much as 45% of the total operating costs. These ways include the use of the off-gases to pre-heat the feed as well as the use of off-gases to generate steam to drive turbines and generate power. In this way, companies can save on the electricity bill and increase their margins.

In addition, the increasing popularity of Direct Current (DC) smelters appears to be a trend going forward given that these smelters can take a wide range of feed grade as well as fines, which cannot be smelted in submerged arc furnaces without agglomeration / pelletising.

For more information on mineral processing and metallurgical test work, contact Munyar Chirisa at +27 11 783 9903

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David Graham

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