Zimasco’s ferrochrome smelting operations are situated at Kwekwe.  The smelter produces a high carbon ferrochrome product and has an annual production capacity of 180 000 tonnes.  The smelting complex has six submerged electric arc furnaces with the following capacities:

The submerges electric arc furnaces are used for the reduction of chromite ore and produce a half clean alloy when tapped.  An induction furnace of 3.5 MVA (3MW) is used to treat partially reduced fines recovered through hydraulic processing at the Alloy From Slag Plant (AFS)

 

West Plant		East Plant
No. 1	18MVA	No. 5	18MVA
No. 2* (Non operational)	15MVA	No. 6	18MVA
No. 3** (Operating at 18MVA)	30 MVA
No. 4	18 MVA

 

The smelting process as it is carried out in Kwekwe is set out below. 

Raw Material Preparation & Planning - insert image
Chrome Ore, fluxes, together with coke and coal are delivered by rail and road and once sized are placed in raw material storage bins.  Weighing Conveyer Belt Systems produce a furnace blend which is stored in furnace holding bins, prior to being fed into the furnace.

Product Preparation
The tapped alloy is sent to the product preparation area where it is crushed and sized.  A hand picking process in which slag is picked off a sorting belt upgrades the +12mm  -  150mm product.  The -12mm product is forwarded to the AFS plant where it is blended with crushed slag and subjected to a gravity concentration process.
AFS Plant
The AFS plant produces approximately 13 500 tonnes of alloy per annum from current arising slag and reprocessing of the existing old tailings dump.  The slag is crushed and sized and together with the -12mm fraction from the product preparation process is sorted into alloy and dead slag in a mechanical gravity process using Batac Jigs (for the +3mm to  25mm material) and Delko Jigs (for -3mm material).  The spiral plant separates the -1mm fraction into saleable alloy and non-saleable alloy which is re-melted at the induction furnace.