KIVCET process

S. kitasatoensis Kitazin P Kitchen cabinets Kivcet process... 

These operations are all conducted in the single unit of the Kivcet furnace, which consists of a smelting shaft, gas removal shaft, and electrothermic part. A schematic of the Kivcet process is shown in Figure 5 (13). The electrothermal part is separated from the smelt shaft in the gas space by a partition... 

Fig. 5. Kivcet process A, concentrate burner B, fume-laden gas C, lead tap D, slag tap E, 2inc tap F, water-cooled underflow wall G, electrodes H,...

Two processes, developed for the direct processing of lead sulfide concentrates to metallic lead (qv), have reached commercial scale. The Kivcet process combines flash smelting features and carbon reduction. The QSL process is a bath-smelting reactor having an oxidation 2one and a reduction 2one. Both processes use industrial oxygen. The chemistry can be shown as follows ... 

Boliden s Kaldo process of, 14 742-743 Isasmelt process of, 14 743-745 Kivcet process of, 14 739-740 Outokumpu process of, 14 745 QSL process of, 14 740-742 Lead stabilizers, for PVC polymers, 25 671 Lead storage battery, 14 783. See also Lead-acid batteries Lead-calcium alloy batteries... 

The Kivcet process is able to treat a wide variety of raw materials. The reported ratio of primary to secondary materials was 73 27 in one plant (Portovesme) and reversed in the second (Cominco). At the Cominco plant, the bulk of the secondary material consists of zinc leach residues. The flash smelting process, however, requires drying the feed material, prior to its being charged into the furnace, to a moisture content of less than 1%. 

D.W. Ashman, Pilot Plant and Commercial Scale Test Work on the KIVCET Process for Trail s New Lead Smelter , Zinc and Lead Processing. J.E. Dutrizac, G.L. Bolton and P. Hancock, Eds., The Metallurgical Society of CIM, Montreal, Quebec, 1998, 783-794. 

A distinctive feature of the Kivcet process is its environmental friendliness, ability to run with high metals recovery and gaseous sulphur dioxide recovery. Originally, the Kivcet process was designed as a process for sulphide concentrate smelting. With that feed excellent process and cost attractive results were achieved. 

Besides the metallic iron, a Waelz slag produced from lead residues is advantageous to add into the feed of the Kivcet process. The size of the Waelz slag should be minus 20 mm its moisture content should be no more than 3%. The composition of the mixed feed using Waelz slag is shown in Table I. 

Figure 1.5 indicates that almost half of the primary production capacity (or 1 750 0001), is attributed to plants above 100 000 t/a, and 80 per cent of the primary production capacity (or 2 800 000 t) is attributed to plants above 50 000 t/a capacity, of which there are only 25 presently operating, as detailed in Table 1.6. Of those 25, three use the Kivcet process, three use the QSL... 

The Kivcet Process (an acronym in Russian for oxygen flash cyclone electrothermal process), was developed by the Vniitsvetmet Institute in Kazakhstan in 1967 for the treatment of both copper and lead concentrates (Sychev et al, 1985). A 25 t/d pilot plant was built and operated for a number of years followed by a plant to treat 500 t/d of mixed copper-zinc concentrates at Glubokoe in 1970. That plant produced a copper matte and zinc rich slag for slag fuming in the electric furnace to recover zinc oxide. 

Extra carbon is added to the coke layer as unbumed coke from the burner to make up for consumption by the reduction reactions. Coal or coke at a particle size in excess of 5 mm is usually added for this purpose, and is carbonised in the shaft but is not burned to any significant extent. Since the shallow coke layer has minimal strength requirements, as distinct from a shaft furnace, it is not necessary to conform to normal rigid coking coal specifications. On the other hand it is still necessary for the carbon to arrive at the coke layer in granular form. If it decrepitates to a fine powder under the thermal shock of entering the burner flame, it is more likely to be carried out in the gas stream than enter the coke layer. It would appear that any low volatile coal with reasonable coking properties is a suitable reductant for the Kivcet process. 

The Kivcet process is robust and highly flexible in the range of possible feed materials, from high-grade concentrates through to secondary leach residues. It produces a low volume of smelter gas rich in SO2 and suitable for sulfuric acid production. It is also well contained with minimal opportunity for environmental emissions, particularly in comparison with sinter plant-blast furnace technology. 

The QSL process has significant advantages over sinter plant-blast furnace technologies. It is a single step smelting process, is well contained with low emissions and can accept a wide range of feed materials. It does not require dry feed as with the Kivcet process however, in its early stages it did not prove to be as robust or as flexible as the Kivcet process, particularly with attempts to use natural gas for reduction and in its ability to handle quantities of zinc plant residues. 

Lyamina, M A and Shumskii, V A, 2006. Theoretical questions in the treatment of lead-bearing raw materials by the Kivcet process (translated by D H Ward) (The Eastern Mining and Metallurgical Research Institute for Non-Ferrous Metals (Vniitsvelmet), Ministry of Industry and Trade Kazakhstan Republic). 

Normally thallium, like mercury, is effectively removed by volatihsation in the sintering process. For direct smelting processes there may not be sufficient volatihsation with direct capture into the lead bulhon, and a direct method of separation may be required, as is the case at the Trail smelter with the introduction of the Kivcet process. In this case thallium is removed by the addition of zinc chloride to molten buUion, displacing thalhum as a thalhum chloride dross, and leaving zinc in the bullion for later removal. 

Direct smelting processes provide alternatives to the sinter plant-blast furnace above, up to the stage of crude bullion production, but still require the addition of refining operations to produce high-grade lead. Three alternatives have been evaluated - the Kivcet process, the QSL process and the Isasmelt process - as typical of the top submerged lance slag bath reactor. Evaluations are based on comparable feeds, predominantly lead concentrates with low residue inputs. 

Operating parameters for the Kivcet process have been assumed as follows per tonne of product lead ... 

On this basis the Kivcet process has very similar net energy consumption to the sinter plant-blast furnace. This may be surprising for an intensive process, but results from the high use of electric power for both the electric furnace and for oxygen production and the low efficiency of conversion of heat energy to electrical energy in comparison with its direct use. 

Table 17.5 gives the capital cost estimate for the production of 100 000 t/a of lead in bullion by the Kivcet process. 

Lead smelter capital costs - Kivcet process (cost basis - June 2005). 

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