Oxygen-weighted or oxygen torch melting (KVP or CDF) is a variation of the method of autogenous flash smelting of sulphide copper concentrates, carried out in suspension.The main features of this process are used as blasting technical oxygen and burning of sulfides in the horizontal plume, as well as fabric compensator.
INCO process (KVP) arose primarily as a way to produce liquid sulfur dioxide days pulp and paper industry in the processing of copper sulphide concentrates.Autogenous smelting process using an oxidant of pure oxygen process (95% O2) in an industrial scale is carried out from 1953 to Copper Cliff plant in Canada.A similar process has been developed and introduced in the USSR in the copper plant in Almalyk (Uzbekistan).The main difference from the CFP PVP is that the shredded and dried batch will yield deeply into the furnace through the burner feedstock directed horizontally (vertical smelting shaft offline) and the oxidizing air blast is used purely technological oxygen.The melting process are to produce mattes 45-55% (when receiving a rich matte due to excess heat oven overheats).Exhaust gases contain up to 80% SO2.Prospects for broad industrial application process INCO has.
important technological features of the CFP are: the presence of the flame in the furnace of the horizontal increases the residence time of the particles in it, which in theory should help to intensify the processes of oxidation of particulate batch processed, as well as heating and fabric expansion joints;limited possibility of regulating the degree of desulfurization in the direction of its inability to obtain larger and matte with a copper content of over 65-70% of the allocation in this case a large amount of excess heat and raising the temperature in the furnace to 1550-1600 ° C or more, thereby drastically reducingresistance refractory;the impossibility for the same reasons a significant increase in the specific performance of the smelter;small volume resulting in the smelting of sulfur-rich gas, the theoretical content of SO2 which can reach 90-95%.When CFP recycled pulverized concentrate introduced into the furnace fiery jet of oxygen from the technical Kompenz Elastic, which leads to the formation of dust and gas flare, which are oxidized and melted materials.The process of the formation of the melt in the bath furnace, stratified into matte and slag.Finely disperse the dried concentrate is mixed with fluxes horizontal jet blown into a special burner in the flame of the furnace.Physico-chemical interactions between the components of the charge blast oxygen flow in the dust flow.Melt drops are deposited from plume into the lower part of the furnace and form the molten bath.
CFP in the oven, the following areas:
- charge-oxygen torch, where the oxidation of sulphides occur partly processes Stein and slag (I);
- the surface of the slag bath, where the flux is completely absorbed and reactions of the interaction of sulfides with oxides (II);
- matte-slag bath, where the terminated process, and slag Stein (II, III).
- fabric expansion joints
Charge furnaces CFP consists of copper concentrate and quartz.The mixture was filtered, and 12-16% humidity in the drum is dried to a residual concentration of 4-7%, while applying compensators.The second drying stage is carried out in vertical tubes dryers in which the bottom part serves hot gases, heated to 400-500 C at a rate of 12-14 m / s.The final moisture content of 0.1-0.5%, performance dryers for the concentrate is 80-85 t / h, according to remove moisture up to 4 t / h.
High speed oxidation processes, which is proportional to the surface of the contact phase, difficult adjustment of structure and thermal regime of the matte smelting.Preparation richer matte leads to the formation of excess heat and causes wear on the lining.For the thermal process in this case it is necessary to reduce the capacity of the unit for the concentrate.To increase the resistance of the lining kessoniruyut vault and the walls of the furnace, process recycled materials (dust, converter slag) that allows you to increase the amount of copper in matte without increasing the thermal stress in the unit and fabric expansion joints.
CFP masonry ovens made of brick and compensators hromomagnezitovogo Kompenz-Elastic.The gases from the furnace through the flue in the center of the fierce space unit.As blasting technology applied to the oxygen content of about 95-98.%.Matte containing 40-50% copper, is discharged through holes in buckets siphons.The slag is poured through the tap hole in the slag, and sent to the dump.Furnace gases and dust is guided through the connecting flue gas cooler in.Dust removal of about 10% by weight of the mixture.Gas dust content of 300-400 g / m≥ entering the recovery boiler and exit from it - 200-250 g / m≥.
CFP may also be successfully used for processing Cu-Zn-, Cu-Ni- and others. Sulphide concentrates.
