The Selection And Design Of Electric Furnace Smelting Special Ferrochrome Using Chromium Slag

Chromium salt,metal chromium and chromium alloy play a very important role in the national economy,and are widely used in many industries as chemical industry,metallurgy,dyeing etc.With the increasing demand of the market for products containing chromium,produce large amounts of toxic chromium slag.The chromium slag that was piled up at random is industrial waste residue,but also a possible raw material smelting special ferrochrome,in order to achieve resource utilization.There is a large amount of chromium slag in producing sodium dichromate which using non-calcium roasting method in a chemical plant in western Gansu.This topic introduces selection of electric furnace type and the design of the furnace parameters such as size,secondary voltage in the process of smelting special ferrochrome using this chromium slag.At present,examples using electric arc furnace and submerged arc furnace to smelt are successful.So appropriate selection of furnace type and parameter design for the new 6300 k VA electric furnace to ensure its high efficiency,energysaving is necessary.Firstly,this paper analyzes the process,electrical equipment and the geometry size etc.of 3500 k VA electric arc furnaces,and then draws its characteristic curve at 10 k V/265 V by statistic analysis of practical dates.It was found that the working voltage,operating resistance,electrical efficiency ?,power factor cos are high,at the same time,high thermal efficiency results some issues as electric power consumption is low.Finally the high secondary voltage can protect to improve electrical efficiency,but can not guarantee to energy-saving was gained.Secondly,used coke particles to simulate experiment under direct current electric and to study the factors influencing the thermal efficiency.The thermal efficiency will decreases whlie the secondary voltage,charge size and electrode diameter increases.By analyzing a single-phase equivalent circuit,deduce the expression of the electrical efficiency and thermal efficiency,moreover,analysis the effect of various factors for this expression.the final hoice for the submerged arc electric furnace.Combined with the actual situation,decide to choose the submerged arc furnace.By calculating the material balance and the heat balance,power consumption per ton is 5400 k W·h.Designing the related parameters of 6300 k VA submerged arc furnace.The self baking electrode is 740 mm in diameter,secondary rated voltage is120 V and secondary rated current is 30 k A.Simply calculate the sizes of the short network and copper tile were simply calculate,also the layout of short network and submerged arc furnace were designed.