Address: No. 88 Anteng Road, Nandihao Village, Xincheng Street Office, Tiexi District, Anshan City
Contact: Chairman Zheng Wanbo
Phone: +86 150-4067-2222
Business Manager Wu Wenju
Phone: +86 139-4122-1119
Carbon ferrochrome is smelted in a reduction electric furnace, and chromite powder uses coke as a reducing agent and silica or bauxite as a flux. The slag composition is generally 227 to 33% SiO, 30 to 34% MgO, 326 to 30% Al2O, and Cr2O3 <9.0%. Due to the formation of chromium carbide, the product contains 4-9% carbon. The capacity of a modern reduction electric furnace for smelting ferrochrome is 10,000 to 48,000 kVA. Generally, a closed fixed type is used. H / ton. Electric furnaces for smelting silicon-chromium alloys are similar to ferrochrome reduction furnaces. There are two methods of smelting, one-step and two-step. One-step smelting with chromite, silica, coke and flux. The two-step method uses carbon chromium iron, silica, and coke as raw materials for slag-free smelting. The smelting process is generally similar to ferrosilicon production. Smelting electricity consumption of 3000 to 4000 kilowatts per ton? Around the hour.
Medium, low, and micro-carbon ferrochrome generally uses silicon-chromium alloy, chromite, and lime as raw materials. The silicon is refined and desiliconized using an electric furnace of 1500 to 6000 kVA, and a high-basicity slag operation is used (CaO / SiO2 is 1.6 to 1.8). Low- and micro-carbon ferrochromium is also produced on a large scale using the heat transfer method. During production, two electric furnaces are used, one furnace is used to smelt silicon chromium alloy, and the other furnace is used to melt slag composed of chrome ore and lime. The refining reaction is carried out in two stages in two stages: ① After the slag of the slag furnace is injected into the stage, the silicon-chromium alloy that has been initially desiliconized in the other stage is added. Large, desiliconization, micro-carbon ferrochrome containing less than 0.8% silicon and as low as 0.02% carbon can be obtained. ② After the reaction slag (containing about 15% of Cr2O3) in the vat is transferred to the second vat, the silicon-chromium alloy (containing 45% of silicon) smelted from the silicon-chromium electric furnace is heat exchanged into the slag. The initially desiliconized silicon chromium alloy (containing about 25% silicon) is further desiliconized in a vat, and the slag containing Cr2O3 below 2-3% can be discarded.
Oxygen blowing method is used for refining medium and low carbon ferrochrome. Liquid carbon ferrochrome is used as raw material. A small amount of lime and fluorite are added to the molten pool during blowing, and silicon chromium alloy or ferrosilicon is added before iron extraction to recover the slag. chromium. Smelting of micro-carbon ferrochrome is only possible under a certain degree of vacuum.
Vacuum solid state decarburization refining, using ground high-carbon ferrochrome as a raw material, wherein a part of the ground high-carbon ferrochrome is oxidized and roasted as an oxidant, mixed with water glass or other binders, pressed into agglomerates, and subjected to low temperature After drying, in a car-bottom vacuum furnace, heat reduction is performed at a vacuum degree of 0.5 to 10 mm Hg and a temperature of 1300 to 1400 ° C for 35 to 50 hours. Microcarbons containing less than 0.03% or even less than 0.01% carbon can be obtained. Ferrochrome.