密闭直流电弧炉钛渣生产还原剂碳因素分析

Factor of Reductant Carbon During Titanium Slag Smelting in Closed Direct Current Arc Furnace

密闭直流电弧炉冶炼钛渣所用原料主要为钛铁矿和无烟煤,利用无烟煤中的碳高温冶炼还原.钛渣冶炼过程中,控制直流电弧炉入炉物料中无烟煤用量与钛铁矿用量的比例,使生产过程在密闭直流电弧炉输入功率保持一定、钛铁矿成分相对稳定的条件下,以获得良好的钛渣产品品质.无烟煤比例过大,产品钛渣中TiO2的含量下降,同时会增大熔渣的还原度,渣中低价氧化物的量增多,导致熔渣黏度和电耗增加.如果无烟煤比例偏小,达不到需要的还原度,碳最大可能的消耗在FeO的还原上,直接影响产品品质.当无烟煤比例达到一定程度,继续提高该比例,抑制了FeO的还原反应,杂质还原后富集进入渣相,使钛渣中TiO2受到稀释而贫化,不能提高钛渣的品位.在功率一定的条件下,入炉物料中无烟煤比例成为影响钛渣品位高低的关键因素.以云南某密闭直流电弧炉熔炼周期的生产数据得到其冶炼中无烟煤配碳比为12.403%.

Titanium slag smehing by ilmenite and reduction under the high temperature surroundings. anthracite in closed direct current The ratio of anthracite to ilmenite arc furnace adopts carbon must be controlled strictly in order to produce high quality titanium slag under the condition of steady energy and ilmenite composition. With oversize anthracite, TiO2 content in titanium slag will be decreased, while the increase may be seen in re- duclion degree, viscosity of molten slag, quantity of low- valent titanium and power consumption. If the ratio is smaller than needing, the reduction degree of slag cannot meet smelting requirement. In this case, the carbon will be consumed mainly in FeO reduction which, in turn, will affect the production quality directly. With in- creasing of the ratio, it restrains FeO reduction because that impurity enriches in mohen slag. For all the above, the grade of slag cannot improve through ratio increasing continually. With a certain power input, the ratio of an- thracite is the key factor that determines the grade of titanium slag. Based on production data of a Yunnan closed direct current arc furnace, the ratio of anthracite to ilmenite is 12. 403%.