CO_2对转炉冶炼中、低碳铬铁过程熔体温度的影响

Influence of CO_2 on the melt temperature of medium and low carbon ferrochrome during refining in converter

针对当前氧气转炉冶炼中、低碳铬铁工艺中存在的温度过高、耐火内衬寿命短、铬回收率低的问题,提出在转炉内喷吹CO_2-O_2混合气体,由高碳铬铁脱碳冶炼中、低碳铬铁的新思路。首先计算了CO_2与铬铁熔体内各元素反应时引起的体系温度变化,并通过实验验证了CO_2在中、低碳铬铁冶炼过程中的降温作用。然后对冶炼不同碳含量的中、低碳铬铁产品时的CO_2最大理论加入量进行了计算,结果表明冶炼碳质量分数分别为4.0%、3.0%、2.0%的产品时,CO_2的最大加入量(质量分数)分别为42.99%、29.87%和16.30%;加入CO_2较适合冶炼碳质量分数大于2.0%的铬铁产品,不推荐冶炼碳质量分数低于1.0%的铬铁产品。本研究可为CO_2参与转炉冶炼中、低碳铬铁的新工艺提供理论基础。

To solve the problems of excessive temperature, short lifetime of lining and low yield of chromium in current refining process of medium and low carbon ferrochrome （M-LFeCr） in converter, a new process for producing M-LCFeCr alloy from high carbon ferrochromium （HCFeCr） by injecting CO2-O2 gas mixture in converter was proposed. The temperature variation of the system caused by the reaction between CO2 and different elements in the melt was calculated firstly. And the role of CO2 in de-creasing the temperature during M-LCFeCr refining process was verified by experiments. Then the theoretical maximum amount of CO2 addition was evaluated for producing M-LCFeCr with different carbon contents. The results show that the maximum CO2 addition amount was 42.99 mass%, 29. 87 mass% and 16.30 mass% when refining FeCr with carbon content of 4. 0 mass%, 3.0 mass% and 2. 0 mass%,respectively. And it is suitable to produce FeCr with carbon content higher than 2.0 mass% when blo-wing CO2 , while it is not recommended to refine FeCr with carbon content lower than 1.0 mass%. The study can provide theo-retical basis for the new process of M-LCFeCr refining in converter with introduction of CO2 .