Study On Resource Utilization Of Chromium Slag Metallurgical Sintering

With the wide application of chromium salt in various fields of the national economy,the output of chromium salt has increased year by year,and the environmental pollution problems caused by the increase of its subsidiary product chromium slag have become increasingly prominent.In this paper,according to the composition and toxicity characteristics of chromium slag,the method of detoxification and resource utilization of chromium slag with chromium slag is proposed.The detoxification effect and leaching toxicity behavior of sintered ore with added chromium slag were analyzed,and a new way of resourceful and harmless disposal of chromium slag was proposed.The characteristics of chromium slag basic research shows:chromium slag has strong water absorption,the average moisture content is 22.5%.The chromium slag has a relatively uniform particle size distribution,in which the mass ratio of 0.7-3mm is35.67%.The main elements in chromium slag are Fe,O,Mg,Al,Cr,Si and other elements,which mainly exist in chromium spinel structure,in which the content of TFe,Mg O and Al₂O₃are 36.31%,8.26%and 19.76%,respectively It contains more TFe,which provides the possibility to increase the amount of chromium slag properly.The experimental study on the influence of chromium slag ratio on the sintering process shows that the sintered ore powder added with chromium slag has the most comprehensive performance when the alkalinity is 1.0,the carbon content is 7.16%,and the chromium slag ratio is 15%.Excellent,in which the sintering rate and utilization factor in the sintering process are 24.63 mm/min,1.55 t·m^-2·h^-1,the sintered product yield is 81.67%,the drop strength and drum strength are 83.33%and 73.33%,The reduction degree is 54.11%,and the low-temperature reduction pulverization rate is97.13%(RDI_+3.15).After adding chromium slag,research on the suitable carbon content of sintered ore:the increase of carbon content can generally improve the yield and cold strength of sintered ore.When the addition amount of chromium slag is 30%and the carbon content is increased to 9.21%,the finished product rate of sintered ore is 82.31%,and the drop strength and drum strength are 83.56%and 72.77%respectively.When the carbon content reaches 10.23%,the comprehensive performance of the sinter has decreased.As the carbon content increased from 7.16%to 10.23%,the Fe O content in the sintered ore showed an upward trend,from 7.56%to 8.21%.Comprehensive analysis shows that the suitable carbon content of acid sintering of limonite with chromium slag is about 9.21%.The sintering experiment of mixed slag powder added chromium slag shows that:under the condition of alkali sintering of 2.0 and the ratio of chromium slag is 20%,the comprehensive performance of sintered ore is the best.The finished product rate of sintered ore is 80.35%.The drum strength was 86.78%and 73.13%,the reduction degree index was 87.32%,and the low-temperature reduction pulverization rate was68.97%(RDI_+3.15).The sinter ore leaching toxicity study shows that the chromium slag has a good detoxification effect after adding slag,and the sinter ore leaching toxicity test results show that when the chromium slag is added at 30%,the sinter ore leaching toxicity test result is 0.57mg/L,far It is far lower than the national solid waste hexavalent chromium leaching toxicity standard(5mg/L),and the reduction rate of Cr⁶⁺reaches more than97.52%.Comprehensive sinter metallurgical properties and economics of sintering,as well as the harmlessness and resource utilization of chromium slag,the suitable proportion of sintering chromium slag should be controlled at 15%-20%.