煤矸石酸浸除杂合成SiC的研究

Study on Synthesis of SiC by Acid Leaching of Coal Gangue

选择煤矸石作为合成碳化硅的原料,采用加压酸浸法一步去除煤矸石中的杂质。研究结果表明:废盐酸的酸浸除杂效果明显优于钛白废酸。煤矸石酸浸除杂最佳工艺条件为:液固比6∶1、酸浸温度180℃和酸浸时间4h。在此条件下,除杂后煤矸石灰分中的SiO_(2)含量达到97.76%。以除杂后煤矸石为原料合成碳化硅,随着合成温度的升高,碳化硅的产率不断上升。与工业合成碳化硅相比较,煤矸石经酸浸除杂后可代替石英砂合成碳化硅。

In this paper,coal gangue is chosen as raw material for synthesis of silicon carbide to realize waste utilization.The impurities in coal gangue were removed by pressure acid leaching in one step.The results show that the optimum process conditions of acid leaching of coal gangue are as follows:liquid-solid ratio 6:1,acid leaching temperature 180 ℃ and acid leaching time 4 h.Under these conditions,the content of SiO2 in coal gangue lime reaches 97.76%.The SiC was synthesized from the coal gangue after impurity removal.With the increase of the synthesis temperature,the yield of SiC is rising.Compared with the industrial synthetic silicon carbide,the gangue can replace quartz sand to synthesize silicon carbide after acid leaching.