铵盐浸出碳酸钙试验研究
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摘要
以-0.074 mm石灰石粉末为原料,通过铵盐浸出得到可溶性钙盐溶液,对氨水碳化制备碳酸钙进行了初步试验。通过单因素变量法探究了铵盐浸出试验中真空度、铵盐浓度、浸出温度、浸出时间、石灰石粉末添加量、搅拌速率的影响。结果表明,以硝酸铵为原料,浓度为7 mol/L,石灰石粉末添加量69.66 g(碳酸钙与硝酸铵摩尔比为0.3∶1)时,在相对真空度为-0.09 MPa下浸出6 h,浸出温度90℃,搅拌速率480 r/min,钙离子浸出率可达94.5%。同时,进行了常压和减压下热力学分析。液相法浸出碳酸钙能为免高温煅烧制备碳酸钙提供依据,从而达到节能降耗的目的,是一种新型浸出工艺。
To-0.074 mm limestone powder as raw material, soluble calcium salt is obtained by ammonium salt leaching solution, and preliminary experiment of adding ammonia carbonization of calcium carbonate is prepared. By single factor variable method, explores the ammonium leaching of vacuum degree, ammonium salt concentration, leaching temperature, leaching time, limestone powder addition, mixing rate. The results showed that the concentration of ammonium nitrate as raw material for 7 mol/L, limestone powder addition of 69.66 g(calcium carbonate to ammonium salt mole ratio of 0.3∶1),leaching temperature 90 ℃ at-0.09 MPa relative decompression, 6 h time, stirring speed 480 r/min, calcium ion leaching rate can reach 94.5%. At the same time, under normal pressure and decompression was performed thermodynamic analysis. Liquid phase method leaching calcium carbonate to lay a good foundation for preparation of calcium carbonate from high temperature firing, so as to achieve the purpose of saving energy and reducing consumption, is a new kind of leaching process.
To-0.074 mm limestone powder as raw material, soluble calcium salt is obtained by ammonium salt leaching solution, and preliminary experiment of adding ammonia carbonization of calcium carbonate is prepared. By single factor variable method, explores the ammonium leaching of vacuum degree, ammonium salt concentration, leaching temperature, leaching time, limestone powder addition, mixing rate. The results showed that the concentration of ammonium nitrate as raw material for 7 mol/L, limestone powder addition of 69.66 g(calcium carbonate to ammonium salt mole ratio of 0.3∶1),leaching temperature 90 ℃ at-0.09 MPa relative decompression, 6 h time, stirring speed 480 r/min, calcium ion leaching rate can reach 94.5%. At the same time, under normal pressure and decompression was performed thermodynamic analysis. Liquid phase method leaching calcium carbonate to lay a good foundation for preparation of calcium carbonate from high temperature firing, so as to achieve the purpose of saving energy and reducing consumption, is a new kind of leaching process.
引文
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[2]韩伟,高新,白海涛,等.我国纳米碳酸钙的生产技术应用及发展趋势[J].西北大学学报(增刊),2005,(36):36-38.
[3]陈吉明.循环法制备高纯碳酸钙[J].矿产综合利用,2004(2):15-17.
[4]胡庆福,宋丽英,刘树宝.高纯纳米碳酸钙制备研究[J].非金属矿,2003,26(2):42-44.
[5]刘启光.化学化工物性数据手册(无机卷)[M].北京:化学工业出版社,2002.