石棉尾矿综合利用中试技术研究

Study on The Pilot Technique of Comprehensive Utilization of Asbestos Tailing

以石棉尾矿为原料,采用酸浸、氧化除铁、控制碱析Mg(OH)2以及酸浸渣碱溶、稀酸法控制沉析SiO2工艺,并在碱析和稀酸沉析过程中适时添加表面处理剂和粒径控制剂,制备了超细Mg(OH)2和超细高比表面积SiO2。中试主要产品的技术指标为:①超细氢氧化镁,d50=1.0±0.2μm,Mg(OH)2=98±0.5%,白度>92.0%;②超细二氧化硅:BET比表面积190～479m2/g,孔体积0.47～1.01cm3/g,平均孔径30～80?,干基SiO2含量为≥99%,白度≥93.0%;③产出率(以加工1000kg尾矿计),超细氢氧化镁≥420kg,超细高比表面积二氧化硅≥310kg,尾矿中氧化镁和二氧化硅的回收率在80%以上。

The ultra-fine Mg(OH) 2 and large surface area precipitated SiO2 have been made by integrating of acid leaching,oxidizing and purifying,alkali leaching of the acid leaching residue and precipitating technology from asbestos tailing. The major properties of Mg(OH) 2 produced by pilot-scale test showing that middle particle size is 1.0±0.2μm,content of Mg(OH) 2 is 98%±0.5%,whiteness is more than 92%. And the major properties of precipitated SiO2 produced by pilot -scale test showing that specifi c surface are...