The Pilot-scale Experiment on the Compositive Utilization of Asbestos Tailing

摘要

The main chemical components of asbestos tailing are MgO and SiO2.It's a efficient method to produce the precipitated amorphous silica and magnesium hydroxide from asbestos tailing. In this paper, the author reported the research work about the pilot scale experiment of the preparation of nanoscale precipitated amorphous silica and nano-Mg (OH)2 powder from asbestos tailing. The processing is mainly including the treatments of acid leaching of the asbestos tailing, alkali leaching of the acid leaching residue, preparations of the precipitated amorphous silica, purification of the acid leachate, the precipitation of nano-Mg (OH)2.The samples is obtained successfully those of nano-precipitated amorphous silica with a spheroid-shape and nanomagnesium hydrate with a plate-shape. The results shown that 140.6kg magnesium hydroxide and 93. 6kg precipitated amorphous silica is obtained per 300kg asbestos tailing. The MgO recovery ratio of asbestos tailing is 82.02%, that of SiO2 is 68. 90%. The consumption of each raw material of 100kg asbestos tailing are: 31% Chlorhydric Acid 392kg, Perhydrol (30%) 3.45kg, NaOH (commercial grade) 98kg, Sulphuric acid (93%) 14kg, Coupling Agent of Organic Titanate (YB-502) 0.7kg, Triton X-100 (OP-10) 1.56kg. Though there need to do more researches on the waste water and waste solid producing during this processing, this craft still has some evident economic and social benefits.