风积沙制备水化硅酸钙的工艺研究

Research Process of Preparation Hydrated Calcium Silicate by Desert Sand

利用风积沙和工业废渣水热合成硅酸钙晶体材料,首先擦洗处理风积沙去除杂质,然后加助剂湿磨活化获得氧化硅超细粉体;脱硫石膏经炭热还原处理制备石灰粉体,石灰消化后过滤成为石灰膏参与配料;采用二步活化法合成工艺进行水热反应,原料分段加入,加入激活剂粉煤灰使得最终CaO/SiO_2(摩尔比)达到0.98~1.0;控制工艺参数为:水固比20~40mL/g,合成压力2.0~3.0MPa,合成温度200~220℃,保温时间8h;搅拌速率升温阶段300~350转/min,保温阶段60~80转/min;水热合成反应结束后,料浆成型干燥获得水化硅酸钙制品。

Desert sand and industrial waste are utilized to synthesize hydrothermal calcium silicate crystal material. Scouring desert sand to remove impurities, wet grinding of adding agents to obtain silica superfine powder, FGD gypsum is disposed by carbon thermal reduction reaction to produce lime powder and preparation lime milk by slaking and straining. The process adopt two-step activating treatment to react, raw material is mixed times to CaO/SiO2 reach 0.98-1.0 by fly ash as activator. Technological parameter is ratio of liquid to solid 20-40mL/g, pressure 2.0-3.0MPa, temperature 200-220℃, reaction time 8h, and stirring speed 300-350rpm in temperature rise period and 60-80rpm in heat preservation. After hydrothermal reaction, the slurry is mould and dry to be hydrated calcium silicate product.