稻壳灰的综合利用研究

Comprehensive Utilization of Rice Husk Ash after Power Generation

用稻壳发电后的剩余物稻壳灰联产纳米二氧化硅和高档活性炭,使稻壳的利用率大于90%.采用氢氧化钠为稻壳灰的硅碳分离处理剂,分离后的滤液采用改良沉淀法制备纳米二氧化硅.滤液中通入二氧化碳作为成核剂,在滤液中形成微小晶种,然后再加入硫酸进行沉淀.所制得的纳米二氧化硅分散均匀,粒径为20 nm左右.废液制备出长度40～150μm,直径为0.5～1μm的硫酸钙晶须.分离后滤渣在高温下用氢氧化钠进行活化,得到比表面积1140 m2/g,碘吸附值为1072 mg/g的活性炭产品,洗液可以循环到稻壳灰硅碳分离步骤中使用.

Rice husk can be used for power generation,and the ash after power generation can be used to prepared white black and activated carbon.The ratio of rice husks＇ utilization in this article was more than 90%.Sodium hydroxide was used as separation reagent for carbon and silica.CO2 was used as nuclearing agent in the process of silica preparation,which reduced greenhouse gas emission.Using improved chemical precipitation method,it could successfully prepare nano-silica particles in about 20～30 nm diameter and each index could reach to national standard requirement.The residue were activated by sodium hydroxide,activated carbon with different properties were prepared.The specific surface area of obtained activated carbon is about 1140 m^2/g,and the iodine number is about 1072 mg/g.The alkali solution could be used circularly and the production cost was decreased.