以煤矸石为原料、水玻璃和NaOH为碱性激发剂合成矿物聚合物,以添加硫化物的矿物聚合物对Cr(VI)进行解毒与固化,对固化体进行了检测.结果表明,当硫化物与Cr(VI)的摩尔比大于3:1时,矿物聚合物中总铬的浸出浓度小于1mg/L时,铬固化率大于99%,对Cr(VI)的最大固化量为1.2%.添加硫化物的矿物聚合物对Cr(VI)的解毒与固化是基于氧化还原反应,Si2-被氧化为Si2+(平均化合价),Cr(VI)被还原为Cr(III),Cr(III)被矿物聚合物中的-OAI(-)(OH)3吸引并固化在非晶质结构中.
A geopolymer was synthesized using coal gangue as raw material, and water glass and sodium hydroxide as alkaline exciting agents. The geopolymer added by sulfide was used in detoxification and immobilization of Cr(VI). Then the curing geopolymer was tested. The results show that when the molar ratio of sulfide to Cr(VI) is more than 3:1, the leaching concentration of total chromium is less than 1 mg/L and the fixation rate of chromium above 99%. The best fixation rate of Cr(VI) is 1.2%. The detoxification and immobilization mechanism of Cr(VI) is due to oxidation-deoxidation reaction. S2- is oxidized to S2+ and Cr(VI) deoxidized to Cr(III) during the synthesis of geopolymer, then Cr(III) is attracted by -OAI(-)(OH)3 in the geopolymer and fixed in a non-crystalline structure.