磷渣-粉煤灰基地聚物材料固化含砷废渣

为了处理有色金属冶炼厂产生的含砷废渣，利用磷渣-粉煤灰基地聚物材料对其进行固化处理。在磷渣：粉煤灰=60：40的基础上，通过单因素实验考察了石灰的掺量、化学激发剂水玻璃的模数及掺量、含砷废渣掺量等因素对砷固化体力学性能及砷毒性浸出特性的影响。结果表明：石灰外掺掺量为10%，水玻璃的模数为M=1.2，且其掺量为4%时，砷固化体的抗压强度和As毒性浸出浓度等指标综合效果达到最佳，地聚物材料对含砷废渣的最大固化容量为34%，其固化体抗压强度可达13.6 MPa，砷毒性浸出浓度为2.4 mg·L-1，满足危险废弃物堆存国家标准要求。通过XRD、SEM等手段分析可以得出，固化后砷通过化学键合的方式变成难溶盐的形式被地聚物材料牢牢地包裹，结构更加密实。

Solidification of arsenic-containing solid wastes using phosphorus slag-fly ash based geopolymer

A geopolymer based on phosphorous slag-fly ash was used to solidify the arsenic-containing waste discharged from a nonferrous metal metallurgical process. The effects of factors including the addition of lime, the modulus and dosage of sodium silicate, and the content of arsenic-containing wastes on the physical properties and arsenic-leaching characteristics of the arsenic-solidified forms were researched through single-factor experiments. The results showed that the compressive strength and arsenic-leaching concentration reached their optimal states when lime addition was 10%, a modulus of sodium silicate at M=1.2 was used, and the water glass dosage was 4%. The maximum content of the arsenic-containing waste solidified with the geopolymer was 34%. The compressive strength of the solidified form was 13.6 MPa and the arsenic-leaching concentration was 2.4 mg·L-1, which could meet the national standards for storage of hazardous wastes. The phase composition and structure of the solidified form were characterized using XRD and SEM, which showed that arsenic was transformed into insoluble salts that were enveloped in the compact structure of the geopolymeric materials.