地聚物材料固化含砷废渣抗硫酸盐侵蚀性能研究

用磷渣-粉煤灰基地聚物材料对含砷废渣进行固化处理,研究含砷固化体的抗硫酸钠侵蚀性能,考察不同硫酸钠浓度、干湿循环次数等因素对固化体质量、抗压强度、砷毒性浸出特性的影响,并采用XRD和SEN分析硫酸钠侵蚀前后固化体的物相组成及形貌变化.结果表明:当干湿循环为1～4次时,材料强度可提高11％～21％;当干湿循环为5～8次时,固化体结构在干湿周期性作用下被破坏,逐步出现微孔、大孔,固化体的结构缺陷致使固化体抗压强度降低(5％～20％),砷浸出率增大,但其不超过0.3％,可见含砷地聚物材料固化体有较强的抗硫酸盐侵蚀性.

Resistance to Sodium Sulfate Attack of the Arsenic-containing Waste Solidified Form with Geopolymer

Phosphorous slag and fly ash based geopolymer was used to immobilize the arsenic-containing waste residue discharged from a nonferrous metallurgical process.The effects of the concentration of sodium sulfate on the mass change,compressive strength and arsenic leaching concentration of the solidified forms were investigated.Meanwhile,the phase composition and microstructure of the solidified forms were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM).After aging for 4 cycles in the sodium sulfate solution,the compressive strength can be improved by 11％-21％.When the dry wet-cycle is 5-8 times,structure of geopolymeric matrix was destroyed,which is leaded to the compressive strength of solidified body decreases by 5％-20％ and the arsenic leaching concentration increases by O.3％.Thus the property of solidified form is stable in sodium sulfate solution.