磷石膏转晶制备α型高强石膏工艺条件的优化研究

Study on optimization of technological conditions for preparing α high-strength gypsum from phosphogypsum by crystal conversion

以工业固体废弃物磷石膏为原料,采用半液相蒸压法制备α型高强石膏。以蒸压温度、蒸压时间、1#转晶剂、2#转晶剂以及料浆含水率为因素,进行了5因素4水平的正交实验。以力学性能为指标,对磷石膏转晶制备α型高强石膏的工艺条件进行了优化研究。结果表明,在反应温度为137℃、料浆含水率为20%(质量分数)、1#转晶剂用量为0.3%(质量分数)、2#转晶剂用量为1.27%(质量分数)、反应恒温时间为20 min时,可以制得2 h抗折强度、2 h抗压强度以及绝干抗压强度分别达7.0、21.7、44.7 MPa的α型高强石膏。

Based on industrial solid waste phosphogypsum as raw material,α high-strength gypsum was prepared by semiliquid autoclave method.By taking autoclave temperature,autoclave time,1# crystal conversion agent,2# crystal conversion agent and slurry moisture content as factors,an orthogonal test of 5 factors and 4 levels was carried out.By taking the mechanical properties as an index,the process conditions for the preparation of α high-strength gypsum by crystal conversion were optimized.The results showed that when the reaction temperature was 137 ℃,the slurry moisture content was 20%(mass fraction),the dosage of 1# crystallizing agent was 0.3%(mass fraction),the dosage of 2# crystallizing agent was1.27%(mass fraction),and the constant temperature of reaction was 20 min,α high-strength gypsum with 2 h flexural,2 h compressive and dry compressive strengths of 7.0,21.7 and 44.7 MPa could be prepared,respectively.