磷石膏再结晶体力学特性试验研究

采用比较法设计了磷石膏失水与再结晶试验, 分析了各参数对再结晶体力学性能的影响, 获得了最优参数。研究了失水磷石膏与常态磷石膏混掺情况下固化体的力学特性。研究表明: 掺加2%生石灰的磷石膏, 在180 ℃下热处理3 h、陈化3 d、以55%浓度充填井下, 其浆体pH呈中性, 再结晶体28 d抗压强度达到6.82 MPa, 可适用于各种充填采矿方法; 常态磷石膏和失水磷石膏按1∶2配制的混合材料, 固化体28 d抗压强度仅为失水磷石膏强度的6%。

Experimental Research on Mechanical Properties of Recrystallized Solid of Phosphogypsum

With comparative method, tests on phosphogypsum dehydration and recrystallization were conducted. After analyzing the effect of each index on mechanical properties of recrystallized solid of phosphogypsum, the optimal indexes were decided. The mechanical properties of solid prepared with dehydrated and ordinary phosphogypsum was also studied. Results show that phosphogypsum with the addition of 2% quicklime, after being heated at 180 ℃ for 3 hours and aged for 3 days, was used for backfilling underground at the concentration of 55% with neutral pH value. Its recrystallized solid can reach 6.82 MPa in compression strength after 28 days, suitable for all kinds of backfilling in underground mining. The material prepared with ordinary phosphogypsum and dehydrated phosphogypsum in the proportion of 1∶2 solidified for 28 days, resulted in the compression strength merely 6% of dehydrated phosphogypsum.