磷石膏膏体充填材料强度优化配比试验研究

为研究贵州开磷矿业总公司采用磷石膏和黄磷渣胶结充填采空区的可行性, 在实验室测试了磷石膏及黄磷渣的主要物理化学性质, 制备了不同浓度不同配比的充填料浆, 并测试其坍落度、泌水率和不同龄期的单轴抗压强度。采用正交试验设计优化磷石膏膏体配比, 并采用Mathematica对强度数据进行拟合, 得出本次试验的最优结果为;磷石膏膏体充填料的最优质量比为黄磷渣∶磷石膏=1∶4, 添加CaO质量为5%, 磷石膏膏体质量浓度为67%~68%。在该配比条件下, 磷石膏膏体充填体28 d单轴抗压强度为2.15~3.42 MPa, 可满足矿山安全生产需求, 并显著降低料浆泌水率。

Experimental Study on Optimization of Phosphogypsum Plaster Mix Proportion for Backfill Strength

In order to probe into the feasibility of backfilling the mined-out area with cemented mixture of phosphogypsum and yellow phosphorus slag for Guizhou Kaiyang Phosphorous Mine Bureau, backfill material with different slurry concentration and different proportioning were prepared based on the laboratory tests on the physical and mechanical properties of phosphogypsum and yellow phosphorus slag, for which the slump, bleeding rate and uniaxial compressive strength were also tested. Afterwards, orthogonal regression method was adopted to optimize the proportion of phosphogypsum plaster in the design and Mathematica was then used for strength data fit, leading to the optimized proportions of phosphogypsum plaster as backfill material as follows: the ratio of yellow phosphorus slag to phosphogypsum at 1∶4, addition of CaO in quantities of 5%, mass concentration of phosphogypsum plaster at 67%~68%. With such proportioning, the phosphogypsum plaster has a uniaxial compressive strength of 2.15~3.42 MPa after 28 days of aging with bleeding rate notably reduced, which can meet the safety requirement for mining production.