摘要
采用半水磷酸工艺副产物半水磷石膏及炉渣、尾砂等作为主要充填材料,进行不同物料组合配比实验,以料浆泌水率、扩展度、不同龄期试块单轴抗压强度等指标为判据,研究炉渣和半水磷石膏胶凝特性及最优物料组合与配比。结果表明,将炉渣与尾砂作为充填材料时,炉渣不具有胶凝性;半水磷石膏具有自胶凝性,料浆浓度70%,半水磷石膏与尾砂比例大于3∶1时,充填体单轴抗压强度能满足3 d不低于3 MPa的技术要求;随半水磷石膏添加量的增多,料浆流动性变差,泌水率升高;最优物料配比推荐半水磷石膏与尾砂质量比例为3∶1~4∶1可调。料浆浓度70%,泌水率3.5%~5.0%,满足膏体特征。此外,半水磷石膏作为充填材料时产生有害气体CO2、SO2,添加石灰可以有效抑制有害气体产生;添加石灰会影响充填体强度,最佳石灰添加量为其占半水磷石膏干料质量的3%。
The semi-water phosphogypsum, which was produced from semi-water phosphoric acid process, as well as other backfill materials like slag and tailings were chosen as the main filling materials to carry out proportioning experiments with dif- ferent material combinations. Taking the bleeding rate and expansion of slurry, as well as the uniaxial compressive strength of test blocks in different ages as the criterion, the gelling characteristics of slag and semi-water phosphogypsum were studied, a- long with their optimal combination and proportion. The results showed that the slag had no gelling when it was mixed with tailings as filling material, but the semi-water phosphogypsum presented good gelling property. The filling strength could ex- ceed 3.0 MPa in 3 days that met the mining technical requirements when the concentration was 70%, and the mass ratio of semi-water phosphogypsum and tailings was greater than 3 z 1. However, the fluidity of slurry became worse and the bleeding rate increased with the addition amount of phosphogypsum. Thus, the best combination of semi-water phosphogypsum and rail- ings was adjustable between 3 ： 1--4 ： 1. When the concentration was 70% and the bleeding rate was 3.5%-5.0%, the slurry could meet the paste characteristics. Furthermore, adding semi-water phosphogypsum would produce harmful gas like COz and SO2 But adding the lime would restrain the gas and affect the filling strength. Thus, the best addition amount of lime accoun- ted for 3 of dry semi-water phosphogypsum.
出处
《矿业研究与开发》
CAS
北大核心
2018年第1期15-19,共5页
Mining Research and Development
基金
国家重点研发计划项目(2016YFC0801600)
关键词
半水磷石膏
尾砂
膏体充填
有害气体
Semi-water phosphogypsum, Tailings, Paste filling, Harmful gas
