钨钼选矿废水的资源化利用

某钨钼选矿废水中含有磷、钙、氯和氟等元素。通过二段加入氧化钙中和，即首先在45 ℃、200 r/min的条件下反应3 h，基本脱除废水中的氟，同时沉淀少部分磷，过滤后得到一段固体产物；再在滤液中继续加入氧化钙\m(CaO)∶m(H₂O)=1∶4\]，在50 ℃、600 r/min的条件下反应1 h，过滤得到二段固体产物，滤液返回选矿工段循环再利用。经XRD分析，一段过滤的固体产物为氟化钙、氟磷酸钙和磷酸氢钙，二段固体产物为二水磷酸氢钙，经该工艺处理的磷回收率达到99%，实现了钨钼选矿废水的资源化利用。

Research on resource utilization of tungsten and molybdenum beneficiation wastewater

There are such elements as phosphorus,calcium,chlorine,and fluorine in tungsten and molybdenum beneficiation wastewater.Firstly,calcium oxide was added under the reaction conditions of 45 ℃,200 r/min,and 3 h.The fluorine of wastewater was basically removed and the phosphorus-containing deposit would be obtained by filtration.Secondly,with the conditions of 50 ℃,600 r/min,and 1 h,other solid product would be obtained after calcium oxide was added in the filtratem(CaO)∶m(H2O)=1∶4].The residual solution was recycled and returned to beneficiation process.XRD results showed that the solid products were calcium fluoride,calcium fluophosphate,and calcium hydrophosphate in the first stage.In the second stage there was calcium hydrogen phosphate dihydrate.It is showed that phosphorus recovery could be up to 99%,and the resource utilization can be achieved for the wastewater from the molybdenum-tungsten beneficiation process.