精矿湿法提取磷和稀土的研究探讨

某地含稀土磷矿是以胶磷矿、隐晶质磷灰石等矿物组成的磷块岩石,由于稀土以类质同象形式存在于胶磷矿、磷灰石中,物理选矿同步富集在磷精矿中,再通过化学方法分离磷和稀土。根据该矿浮选磷精矿的化学成分和矿物性质,对精矿进行了硝酸浸出—浸出液分步提取磷和稀土的详细湿法试验研究,即精矿在质量液固比5:1,硝酸浓度400g/L,常温条件下分解2小时得到硝酸浸出液,硝酸浸出液先用氢氧化钠将浸出液酸度调至pH=1.8~2.0,加入草酸沉淀得到草酸稀土；稀土尾液用氢氧化钠将液体酸碱度调至pH=8.0~9.0,加入氯化钙沉磷得到沉磷固体产品；最终获得了P2O5品位38.54%的沉磷固体产品(活性磷酸钙),P2O5回收率99.04%,REO品位1.673%的草酸稀土,REO回收率为95.28%,实现了常温条件下磷和稀土的有效分离。

Study on Wet Extraction of Phosphorus and Rare Earth form Concentrate

The rare earth phosphate ore in a certain area is a phosphorous block rock composed of collophanite, cryptocrystalline apatite and other minerals. Because rare earth exists in apatite in the form of homogeneity, it is enriched in phosphorus concentrate simultaneously by physical dressing, and then phosphorus and rare earth are separated by chemical method. According to the chemical composition and mineral properties of the flotation phosphorus concentrate, A detailed experimental study was carried out to step by step to extract phosphorus and rare earth form the concentrate by nitric acid leaching. That is, concentrate in the liquid solid ratio of 5:1, nitric acid concentration 400g/L, under the condition of room temperature decomposition for 2 hours to get nitric acid leaching solution, in the nitric acid leaching solution with sodium hydroxide to adjust the acidity of the leaching solution to pH=1.8~2.0, adding oxalic acid precipitation to get rare earth oxalate; The rare earth tail liquid was adjusted to pH=8.0~9.0 with sodium hydroxide, and calcium chloride was added to precipitate phosphorus to obtain precipitate phosphorus solid product. Finally active calcium phosphate products P2O5 grade of 38.54% and P2O5 recovery of 99.04%, rare earth oxalate REO grade of 1.673% and REO recovery of 95.28%, The separation of phosphorus and rare earth was realized at room temperature.