A Novel Process for Uranium Yellowcake Production From Leach Liquor of High Concentration

摘要

A novel process for recovering uranium from leach liquor of serial heap leaching ofrnuranium ore through fractional precipitation is presented. First, the iron in leach liquor isrnprecipitated as jarosite crystal at about pH=1.8 while uranium remains in solution,rnaccomplishing the separation of uranium from iron. Second, the uranium is settled downrnas uranium peroxide precipitate using hydrogen peroxide as precipitant at a pH range ofrn2.8 to 3.5, with impurities such as aluminum and other metal and nonmetal ions being keptrnin solution and thus separated from uranium. The principles of iron removal by means ofrnthe jarosite formation and uranium precipitation with hydrogen peroxide are introduced.rnFactors influencing the jarosite formation and uranium precipitation processes such asrntemperature, acidity and ferric and sulfate concentrations, are discussed. Test results andrncommercial production data show that this new fractional precipitation process can bernadvantageous technologically and economically for uranium recovery from leach liquor ofrnheap leaching with U>4g/L. The yellowcake produced is a high quality crystal precipitaternwith high uranium grade (>65%) and good filtration property. The process has beenrnapplied in two China's uranium projects and the overall uranium recovery exceeds 98%.