Improving uranium extraction efficiency of yellow cake production from one shale deposit by acid pugging and curing with D263B resin adsorption

The improving uranium extraction efficiency of yellow cake production from shale deposit by acid pugging and curing with D263B resin adsorption is described in this paper. The analysis and examination show that the composition of uranium minerals in one of uranium ores is very complex, which directly influence the extraction efficiency of uranium and processing technology. Conventional experimental results indicate that uranium leaching efficiency is changed between 50∼60% by conventional agitation method. In this case, acid pugging and curing experiments are employed in order to improving the extraction efficiency. A series of acid pugging and curing experiments are carried out to get parameters for heap leaching in pilot plant experiment. The experiment results by acid pugging and curing technology showed that uranium leaching efficiency can reach to 90% of extraction efficiency mixed with 1% manganese dioxide, 12% sulfuric acid pugging, curing 3 days and leached out with 5 g.L-1 diluted sulfuric acid by agitation method. Column experiments show that column leaching rate of uranium efficiency or heap leaching is over 93% with 1% MnO2, amount of acid (8∼12%), and curing (7∼10)days. The spray leaching density can reach 1.987m3.d-1·m-2. Comparing the result with conventional experiment result indicates that acid pugging and curing is one best way to improve uranium extraction efficiency. The net extraction rate is 30% over. The experimental results indicate that permeability aid reagent 802 improves the conventional heap leaching flow rate over 10 times. Because of the complex mineralization of the deposit, by the acid pugging and curing, the composition of the adsorption solution is complicated too, such as higher iron, organic materials and other elements. The resin D263B shows a good adsorption and elution property. The adsorption feed solution pH is 1.2∼ 1.5. The breakthrough capacity is 8.27 mg.U.mL-1. R. The resin saturation capacity of D263B is 26.31 mg. U.mL-1.R. Experiment results also indicate that the higher concentration of the iron and feed solution pH value greatly affect adsorption capacity of D263B resin. The higher feed solution pH, the higher content of iron is adsorbed on the resin. The resin capacity of the iron can reach to 24 mg.Fe. mL-1. R. It is suitable for recovery uranium from shale by acid pugging and curing technology for heap leaching - ion exchange resin - precipitation method. High quality yellow cake is gotten. The content of uranium in products is about 66%. (author)