Study On The Content Of Associated Elements And The Occurrence And Enrichment Method Of Rare Earth Elements In Anning Phosphate Mine In Yunnan Province

China is a big country with the second basic reserve of phosphate ore in the world,but there are fewer rich ore and more lean ore in phosphate ore in China.Due to the characteristics of more difficult ore dressing and less easy ore dressing,the comprehensive utilization of associated phosphate resources is very important.In this paper,the mineral characteristics of Anning phosphate mine in Yunnan were studied by X-ray diffraction(XRD),scanning electron microscope(SEM),energy spectrum analysis,LA-ICPMS analysis and electron probe light microscopy.The results show that the main phase of Anning phosphate ore is fluorapatite(collophanite)dolomite quartz,the associated minerals are mainly glauconite,mica pyrite and clay minerals.The average content of P₂O₅ in phosphate ore is about 25%,the average content of rare earth is 0.02%,the content of impurities is high,and the associated elements are rich.Heavy metal elements and radioactive elements associated with phosphate ore mainly occur in phosphate ore and carbonaceous sand shale.The content of Sr element in phosphate rock,Mn element in dolomite and Ti element in carbonaceous sand shale is relatively rich.The associated rare earth elements are mainly concentrated in phosphate ore and carbonaceous sand shale,with an average content of 258.48?g/g and 230.35?g/g,respectively.Based on phase analysis,micromorphology analysis,energy spectrum analysis and electron probe analysis of single mineral elements,as well as the comparison between the radius of calcium ions and rare earth ions,it is confirmed that rare earth elements occur in glauconite in the form of a few independent rare earth minerals,and the vast majority of rare earth elements occur in collophanite in the form of isomorphism.In the extraction experiment of rare earth elements,nitric acid method is used for acidolysis,and ion exchange method is used for enrichment and extraction.The experimental results are as follows:the mass fraction of 25%nitric acid is used for acidolysis of phosphate ore powder,the ion exchange time is 50min,the elution agent is 0.02mol/L EDTA solution,the elution time is50min,the resin adsorption and desorption effect is the best,that is,the above conditions are the optimal conditions for the enrichment of rare earth elements,the adsorption rate is more than 50%,The first desorption rate was above 79%.In addition,the effective removal of calcium from the nitrite solution before ion exchange can effectively promote the adsorption of rare earth elements by the resin.In the whole process of adsorption and elution,the effect of the resin on each rare earth element is basically the same.With the increase of phosphate ore consumption demand and the decrease of rich ore resources,it is an inevitable trend to strengthen the comprehensive utilization of phosphate ore associated resources.Based on the existing technology of comprehensive utilization of phosphate ore associated calcium,fluorine,iodine and rare earth resources,new multidisciplinary technology such as geology,material science and chemical technology is adopted.New methods,and constantly explore the new technology of comprehensive utilization of phosphate ore associated resources,to realize the efficient utilization of phosphate ore associated resources is particularly important.