Recycling Of Rubidium And Potassium From A Tailing

After the fluorite flotation of the main mineral fluorite in the Jiepailing Mine area of Chenzhou,Hunan Province,the rare alkali metal rubidium and potassium elements have relatively high value,which lost in the tailing.In order to improve the utilization level of resources and expansion of rubidium and potassium resources,this project collected a large number of Chenzhou Jiepailing fluorite flotation tailings and carried out detailed process mineralogical research,which showed that fluorite flotation tailings content 0.44%rubidium,the content of potassium is 9.23%and the content of fluorite in the fluorite flotation tailings is18.60%,containing rubidium and potassium minerals mainly in iron-lithium mica,muscovite and phlogopite,and the floating performance of the three is similar,and it is not easy to separate in the flotation process.They will enter into the flotation tailings together,so that after the flotation,the K₂O grade is 11.43%and the Rb₂O grade is 0.57%.The process of rubidium and potassium leaching of flotation tailings was carried out.The mica Al-Si-O framework structure was almost not decomposed by acid and alkali under normal temperature and pressure except for hydrofluoric acid.The rubidium and potassium were leached under the conditions of microwave irradiation-sulfuric acid-fluorosilicic acid system.Under microwave irradiation,different mineral components in the sample have different absorption characteristics for microwave energy.The internal stress generated by different thermal expansion of each mineral destroys the ore structure inside the sample,causing damage and microcracks,which is beneficial to the leaching of rubidium and potassium.Fluorosilicic acid can also react to form hydrofluoric acid under acidic conditions,which can decompose the mica Al-Si-O framework structure in minerals,and make the poorly soluble rubidium-potassium minerals into soluble rubidium sulfate and potassium sulfate salts.Achieve the purpose of rubidium potassium leaching.The effects of leaching temperature,leaching time,sulfuric acid dosage,fluorosilicic acid content and liquid-solid ratio on the leaching rate of rubidium potassium were investigated by single factor experiments.The results showed that under the direct acid leaching conditions,the leaching effect of rubidium potassium was not ideal.The optimum leaching conditions under microwave irradiation were determined as leaching time 2h,leaching temperature 95°C,sulfuric acid dosage 60%,fluorosilicic acid dosage.20%,the leaching slurry solid-solid ratio is 2.5:1.Under this condition,the leaching rate of rubidium can reach 83.6%,and the leaching rate of potassium can reach 88.4%.The process conditions of extraction and back extraction of the leachate after impurity removal were explored and optimized.The choice of diluent,extraction time,concentration of extractant（t-BAMBP）and extraction of O/A were investigated by single factor experiment.The effects of pH and extraction temperature on the extraction rate of rubidium were compared.The choice of stripping agent,the concentration of sulfuric acid in stripping agent,the stripping time and the stripping rate of stripping O/A compared to the stripping rate were studied.influences.The optimized experimental conditions for the extraction and stripping of hydrazine were obtained.The diluent was sulfonated kerosene,the extraction time was 3 min,the concentration of t-BAMBP was 1.0 mol1/L,the pH was 13.5,and the extraction ratio was4:1.The extraction reaction is carried out at room temperature,the extraction rate of rubidium is 83.4%;the sulfuric acid is selected as the stripping agent,the concentration of the stripping agent H₂SO₄ is 0.8mo1/L,the stripping time is 60s,and the stripping ratio is 5:1compared to O/A.The stripping rate of rubidium was 95.1%.Using the difference in solubility of K₂SO₄ and Rb₂SO₄ at different temperatures in solution,a three-stage fractional crystallization method was prepared for the preparation of potash products and rubidium sulfate products,and the crystallization time and stirring speed were investigated.For the influence of crystallization rate of potassium sulfate and rubidium sulfate,potassium sulfate in the raffinate is separated to prepare K₂SO₄ content≥50%potassium fertilizer product;rubidium sulfate in the stripping solution is separated to prepare Rb₂SO₄ content≥96%rubidium sulfate.