Field-enhanced Lithium Leaching Process Experiment Of Spodumen

The lightest metal in nature is Li,with unique electrochemical properties,lithium products are used in various fields in China,so lithium is called "white oil".The new energy field is developing rapidly,the world has set off an unprecedented wave of electrification,lithium industry has become a new sunrise industry developed by countries around the world.Although China is rich in lithium resources,but about 80%of the brine for the salt lake,the Qinghai-Tibet Plateau is the most,but the magnesium lithium is relatively high,the cost of lithium extraction is high.The ore lithium extraction method is mainly based on sulfuric acid method,although the sulfuric acid method is highly adaptable and has high recovery rate,which is the preferred method for production applications in the industrial chain,but with high energy consumption.In this study,based on the existing sulfuric acid method,an experimental technique of microwave-enhanced lithium leaching from lithium pyroxene is proposed,and the influencing factors and strengthening mechanism in the reaction process are analyzed.The paper takes Australian lithium pyroxene concentrate as the research object,firstly,the influence of roasting temperature and roasting time on the α-lithium pyroxene crystalline transformation process is studied,and the best roasting temperature of lithium pyroxene is determined to be 1050℃ and time is 30 minutes.The analysis of the crystalline phase of the minerals under different conditions showed that the XRD(210diffraction peaks of lithium pyroxene ore gradually increased with the increase of temperature and time,and the large-angle and small-angle diffraction peaks were shifted to the left and right,respectively,which laterally indicated that the degree of orientation of the material increased,the crystalline grains of the crystalline phase gradually became larger and the crystal spacing expanded.The particle size results verify that the particle size increases after roasting,and in addition there is a transition phase during the temperature change.Experimental study of microwave external field enhanced selective heating properties and dielectric properties.By measuring the dielectric constant(,,dielectric loss(,,and dielectric loss angle tangent(tan analysis of mineral dielectric properties,lithium pyroxene 250 ℃,the weakest dielectric properties;apparent density increases to improve the dielectric properties of minerals;adding sulfuric acid to improve the wave absorption properties of materials,sulfuric acid method measured at 120% of the theoretical amount,the strongest dielectric properties The main influence of different power conditions;heating characteristics.Compared with the conventional process microwave heating to improve the rate of temperature rise,the feasibility of microwave sulfuric acid method roasting was judged.The test compared the leaching effect after conventional roasting and microwave roasting,in the same to achieve the maximum leaching rate of 97% achieved by conventional roasting-leaching,microwave roasting-leaching reaction temperature from conventional roasting 250 ℃ to 190 ℃,roasting time from conventional roasting30 min to 15 min,the amount of sulfuric acid from conventional 0.157 to 0.133.In the roasting temperature of 190 ℃,the amount of sulfuric acid is reduced to 0.133.Under the same reaction conditions with roasting temperature of 190℃,roasting time of 15 min,liquid-solid ratio of sulfuric acid dosage of 0.157 and microwave roasting power of500 W,the lithium leaching rate of microwave roasting-leaching process increased from94.06% to 96.53% compared with the conventional roasting-leaching process.From the roasting mechanism exploration found that: microwave roasting can reduce particle size,improve the specific surface area,enhance cracking.In summary,lithium pyroxene microwave acid roasting can reduce the roasting temperature,shorten the roasting time and reduce the amount of sulfuric acid compared to conventional acid roasting process.This study provides a theoretical research and experimental basis for the industrial application of microwave-enhanced lithium leaching from lithium pyroxene,which is of significance for the development of green and efficient lithium extraction technology.