Thermodynamic mechanismand purification of hot press leaching with vein quartz

The mineralogical investigation of vein quartz has been done by using optical microscope,electron microprobe analysis and Chemical analysis.The result shows that,there are plenty of micro-fine mineral inclusions in quartz lattices such as feldspar,albite,mica and pyrite.Fe、Al、Ca、Mg、K、Na、Li、Mn are main impurities elements of it.Hot press leaching shows that leaching agent make the quartz lattice distortion and dissolved the impurities element which interstitial in it.Total amounts of impurity elements of the quartz sands were decreased from 300.37μg/g to 39.18μg/g.The content of SiO₂ is 99.996%.The total removal rates are 86.96%.Pure mineral experiment of Feldspar,Albite,Mica and Pyrite had been done to discussion their leaching behavior and mechanism in hot press leaching System.The thermodynamic analysis of hot press leaching showed that the Gibbs free energy of HF reacted with Quartz,Feldspar,Mica and Pyrite are all less than zero,but the Gibbs free energy of HF reacted with mineral impurities are much less than it with Quartz,the HF is easy to react with Feldspar,Albite,Mica and Pyrite in hot press leaching system.