Comprehensive Utilization Of Silicon And Vanadium In Stone Coal

The main useful elements in stone coal were silicon and vanadium. The current technologies only extracted vanadium from stone coal with low recovery, and rarely comprehensively extracted silicon. The experiments were made by stone coal from Yuyang in Hunan. A new process of comprehensive utilization of vanadium and silicon was invented, and hydrated silica and vanadium pentoxide were made. We researched many factors of the new process, and ensured the optimal conditions. The main research contents and results as follows:The new technology could realize the silicon and vanadium leaching efficiently by two steps. Stone coal was melt with sodium carbonate, and water quenched. Silicon turned into sodium silicate which was amorphous state and soluble well in alkaline solution. Vanadium was not oxidized because it was parceled by liquid phase. Vanadium was+3valence which was soluble in acidic solution and insoluble in alkaline solution. By alkali leaching first and then acid leaching, silicon and vanadium could be leached in two steps.High specific surface area of hydrated silica could be made from leaching silicon liquid. Harmful metal in leaching silicon liquid was seldom, so the leaching silicon liquid could used for the preparation of hydrated silica. The specific surface area of hydrated silica could be360m2/g in the best condition. The hydrated silica could be modify in the generation of production process.Vanadium was the main product of the technology. By test analysis and calculation of thermodynamics and kinetics, vanadium could be leached on+4valence, and the leaching control link and the reaction activation energy were found out.The new flow path was invented, and the process was stone coal melting roasting with sodium carbonate-water quenching-silicon and vanadium extraction-preparing hydrated silica and vanadium pentoxide. The process realized the comprehensive utilization of vanadium and silicon, and reduced the emissions. It could realized the double benefit of resources and environment.