Study on migration law of main associated elements in stone coal gangue in southern Shaanxi

Stone coal is a special kind of coal which is famous for its associated elements.The southern Shaanxi area is rich in stone coal resources.There are many harmful elements associated with stone coal and its vermiculite in this area.By testing the contents of vanadium,chromium,molybdenum and phosphorus in stone coal and its vermiculite,it is found that the content of vanadium,chromium,molybdenum and phosphorus in the samples of southern Shaanxi stone coal is generally higher than that of Chinese coal.The characteristic of element enrichment molybdenum is obvious.Vanadium,chromium,molybdenum and phosphorus are also commonly enriched in vermiculite samples.The leaching experiment was carried out to simulate the leaching （migration） of vanadium,chromium,molybdenum and phosphorus in stone coal gangue under four conditions.The experimental period was up to 12 months,and the leaching rate of four elements in the meteorite sample under immersion conditions was calculated.The results show that the acidic environment is more conducive to the migration of vanadium.The acid and alkali conditions can increase the migration of chromium.The migration of molybdenum in the stone gangue sample is weak in the four types of solutions.The acidic environment is more conducive to the migration of phosphorus,and the alkaline environment inhibits the migration of phosphorus to a certain extent.The acidic solution has higher leaching rate for vanadium,chromium and phosphorus in stone coal gangue.The leaching rates of vanadium,chromium and phosphorus in different samples are similar.The leaching efficiency of alkaline solution for vanadium,chromium,molybdenum and phosphorus in stone coal gangue is generally low,and the alkaline environment inhibits the migration of molybdenum and phosphorus in vermiculite to some extent.The leaching efficiency of the four aqueous elements of vanadium,chromium,molybdenum and phosphorus in the coal gangue is not high.The water environment around the mining area is conducive to the migration of chromium and phosphorus,which should be highly valued.