Study on Extracting Vanadium from Vanadium-bearing Stone Coal of Guizhou Tongren by Acid Leaching Extraction under Oxygen Pressure

A new process of extracting vanadium from vanadium-bearing stone coal by acid leaching extraction under oxygen pressure was introduced systematically.The mineralogy characteristics of vanadium in stone coal of Guizhou Tongren were investigated by various detecting methods and on the basis of it the factors which influence the leaching rate of vanadium were also investigated.The results show that after oxygen pressurized acid leaching,the leaching rate of vanadium can reach above 92% under the conditions that leaching time is 3～4 h,leaching temperature is 150 ℃,the dosage of sulfuric acid is 39%～42%,the liquid-to-solid ratio is 1.2 ∶1,the particle size is-0.074 mm,P o 2 is 1.2 MPa and the additive dosage is 3%～5%.The technological process of acid recovery-reduction deferrization-solvent extraction-precipitating vanadium by ammonium water-pyrolysis was used for the leaching solution,the powder products with V 2O 5 content of 99.5% was obtained and the gross recovery of vanadium achieved above 80%.