Pre-Concentration of Vanadium from Stone Coal by Gravity Using Fine Mineral Spiral
Due to the low grade of V2O5 in stone coal, the existing vanadium extraction technologies face challenges in terms of large handling capacity, high acid consumption and production cost. The pre-concentration of vanadium from stone coal before the extraction process is an effective method to reduce cost. In this study, detailed mineral characterization of stone coal was investigated. It has been confirmed that the vanadium mainly occurs in muscovite and illite. A significant demand for an effective pre-concentration process with simple manipulation for discarding quartz and other gangue minerals is expected. Based on the mineralogical study, a new vanadium pre-concentration process using a fine mineral spiral was investigated. The experimental results showed that the separation process, which was comprised of a rougher and scavenger, could efficiently discard quartz, pyrite and apatite. A final concentrate with V2O5 grade of 1.02% and recovery of 89.6% could be obtained, with 26.9% of the raw ore being discarded as final tailings.
Development and Application of Out-Limited h/D Helical Chute
Based on the sizing principle of conventional fine helical chute,this article advanced and developed an out limited h/D helical chute,which successfully solved some problems experienced in the desliming and primary beneficiation of andalusite.Under the same conditions,the yield of rough concentration by desliming with out limited chute is 10% more than with conventional chute,and the content of Al 2O 3 is about 4% more.
Recovery of vanadium from stone coal acid leaching solution by coprecipitation, alkaline roasting and water leaching
Abstract The recovery of vanadium from stone coal acid leaching solution by coprecipitation, alkaline roasting and water leaching was studied. A method used to recover vanadium from stone coal acid leaching solution was developed, and it primarily included vanadium coprecipitation with iron in the solution, vanadium extraction by alkaline leaching from the precipitate, and vanadium pentoxide preparation with the alkaline leaching solution. Experiments found that the vanadium in stone coal acid leaching solution can be effectively enriched in the precipitate obtained by adding 3.64 g NaClO 3 per liter solution with initial pH 1.73 under stirring for 0.5 h at 95 °C. By roasting the mixture of 25 g of the precipitate with 22.5 g NaOH at 170 °C for 1.0 h, and then water leaching the roasted mixture at 98 °C for 1.0 h under stirring with L/S ratio of 3.3:1 mL/g, 97.0% of vanadium was extracted from the precipitate. After purifying with MgCl 2 , the vanadium pentoxide with purity 99.3% was obtained by adding NH 4 Cl to precipitate ammonium vanadate from the solution at pH about 2.0, and then roasting the ammonium vanadate at 520 °C for 2.0 h. The essential components of the coprecipitate are KFe 3 (SO 4 ) 2 (OH) 6 and HNaV 6 O 16 ·4H 2 O.