The Preparation Of Vanadium Pentoxide And Co-production White Carbon Black By Alkali Leaching From Stone Coal Vanadium Ore

In order to make full use of valuable element silicon in stone coal, Alkali leaching vanadium process was used in extracting vanadium and silicon from stone coal, the phase and main components of stone coal were analyzed, the affect factors on leaching rate of vanadium and silicon in direct alkali leaching and pre-roasting alkali leaching were explored, the effect of additive was investigated. The vanadium and silicon in lixivium were separated, and vanadium pentoxide and white carbon black were obtained. Using this process, not only the multipurpose utilization of stone coal resources was increased, but also the smoke pollution was reduced greatly.In the direct alkali leaching vanadium process, under the conditions of manganese dioxide dosage was 2%, partical size was 220 mesh, solid-liquid ratio was 1:0.8, leaching temperature was 95℃, leaching time was 7h, ratio of alkali and ore was 1.7:1, the leaching rate of vanadium was 59.3%, leaching rate of silicon was 49.6%, compared with without additive, the leaching rate of vanadium improved by 11.5%, the leaching rate of silicon improved by 7.6%. Under the conditions of roast temperature was 850℃, roast time was 2h, leaching temperature was 95℃, leaching time was 4h, solid-liquid ratio was 1:1.4, ratio of alkali and ore was 1.2:1, manganese dioxide dosage was 2%, the leaching rate of vanadium was 95.5%, leaching rate of silicon was 67.2%. The pH was adjusted by hydrochloric acid, the stirring rate was controlled at 100r/min, slowly adding hydrochloric acid until the pH was 7.5, controlled the temperature was 70℃, and reacted 1h, the precipitation rate of silicon dioxide was 91.2%, the loss rate of vanadium pentoxide was 3.5%, the separation effect of vanadium and silicon was good. The silicon slag after separation was washed by hydrochloric acid solution which pH was 3, and the white carbon black was obtained, the silicon dioxide content was 95.6%, the recovery rate of silicon was 61.3%. The specific area of white carbon black was 224 m2/g,the products are proven to be amorphous structure of the hydration SiO2 by FTIR and XRD analysis, the product quality indicators attained the chemical industry standards. The 201 resin was used in separation and enrichment of vanadium, under the conditions of temperature was 303 K, pH was 7.5, vanadium pentoxide concentration was 6g·L-1, the saturated adsorption capacity was 278mg?g-1, When the flow rate of vanadium solution was 1.2L·h-1, the dynamic equilibrium adsorption quantity was 148mg?g-1.Under the conditon of pH was 8.5, the ammonification coefficient(K) was 1.6, reaction time was 2h, the vanadium precipitation rate was more than 99%. The FTIR and XRD spectrogram of ammonium metavanadate were in accordance with the standard ammonium metavanadate spectrogram. The FTIR and XRD spectrogram of V2O5 were in accordance with the standard V2O5 spectrogram, and the main technical parameters of product all reached the YB/T 5304-2011 standard of vanadium powder.