| In this papers, the recovery of vanadium from the argillaceous vanadium ore was studied detailedly in Xichuan of Henan province, where the content of vanadium is about 2.05%. We adopted a comparatively perfect technics, such as calcineing ore with Calcium, soaking through NH4HCO3, enriching the vanadium with 717 anion exchange resin and depositing vanadium with NH4C1, to recover the vanadium from argillaceous vanadium ore. At this rate, those problems that high content of SiO2 in the ore, agglomeration in calcination, low transformation rate of dissoluble vanadium and unavailable enrichment of mill run, can be raveled out. The vanadium recovery rate reached beyond 62% and settle the problems of environmental pollution in the recovery technology of vanadium. Besides, the preparation and characterization of vanadium catalyst were studied, combining its activity evaluation.The study of the recovery of vanadium showed that : (1)The optimal conditions of roasting were: The additive was Ca(OH)2(5% Ca of the vanadium ore), the roasting time was 3.0h and the roasting temperature reached 900℃. (2)The optimal conditions of extraction were: The concentration of NH4HCO3 was 5%, the leaching temperature was 70℃,the leaching time was 3.0h,the ratio of liquid-solid was 2:1, the agitation rate was 200r/min, Reflux condensation was taken when aerated the CO2. (3)The optimal conditions of adsorption of 717# anion exchange resin were: The temperature of adsorption was 50℃,pH was 10.0 and the velocity of flow was 0.4 ml/min.g. And the adsorption rate was higher than 98%. (4)The optimal conditions of desorption were: using the NaCl , and the concentration was 1.6mol/L, pH was 10.0, the temperature of desorption was 50℃and the velocity of flow was 0.8 ml/min.g. And the desorption rate was higher than 98%. The optimal conditions of precipitation of vanadium were: The modulus K was 4.0,pH was 10.0, the temperature of precipitation was 25℃, the time of reaction and standing were 30min and 3.0h respectively. And precipitation rate of vanadium was higher than 98.5%.Five vanadium catalysts were made withγ-Al2O3 and the mesoporous molecular sieve MCM-41 as carrier, and were made by dipping method, intermingle process and functionalizing method respectively. The characterization of their pore size, crystal structure, specific surface area and V2O5 load of catalysts were studied by XRD, the adsorption /desorption of N2 technique, Raman spectroscopy and XRF. The activities of the catalysts estimated by the synthesis of DPC with DMC and phenol. The investigation showed that the best catalyst was made by using V2O5 as the fundamental components, mesoporous molecular sieve MCM-41 as carrier and dipping method.From above experimental investigation, the target of recovery of vanadium was achieved effectively. This provides the technological flowsheet and technical conditions which are feasible on technique and reasonable on economy for exploitation of ore. Meanwhile, the achievement obtained is guiding significance for the exploitation and utilization of similar ore. And the investigation on the vanadium catalyst is guiding significance for the studies and applies. |
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