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Stone coal is an important mineral containing vanadium containing vanadium grade (V 2 O 5 dollars) reached 0.8% of the value of industrial exploitation. This paper a stone coal mine in Hunan wet vanadium extraction process, through the the comparative study H 2 SO 4 direct leaching process, intensified by microwave H 2 < / sub> SO 4 leaching process and help infusion-H2SO4 leaching process, the combination of all the advantages of the leaching process, proposed the microwave strengthening the the aid infusion-H 2 SO < sub> 4 leaching process. Directly by sulfuric acid leaching process to extract vanadium from vanadium-containing stone coal mines V 2 O 5 leaching rate of 63.4%. The process high acid consumption, the leaching rate is low, the operation is more difficult to control the leaching process, but no microwave equipment, low investment costs, the process is simple, the the optimum leaching process conditions of the process: mineral grinding fineness is less than 0.074 mm, H 2 SO 4 amount of 40% of the liquid to solid ratio of 1.5:1, temperature 90 ° C, leaching time 6 h. Intensified by microwave leaching the process mentioning vanadium, vanadium leaching rate of up to 77.3%. Microwave heating can easily achieve the desired leaching temperature, leaching reaction time, is conducive to shorten the production cycle, but the high acid consumption, the application of microwave equipment energy consumption is relatively high, and the ratio of liquid to solid, more acid leaching wastewater generated. The optimum leaching conditions: microwave power 2960 W (reference power 3000 W), 40% of the H 2 SO dosage , leaching time of 80 min, the ratio of liquid to solid : 1. The the aid infusion-H 2 SO 4 the leaching process V2O5 leaching rate reached 75.4%. Low acid consumption, liquid to solid ratio and conventional heating method, no microwave equipment HF acid is volatile because the concentration is too high, but to prevent the pollution of the environment. Leaching process conditions parameters: H 2 SO 4 amount of 30%, liquid to solid ratio of 1:1, the the HF amount of acid 8%, leaching time of 6 h, the leaching temperature of 90 ° C. . Orthogonal design experiment of microwave strengthen to help infusion-H 2 SO 4 leaching process, the main test of the influencing factors of the leaching process, the optimum leaching conditions parameters: H 2 SO 4 amount of 25% of HF acid amount of 7%, microwave power of 2960 W, leaching time of 80 min, the liquid to solid ratio of 1:1, the process V 2 O 5 leaching rate the highest, reaching 85.6%. After pretreatment, acid leaching solution into the extraction section, with a ratio of 15% P204 5% TBP 80% organic sulfonated kerosene as the extractant. Extraction of vanadium from acid leaching solution by solvent extraction, the extraction rate of 99%; stripping the high concentration of vanadium liquid hydrogen peroxide oxidation, the ammonium salt Shen vanadium, resulting V2O5 product meets the national standard (GB 3283-87) 98-class standards. Using thermodynamic calculation method has been the reaction enthalpy of the chemical reaction of the leaching process and the reaction Gibbs free energy value, and made △ r H T θ -T diagram and the △ of rG T θ -T diagram, theoretical analysis of the impact of temperature on the leaching rate of vanadium. The dissociation equilibrium in the reaction system, by studying the leaching agent and the co-infusion made lgC-pH FIG. The balance and charge balance of the main mineral composition of oxides of the elements dissolved in the solution, and were made of each oxide solubility in solution logarithmic chart. Leaching process of vanadium, as the reaction proceeds, the reaction control type by a chemical reaction control into the control of the solid film. Experimental data calculated the dynamic model of the two control conditions: chemical reaction controlled kinetic model: 1 - (1-η) 1/3 = 0.0062t solid membrane control dynamics model: -2/3η- (η) the 2/3 = 0.0014t new wet vanadium extraction process, virtually eliminating air pollution, burning vanadium products on NH < sub> 3 cooling recovery of dilute ammonia; reuse wastewater generated after simple treatment; solid waste can be made of refined stone pulverized coal used as accelerant or cement system.
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