Stone Coal Vanadium Green Technology And Energy Conservation A Key Technology Research

It is an important development direction to extract vanadium in stone coal. In this field, there are polular problems, such as high consumption of resources and energies, environmental pollution. In order to solve the problems and attain the goal of energy-saving and emission reduction, study on a new technology for recovering V2O5 from stone coal and key technolgies of energy-saving and emission reduction was made in this paper.Optimization of process conditions was made in the course of experiment, such as roasting, leaching, extration, back-extration and sedimentation. Roasting process parameters were of entrance temperature 250℃,roasting temperature 850℃, CaO 16%, AF-QM 1.5%,roasting time 2.1h, rate of conversion of vanadium was 80.1% in roasting process. Leaching process parameters were of a ration 3:1 of liquid to solid, RTGJ 0.3%, leaching temperature 90℃, leaching time 1.5h, vitriol concentration 4.5%, the rate of leaching was 85.2% in leaching process. Extration process parameters were of a ration 1:1 of liquid to solid, pH 3.0, five–rate extration, vibrating time 2min, the rate of extration was 99.1%. Back-extration process parameters were of a ration 8:1 of water phase to organic phase, six–rate back-extration, vitriol concentration 10%, the rate of back-extration was 98.5%. Sedimentation process parameters were pH 2.0, sedimentation temperature 90℃,sedimentation time 2.5h, the rate of sedimentation was 95.0%. The product of V2O5 was in accord with the standard of GB3283-87.Key technolgies of energy-saving and emission reduction in extracting vanadium in stone coal were as follows: circulation utilization of waste water, exhaust emission accord to standard, surplus heat utilization, complex utilization of solid waste. Waste water from the process were faffinate, ammonium metavanadate waste water and sewage from sedimentation of vanadium. Ammonium metavanadate waste water returned to grain-making process, sand-fitering and secondary reverse osmosis process was adopted to dispose sewage from sedimentation of vanadium. Neutralization,floatation and membrane separation process was adopted to dispose faffinate. Waste waste was used for circulation utilization. Exhaust gas from the process were roasting gas and calcined fume, bag-type dusting and cyclone desulfurization process was adopted to dispose roasting gas, and circulation absorption method with diluted H2SO4 solution was adopted to absorb NH3 from calcined fume. Waste slag included leaching slag, purification slag and plaster slag. Concrete performance could be improved with plaster slag and leaching slag from the process, and purification slag was disposed according to hazardous waste standard. Furnace in fluid bed was used to dispose carbon, and the steam was used to generate power.