Study Of Extraction Raffinate And Vanadium Precipitated Liquor Recycling Utilization Of Extraction Of Vanadium From Stone Coal

Extraction raffinate and vanadium precipitated liquor are two kinds of significantindustrial wastewater in the process of vanadium extraction from stone coal enhancedby aid-leaching reagent. However, few studies about recycling these wastewater andmost practical processes only discharge them by disposing of wastewater to theemission standard. In order to achieving eco-friendly production, energy saving andemission reduction, therefore, it is necessary to recycling the extraction raffinate andvanadium precipitated liquor for vanadium extraction process, which has positiveeffects on practical production and environmental protection.In this paper, the cyclic utilization of the extraction raffinate and the vanadiumprecipitated liquor were systematically studied, developing a process of the cyclicutilization of the extraction raffinate and the vanadium precipitated liquor which canachieve zero discharge of wastewaters and revealing the cumulative behaviors of themain elements in recycling the extraction raffinate and the vanadium precipitated liquor.Studies have shown that the circulation utilization of the extraction raffinate andthe vanadium precipitated liquor can produce no emission in the way of mixing39.91%extraction raffinate and concentrated sulfuric acid (mass fraction of98.3%) to preparethe leaching acid, using60.09%extraction raffinate to wash the leaching slag, andadding the Calcium Hydroxide to adjust the pH of vanadium precipitated liquor to10,then mixing the filtrate (solid-liquid separation) and concentrated sulfuric acid (massfraction of98.3%) to be formulated as a stripping agent to returning to the process ofstripping, while adding new water (170L/t· raw ore) in the solid-liquid separation phaseof leaching and adding new water (0.66L/t· raw ore) in the stripping agent preparationphase.In recycling the extraction raffinate and the vanadium precipitated liquor, theconcentration of these elements (Al, Fe, Mg, K, Si, Ca, P, Na, F, etc.) can be up tobalanced and do not be harmful to the qualifications of raw process, the leachingefficiency of vanadium fluctuates between92%~94%and the first extraction rate ofvanadium fluctuates between76%~77%, the sixth back extraction ratio of vanadium canbe always above99.2%, the product quality of V2O5can achieve to the standard of GB3283-1987(V2O5-98), the dosage of ammonia reduction is11.81L·NH3·H2O/t· rawore in every recycling.