New Technology For Taking Vanadium From Vanadium-containing Tailings Immersed

The vanadium is producing the alloy steel and the super alloy principal element, is the important strategic resources, has the widespread application, the market prospect is very good. Our country is the vanadium resources'great nation, including the vanadium ore great variety, extracts vanadium craft also to change with each new day. Along with the international and domestic market vanadium pentoxide price rising suddenly, each region starts in abundance proposes the vanadium project. But in extracts vanadium process, not only the vanadium recoverys-ratio is low, and has caused the serious environmental pollution and the resources waste. With mine resources unceasing mining, Islag tails discharging quantity and ore inventory day by day sharp increase, because the mineral resources is the non-recovery resources, resources demand is big, and mineral resource deficient today, executions to the slag tails comprehensive utilization, carries out the valuable element the recycling imperative.Extracted vanadium residue is the end of vanadium slag after several extraction of tailings, was one kind difficult to process mineral containing the vanadium. In the tailings contained the vanadium to be very still high, from the use of resources and environmental protection, both in terms of recovery of vanadium which is of great significance. The present paper is summarizing the domestic and foreign tailings research comprehensively in the foundation, in view of its mineral's characteristic, proposed the leaching vanadium new craft, and has conducted the correlation theories research.This study used Panzhihua Iron and Steel Vanadium slag as raw material, reference to the Panzhihua Iron and Steel Vanadium converter to extract vanadium craft, unioned the related research of extracts vanadium from vanadium slags, the steel slag and the bone coal and so on, begins from the vanadium valent state and the solubility of the tailings, union sulfuric acid leaching thermodynamics, pressure leaching and hydrofluoric acid nature, analyze plan's feasibility. Uses the direct pressure acid leaching and the atmospheric pressure combination leaching craft reasearch separately to Panzhihua Iron and Steel Co. the vanadium tailings, proposed the atmospheric pressure does not have the pollution not to roast the high recoverys-ratio leaching vanadium the technical process. First through carries on the mineral's chemical analysis, the X-ray phase analysis and the grain size analysis, examines the vanadium content and the form and so on in the tailings; Next carries on the pressure and the atmospheric pressure exploration experiment separately under the test condition, carries on the contrast from all quarters facing the vanadium leaching percent, the confirmation leaching theory accuracy; The element has carried on the condition experiment through influence vanadium leaching percent's several influences factor to the pressure and the atmospheric pressure leaching, and has carried on the orthogonal and two stage of contrast verification test to the atmospheric pressure leaching; Then to leached mud and the leachate has conducted the analytical study; Finally obtains the vanadium tailings leaching vanadium optimally leaching condition and the technical process.The experimental study result indicated that:1. In order to enable leach vanadium from the vanadium tailings, must destroy the mineral structure, releases the vanadium, then oxidizes the low valence vanadium to the high valence vanadium which may dissolve through the oxidant. The contrast experiment indicated that, sulfuric acid leaching's leaching percent is quite low, but under the pressure field and the atmospheric pressure combination leaching, all can destroy the tailings'mineral structure, the leaching percent enhances greatly.2. A pair of acid leaching influencing factor of extracting vanadium craft like acid concentration, the oxidant amount, the leaching temperature, the leaching time, the oxidant type and so on to carry on the survey and the optimization, obtained the various parameters optimum operating point. The vanadium tailings pressure leaching and the atmospheric pressure combination leaching's vanadium leaching percent reach above 68% and 85% separately. Among them, the reagent amount and liquid solid is bigger to the vanadium leaching influence, but the material granularity, the reaction time and the temperature and the oxidant type are small to its influence.3. Through the orthogonal experiment and two-stage leaching's exploration, the vanadium tailings is not suitable carries on two-stage leaching. Finally obtains the vanadium tailings leaching optimum technological conditions and the flow sheet. The optimum technological conditions are as follows:Raises the vanadium tailings to rub is smaller than to the granularity 0.25mm (60 items) accounts for 95%, the pulp liquid solid compared to L:S=5:1, initial H2SO4 is 150g·L-1, R1 concentration is 30g·L-1, oxidant KMO4 is 3.33wt%(5g), leaching temperature 85℃, time 4h, stirring speed 500r/min.Compares with the traditional sodium roasting, uses the pure wet method leaching vanadium, both has solved waste gas pollution in the production, and can the comprehensive utilization resources, have the cost lowly, not to have the pollution, the simplicity of operator, the equipment investment few and so on merits, has the good economic efficiency, the environmental protection benefit and the social efficiency.