Study On Separation Of Vanadium From Low-grade Resources Containing Vanadium

Vanadium and its oxides are an important resource and are widely used in metallurgy,chemicals,materials and other fields.Stone coal containing Vanadiumand vanadium?titanium?magnetite are the two most important vanadium containing mineral resources,which account for more than 90%of vanadium reserves.At present,Stone coal containing Vanadium is directly used as the raw material for wet extraction of vanadium,but because of its low grade,it brings about high energy consumption and serious environmental pollution.Vanadium?titanium?magnetite is used as a raw material for iron making.Whether or not the vanadium slag process is used,a large part of vanadium eventually enters the steel slag to form vanadium steel slag.Due to the low vanadium content,there is no effective vanadium recovery method.In view of this,this study proposes that vanadium containing coal and vanadium containing steel slag combine to enrich vanadium,that is,by combining acid vanadium containing coal with highly alkaline vanadium containing steel slag at high temperatures,create suitable physical and chemical conditions to form High-grade vanadium enrichment phase among them.The high grade extracted vanadium raw material was obtained by separating the enriched phase.This not only reduces the amount of subsequent wet extraction vanadium mineral treatment and reduces pollution,but also facilitates the use of tailings after separation.For this reason,through thermodynamic analysis,this paper firstly designs a suitable vanadium phase,and finally determines that:high thermodynamic stability,high vanadium content,and strong magnetic ferrovanadium spinel phase Fe₃O₄·FeV₂O₄ is a vanadium enrichment phase.Based on the results of thermodynamic predictions,the effects of alkalinity and the content of the main oxides FeO,MgO,and Al₂O₃ on the formation of ferrovanadium spinel phase crystals were experimentally studied.The experimental results show that when the dualinity is less than 1.7,the ferrovanadium spinel phase can be formed,vanadium is mainly concentrated in the ferrovanadium spinel phase,and phosphorus is present in the dicalcium silicate phase or liquid phase;The increase of FeO content is conducive to the formation of ferrovanadium spinel phase,but the vanadium grade in this phase decreases accordingly;The increase of MgO content can increase the activity of FeO in the slag and promote the formation of spinel phase,but the MgO content in this phase also increases,reducing the grade of vanadium;When the content of Al₂O₃ is greater than 6%,the vanadium enrichment phase is dominated by magnesium aluminum spinel,and the vanadium grade is less than 12%.Taking into account the influence of various factors,the suitable physical and chemical conditions for the formation of ferrovanadium spinel phase are obtained:the degree of dibasic R is 1.3-1.5,the content of FeO is 15-20%,the content of MgO is 3-7%,and the content of Al₂O₃ is less than 6%.Under this experimental condition the?Fe,V,Al?₃O₄ is easier to form,of which V₂O₃content is higher than 19.4%.Based on the results of the thermodynamic equilibrium study of synthetic slag,the combined treatment experiments of vanadium containing steel slag and vanadium containing coal were carried out.The results showed that the magnetic concentration effect was not obvious at low temperatures.1573K was a relatively ideal temperature.when the temperature was controlled at 1573K.and the binary alkalinity R is controlled at 1.0-1.2,the vanadium separation rate reaches more than 80%,and the content of V₂O₅ in the resulting vanadium mineral reaches more than 5%.Vanadium levels increased to five times their original level.The study provides theoretical support and technical guidance for vanadium enrichment and recovery from Stone coal containing Vanadium and vanadium contained slag.