Vanadium has good plasticity and malleability. It can be made into sheet, drawn into wire and processed into foil at room temperature. But a small amount of impurities, especially interstitial elements (such as carbon, hydrogen, oxygen, and nitrogen) can significantly affect the physical properties of vanadium. For example, when hydrogen in vanadium is 0.01%, it will cause embrittlement and reduce plasticity. The melting point rises to 2,458 when carbon is 2.7%. K. Vanadium has high melting point, high hardness, high resistivity, weak paramagnetism, small linear expansion coefficient, and similar elastic modulus density to steel, so it can be used as structural material.
Vanadium is one of the important strategic materials, mainly used in the metallurgical industry, as an alloying element additive, to improve the structure, performance, strength and toughness of steel, followed by titanium made with high temperature and high strength alloy, and again is the chemical industry, in the form of vanadium oxide, used for the production of catalysts, catalysts and so on.
Vanadium extraction from vanadium-titanium magnetite can be divided into two categories: fire and wet. The pyrotechnic process can process low-grade vanadium containing raw materials, which can be enriched by pyrolysis and then treated and recycled, also known as the reduction process. The wet process has the advantages of short flow and high recovery rate, but the raw material requiring treatment has relatively high vanadium grade, which is also called direct process.
1. Fire process flow
The selected ferrovanadium concentrate is added to the blast furnace or electric furnace for iron smelting. Most of the vanadium in the ore enters the molten iron, which is then sent to the converter to be converted into steel. Vanadium is highly concentrated in the surface slag, namely vanadium slag. This is the approach used by countries such as the former Soviet union, Norway and South Africa. Similar methods are used to recover vanadium in China.
2. Wet process flow
The concentrate containing ferrovanadium and mirabilite was used to make pellets, roasting and water leaching. Sodium vanadate was added into the solution and then sulfuric acid was added to convert it into V2O5 precipitation. After filtration, V2O5 was obtained directly.
