1. Thermal Process Of Electrosilicon Production (Smelting In An Electric Arc Furnace)
Scenario: Production of ferrovanadium with low and medium vanadium content (e.g. FeV50) suitable for large-scale production.
Raw Materials:
Vanadium oxides (e.g., vanadium pentoxide V₂O₅ or vanadium slag).
Reducing agents: ferrosilicon (FeSi75), aluminum granules
Flux: lime (CaO), fluorspar (CaF₂).
Technological process:
Mixing ingredients: mix V₂O₅, ferrosilicon, lime in proportion (lime is used for slagging).
Electric arc furnace restoration:
Heating up to 1600~1750°C in a three-phase electric arc furnace.
Silicon in ferrosilicon reduces V₂O₅:
V2O5+5Si→2V+5SiO2
A small amount of aluminum is added to improve the efficiency of recovery, and fluorite is added to improve the fluidity of the slag.
Slag and gold separation: After the reduction is complete, the vanadium-iron alloy (high density) sinks to the bottom of the furnace and the silicate slag (low density) floats.
Casting and crushing: The liquid alloy is poured into ingots and after cooling, it is crushed into lump products.
Specifications:
Higher energy consumption, but vanadium can be recovered from slag (secondary smelting).
The product typically contains 50 to 60% vanadium (e.g., FeV50), with a high silicon content (subsequent silicon desilization is required).
2. Thermal Process Of Aluminum Production
Scenario: Production of ferrovanadium with high vanadium content (e.g. FeV80) or high purity ferrovanadium, suitable for small batches of high value-added products.
Raw Materials:
Vanadium oxides (V₂O₅ or V₂O₃).
Reducing agent: aluminum powder (Al)
Additives: iron filings (to regulate the iron content of the alloy), potassium chlorate (KClO₃, as a heat generator)
Technological process:
Mixing ingredients: mix V₂O₅, aluminum powder, iron filings according to the stoichiometric ratio (excess aluminum about 10%~15% to ensure complete recovery).
Calcination reaction:
The mixture is loaded into a magnesium crucible and ignited with a magnesium strip to initiate an aluminothermic reaction:
3V2O5 + 10Al → 6V + 5Al2O3 + a large amount of heat (temperature up to 2000°C and more).
The reaction is violent, so it is necessary to control the speed to avoid splashing.
Precipitation and separation: After the reaction is completed, liquid ferrovanadium is layered on the Al₂O₃ slag, and after cooling, the slag is separated.
Refining and casting: Oxygen is passed to remove the aluminum if necessary, and finally the ingots are cast.
Specifications:
There is no need for an external heat source, using the heat generated during the reaction, but the high cost of aluminum.
The product may contain up to 80% vanadium or more (e.g. FeV80) with a small amount of impurities (Si, C, etc.).