Industrial production of ferrotitanium raw materials are ferrotitanium concentrate (Fe-TiO3), rutile (TiO2), titanium dioxide (TiO2) and waste titanium metal materials (Ti, Ti-V-Al, etc.), which in addition to waste titanium metal materials, to use reducing agent reduction to obtain ferrotitanium and titanium alloy. TiO2 is a difficult oxide to reduce. Reducing TiO2 with carbon is only possible at high temperatures and produces TiC instead of Ti. You get high carbon titanium iron. It is impossible to reduce TiO2 with silicon, but the addition of CaO flux can promote the silicon reduction reaction. Titanium and silicon form stable silicide, which is favorable for silicon reduction reaction, but the produced ferrotitanium contains high silicon. It is possible to reduce TiO2 with aluminum to produce Ti. However, if the aluminum composition is lower than the calculated chemical value, a large amount of TiO is generated. TiO is more stable than TiO2 and cannot be reduced with aluminum. It is a strong alkaline oxide, can form slag with Al2O3 or SiO2. Therefore, CaO should be added to prevent TiO slag-forming reaction, and it is also beneficial for TiO2 reduction. Comparing the reaction in Figure 2, it is easier to reduce ilmenite (FeTiO3) with aluminum than TiO2, and the addition of CaO has the same effect. So reducing titanium concentrate with aluminum is the main method of producing titanium iron. The resulting product is low in carbon, but high in aluminum and silicon. Based on the above analysis, the main production methods of ferrotitanium include thermo method, electrosilicontherm method, electrocarbontherm method, and waste titanium material remelting method.
Remelting process
Using titanium waste and scrap steel as raw materials, the ferrotitanium of about 70%Ti (Fe-Ti series with low eutectic point at about 68%Ti) is produced by remelting in induction furnace. In order to reduce the burn loss of titanium during the remelting process, the titanium scrap is packed in the steel cylinder and then pressed. A mixture of barium chloride and sodium chloride, or cryolite, or a similar low melting point mixture, is added as a flux to cover the ferrotitanium melt. Various titanium composite alloys can also be produced by remelting method.
Electrosilicothermal method
Reduction of TiO2-FeO-CaO-CaF2 melt with ferrosilicon in electric furnace. It can produce Fe-Ti-Si, Si-Ca-Ti composite alloys. If other oxides are added or other ferroalloys are added, multiple titanium composite alloys can be made.
Electrocarbonothermal method
High carbon ferrotitanium containing i20% ~ 25%, C5% ~ 8%, Sil% ~ 2%, Al1% ~ 2%, with a surplus of iron can be produced by using coke as reducing agent and lime as flux in small electric furnace. To obtain low carbon ferrotitanium, silica can be added to the charge. Such as the composition of the charge is: 47% ilmenite (TiO251.5%), 28.5% silica, 24.5% coke, can be refined out of Ti29% ~ 30%, Si17% ~ 20%, C1.8% ~ 2% of carbon titanium iron. By increasing the proportion of silica in the charge, low carbon and high silicon ferrotitanium with Si about 30% and C0.1% ~ 0.3% can be refined. If bauxite is added to the charge, Ti-Al-Si-Fe composite alloy can be refined.