Study On Preparation Of High Titanium Ferroalloy With Rutile

High titanium ferroalloy is a kind of special type and widely used ferroalloy, which contains65%-75%titanium. At present, The main method of producing high titanium ferroalloy is remelting. But it is uneconomical to use waste titanium as raw material. This paper presents a new process against the traditional aluminothermy reduction method problems:high oxygen, aluminum and impurity contents. Produce crude high titanium ferroalloy with rutile by aluminothermy reduction. Then refine the crude high titanium ferroalloy favorable pre-slag, obtaining top-quality high titanium ferroalloy with low oxygen, aluminum and impurity contents.At first, calculating the adiabatic temperatures and unit thermal effect of main reaction by using Al, Mg, Ca as reducer. It shows that the heat released only by redox reaction is not enough to maintain the system’s energy balance. It needs add heating agent NaClO3to increase reaction system’s unit thermal effect. According to calculating the Gibbs free energy, it shows that adding CaO with stronger alkaline can inhibit TiO generating, the thermal reduction reaction will be more thorough, and the rate of titanium recovery will be increased. Furthermore CaO can as slag agent, and the metal will be easier separate from the slag.Secondly, with rutile and iron scale as raw materials, aluminum as main reducer, study the effects of the units thermal effect, lime ratio, fluorite ratio, furnace diameter, aluminum coefficient and compound reducer on high titanium ferroalloy preparation. The results show that the rate of titanium recovery is maximum when the unit thermal effects is for3000kJ·kg-1, lime and fluorite ratio are for20%-25%and10%-14%with, and the furnace diameter is for30cm, and the contents of aluminum and oxygen are still high; the experiments of aluminum coefficient and compound reducer show that with aluminum coefficient increases, the rate of titanium recovery and the contents of aluminum in high titanium ferroalloy are increased, it can reduce the aluminum content with some Mg, Ca instead of Al. chemical composition and XRD of the high titanium ferroalloy have been analyzed, in addition to aluminum and oxygen are higher, the other ingredients meet the requirements; Al and O are mainly in the form of Al2O3.Finally remelting and refining the high titanium ferroalloy prepared by aluminothermy. Choose and melt pre-slag with low melting point and good mobility, then remelt and refine the crude titanium ferroalloy with pre-slag. The results show that it can reduce the contents of and oxygen to1.04%and0.88%by pre-slag of CaO-SiO2-CaF2; the pre-slag of CaO-SiO2-MgO-CaF2can reduce them to1.38%and1.41%; the best results of aluminum and oxygen by the pre-slag of CaO-SiO2-Li2O-CaF2are1.28%and0.79%. The results of XRD analysis show that the mainly phases in refined titanium ferroalloy are TiFe and Fe2Ti, only a bit of impurity phases, achieving the purpose of deoxidation and aluminum removal. There are others pre-slag have be done, the results show that they can’t be separated the metal from slag.