Process for smelting low-silicon ferrotitanium by fusing titanium-containing blast furnace slag

Abstract

The invention discloses a process for smelting low-silicon ferrotitanium by fusing titanium-containing blast furnace slag. The process comprises the following steps: preparing slag, ferro-aluminium and calcium oxide in a mass ratio of 100 to 37.94 to (10-15); crushing ferroaluminum alloy, grinding the ferroaluminum alloy into powder with particles sizes which are more than or equal to 300 meshes, adding calcium oxide, mixing a calcium oxide mixture until the surface of the ferroaluminum alloy powder is uniformly coated; putting the titanium-containing blast furnace slag into a magnesia crucible, putting the magnesia crucible into a resistance furnace, carrying out furnace heating to 1450-1650 DEG C, and carrying out constant-temperature control; uniformly adding the mixed material into a fusion tank in a speed of 4.5g/min-5.5g/ml, and after the adding, maintaining the temperature for 5-10 minutes; taking out the material at 1450-1650 DEG C, carrying out water cooling, and drying; and separating slag and alloy by virtue of a mechanical method. According to the process, the particle size of the ferroaluminum alloy powder is more than 300 meshes; and meanwhile, by controlling the adding speed so as to control the reduction reaction time of aluminum and silicon, so that the reduction efficiencies of aluminum and silicon are improved, the consumption of the ferroaluminum alloy powder is reduced, the contentsof silicon and residual aluminum in the alloy is reduced, the process cost is lowered, and the silicon decrease and the titanium increase in the alloy are realized.

Description

technical field [0001] The invention belongs to the technical field of blast furnace slag utilization, in particular to a technology for utilizing molten titanium-containing blast furnace slag, which uses molten titanium-containing blast furnace slag to produce low-silicon ferro-titanium. Background technique [0002] my country is rich in titanium resources, the largest reserves in the world, mainly in the vanadium-titanium magnetite in Panxi area, and its utilization rate is very low. The main reason is that only vanadium and iron are recovered in blast furnace ironmaking, and titanium enters blast furnace slag in the form of titanium dioxide ( The mass fraction is about 25%), forming complex mineral phases, which is difficult to recycle. At present, 70 million tons have been accumulated in the slag factory, which is still increasing at a rate of 3 million tons every year, occupying land, polluting the environment, and wasting resources. If the titanium-containing blast fur...

AI Technical Summary

Problems solved by technology

[0002] my country is rich in titanium resources, the largest reserves in the world, mainly in the vanadium-titanium magnetite in Panxi area, and its utilization rate is very low. The main reason is that only vanadium and iron are recovered in blast furnace ironmaking, and titanium enters blast furnace slag in the form of titanium dioxide ( The mass fraction is about 25%), forming complex mineral phases, difficult to recycle

At present, 70 million tons have been accumulated in the slag factory, and it is still increasing at a rate of 3 million tons every year, occupying land, polluting the environment, and wasting resources. If the titanium-containing blast furnace slag can be well utilized, it will be of great significance to the utilization of titanium resources in my country.

[0003] Many domestic scientific and technological workers have done a lot of research on the utilization of titanium-containing blast furnace slag, mainly focusing on the following methods: 1) Using it to prepare cement, if it can be successfully applied, it is necessary to reduce the TiO in blast furnace slag 2 content, otherwise the cement activity is poor and easy to crystallize; 2) Wet titanium extraction, mainly acid and alkali treatment to prepare titanium dioxide, has the disadvantages of large acid and alkali consumption, large amount of residue, environmental pollution and corrosion of equipment; 3) high temperature carbonization and low temperature Chlorination to prepare TiCl 4 The disadvantage is that CaCl with high boiling point and high viscosity is easily formed during the chlorination process. 2 and MgCl 2 , so that the chlorination equipment cannot operate normally for a long time; 4) High-temperature titanium enrichment, enriching the dispersed titanium into perovskite or black ore, and selecting rich titanium ore by mineral processing, this method is actually very difficult Realization; 5) to produce titanium alloy, use aluminum, silicon and other elements to reduce titanium in the slag to prepare titanium alloy. Although this method has achieved some results, three key problems have not been solved. The first is that the process cost is high and the smelting time is long , high power consumption, large amount of reducing agents such as aluminum and silicon

Second, the content of impurities such as silicon and aluminum in the preparation of titanium alloys is high, and the steel types that can be used in the alloying process are limited.

The third is the use of residues after titanium extraction and environmental pollution.

However, what the author ignores is that TiO in titanium-containing blast furnace slag 2 and SiO 2 The content of aluminum is more than 20%, the reduction ability of aluminum is much stronger than that of silicon, and its reduction of TiO 2 and SiO 2 The capacity is similar. Titanium and silicon in the molten titanium-containing blast furnace slag are simultaneously reduced by aluminum. Using silicon-aluminum iron as the reducing agent does not improve the reduction efficiency much, but results in high silicon content in the preparation of titanium alloys.

Images