Mineralphase Transformation And Selective Separation Of Titanium In Titaniumbearing Slagvia Super-gravity

In China’s Panxi region,the resource of vanadium titanium-magnetite ore is abundant.At present,these vanadium titanium-magnetite resources are mainly utilized by blast furnace ironmaking process and direct reduction-electric furnace smelting process.In the high-temperature smelting process,the titanium in the ore was tend to enter into the slag,where a large amount of titanium bearing blast furnace slag,titanium bearing smelting slag and other titanium bearing slags were produced.While the titanium resources in the slag are dispersed in a variety of low-grade titanium bearing phases.Thus it is difficult to achieve efficient separation and recovery of titanium resources from the titanium bearing slag through traditional metallurgy and beneficiation methods.Three typical titanium bearing slags including titanium bearing blast furnace slag,carbonized titanium slag and titanium bearing smelting slag were selected to achieve the efficient extraction of titanium resources from titanium bearing slags in China.Firstly,the mineral phase transformation behavior of titanium in titanium bearing slag was investigated and the titanium in slags was selectively enriched into specified titanium-rich phases by controlling different physicochemical conditions.On the basis of this,the super-gravity field was introduced in the crystallization zones of the titanium-rich phases to enhance heterogeneous phase separation.Various of titanium-rich phases were selectively separated from titanium bearing slag under the super-gravity field.Furthermore,the application properties of these titanium-rich phases were explored and investigated respectively.The following results were obtained:For titanium bearing blast furnace slag,the effect of slag basicity and titanium content on the crystallization phases of Ti was investigated first.Meanwhile,the physicochemical laws for the phase transition of Ti from perovskite to rutile and the crystallization laws of rutile at different temperatures were investigated.On the bases of this,the super-gravity separation was conducted at the crystallization temperature range of rutile and high-purity rutile was separated from titanium bearing blast furnace slag under super-gravity field.The TiO2 content in separated rutile was up to 95.56 wt.%.The separated rutile possessed relatively high dielectric constant(about 200)and low dielectric loss(<0.1).Under the inspiration of high temperature carbonization-low temperature chlorination process of titanium bearing blast furnace slag,the effect of carbon content and carbothermal reduction time on the carbothermal reduction behavior was investigated first.Secondly,the single solid-liquid temperature range of TiC in carbonized titanium bearing slag was obtained through investigating the crystallization behavior of slag at different temperature ranges;After that,the motion and separation behavior of TiC powders in slag melt was investigated and high-purity TiC powders were separated from carbonized titanium bearing slag under super-gravity field.The Ti content and average particle size of separated TiC powders were 75.89 wt.%and 2.75 μm.For titanium bearing smelting slag,the crystallization behavior of anosovite at different crystallization temperature ranges was investigated first to promote the selective enrichment of Ti into anosovite.On the basis of this,the replacement behavior of Ti and Mg in anosovite under different cooling rate were investigated and the law for solid solution of Mg into anosovite was obtained.On the basis of this,the selective super-gravity separation of various anosovite(MgxTi3-xO5(x=1,0.9,0.75,0.6))was conducted.Under the super-gravity separation,high-purity anosovite crystals were separated.Through the characterization of various anosovite,the replacement behavior of Ti and Mg in anosovite was verified further.In addition,on the basis of results and experience obtained from the laboratory research,the large-scale super-gravity equipment was improved.The large-scale experiment of selective crystallization,phase transformation and super-gravity separation for titanium bearing slags were conducted further using the improved experiment.The motion behaviors of various titanium-rich phases were verified under super-gravity,which further provide the research basis for the industrial application of super-gravity separation for titanium bearing slags.