Methods On Strengthening Reduction Of Ilmenite In Solid State

Titanium is a strategic resource, based on the fact that titanium-bearing materials arewidely used in the departments of national defense and economy. Among the titanium-bearingmaterials, metallic titanium and titanium-bearing alloys play important roles in aerospace,aviation and navigation, etc; titanium white is mainly used in chemical industry, textile andmedical treatment. As the main raw materials to produce titanium-bearing materials, Ourcountry each year a large number of titanium concentrates in panxi region but because of itslow grade, thus necessitating the enrichment processing of ilmenite to be titanium-rich rawmaterials before production, which actually becomes an important procedure for titaniumindustrial production process. At present, titanium-rich raw materials are mainly obtained inindustry by electric furnace process, which is characterized by high energy consumption, thebackward process and the difficulty of smelting. Therefore, study on improvement of electricfurnace process towards high efficiency and low energy consumption can make a difference inthe development of titanium industry. Thus, it is essential to explore a method forstrengthening reduction of titanium concentrate, by focusing on carbon thermal reductionbehavior of titanium concentrate as a special material in Panzhihua, China.The aim of present study takes additives and mechanical activation to enhancementcarbothermic reduction behavior of Panzhihua ilmenite was system investigated by isothermaland non-isothermal reduction experimental methods. The main conclusions are included：①Grinding behavior of ilminite was studied and the principal findings of wet grindingand ball milling. The grinding kinetics approach was successfully applied to the analysis ofproduct size distribution. The following conclusions are obtained: The Grinding kineticsanalysis of experimental data resulted with model suitable for prediction of particle sizedistribution during grinding of ilmenite in damp milling and ball milling were obtained:R(x, t) R(x,0)exp(0.000115x1.22t0.87)for damp millingR(x, t) R(x,0)exp(0.000404x0.58t1.48)for ball millingWhere x is the particle size in μm, and t is the grinding time in minutes. The damp milling issuitable for the target about35.5mm mineral and balling milling is good for the very fineparticles grinding.②After wet grinding and ball milling pretreatment of ilmenite the average particle size decreases, the fine fraction content increased significantly; specific surface area increasedgradually and generate many new surface, grain roughness increases, these were conducive topelletizing and reduction. Thermal analysis results show that the loss of weight and themaximum reaction rate increase with extend of the milling time. The iron metallization rateincrease gradually and ferrous oxide and carbon residue content gradually decrease with theincrease of the milling time. When the wet grinding time was60min and ball milling timewas30min, the metallization rate reached86.8%and86.6%respectively, the ferrous oxidecontent were5.85%and6.02%respectively, the residual carbon amount were1.72%and1.54%respectively; XRD analysis after the reduction of ilminite sample shows that: XRD spectrumwas similar. The main phase were: Fe、（Fe Mg）xTiyO5(iron magnesium plate titanium oretype) and TiO2.③The carbothermic reduction behavior of ilmenite with addition of additives wassystem investigated using isothermal and non-isothermal reduction experimental methods.The following conclusions were obtained: The additive of Na2B4O7and Na2CO3makeweightlessness rate increases, the maximum weight loss rate increases, the temperature ofachieve the maximum weight loss rate reduce during restore of ilminite. The additive of Fe-Simake weightlessness rate and the temperature of achieve the maximum weight loss rate lower.,When the Na2B4O7content was2%, the metallization rate was maximum,87.8%, FeO andcarbon residue were minimum,4.95%and2.1%respectively. Na2CO3additive can make theFe metallization rate increased，FeO and carbon residue decreased. When adding quantity4%,the metallization rate, FeO and residual carbon were89.5%,4.5%and2.3%respectively.Fe-Si additive can make the Fe metallization rate increased，FeO and carbon residuedecreased. When adding quantity4%, the metallization rate, FeO and residual carbon were91.1%,4.79%and4.02%respectively. XRD analysis after the different additive pretreatmentreduction of ilminite sample shows that: There was similar XRD spectrum with mechanicalactivation.