Investigation On Ilmenite Reduction Strengthening Technology And Mechanism

To develop the emcient utilization technology based on resource characteristics of ilmenite concentrate in china, Panzhihua ilmenite concentrate was taken as raw material to study the solid state reduction behavior and strengthening technology of reduction. object. The effects of additives and high pressure roll grinding on reduction of the ilmenite and kinetics behaviors were systematically studied process by thermodynamic principle and modem analysis equipments such as X ray powder diffraction and optical microscope. Following conclusions were obtained:Studies on effect of HPRG on reduction behavior of ilmenite showed that HPRG was able to increase the metallizaiton ratio of reduction product. Reduction reaction was controlled by interfacial chemical reaction, and apparent activated energy of reaction was 90.062 kJ/mol in the range of temperature from 1000℃to 1150℃. Compared with non HPRG, apparent activated energy of reaction was decreased by 18.751 kJ/mol. Microscopic mechanism on HPRG strengthening reduction process showed that HPRG could improve the surface areas and increase the finer size fractions, but can not change the kinetics. The strengthening effects of Alkali metal additives on ilmenite are different:metallizaiton is highest adding Na2B4O7, followed by Na2CO3, NaF, NaOH, Na2SO4, NaCl. The results show that the additives have a significant impact on reduction reaction of ilmenite.Studies on effect of additives on reduction behavior of pre-treatment ilmenite showed that it was an important effect of the additives on reduction of ilmenite. The borax could greatly speed up reduction reaction ratio of ilmenite and increase the metallization ratio of reduction product. Reduction reaction was controlled by interfacial chemical reaction, and apparent activated energy of reaction is found to be 81.375kJ/mol in the range of temperature from 1000℃to 1150℃. Compared with non-additive, apparent activated energy of reaction was decreased by 8.687kJ/mol. The mechanism of adding borax was that borax could decrease the melting point and accelerate the diffusion of mass unit. Sodium ion could bring the deformation of ilmenite crystal lattice and increase the activity of ilmenite. Boracic acid radical ion could react with MgO and MnO in the ilmenite, which held down the transfer of Mg and Mn towards the inner of reduction product particle and cancel the enrichment effect of Mg and Mn in the unreacted core.In this Paper, the effects and mechanism of high pressure roll grinding on reduction of the ilmenite were put forward firstly. Based on the above investigations, the mechanism of adding additives were studied deeply, and the new technology of reduction of ilmenite synergistic strengthening effect of high pressure roll grinding and additives had been developed. The research is to provided theory and technic supporting to the development of making titanium rich materials.