氧化锆对低品位菱镁矿制备镁橄榄石的影响

以低品位菱镁矿与天然硅石为原料，以氧化锆为添加剂，通过固相反应烧结制备镁橄榄石。研究讨论了氧化锆对镁橄榄石材料相组成、晶胞参数、微观结构及常温性能的影响。用X射线衍射（XRD）和扫描电镜（SEM）对烧后试样的相组成和显微结构进行研究。利用X′ Pert plus软件对试样中镁橄榄石相的晶胞参数进行计算。结果表明：加入适量氧化锆可以促进低品位菱镁矿轻烧氧化镁粉与天然硅石通过固相反应烧结合成制备镁橄榄石。锆离子的置换作用导致镁橄榄石相的晶胞参数和晶胞体积减小。氧化锆加入质量分数为1.2%时，镁橄榄石综合性能最好，其密度为1.87 g/cm³，显气孔率为35.1%，吸水率为18.7 %，常温耐压强度为17.9 MPa。

Effects of zirconia on synthesis of forsterite from low-grade magnesite

Forsterite was prepared by solid sintering reaction with low-grade magnesite and natural silica as raw materials，and with zirconia as additive.The effect of zirconia on composition，cell parameters，microstructure，and property of forsterite material at normal temperature was studied.XRD and SEM were used to characterize the phase composition and microstructure of sintered samples.The cell parameters of the forsterite phase were calculated by X′Pert plus software.Results showed，forsterite  could be prepared through solid sintering reaction between magnesia sintered from low-grade magnesite and silica from natural silica by adding appropriate ZrO₂.The substitution of Zr⁴⁺ caused the decreasement of cell parameters and volume of the forsterite.When the addition of ZrO₂ was 1.2%（mass fraction），the comprehensive performance of forsterite was the best and its density was 1.87 g/cm³，apparent porosity was 35.1%，water absorption 18.7%，and cold crush strength was 17.9 MPa at room temperature.