铁矿石矿物组分的X射线粉晶衍射半定量分析

Semi-quantitative analysis of the mineral components of iron ores by X-ray powder diffraction

为了确定大台沟铁矿含铁矿物种类与含量,在大台沟超深铁矿采集29件铁矿石样品,利用X射线粉晶衍射物相分析方法对铁矿矿物组分进行检测。物相分析结果表明,大台沟铁矿中可作为炼铁原料的含铁矿物组分为磁铁矿、赤铁矿和菱铁矿,不能作为炼铁原料的含铁矿物组分为滑石、角闪石、绿泥石和黄铁矿;结合全谱拟合半定量矿物分析技术,计算出各矿物组分的半定量结果,从而查清了大台沟铁矿含铁矿物的种类与含量。为了考察分析方法的精密度,在相同条件下对同一铁矿石样品进行X射线粉晶衍射半定量分析,样品中石英质量分数在59.0%-60.7%之间,相对标准偏差（RSD,n=5）为1.0%;磁铁矿质量分数在27.8%-29.5%之间,RSD为2.1%;滑石质量分数在9.6%-10.3%之间,RSD为2.9%;白云石质量分数在1.2%-1.6%之间,RSD为11.3%。为了考察分析方法的准确度,按不同比例配制4个标准样品,每个标样平行测定5次,计算出铁矿物参考值10%、30%、50%、70%的相对偏差分别不大于12.8%、4.7%、2.8%、2.5%。精密度及准确度的考察结果显示,方法基本满足X射线粉晶衍射矿物半定量分析的质量要求。

In order to determine the species and content of the minerals containing iron in Dataigou iron mine, twenty nine iron ore samples were collected from Dataigou deep iron mine for determining mineral composition by X-ray powder diffraction method. The physical phase detection showed that minerals con raining iron that can be used as iron making raw materials are magnetite, hematite and siderite; while that cannot are talc, hornblende, chlorite and pyrite. In combination with full spectrum semi-quantitative mineral analysis technique, the semi-quantitative results of each mineral constituent was calculated, so that the species and content of the minerals containing iron in Dataigou mine were identified. In order to examine method precision, the same iron ore sample was determined by X-ray powder diffraction method in a semiquantitative manner under the same conditions, obtaining the mass fraction of quartz in the sample at 59.0% 60.7% and the relative standard deviation （RSD, n=5） of 1.0% ; the mass fraction of magnetite at 27.8%-29.5% and RSD of 2.1% ; the mass fraction of talc at 9.6%-10.3% and RSD of 2.9% ; the mass fraction of dolomite at 1.2%-1.6% and RSD of 11.3%. In order to examine method accuracy, four standard samples were prepared according to different ratios. Each sample was determined for five parallel times. The relative deviation of iron minerals with reference values of 10%, 30%, 50% and 70% were all not more than 12.8%, 4.7%, 2.8% and 2.5%. The accuracy and precision test indicated that the proposed method basically met the quality demand of semi-quantitative determination of minerals by X ray powder diffraction method.