根据3种不同类型镍矿床选取了20个镍矿石标准物质绘制校准曲线,解决了镍矿石赋存状态的复杂性问题.采用混合熔剂(m(Li2 B4 O7):m(LiBO2):m(LiF)=4.5:1:0.4)和标准物质以质量比为40:1进行稀释熔融,加入1 g氧化剂LiNO3、6滴加入脱模剂LiBr溶液(1 g/mL),针对Cu含量高的铜镍硫化矿样品在熔融时易脆裂和裂痕的问题,采用加入LiBr溶液后用混合熔剂完全覆盖的方法有效防止Br的挥发,成功地制备出高精度的玻璃熔片.建立了测定镍矿石中NiO、Cr2 O3、CuO、PbO、MgO、ZnO、SiO2、Al2 O3、MnO、TiO2、CoO、TFe2 O3、CaO、K2 O、Na2 O、P2 O516种主次成分的定量分析方法.采用此方法分析GBW07147国家镍矿石标准物质,16种主次成分测定结果的相对标准偏差(RSD)为0.09%~4.5%,对不参加建立校准曲线的GBW07148、GBW07196国家镍矿石标准物质进行分析,分析结果与认定值相符合,满足日常生产任务需要.
Twenty certified reference materials of nickel ore were selected to prepare the calibration curve according to three types of nickel ore deposit .The complex problem of existing states of nickel ores was solved .The flux (m(Li2B4O7 ): m(LiBO2 ): m(LiF)=4 .5:1:0 .4) was mixed with certified reference material in mass ratio of 1:40 for dilution and fusion .1 g of oxidizer (LiNO3 ) and 6 drips of release agent of 1 g/mL LiBr solution were added .Aiming at the embrittlement and cracking problems of copper-nickel sulfide ore samples with high content copper in fusion ,LiBr solution was added followed by complete cov-erage of sample with mixed flux to effectively prevent Br from volatilizing .The fusion sheets with high precision were successfully prepared .Thus ,a quantitative analysis method of 16 major and minor compo-nents in nickel ores (including NiO ,Cr2 O3 ,CuO ,PbO ,MgO ,ZnO ,SiO2 ,Al2 O3 ,MnO ,TiO2 ,CoO , TFe2 O3 ,CaO ,K2 O ,Na2 O and P2 O5 ) was established .The proposed method was applied to the analysis of national certified reference material of nickel ore (GBW07147) .The relative standard deviations (RSD) of determination results of 16 major and minor components were between 0 .09% and 4 .5% .The proposed method was applied to determination of national certified reference materials of nickel ore (GBW07148 and GBW07196) which did not participate in the preparation of calibration curve .The results were consistent with the certified values .It could satisfy the requirements of routine production .