熔融制样-X射线荧光光谱法测定氮化硅锰中主次组分

氮化硅锰是一种新型的炼钢增氮原料,目前采用化学湿法分析硅、锰、磷和铁的含量,实验流程相对较长,操作相对繁琐。实验采用碳酸锂作氧化剂、四硼酸锂作熔剂、溴化铵作脱模剂,熔融制样,建立了氮化硅锰中硅、锰、磷和铁的X射线荧光光谱(XRF)分析方法。绘制校准曲线时,考虑灼烧减量的影响,采用硅锰标准样品中加入二氧化硅、三氧化二铁等纯物质的方法扩展了校准曲线线性范围。实验表明,稀释比为1∶20,在1 150℃熔融炉中熔融8min,制得的玻璃片表面光滑、无气孔;碳和氮元素无残留。精密度结果显示,硅、锰、磷、铁测定结果的相对标准偏差(RSD,n=10)在0.36%～2.3%之间;按照实验方法对3个氮化硅锰合金样品进行测定,结果与国家标准的化学湿法结果相一致。

Determination of major and minor components in silicon-manganese nitride by X-ray fluorescence spectrometrywith fusion sample preparation

Silicon-manganese nitride is a new type of raw material for nitriding in steelmaking. At present, the contents of silicon, manganese, phosphorus and iron are usually analyzed by wet chemical method. The experimental procedures are relatively time-consuming and the operation is relatively tedious. The determination method of silicon, manganese, phosphorus and iron in silicon-manganese nitride by X-ray fluorescence (XRF) was established using lithium carbonate as oxidant, lithium tetraborate as flux and ammonium bromide as release agent. The influence of loss on ignition (LOI) was considered during the preparation of calibration curve. The linear range of calibration curve was extended by adding pure materials (such as SiO₂ and Fe₂O₃) into the standard sample of ferromanganese-silicon. Experiments showed that the prepared glass beads had smooth surface without gas pores under the following conditions: the dilution ratio was 1∶20; the mixture was fused in a melting furnace at 1150℃ for 8min. Meanwhile, there were no residues for carbon and nitrogen. The precision results showed that the relative standard deviations (RSD, n=10) of Si, Mn, P and Fe were between 0.36% and 2.3%. Three samples were determined according to the experimental method, and the found results were consistent with those obtained by wet chemical method in national standard method.