微波消解高碳铬铁样品及其中铬硅磷的测定

Determination of Cr,Si and P in High-carbon Ferrochromium with Microwave Assisted Digestion of the Sample

提出了微波消解法溶解高碳铬铁。将粒径小于0.076 mm样品0.200 0 g置于消解罐中,加入高氯酸5 mL,氢氟酸1 mL,按设定程序消解。于消解所得溶液中加入饱和硼酸溶液5 mL后,定容至200 mL。分取100.0 mL溶液用过硫酸铵氧化,硫酸亚铁铵标准溶液电位滴定法测定其铬量。另分取50.00 mL溶液,用电感耦合等离子体原子发射光谱法测定硅及磷量,选择251.612,213.618 nm分别作为测定硅和磷的分析线。按此方法分析了3个标准样品,测得结果与认定值一致。铬、硅、磷3元素测定值的平均相对标准偏差(n=6)依次为0.09%,0.49%和2.2%。

Dissolution of high-carbon ferrochromium sample by microwave assisted digestion was proposed.The sample（0.200 0 g,with size0.076 mm） was dissolved with HClO4 5 mL and HF 1 mL in a microwave digestor,and 5 mL of sat′d solution of boric acid were added to the digested solution,which after diluting to 200 mL was used for determination of the 3 elements.One hundred mL of the solution were taken for determination of chromium by oxidation with ammonium persulfate and potential titration with standard ammonium ferrous sulfate solution.Another aliquot of 50.00 mL was taken for determination of Si and P by ICP-AES.Analytical spectral lines selected for Si and P were 251.612 nm and 213.618 nm respectively.Three standard samples were analyzed by this method,giving results in consistency with the certified values,and values of average RSD′s（n=6） of 0.09% for Cr,0.49% for Si and 2.2% for P.