微波消解ICP法测定磷尾矿中硫

Determination of Sulfur in Phosphorus Tailings by Microwave Digestion-ICP

运用微波消解技术用混合酸消解磷尾矿样品,磷尾矿中含钙,镁离子高,对硫的测定谱线重叠干扰大。把消解液用氢氧化钠溶液调节至pH值≥13,滤液中钙、镁离子生成的钙、镁沉淀用滤纸过滤,滤液直接进容量瓶,到达容量瓶一定体积时,再用硝酸调节至pH值≈6,定容;实验并找出仪器最佳实验条件。此法硫的加标回收率在90.00%~107.50%之间,对同一样品做7次平行实验,硫测得值相对标准偏差(RSD%)均小于5%,精密度良好,方法测得结果与国标法(重量法)结果基本一致,具有快速,易操作的特点。

Microwave digestion technology is used to digest phosphorus tailing samples with mixed acid.The phosphorus tailing contains high content of calcium and magnesium ions,which greatly interfere with the overlapping of sulfur determination spectral lines.The digestion solution is adjusted to pH≥13 with sodium hydroxide solution,and the calcium and magnesium precipitates generated by calcium and magnesium ions in the filtrate are filtered with filter paper.The filtrate directly enters the volumetric flask.When it reaches a certain volume of the volumetric flask,it is adjusted to pH≈6 with nitric acid,and the volume is constant;Do experiment and find the optimal experimental conditions for the instrument.The sulfur recovery rate of this method is between 90.00%and 107.50%.Seven parallel experiments were conducted on the same sample,and the relative standard deviation(RSD)of the sulfur measurement values was less than 5%.The precision was good,and the results obtained by the method were basically consistent with those obtained by the national standard method(weight method),which is fast and easy to operate.