高压消化-原子吸收法间接测定火电厂粉煤灰中的硫化物

开发了一种测定固体样品中硫化物的方法.采用高压密封消化法处理火电厂粉煤灰,使硫化物转变成硫酸盐并与铬酸钡进行定量反应生成硫酸钡沉淀,采用原子吸收法对置换出的铬元素进行测定,即可间接得到粉煤灰中硫化物的含量.试验结果表明,该方法的相对标准偏差在土5%之内,所得标准曲线的相关系数r=0.999 2,加标回收率为94%和105%,具有较高的准确度和精密度.实践表明,该方法在分析多个样品时更显其优越性.

INDIRECT DETERMINATION OF SULFIDE IN ASH OF PULVERIZED COAL IN THERMAL POWER PLANTS BY USING HIGH-PRESSURE DIGESTION-ATOM ABSORPTION METHOD

A determination method of sulfide in solid samples has been developed. The fly ash from burning pulverized coal in thermal power plant is pretreated by using high-pressure sealed digestion method, making the sulfide to react quantitatively with the barium chromate, and then the excess atoms of barium is measured by using atom absorption method,thereby,the sulfide content in fly ash of pul-verized coal can be indirectly obtained. The results of test show that the relative standard deviation of this method is within ±5%, the corelation coefficient of the obtained standard curves being r=0. 999 2,the marked recovery rate being 94% and 105%,having higher precision. Practice shows that the superiority of this method will be even better in the event of analysing many samples.