Abstract：The silica contained in limestone is abrasive, and the determination of silica in limestone is the basis for the field engineer of coal-fired power plant to judge the wear severity of equipment in limestone/gypsum wet desulfurization system. Since there is no unified analytical standard for limestone used as desulfurizer, most of them refer to the current determination methods of silica in building materials, chemical industry, cement and other industries. Based on the principle of absorbance spectrophotometric colorimetric analysis, a detection method of silica was proposed in the user program of HACHDR2800 portable spectrophotometer, according to the absorbance of the measured solution at 660 nm, the instrument automatically detected the content of silicon in the sample. The results show that the maximum absolute error is less than 1% compared with the average value when the content of limestone samples less than 7% is determined by silicon molybdenum blue colorimetric method, which meets the error requirements of production analysis.
