煤中有机硫测定结果为负值的原因分析

Analysis on causes of relatively low determination result of organic sulfur in coal

分析了造成煤中有机硫测定结果为负值的3个原因,即全硫测定结果偏低、硫酸盐硫及硫化铁硫测定结果偏高。从燃烧温度、催化剂、载气、电解液的pH值、仪器系统误差等方面分析了全硫测定结果偏低的原因,并从硫酸盐硫、硫化铁硫的测定方法及原理等方面探讨了硫酸盐硫、硫化铁硫测定结果偏高的原因,指出将硫酸钡沉淀洗净可避免硫酸盐硫测定结果偏高,采用5mol/L的盐酸、避免硝酸浸出液呈棕褐色及加入适宜的氯化亚锡溶液量等措施可有效避免煤中硫化铁硫测定结果偏高。

This paper analyzed the three reasons which made the determination result of organic sulfur in coal relatively low,these reasons were relatively low total sulfur,relatively high sulfate sulfur and iron disulphide sulfur.Those reasons why the result was relatively low were analyzed from aspects such as combustion temperature,catalytic agent,carrier gas,PH value of electrolyte and system error of equipment.The factors which led to high sulfate sulfur and iron disulphide sulfur were also discussed from the testing method and principles,washing the barium sulfate precipitation clearly could avoid the relatively high sulfate sulfur detection,and adopting 5 mol/L of hydrochloric acid,avoiding hydrogen nitrate leach liquor became brown and adding some stannous chloride could avoid the detection of high iron disulphide sulfur.