【摘要】 建立了氧弹燃烧-离子色谱测定煤中氯含量的方法。在加有(NH4)2CO3溶液和过量氧气的氧弹中燃烧煤样,释放的氯被(NH4)2CO3溶液吸收,过滤溶液后,采用离子色谱外标法测定滤液中氯的浓度,最后计算出煤中氯的含量。色谱工作条件:淋洗液为1.8mmol/LNa2CO3与1.7mmol/LNaHCO3混合液,流速1mL/min;再生液为40mmol/LH2SO4,流速0.5mL/min;进样量20μL。色谱标准工作曲线线性相关系数0.9996;10次测定1mg/LCl-标准溶液的均值为1.0012mg/L,相对标准偏差为1.34%;8个煤样加标回收率为90.7%～104.3%;测定标准物质GBW11119及GBW11120的相对误差分别为1.75%和1.36%;对比研究显示,氧弹燃烧-离子色谱测定8个煤样(除两个煤样外)氯含量结果远高于艾士卡剂混合熔样-离子色谱测定结果,表明艾士卡剂混合熔样过程由于煤样未处于完全密闭状态导致部分氯的散失。更多还原

【Abstract】 A novel method is developed for the determination of Chlorine content in coal by oxygen bomb-ion chromatography.The coal sample was combusted in the oxygen bomb containing ammonium carbonate solution and enough pressed oxygen.The chlorites released from coal combustion were absorbed by ammonium carbonate solution,after filtration,the solution was analyzed by ion chromatography and chlorine content in coal was finally calculated.The working conditions of ion chromatography were as follows:mixture of 1.8 mmol/L Na2CO3 and 1.7 mmol/L NaHCO3 at flow rate of 1 mL/min as the eluant,40 mmol/L H2SO4 at flow rate of 0.5 mL/min as the regeneration fluid and with injection volume of 20 mL.The correlation coefficient of standard working curve is 0.9996.Cl-standard solution(1 mg/L)was determined 10 times with average value of 1.0012 with a relative standard deviation of 1.34%.Chlorine contents in 8 coal samples were determined.Their standard recoveries were from 90.7% to 104.3% and 6 of them were between 95% and 105%.The relative error of determination of standard coal samples GBW11119 and GBW11120 were 1.75% and 1.36% respectively.A comparison between oxygen bomb combustion and combined combustion by Eschkal mixture was carried out.Except 2 samples,the contents of coal samples treated by oxygen bomb were larger than those by Eschkal mixture.No extraneous component was led in during the oxygen bomb combustion and the reason must be that the coal sample wasn’t in complete sealing condition and some of chlorites dissipated during combined combustion by Eschkal mixture.In a word,the method established is simple,fast and economical with high accuracy and precision.It is suitable for the determination of chlorine in most of the coals(containing low chlorine content coals).更多还原