准东煤化学处理后碱金属含量的激光测量研究

Measurement of alkali content in Zhundong coal after chemical fractionation treatment by LIBS method

为了评价水洗、醋酸铵洗和盐酸洗等化学处理方法去除准东煤中碱金属的能力,分析激光诱导击穿光谱(LIBS)技术快速测量煤中碱金属含量的可行性和准确性,采用去离子水、醋酸铵溶液和稀盐酸溶液依次对准东煤进行化学处理,并利用LIBS技术对各样本中的Na,K元素进行测量,同时与电感耦合等离子光谱(ICP)检测结果进行对比,得到了验证LIBS技术测量准东煤中碱金属含量可靠性的实验数据。结果表明,水洗等化学处理可高效地去除准东煤中的碱金属,而LIBS技术对不同样本中的Na,K元素测量重复性较好,并且具有较高的灵敏度和较低的检测极限,LIBS检测结果与ICP的相对误差不超过7%。该结果说明LIBS可作为在线测量煤样中碱金属含量的一种有效手段。

In order to evaluate the ability of chemical fractionation treatments, including water （H2O） washing, ammonium acetate washing （NH4Ac） and hydrochloric acid （HCl） washing, for the removal of alkali metal, and analyze the feasibility and accuracy of laser induced breakdown spectroscopy （LIBS） measuring the alkali content in coal, a sequence of solutions including deionized water, ammonium acetate and hydrochloric acid were employed to treat Zhundong coal. The contents of sodium and potassium in treated coal were measured by LIBS and compared with the measurements of inductively coupled plasma （ICP） spectroscopy. The experimental results of confirming the ability of LIBS in measuring the alkali content in coal were obtained. The results show chemical treatment such as washing can effectively remove the alkali metal from Zhundong coal, and LIBS technique has good repeatability of Na, K measurement for different samples. The measurements of Na and K by LIBS had high sensitivity and low detection limit. The relative error between LIBS and ICP was less than 7%. LIBS could be a valid method to achieve the online measurement of alkali metal in coal.