ABSTRACT

Lignite briquetting provided an effective method for the utilization of lignite powder. Based on the briquetting conditions of lignite, two kinds of binders (sodium humate and polyvinyl alcohol) were selected for the present study. The compressive and drop strengths of briquette were used as indicators to design an orthogonal experiment to examine the effect of composite binders. From the analysis of Fourier transform infrared spectroscopy, sodium humate contained active oxygen-containing groups of -OH and -COOH, it would have strong adsorption during briquetting. Polyvinyl alcohol was a long-chain structure containing -OH functional groups, which played a role in the briquetting process. Using the orthogonal design method, the optimal composite ratio of polyvinyl alcohol and sodium humate was obtained as follows: 2 wt% of sodium humate and 0.5 wt% of polyvinyl alcohol. From the scanning electron microscope, there was a fibrous structure of polyvinyl alcohol and solid bridge formed by the solidification of sodium humate on the surface of the briquette, which made the mechanical strength of briquette stronger.

摘要

褐煤压块为褐煤粉的利用提供了一种有效的方法。根据褐煤的压块条件，本研究选用腐植酸钠和聚乙烯醇两种粘合剂。以型煤的抗压强度和跌落强度为指标，设计正交试验，检验复合粘合剂的效果。由傅里叶变换红外光谱分析可知，腐植酸钠含有-OH和-COOH等活性含氧基团，在压块过程中具有较强的吸附作用。聚乙烯醇是一种含有-OH官能团的长链结构，在压块过程中发挥了作用。采用正交设计方法，得到聚乙烯醇与腐植酸钠的最佳复合配比为：腐植酸钠2wt%，腐植酸钠0. 5 wt%的聚乙烯醇。从扫描电镜看，型煤表面存在聚乙烯醇的纤维结构和腐植酸钠固化形成的固体桥，使型煤的机械强度更强。