Improvement of Energy Use Efficiency and Reduction of Environmental Load by Upgrading of Unused Low Rank Coal

在不同温度(2 70、30 0、330℃)下进行热水干燥处理。随着温度的升高，两种煤的含水率和羧基含量均降低，可浮性提高。HWD浮选处理煤的可燃物回收率比原煤高20~30%，泡沫产物灰分低于原煤。经HWD处理的细粒白鲸煤也可通过油凝聚回收灰分为4.1~4.3%的产品。采用水碱法对HMD处理后的煤进行化学洗煤，可使灰分大幅度降低，可燃物回收率高于原煤。采用水煤浆、浮选和化学清选三种工艺相结合的方法生产出灰分为0.5%、可燃物回收率为86%的超洁净煤，并用GC/MS、高效液相色谱、凝胶渗透色谱(GPC)、差示扫描量热仪(…)对其液体产物进行了表征更多的TOC测量和循环伏安法。通过对液体和六价铬溶液的分析和荧光光谱分析，考察了液体产物对六价铬的还原能力。随着处理温度的升高，液体产物的TOC浓度变大。反应温度为270℃时，液体产物中含有醋酸、醋酸甲酯和低聚物，质量在1600~3400之间。在30 0℃和330℃下的液体产物含有儿茶酚和苯酚，且后者含有更多的儿茶酚基团。在30 0℃以上得到的两种液体的还原行为与邻苯二酚的循环伏安行为相似，所有液体产物都将铬(VI)还原为铬(III)，且随着pH的降低，还原能力增强。对于含铬(VI)浓度较高的溶液，在pH=2时，在330℃下得到的溶液能成功地将Cr(VI)还原到允许的水平以下。荧光光谱分析发现，在液体产物中，Cr(VI)被还原成邻苯二酚。较少

Hot water drying (HWD) treatment was carried out at different temperatures such as 270, 300 and 330℃. With increasing temperature water content and carboxyl content of the both coals were decreased and their floatability became higher. Combustible matter recovery of the HWD treated coals by flotation was 20-30% higher than that of the raw coals and the ash content of the froth product was lower for the treated coals than the raw coals. Products containing 4.1-4.3% ash were also recovered by oil agglomeration of the fine HWD treated Beluga coals. Chemical coal cleaning method of the HMD treated coals with aqueous caustic process leads to a drastic decrease in ash content with a high recovery of combustible matter than that of raw coal. The ultra clean coal with 0.5% ash and 86% recovery of combustible matter was produced by a combination of three treatments such as the HWD, flotation and chemical cleaning.Liquid products produced in a HWD process were characterized by GC/MS, HPLC, GPC, … More TOC measurement and cyclic voltammetry. The ability of the liquid products to reduce Cr(VI) was investigated by analyzing solutions containing the liquids and Cr(VI), and by fluorescence spectrometry. With increasing treatment temperature TOC concentration of the liquid products became larger. The liquid product at 270℃ contained acetic acid, acetic acid-methyl ester and oligomer of mass weight 1600-3400. The liquid product at 300℃ and 330℃ contained catechol and phenol, and the latter product included more catechol groups. The reduction behavior of both liquids obtained above 300℃ was similar to that of catechol in cyclic voltammetry.All liquid products reduced the Cr(VI) to Cr(III), and their reduction ability became stronger with decreasing pH. For a solution containing high Cr(VI) concentration the liquid obtained at 330℃ successfully reduced Cr(VI) below the allowed level at pH 2. It was found by fluorescence spectroscopy that Cr(VI) was reduced to catechol groups in the liquid products. Less