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

在270、300和330℃下进行热水干燥处理。随着温度的升高，两种煤的含水量和羧基含量均降低，可浮性提高。HWD处理煤的浮选可燃物回收率比原煤高20-30%，泡沫产物的灰分含量比原煤低。还通过细HWD处理的Beluga煤的油附聚回收了含有4.1-4.3%灰分的产物。HMD处理煤的碱洗化学选煤方法可使灰分大幅度降低，可燃物回收率高于原煤。采用HWD、浮选和化学洗选三种工艺相结合的方法，获得了灰分0.5%、可燃物回收率86%的超洁净煤，并采用GC/MS、HPLC、GPC等方法对HWD工艺的液体产物进行了表征， 关于我们 TOC测量和循环伏安法。通过分析含有液体和Cr（VI）的溶液以及通过荧光光谱法来研究液体产物还原Cr（VI）的能力。随着处理温度的升高，液体产物的TOC浓度变大。在270℃下的液体产物含有质量为1600 ~ 3400的乙酸、乙酸甲酯和低聚物。300℃和330℃下的液体产物中含有邻苯二酚和苯酚，330 ℃下的产物中邻苯二酚基团较多。在循环伏安法中，300℃以上得到的两种液体产物的还原行为与邻苯二酚相似，均能将Cr（VI）还原为Cr（III），且还原能力随pH值的降低而增强，对于高浓度Cr（VI）溶液，330℃得到的液体产物在pH 2时能将Cr（VI）还原到允许值以下。通过荧光光谱法发现，在液体产物中Cr（VI）被还原成邻苯二酚基团。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