Upgrading of Low Rank Coal by Advanced Technology.
Upgrading of Low Rank Coal by Advanced Technology.
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利用先进技术升级低阶煤。
DOI：
10.2473/shigentosozai.118.695
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
T. Oki
中科院分区：
文献类型：
--
作者：
K. Yukawa;T. Hirajima;M. Tsunekawa;C. Suyama;T. Oki
介绍了低阶煤的热水干燥、浮选、油团聚和化学洗选等提质工艺。使用的煤是Asam-Asam煤（3.4db %灰分，73.7dafb % C）和Beluga煤（8.0db %灰分，71.5dafb % C）JWD处理在不同温度如270、300和330 °C下进行。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。根据Beluga原煤的浮沉试验结果，估计对于比重为1.45的中等尺寸煤（-1，000 +425 μm），通过重介质分选可有效地获得灰分为4%、产率为92%的煤精矿。通过浮选的两种HWD处理的煤的可燃物回收率比两种原煤的可燃物回收率高20- 30%，并且处理的煤的泡沫产物的灰分含量比原煤低。通过对细HWD处理的Beluga煤（平均粒度53μm）进行3级浮选，获得了灰分低于5%、可燃物回收率为76%的洁净煤产品。还通过细HWD处理的Beluga煤（平均粒度9和3μm）的油附聚回收了含4.1- 4.3%灰分的产品。这一结果与平均粒度为53μm的煤的三级浮选结果相似，表明仅用物理分选方法不可能除去约4%的灰分。HWD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、三级浮选和化学精选三种工艺组合，可获得灰分0.5%、可燃物回收率86%的超洁净煤。
This paper describes the upgrading of low rank coal by hot water drying (HWD), flotation, oil agglomeration and chemical coal cleaning. The coals used were Asam-Asam coal (3.4 db% ash, 73.7 dafb% C) and Beluga coal (8.0 db% ash, 71.5 dafb% C).The HWD treatment was carried out at different temperatures such as 270, 300 and 330 °C. With increasing temperature water content and carboxyl content of the both coals were decreased and their floatability became higher. From the results of float-sink test for Beluga raw coal, it was estimated that a coal concentrate with 4 % ash and 92 % yield is effectively obtained by heavy medium separation for middle size coals(- 1,000 + 425μm) at a specific gravity of 1.45. Combustible matter recovery of the both HWD treated coals by flotation was 20-30 % higher than that of the both raw coals and the ash content of the froth product was lower for the treated coals than the raw coals. By 3 stage flotation of the fine HWD treated Beluga coal(53μm of average size), a clean coal product was obtained with less than 5 % ash and 76 % recovery of combustible matter.Products containing 4.1-4.3 % ash were also recovered by oil agglomeration of the fine HWD treated Beluga coals (9 and 3μm of average sizes). This result is similar to that obtained by 3 stage flotation of 53μm average size coal and it indicated that removal of about 4 % ash is impossible by physical separation method alone. Chemical coal cleaning method of the HWD 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, 3-stage flotation and chemical cleaning.