针对入浮煤泥难浮的问题，以山西矿区1/3焦煤煤泥为研究对象，基于可浮性分析结果对该煤泥进行了单元浮选试验、精选降灰试验，以及精选联合尾煤扫选试验。可浮性试验结果表明：煤泥中的主要密度级为1.4～1.8 g/cm³中间密度级，产率为62.87%、灰分为18.24%，中煤含量大，浮选选择性差；< 0.045 mm粒级产率为32.67%，细泥物导致精煤受到污染，致使煤泥整体可浮性较差。在药剂用量为1.0 kg/t，药剂用量比（煤油∶仲辛醇）为4的条件下进行单元浮选试验，结果表明，一次粗选不能达到要求的产品灰分。精选降灰分步释放浮选试验得到产率为25.01%、灰分为11.57%的精煤，产率为52.70%的中煤，精煤灰分满足指标要求，但一次精选尾煤产率过高，中煤未进行有效分选。采用一粗一精二扫流程试验得到产率为47.64%、灰分为11.75%的精煤，产率为35.65%、灰分为23.64%的中煤和灰分为80.21%的尾煤，精煤、中煤、尾煤指标均达到要求，较一粗二精二扫流程精煤产率提高了16.80个百分点，中煤分选充分，产率降低了17.17个百分点。因此，在难浮煤泥的浮选过程中，适当增加扫选工艺可提高各产品的分选效率，且一粗一精二扫试验可将粗选尾煤中的中煤成分分离，在保证获得高灰尾煤的前提下，降低了精煤受到细泥污染而影响分选效率的可能性。

with an aim to overcome the difficulties in flotation of difficult-to-float coal slime, an experimental study is conducted with the 1/3 coking coal slime as the target. Flotability analysis shows that the density fractions of the slime are predominantly in the 1.4～1.8 g/cm³ intermediate range with a yield of 62.87% and an ash of 18.24%, and it contains a high proportion of middlings, regarding it to be poor in selectivity; and the flotation concentrate is contaminated by fine slime as the < 0.045 mm size in the slime has a high yield of 32.67%, a factor causing the poor flotability of the slime. As indicated by results of batch flotation test, cleaning test on ash reduction as well as the cleaning plus tailings scavenging combined test, when flotation of the slime is carried out with the dosage of agent of 1.0 kg/t and the use of kerosene and secoctanol at a ratio of 4:1, the ash of the concentrate cannot be lowered to the required value simply through a roughing process.Result of test on ash reduction through timed-release cleaning process shows that a concentrate product with a yield of 25.01% and an ash of 11.57% and a yield of middling of 52.70%, with the ash of the concentrate being up to the required level; however, through only the cleaning process, the yield of tailing is excessively high and the middling fails to get effectively separated. By using one roughing + one cleaning + two scavenging combined process, the yield and ash of concentrate are 47.64% and 11.75%, respectively, and the yield and ash of middling are 35.65% and 23.64%, respectively, with the ash of tailing being as high as 80.21%, all up to the standards in quality indicators; and by using such a process, the yield of concentrate can see a rise of yield by 16.80 percentage points while the yield of middling is lowered by 17.17 percentage points due to the possibility of its sufficient separation, in comparison with the use of one roughing + two cleaning + two scavenging process. It is noted that in treating the difficult-to-float coal slime, appropriate increase of scavenging processes can improve flotation efficiency and quality indices of products, and the use of the one roughing + one cleaning + two scavenging process can lead to effective separation of the middling in tailing product of roughing process in a separate manner for reducing the possibility of contamination of concentrate by fine slime while ensuring the high ash of tailing product.