Xinwen Mining Group Co. , Ltd.
Xinwen Mining Group Coal Preparation Branch

基于细粒煤泥分质回收与合理化利用目的,为强化中灰煤泥浮选回收与分离效果,实现细粒煤泥“低灰精煤、中灰煤泥和高灰泥矸”三产品分选,选取浮选精煤和中灰煤泥两种试样,通过浮选试验考查了不同分选参数下的浮选效果,研究了浮选精煤与中灰煤泥浮选行为差异,并借助原子力显微镜测定了液膜薄化过程中强/弱疏水性基板与气泡间的相互作用。研究表明:浮选精煤的接触角为109.25°,较中灰煤泥高28.62°;浮选精煤中含有较多的烷基和氨基等阳离子型基团,中灰煤泥含有较多的羧基和羟基等含氧官能团。增加柴油和仲辛醇用量、提高浮选搅拌转速都有助于提升浮选精煤和中灰煤泥的回收效果;增加充气量能提升浮选精煤回收效果,但中灰煤泥回收效果有所降低。浮选精煤的浮选速率明显高于中灰煤泥,在相同浮选条件下浮选精煤优先浮出。对于强化中灰煤泥回收,分选参数影响次序为搅拌转速>矿浆浓度>充气量>起泡剂>捕收剂。强化粗粒中灰煤泥分选回收时,应采用“高药剂用量、强搅拌转速、低充气量、高矿浆浓度、延长浮选时间”分选条件;对于分离浮选精煤与中灰煤泥,应采用“低药剂用量、低搅拌转速、高充气量、低矿浆浓度、降浮选时间”分选条件。强/弱疏水性基板与气泡间的临界液膜厚度理论值分别为39nm和16nm,在吸引性分离压作用下气泡突破液膜与基板发生黏附。当液膜厚度薄化至疏水力作用程时,总分离压力开始转向吸引,膜薄化驱动压力急剧升高,液膜在疏水力的作用下发生破裂。

Based on the purpose of fine coal slime separation and rational utilization, in order to enhance the flotation recovery and separation effect of medium-ash coal slurry, and achieve the separation of three products from fine coal slime: low ash clean coal, medium ash coal slime, and high ash tailings, we selected two samples of flotation clean coal and medium ash coal slurry, and investigated the flotation effect under different separation parameters through tests. The differences in flotation behavior between flotation clean coal and medium ash coal slime were studied, and the interaction between strong/ weak hydrophobic substrates and bubbles during liquid film thinning process was measured using atomic force microscopy. The results showed that, the contact angle of flotation clean coal is 109. 25°, which is 28. 62° higher than that of medium ash slime; the clean coal contains a large number of cationic groups such as alkyl and amino groups, while medium ash slime contains a large number of oxygen-containing functional groups such as carboxyl and hydroxyl groups. Increasing the amount of diesel and secondary octanol, as well as increasing the flotation stirring speed, can help improve the recovery efficiency of flotation clean coal and medium ash slime; Increasing the aeration rate can improve the recovery efficiency of flotation clean coal, but that of medium ash slime is reduced. The flotation rate of flotation clean coal is significantly higher than that of medium ash slime, and under the same flotation conditions, flotation clean coal preferentially floats out. For the enhanced recovery of medium ash slime, the order of influence of separation parameters is stirring speed>slurry concentration>aeration rate>frother>collector. When strengthening the separation and recovery of coarse medium ash slime, the separation conditions of “high dosage of reagents, strong stirring speed, low aeration rate, high slurry concentration, and extended flotation time” should be adopted; For the separation of flotation clean coal and medium ash coal slurry, the separation conditions of “low reagent dosage, low stirring speed, aeration rate, low slurry concentration, and reduced flotation time” should be adopted. The theoretical values of the critical liquid film thickness between strong/ weak hydrophobic substrates and bubbles are nm and nm, respectively. Under the attractive separation pressure, bubbles break through the liquid film and adhere to the substrate. When the thickness of the liquid film thins to the hydrophobic range, the total separation pressure begins to shift towards attraction, and the thinning of the film drives a sharp increase in pressure, causing the liquid film to rupture under the action of hydrophobic forces.

许光前,王焕忠,耿大将,等.基于强化粗粒中灰煤泥浮选回收与分离效果的调控机制研究[J].煤炭工程,2024,56(11):202-210.