粘土泥化抑制对煤泥浮选的影响

发布时间：2018-07-31 19:21

【摘要】：粘土是煤中主要的杂质矿物,也是主要的成灰矿物。粘土矿物在水中可泥化分散成微米级的晶层颗粒,对煤泥浮选产生影响。泥化抑制旨在从水-粘土接触之初开始,通过水溶液化学调整抑制粘土膨胀分散。这方面研究在调控煤泥水沉降方面已开展。煤泥水粘土泥化抑制不可避免的对煤泥浮选产生影响。有鉴于此,本文开展粘土预先泥化抑制和分散后调控(非抑制)对煤泥浮选影响的对比研究,以期为粘土泥化抑制的实际应用提供参考。本文以蒙脱石和高岭石与纯煤配制的矿浆为研究对象,分别采用Ca2+和TMBAC为抑制剂,探索抑制粘土矿物泥化对浮选的影响。并通过颗粒粒度、Zeta电位和矿浆流变学特性分析其原因。对于蒙脱石-煤体系,在Ca2+抑制与非抑制条件下均表现为Ca2+浓度增加,可燃体回收率增加,精煤灰分增加。抑制蒙脱石泥化使浮选可燃体回收率最高可达92.60%,精煤灰分为5.20%,相同条件下非抑制为81.13%,精煤灰分为4.79%。其原因在于抑制粘土矿物泥化使煤浆中细粒蒙脱石含量降低,流体由牛顿型流体变为非牛顿型流体,这有利于提高泡沫层稳定性。对于高岭石-煤体系,Ca2+抑制或非抑制高岭石泥化时,浮选指标随Ca2+浓度提高其变化趋势同蒙脱石-煤体系相同,但效果相反。当Ca2+浓度大于5 mmol/L,非抑制泥化条件下可燃体回收率最高可达85.59%,精煤灰分为7.01%,相同条件下抑制条件下为80.01%,精煤灰分为7.88%。其原因在于抑制条件下Ca2+明显降低高岭石Zeta电位,SEM-EDS分析证实抑制条件下更多的高岭石罩盖在煤颗粒表面。与抑制条件相比,非抑制条件Ca2+降低高岭石Zeta电位幅度较小。TMBAC抑制粘土矿物泥化时,蒙脱石和高岭石粒度变化较小,所以抑制和非抑制条件可燃体回收率和精煤灰分差异也较小。
[Abstract]:Clay is the main impurity mineral in coal and also the main ash-forming mineral. Clay minerals in water can be mudded and dispersed into micron grained particles, which have an effect on coal slime flotation. The aim of clay inhibition is to inhibit the swelling and dispersion of clay by chemical adjustment of water solution from the beginning of water-clay contact. This aspect of research has been carried out in regulating the subsidence of coal slurry. The inhibition of clay slime in coal slurry inevitably affects the flotation of coal slime. In view of this, a comparative study on the effects of clay pre-mud inhibition and post-dispersion regulation (non-inhibition) on slime flotation is carried out in order to provide a reference for the practical application of clay silting inhibition. In this paper, the slurry prepared from montmorillonite and kaolinite and pure coal was used as the research object, Ca2 and TMBAC were used as depressants respectively, to explore the effect of inhibiting clay mineral sludge on flotation. The causes were analyzed by means of particle size and Zeta potential and rheological properties of slurry. For montmorillonite coal system, under both Ca2 inhibition and non-inhibition conditions, the concentration of Ca2 increased, the recovery rate of combustible body increased, and the ash content of clean coal increased. Inhibition of montmorillonite mudding resulted in the highest recovery of flotation combustible particles up to 92.60 percent, and the fine coal ash was divided into 5.20, 81.13 and 4.79 in the same conditions. The reason lies in the decrease of fine montmorillonite content in coal slurry and the change of fluid from Newtonian fluid to non-Newtonian fluid, which is beneficial to improve the stability of foam layer. For kaolinite coal system, the change trend of flotation index with increasing Ca2 concentration is the same as that of montmorillonite coal system, but the effect is opposite. When the concentration of Ca2 is more than 5 mmol / L, the recovery rate of combustible body can reach 85.59 under the condition of non-inhibition mudding, the fine coal ash is divided into 7.01 and 80.01 under the same condition, and the refined coal ash is divided into 7.88 and 7.88 respectively. The reason is that Ca2 obviously reduces the Zeta potential of kaolinite and SEM-EDS analysis proves that more kaolinite covers on the coal particle surface under the condition of inhibition. Compared with the inhibition condition, when the uninhibited condition Ca2 reduced the Zeta potential amplitude of kaolinite was smaller, the particle size of montmorillonite and kaolinite changed less when inhibiting clay mineral mudding. Therefore, the difference between the combustible recovery and ash content is also small.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD94

【参考文献】