胜利褐煤预先泥化分选试验研究

发布时间：2018-02-14 23:47

  本文关键词： 褐煤洗选 预先泥化 分选工艺 泥化特征 高泥化煤泥水处理　出处：《中国矿业大学》2015年硕士论文　论文类型：学位论文

【摘要】：褐煤因其低变质、易风化、易泥化的特性,被选煤界普遍认为不适合入水洗选,从而使褐煤的利用价值受到了限制。本论文以胜利褐煤为研究对象,分析了褐煤煤质,评价了其可选性,揭示了胜利褐煤的泥化特征,提出了适合胜利褐煤洗选的预先泥化分选工艺。论文针对褐煤泥化后产生的煤泥水,分析了其难沉降的原因,研究了煤泥水沉降性能及煤泥压滤性能。论文主要的研究如下:1、分析胜利褐煤煤质,评价其可选性。胜利褐煤具有高水、高灰、高硫、低热值的特点,直接利用价值低,原煤粒度分布不均匀且矸石易碎。浮沉试验表明:原煤内灰高,难以分选出低灰精煤;浮煤产率高、中煤产率低,说明可选性好且精煤理论产率高。2、胜利褐煤中矸石和不同粒级原煤的泥化特征研究。矸石与煤的泥化程度差别较大:矸石泥化属于高泥化程度,容易成“泥”;煤即使碎成细粒也是以颗粒状存在,不会成“泥”。不同粒级褐煤泥化程度不同,末煤的泥化程度高于块煤;-3 mm粒级可选性差且极易泥化,不宜水洗。3、基于褐煤泥化特征提出预先泥化洗选工艺,并通过分选试验验证了工艺可行性。论文提出“+3 mm预先泥化脱泥跳汰分选、-3mm粒级干法分选或不分选”工艺流程。试验表明:褐煤泥化后经跳汰洗选时,矸石泥化现象明显降低,分选指标好且煤泥水浓度低。4、论文分析了胜利褐煤泥化后煤泥水难沉降原因,研究了煤泥水沉降性能及煤泥压滤性能。煤泥粒度细且粘土矿物含量高,因布朗运动和静电斥力而呈现出的沉降稳定性和聚合稳定性导致煤泥水自然沉降性能差。水质硬度增大可优化沉降效果,煤泥水浓度为29.9 g/L和34.4 g/L时,FOCUSⅡ药剂优化后用量分别为377 g/t和468 g/t。煤泥压滤较困难,将煤泥水浓缩至浓度为374.3 g/L,当压滤时间为40 min、过滤压力为0.8 Mpa时滤饼水分25.86%,可以满足选煤厂实际生产的需要。
[Abstract]:Because of its low metamorphism, easy weathering and easy to muddy, lignite is generally considered unsuitable for washing with water, which limits the utilization value of lignite. In this paper, Shengli lignite is taken as the research object and the quality of lignite is analyzed. This paper evaluates its separability, reveals the mudding characteristics of Shengli lignite, and puts forward a pre-mudding separation process suitable for Shengli lignite washing. The paper analyzes the causes of its difficult settlement in view of the slime water produced by lignite sludge. This paper studies the settling performance of slime water and the pressure filtration performance of coal slime. The main research in this paper is as follows: 1, analyzing the coal quality of Shengli lignite and evaluating its selectability. Shengli lignite has the characteristics of high water, high ash, high sulfur, low calorific value and low value of direct utilization. The floatation test shows that the inner ash of raw coal is high, it is difficult to separate out low ash concentrate coal, the yield of floating coal is high, and the yield of middle coal is low. The results show that there is good selectivity and the theoretical yield of clean coal is high, and the mudding characteristics of gangue and different grained raw coal in Shengli lignite are studied. The mudding degree of gangue and coal is quite different: the mudding of gangue belongs to high mudding degree. It is easy to form "mud"; even if the coal is broken into fine particles, it still exists in the form of granules and does not form "mud." different grain-grade lignite has different degree of mudding, and the mudding degree of the final coal is higher than that of the bulk coal of 3 ~ 3 mm, and it is easy to muddy. It is not suitable to wash. 3. Based on the mudding characteristics of lignite, the pre-mud washing process is put forward. The feasibility of the process was verified by the separation test. The technological process of "3mm pre-mud desliming jig sorting or non-separation" was put forward in this paper. The test results show that: when lignite is mudded and washed by jig, The phenomenon of gangue mudding is obviously reduced, the separation index is good and the concentration of slime water is low. 4. The paper analyzes the reasons for the difficult settling of slime water after lignite mudding in Shengli, and studies the settling performance of slime water and the pressure filtration performance of slime. The slime size is fine and the clay mineral content is high. Due to Brownian motion and electrostatic repulsive force, the stability of sedimentation and polymerization results in poor natural subsidence performance of coal slime water, and the settlement effect can be optimized by increasing the hardness of water quality. When the slurry concentration is 29.9 g / L and 34.4 g / L, the optimized dosage of FOCUS 鈪，

本文编号：1511911