低灰细粒煤泥絮凝浮选试验研究

发布时间：2018-02-22 05:54

本文关键词： 低灰细粒絮凝浮选　出处：《中国矿业大学》2016年硕士论文　论文类型：学位论文

【摘要】：随着采煤机械化的发展、重介选煤粒度下限的降低及粗煤泥分选工艺的完善,浮选入料中微细级含量逐渐增加,这对浮选过程具有重要影响。一方面,以微细粒级为主的煤泥,浮选速度慢,浮选时间长,微细粒煤泥在短时间内难以矿化及升浮,容易损失在尾煤中,而造成精煤产率的下降;另一方面,微细粒煤泥由于其比表面积大,在浮选过程中会吸附大量的药剂,造成药剂消耗过高。因此微细粒煤泥的分选过程研究具有重要意义。本文以山西某选煤厂低灰细粒入浮煤泥为研究对象,对其基本性质进行了分析,考察了其常规浮选行为,并深入探讨了采用絮凝浮选的方法来强化微细粒煤泥回收的可行性及过程,最后对工业浮选系统进行絮凝浮选研究,证实了絮凝浮选的实践意义。论文所研究的煤泥为低灰细粒煤泥,其中灰分约为13.5%,0.045 mm粒级产率约为70%;煤泥中间密度级产率较少,解离较好;煤中矿物质以高岭石、多水高岭石等粘土矿物为主;煤中含有较多的疏水性基团,而亲水性基团含量较少。在煤泥的常规浮选试验中,与捕收剂相比,起泡剂的种类及用量对分选效果具有更加显著的影响,其中采用仲辛醇作为起泡剂,浮选精煤产率及灰分最高;全粒级及窄粒级浮选速度试验证实,煤泥中微细粒级含量越多,其浮选速度越慢,浮选时间越长;在自由充气的条件下,浮选过程中浮选机的转速越高,浮选精煤产率及灰分也越高。在柴油用量均为200 g/t,仲辛醇用量均为100 g/t,浮选机转速均为1800 r/min的条件下,与常规浮选相比,絮凝浮选在絮凝剂X用量为20 g/t时,产率及灰分的增幅最大,分别为4.32%和1.30%;相比常规浮选,絮凝浮选能在一定程度上提高煤泥浮选速度;絮凝浮选能絮凝浮选适合应用于微细粒级含量较多的煤泥分选过程中;絮凝浮选与常规浮选相比,其浮选完善指标在一定程度上是下降的,这可能是由于絮凝剂对微细粒煤泥的非选择性絮凝及絮凝浮选过程中水流的非选择性夹带作用增强所导致。工业浮选试验证实,在相同的分选条件下,与常规浮选相比,絮凝浮选在满足相应精煤灰分要求的前提下,能提高精煤产率7.84%,此时对应絮凝剂的用量为30 g/t;分选产品筛分试验证明,与常规分选相比,絮凝浮选能明显提高0.045mm粒级煤泥的回收;当入料流量为450 m3/h,循环泵频率为41 Hz时,能为絮凝浮选提供较好的分选环境。
[Abstract]:With the development of mechanization of coal mining, the lower limit of coal size in heavy medium preparation and the improvement of separation technology of coarse coal slime, the content of fine grade in flotation feed increases gradually, which has an important effect on the flotation process. The flotation rate is slow, the flotation time is long, the fine coal slime is difficult to be mineralized and floated in a short time, and it is easy to lose in the tail coal, which results in the decrease of the yield of the fine coal. On the other hand, because of its large specific surface area, the fine grained slime has a large specific surface area. A large number of reagents will be adsorbed in the flotation process, resulting in excessive consumption of reagents. Therefore, it is of great significance to study the separation process of fine coal slime. In this paper, a coal preparation plant in Shanxi Province low ash fine particles into floating slime as an object of study. The basic properties were analyzed, the conventional flotation behavior was investigated, the feasibility and process of using flocculation flotation method to strengthen the recovery of fine coal slime were discussed. Finally, the flocculation flotation of industrial flotation system was studied. The practical significance of flocculation flotation is confirmed. The coal slime studied in this paper is low ash fine coal slime, in which the ash content is about 13.5mm / 0.045 mm grain yield is about 70mm, the intermediate density grade yield of coal slime is less and the dissociation is better, and the minerals in coal are kaolinite, kaolinite, kaolinite, kaolinite, kaolinite, kaolinite, kaolinite, etc. Clay minerals such as polyhydrated kaolinite are dominant, and coal contains more hydrophobic groups, but less hydrophilic groups. In the conventional flotation tests of coal slime, compared with the collector, The type and amount of foaming agent have a more significant effect on the separation effect, among which, the flotation concentrate coal yield and ash content are the highest by using secondary octanol as foaming agent, and the test of flotation speed of whole and narrow particle level proves that the more fine particles content in coal slime, the higher the content of fine particles in coal slime. The slower the flotation speed and the longer the flotation time, the higher the speed of flotation machine in the process of flotation. The higher the yield and ash content of floatation coal is, the higher the production rate and ash content are. Under the conditions that diesel oil consumption is 200 g / t, secondary octanol consumption is 100 g / t, and flotation machine speed is 1800 r / min, compared with conventional floatation, flocculating floatation can be achieved when the dosage of flocculant X is 20 g / t. Compared with conventional flotation, flocculation flotation can improve the speed of slime flotation to a certain extent, flocculation floatation can be used in the separation process of coal slime with more fine particle content, and the increase of yield and ash content is 4.32% and 1.30 respectively, and flocculation flotation can improve the speed of slime flotation to a certain extent, and flocculation floatation can be used in the separation process of coal slime with more fine particles. Compared with conventional floatation, the improvement index of flocculation flotation is decreased to some extent. This may be due to the non-selective flocculation of fine coal slime and the enhancement of non-selective entrainment of water flow during flocculation flotation. The industrial flotation experiments show that under the same separation conditions, compared with conventional flotation, Flocculation floatation can improve the yield of clean coal 7.84g / t on the premise of meeting the requirement of ash content of corresponding clean coal, and the corresponding dosage of flocculant is 30 g / t. The screening test of separation product proves that, compared with conventional separation, the flocculating floatation can increase the yield of clean coal. Flocculation flotation can obviously increase the recovery of 0.045mm granular slime, and when the feed flow rate is 450 m3 / h and the circulating pump frequency is 41 Hz, it can provide a better separation environment for flocculating flotation.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD94

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