【作者】 高永明；

【导师】 王怀法；

【作者基本信息】 太原理工大学 ， 矿物加工工程， 2012， 硕士

【摘要】 随着采煤机械化程度的提高,原煤中煤泥含量越来越高,而粗煤泥有效分选是当前选煤技术研究的热点问题,也是影响选煤厂精煤产率提高的技术瓶颈。论文针对干扰床分选机分选粒度范围窄的缺点,在上升水流中引入上升气泡流,应用这一理论,设计了一种新型粗煤泥分选机,在一定程度上拉大了低密度粗颗粒与高密度细颗粒的分选密度,以此强化了低密度粗颗粒的有效分选,从而弱化了颗粒粒度对分选效果的影响,最终实现煤泥的宽粒级分选。论文通过对粗煤泥分选机内部流场数值模拟研究发现,给水口和充气口上方湍流强度较大,能够加强气泡与颗粒之间的相互作用,同时由速度场分布可以看出,在入料口上方存在循环流,可进一步提高宽粒级煤泥的分选效果。论文基于屯兰矿和西曲矿两种煤样,在不加捕收剂、加捕收剂、结构改装等不同条件下,研究了上升水流速度、充气速度、入料浓度、入料速度、水/气混合入料速度等因素对分选效果的影响。实验结果可以看出,不加捕收剂的情况下,最佳的试验条件为：顶水速度、充气速度、入料速度和水/气混合入料速度分别为8.5×10-3、2×10-3、1.4×10-2和4.5×10-3n/s,入料浓度为300g/L。在其他条件相同时,添加捕收剂的分选效果优于不加捕收剂时分选效果,说明添加捕收剂后可强化煤泥的有效分选。通过对改装试验装置后进行试验结果发现,装置改装后的试验结果相比原设计试验效果较差,从而也验证了原结构设计的合理性论文针对最优试验条件,通过对产品浮沉试验进行分选效果评定。结果发现,屯兰煤样各粒级实际分选密度在1.4g/cm3左右,可能偏差E值在0.045左右,不完善度Ⅰ值在0.1左右,从各粒级数量效率可以看出,0.25-1mm分选效果较好；而西曲煤样各粒级实际分选密度在1.45g/cm3左右,可能偏差E值在0.1左右,不完善度Ⅰ值在0.2左右,同样是0.25-1mm分选效果较好。更多还原

【Abstract】 With the improvement of coal mining mechanization, the content of the slime is increasingly high, how to separate the coarse coal slime is not only a hot issue in the current coal preparation technology research, but also a technical bottleneck which affects the clean coal production rate in the coal preparation plant. The teeter bed separator has the shortcomings of narrow particle size sorting range, the thesis introduces the rising bubble stream in the rising water, and a new coarse slime separator was designed with this theory, which widened the separation density between coarse particles with low density and fine particles with high density to a certain extent, thus strengthened the separation effective in the coarse particles with low-density, meanwhile weaken the influence of particle size sorting effect, and it realized wide grain size sorting ultimately.It can be found that the interaction between the bubble and the particle can be enhanced due to larger turbulence intensity in the outlet and above the inflation port; and the circular flow which can be seen in the velocity field above feed inlet will improve the separation effect further on the wide grain size slime by studied on slime separation internal flow field numerical simulation in this thesis.The thesis based on the two coal samples coming from Tunlan mine and Xiqu mine, in order to study the rising rate of water flow, inflation rate, feed concentration, feed speed and water/gas hybrid feeding speed of the effect of separation, the different experimental conditions of without and adding collecting agent and modification structure are selected. The results can be seen without collector, the best experimental conditions:rising water speed, inflatable speed, feed speed and water/gas mixture into the feed speed are8.5×10-3,2×10-3,1.4×10-2and4.5×10-3m/s respectively; feed concentration is300g/L. With the same conditions, the separation effect with collector is better than without collector, it also illustrate that adding collector can enhance the coarse coal slime separation. The results can be found that the original design is better than modification on coarse coal particle separation, which verified the reasonable of the original structural design.The effects of separation are evaluated by float and sink tests of products with the optimal test conditions in the thesis. The results show that the actual separation density around1.4g/cm3in Tunlan coal samples, and the E value is about0.045,I value is around0.1, as can be seen from the organic efficiency in various size fraction, the better separation effect size fraction is0.25-1mm; the actual separation density of Xiqu coal samples is about1.45g/cm3, and E value is about0.1, while I value around0.2, the better separation effect size fraction is also the0.25-1mm.更多还原