炼焦中煤解离规律与浮选工艺研究

发布时间：2019-05-28 10:50

【摘要】：从炼焦煤分选的中煤中分选出低灰精煤,使其合理地用于冶炼制焦,不仅有利于保护我国稀缺煤种资源,而且有利于促进我国国民经济发展。论文依据“不同的界面分选方法适应不同的颗粒粒度”,采用选择性絮凝浮选和常规浮选对磨矿后中煤进行了再选试验研究。筛分和浮沉试验表明:-3mm粒级中煤各粒度级灰分差不大,煤质较匀,平均灰分仅27.30%;-3mm粒级中煤的粘结指数仅为18.00%,只有经过分选才能用于炼焦,有再选的必要性。+1.40-1.80g/cm~3密度级累积产率高达81.79%,说明煤样中矿物质与有机组分密切连生,只有通过破碎磨矿才能实现有效分选。-3mm粒级中煤的煤岩特征表明:高岭石为主要的矿物质,但也存在一定量的黄铁矿、石英和方解石等。粘土矿物大多以4 m左右的颗粒浸染分布在细胞腔和基质内,很难实现完全解离。磨矿试验表明:磨矿5min时,-0.074mm粒级含量已达到84.59%,此时适合粗磨;当磨矿时间为30min时,细磨矿效率较高,进入-0.038mm粒级的物料含量接近100.00%,且-0.010mm粒级含量约81.85%。磨矿2min时,-0.038mm和-0.010mm粒级灰分均达到最小值,中煤中有机可燃组分优先解离。磨矿细度分别为-0.074mm54.66%(对应磨矿时间2min)和-0.010mm86.81%(对应磨矿时间40min)的磨矿产品的小浮沉试验表明:超细粒含量的增加并不能改变其可选性。在规定灰分12.00%时,其分选密度的增幅不大,仅提高了0.033g/cm~3。磨矿细度分别为-0.074mm54.66%和-0.010mm86.81%的磨矿产品的扫面电镜-能谱分析表明:在磨矿细度为-0.074mm54.66%时,+0.2mm粒级颗粒中,黏土类矿物与有机组分依旧以连生方式共存,而-0.010mm粒级中存在大量单体解离的矿物颗粒和有机煤岩单体颗粒。在磨矿细度为-0.010mm86.81%时,细粒级多以50 m的团聚颗粒存在,经超声分散后,可观察到矿物颗粒与有机可燃体基本完全解离。磨矿产品的接触角试验表明:接触角随解离度先增大,极大值为83.1°(磨矿细度-0.074mm67.32%(对应磨矿时间3min),此时颗粒表面疏水性最强)。当磨矿细度超过-0.010mm81.85%后,矿物质颗粒黏附在煤颗粒表面,其精煤接触角相对较低且波动不大。常规浮选试验表明:粗选即使在低药剂用量下(捕收剂用量为100g/t、起泡剂50g/t)时,所得精煤灰分仍高于15.60%,这是由细泥污染引起的。无药剂浮选最佳磨矿细度为-0.074mm~35%,但由于解离不够充分,精煤回收率不足14.00%。常规浮选的最佳磨矿细度为-0.074mm54.66~67.32%。当磨矿细度为-0.074mm54.66%(对应磨矿时间2min)时,通过粗选+精选流程可回收产率约35-38%的合格精煤。选择性絮凝浮选试验表明:絮凝剂与分散剂均有利于分选效果,且絮凝剂优于分散剂。-0.010mm81.85~86.81%为选择性絮凝浮选回收中煤的最佳磨矿细度。当磨矿细度为-0.010mm86.81%时,可回收产率43.44%、灰分11.93%的合格精煤,其浮选精煤数量指数为85.09%。粗磨-粗精选工艺处理炼焦分选中煤,不仅具有较高的分选数质量效率,而且能够大幅度降低磨矿能耗和浮选药耗,同时能避免浮选消泡和减弱后续过滤脱水问题干扰,试验结果表明粗磨-粗精浮选处理炼焦中煤最为适宜。
[Abstract]:The low-ash and fine coal is selected from the middle coal sorted by the coking coal, so that it can be used for smelting the coke, which not only is beneficial to the protection of the scarce coal resources in China, but also to promote the development of our national economy. According to the "Different interface sorting methods are suitable for different particle size", the selective flocculation and conventional flotation are used to study the re-selection of the coal after grinding. The sieving and floating tests show that the content of the coal in the-3mm size fraction is not big, the coal quality is more uniform, the average ash content is only 27.30%, the caking index of the coal in the-3mm size fraction is only 18.00%, and only the separation can be used for coking and the need for re-selection. The cumulative yield of the + 1.40-1.80 g/ cm ~ 3 density is up to 81.79%, which indicates that the minerals in the coal sample are closely related to the organic components, and the effective sorting can only be achieved by crushing and grinding. The characteristics of the coal in the-3mm size fraction show that the kaolinite is the main mineral, but a certain amount of pyrite, quartz and calcite are also present. Most of the clay minerals are disseminated in the cell cavity and the matrix with a particle size of about 4 m, and it is difficult to achieve complete dissociation. The grinding test shows that, when the grinding time is 5 min, the fraction content of-0.074mm has reached 84.59%, which is suitable for coarse grinding; when the grinding time is 30 min, the fine grinding efficiency is high, the content of the material entering the-0.038mm size is close to 100.00%, and the content of-0.010 mm is about 81.85%. When the ore is ground for 2 min, the ash of-0.038 mm and-0.010 mm all reach the minimum value, and the organic combustible components in the medium coal are preferentially dissociated. The grinding fineness is-0.074 mm54.66% (corresponding to the grinding time of 2 min) and-0.010 mm86.81% (corresponding to the grinding time of 40 min). When the ash content was 12.00%, the separation density was not increased, and only 0.033 g/ cm ~ 3 was raised. The grinding fineness is-0.074 mm54.66% and-0.010 mm861.81% of the surface-scanning electron microscope-energy spectrum analysis show that when the grinding fineness is-0.074 mm54.66%, the clay mineral and the organic component are still co-exist in a continuous mode. And a large amount of monomer-dissociated mineral particles and organic coal-rock monomer particles are present in the-0.010 mm size fraction. When the fineness of the grinding is-0.010 mm81.81%, the fine-grained grade is more than 50 m. After the ultrasonic dispersion, it can be observed that the mineral particles are completely dissociated from the organic combustible. The contact angle of the grinding minerals shows that the contact angle increases with the degree of dissociation, and the maximum value is 83.1 掳 (grinding fineness-0.074 mm6.7.32% (the corresponding grinding time is 3 min), at which time the surface hydrophobicity of the particles is the strongest). When the grinding fineness exceeds-0.010 mm81.85%, the mineral particles adhere to the surface of the coal particles, and the fine coal contact angle is relatively low and the fluctuation is not large. The conventional flotation test shows that the ash content of the fine coal is still higher than 15.60%, which is caused by the fine mud pollution, even when the amount of the low-dose agent (the amount of the collecting agent is 100 g/ t and the foaming agent is 50 g/ t). The optimum grinding fineness of the no-agent flotation is-0.074-35%, but due to the insufficient dissociation, the recovery of the fine coal is less than 14.00%. The optimum grinding fineness of the conventional flotation is-0.074 mm54.66-67.32%. When the grinding fineness is-0.074 mm0.66% (the corresponding grinding time is 2 min), the qualified fine coal with the yield of about 35-38% can be recovered by the rough selection + selection process. The selective flocculation and flotation test shows that both the flocculant and the dispersant are favorable to the separation effect, and the flocculant is superior to the dispersant. -0.010 mm81.85-86.81% of the best grinding fineness for selective flocculation and flotation recovery. When the grinding fineness is-0.010 mm81.81%, the recoverable yield is 43.44%, and the ash content is 11.93%, and the quantity index of the flotation refined coal is 85.09%. the coarse grinding-coarse selection process is used for treating the coal in the coking and sorting, not only has higher separation number and quality efficiency, but also can greatly reduce the grinding energy consumption and the flotation drug consumption, and simultaneously can avoid the interference of the flotation defoaming and the reduction of the subsequent filtration and dehydration problem, The results show that the coarse-fine-fine-fine flotation is the most suitable for coking.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD94;TD923

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