磨矿中添加表面改性剂对褐煤浮选的影响研究
发布时间：2018-11-22 20:41
【摘要】：我国褐煤资源储量丰富,褐煤现阶段大部分作为燃料煤用于发电,但是由于高灰且未得到有效的分选,带来各种环境问题。褐煤的有效分选逐渐受到人们的重视,而细粒褐煤因其可浮性差,难以用常规的浮选方法进行高效回收。本论文以锡市褐煤为例,探究了褐煤的难浮特性,提出了表面改性剂及其与磨矿联合作用后改善褐煤浮选效果的有效策略,并采用现代仪器分析手段研究了改善过程中的作用机理。主要研究结论如下:(1)基于褐煤表面物性表征的难浮特性研究,采用FTIR、XPS、SEM和接触角对褐煤进行物性表征,分析其难浮特性,结果表明:导致褐煤表面亲水性强的原因主要为褐煤表面含氧官能团众多,表面含有大量裂缝和沟壑,并含有大量的矿物质覆盖在褐煤表面、填充在其表面沟壑内。因此,褐煤可浮性差,采用常规的浮选方法难以实现高效回收。褐煤的可浮性改善研究中,除了要降低褐煤表面含氧官能团含量外,还应减少其表面矿物含量。(2)不同改性剂增加褐煤可浮性对比及其对褐煤的作用机理研究。对三种药剂改性后的褐煤进行浮选实验,得出褐煤与司盘80作用后可以显著提高其可浮性。司盘系列分子式和XPS结果表明:司盘80由于非极性端链的长短和结构的差异,活化性能更好,与褐煤更有效的吸附,褐煤的疏水性和可浮性得到显著改善。但是与司盘80作用后,褐煤表面高灰矿物也受到少量的覆盖,矿物元素含量有所减少,改性效果好但选择性较弱,导致精煤灰分偏高。(3)浮选条件对褐煤浮选的影响研究。由于褐煤在叶轮剧烈搅拌的作用下沟壑内的矿物质会发生剥离,当总调浆时间一定时,延长预润湿时间可以改善浮选效果,预润湿时间超过5分钟后达到稳定,并且搅拌过程中如果有浮选药剂的加入会相对阻碍此现象的发生。搅拌强度对浮选的影响表现为:当搅拌强度小于1196转/分钟时,主要是受浮选搅拌的影响,由于气泡直径随着搅拌强度的增加而变小,导致精煤可燃体回收率迅速增加。当搅拌强度大于1196转/分钟时,受浮选搅拌和调浆搅拌共同影响,由于雾沫夹带和高灰细泥填充与剥离平衡点的移动,导致精煤灰分增加,可燃体回收率减小。(4)磨矿中添加表面改性剂对褐煤浮选的影响及其作用机制研究。由于表面矿物质的覆盖,褐煤浮选的精煤可燃体回收率偏低、精煤灰分偏高,研磨预处理可以提高粗颗粒的可浮性,细颗粒的选择性。磨矿可以使得吸附在粗颗粒中灰分较大的细粒级矿物质脱离,达到煤和矿物质的解离作用,充分的解离使得浮选出来的精煤灰分更低,并且褐煤表面不再受矿物质的影响能更好的和药剂接触并吸附;细颗粒选择性的增加是由于磨矿过程促进了褐煤与药剂的有效吸附。综上所述,本文在对褐煤难浮特性研究的基础上,提出了磨矿中添加表面改性剂改善褐煤浮选效果的策略,采用研磨的方法解离出表面矿物质来提高分选效果,通过添加表面改性剂来改善可浮性。为褐煤的浮选降灰,提高疏水性提供了一种有效的处理方法。
[Abstract]:The lignite resource in China is rich, most of the lignite is used as fuel coal at the present stage for power generation, but due to high ash and no effective separation, various environmental problems are brought. The effective separation of brown coal is more and more important, and fine-grained lignite is difficult to recover efficiently by conventional flotation method because of its poor floatability. The paper, taking the lignite of tin as an example, probes into the hard-floating property of the lignite, and puts forward the effective strategy for improving the flotation effect of the lignite after the surface modifying agent and the combined action of the surface modifier and the grinding, and the mechanism of the action in the improvement is studied by means of modern instrument analysis. The main results of the study are as follows: (1) The properties of lignite are characterized by FTIR, XPS, SEM and contact angle. The results show that: (1) The properties of lignite are characterized by FTIR, XPS, SEM and contact angle. The results show that: (1) The properties of lignite are characterized by FTIR, XPS, SEM and contact angle. The reason for the strong hydrophilicity of the surface of the lignite is that the surface of the brown coal has a large number of oxygen-containing functional groups, the surface contains a large amount of cracks and gullies, and a large amount of minerals are covered on the surface of the lignite and are filled in the groove of the lignite. Therefore, it is difficult to realize high-efficiency recovery by the conventional flotation method because of the difference of the floatability of the lignite. In addition to reducing the content of the oxygen-containing functional groups on the surface of the lignite, the surface mineral content of the lignite should be reduced, in addition to reducing the content of the oxygen-containing functional groups on the surface of the lignite. (2) The ability of different modifiers to increase the floatability of lignite and its mechanism of action on lignite. The flotation experiment of the three kinds of chemical modified lignite is carried out, and the floatability of the lignite after the action of the pan 80 can be obviously improved. The molecular formula and XPS results of the Si-Si series show that the active performance is better due to the difference of the length and structure of the non-polar end chain, and the hydrophobicity and the floatability of the lignite are improved significantly by the more effective adsorption with the lignite. However, after the action of the pan 80, the high ash mineral on the surface of the lignite is covered with a small amount, the content of the mineral elements is reduced, the modification effect is good, the selectivity is weak, and the ash of the fine coal is high. (3) The effect of flotation conditions on the flotation of lignite. due to the peeling of the mineral in the groove under the action of vigorous stirring of the impeller, the pre-wetting time can be prolonged to improve the flotation effect when the total regulating time is fixed, the pre-wetting time is more than 5 minutes, and the addition of a flotation agent in the stirring process will relatively block the occurrence of this phenomenon. The effect of the stirring intensity on the flotation is as follows: when the stirring intensity is less than 1196 r/ min, the effect of the flotation and stirring is mainly affected, and the recovery rate of the combustible body of the fine coal is increased rapidly due to the increase of the bubble diameter with the increase of the stirring intensity. When the stirring intensity is greater than 1196 r/ min, it is affected by the flotation stirring and the mixing and stirring, and due to the movement of the entrainment of the mist and the filling of the fine mud and the stripping equilibrium point, the ash content of the fine coal is increased and the recovery of the combustible substance is reduced. (4) The effect of adding surface modifier on the flotation of brown coal and the mechanism of its action were studied. Due to the covering of the surface minerals, the recovery of the fine coal in the flotation of the lignite is low, the ash of the fine coal is high, and the grinding pretreatment can improve the floatability of the coarse particles and the selectivity of the fine particles. the ore grinding can make the fine-grain-grade mineral substance which is absorbed in the coarse particles to be separated out, so as to achieve the dissociation action of the coal and the minerals, and the coal and the mineral are fully dissociated, so that the ash content of the fine coal flotation is lower, and the surface of the lignite is no longer influenced by the minerals, and the medicament can be contacted with the medicament and adsorbed; the increase of the fine particle selectivity is due to the fact that the grinding process promotes the effective adsorption of the brown coal and the medicament. To sum up, on the basis of the study of the hard-to-float property of lignite, a strategy for improving the flotation effect of the brown coal by adding a surface modifier into the grinding is put forward, and the surface minerals are dissociated by the method of grinding to improve the separation effect, and the floatability can be improved by adding a surface modifier. and provides an effective treatment method for the flotation and ash reduction of the lignite and the improvement of the hydrophobicity.
【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
本文编号：2350530
[Abstract]:The lignite resource in China is rich, most of the lignite is used as fuel coal at the present stage for power generation, but due to high ash and no effective separation, various environmental problems are brought. The effective separation of brown coal is more and more important, and fine-grained lignite is difficult to recover efficiently by conventional flotation method because of its poor floatability. The paper, taking the lignite of tin as an example, probes into the hard-floating property of the lignite, and puts forward the effective strategy for improving the flotation effect of the lignite after the surface modifying agent and the combined action of the surface modifier and the grinding, and the mechanism of the action in the improvement is studied by means of modern instrument analysis. The main results of the study are as follows: (1) The properties of lignite are characterized by FTIR, XPS, SEM and contact angle. The results show that: (1) The properties of lignite are characterized by FTIR, XPS, SEM and contact angle. The results show that: (1) The properties of lignite are characterized by FTIR, XPS, SEM and contact angle. The reason for the strong hydrophilicity of the surface of the lignite is that the surface of the brown coal has a large number of oxygen-containing functional groups, the surface contains a large amount of cracks and gullies, and a large amount of minerals are covered on the surface of the lignite and are filled in the groove of the lignite. Therefore, it is difficult to realize high-efficiency recovery by the conventional flotation method because of the difference of the floatability of the lignite. In addition to reducing the content of the oxygen-containing functional groups on the surface of the lignite, the surface mineral content of the lignite should be reduced, in addition to reducing the content of the oxygen-containing functional groups on the surface of the lignite. (2) The ability of different modifiers to increase the floatability of lignite and its mechanism of action on lignite. The flotation experiment of the three kinds of chemical modified lignite is carried out, and the floatability of the lignite after the action of the pan 80 can be obviously improved. The molecular formula and XPS results of the Si-Si series show that the active performance is better due to the difference of the length and structure of the non-polar end chain, and the hydrophobicity and the floatability of the lignite are improved significantly by the more effective adsorption with the lignite. However, after the action of the pan 80, the high ash mineral on the surface of the lignite is covered with a small amount, the content of the mineral elements is reduced, the modification effect is good, the selectivity is weak, and the ash of the fine coal is high. (3) The effect of flotation conditions on the flotation of lignite. due to the peeling of the mineral in the groove under the action of vigorous stirring of the impeller, the pre-wetting time can be prolonged to improve the flotation effect when the total regulating time is fixed, the pre-wetting time is more than 5 minutes, and the addition of a flotation agent in the stirring process will relatively block the occurrence of this phenomenon. The effect of the stirring intensity on the flotation is as follows: when the stirring intensity is less than 1196 r/ min, the effect of the flotation and stirring is mainly affected, and the recovery rate of the combustible body of the fine coal is increased rapidly due to the increase of the bubble diameter with the increase of the stirring intensity. When the stirring intensity is greater than 1196 r/ min, it is affected by the flotation stirring and the mixing and stirring, and due to the movement of the entrainment of the mist and the filling of the fine mud and the stripping equilibrium point, the ash content of the fine coal is increased and the recovery of the combustible substance is reduced. (4) The effect of adding surface modifier on the flotation of brown coal and the mechanism of its action were studied. Due to the covering of the surface minerals, the recovery of the fine coal in the flotation of the lignite is low, the ash of the fine coal is high, and the grinding pretreatment can improve the floatability of the coarse particles and the selectivity of the fine particles. the ore grinding can make the fine-grain-grade mineral substance which is absorbed in the coarse particles to be separated out, so as to achieve the dissociation action of the coal and the minerals, and the coal and the mineral are fully dissociated, so that the ash content of the fine coal flotation is lower, and the surface of the lignite is no longer influenced by the minerals, and the medicament can be contacted with the medicament and adsorbed; the increase of the fine particle selectivity is due to the fact that the grinding process promotes the effective adsorption of the brown coal and the medicament. To sum up, on the basis of the study of the hard-to-float property of lignite, a strategy for improving the flotation effect of the brown coal by adding a surface modifier into the grinding is put forward, and the surface minerals are dissociated by the method of grinding to improve the separation effect, and the floatability can be improved by adding a surface modifier. and provides an effective treatment method for the flotation and ash reduction of the lignite and the improvement of the hydrophobicity.
【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】
相关期刊论文 前3条
1 董洪峰;云增杰;曹勇飞;;我国褐煤的综合利用途径及前景展望[J];煤炭技术;2008年09期
2 刘曙光，刘保安;非金属矿物表面改性及应用[J];山东建材学院学报;1995年01期
3 荣天厚;;加快褐煤资源资本化进程 推动资源优势向经济优势转化[J];实践(思想理论版);2010年04期
相关博士学位论文 前1条
1 虞育杰;褐煤水热脱水提质制备高浓度水煤浆的基础研究[D];浙江大学;2013年
，本文编号：2350530
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