高效动力煤分选工艺研究

崔广文,隋文浩

(山东科技大学 化工学院,山东 青岛 266590)

:为解决动力煤分选工艺中脱泥分级筛筛下<2 mm煤泥分级脱水后产品掺入混煤,使部分精煤进入混煤的问题,以高家梁动力煤选煤厂为例,通过分析高家梁动力煤选煤厂煤质特性,使脱泥筛筛下<2 mm煤泥进入三锥角旋流器进行再选,通过改变三锥角旋流器的结构、操作参数等,分析其分选效果及经济效益,最后提出了高效动力煤分选新工艺流程和动力煤分选展望。粗煤泥分选试验结果表明,分选后精煤灰分为8%时,产率为30.91%,尾煤产率为17.41%,灰分为48.34%,细煤泥产率为51.68%。增加三锥角旋流器后,部分粗颗粒煤泥通过分选得到精煤,每年可多出高发热量精煤15.41万t,灰分为8%,精煤价格为298元/t,其余所有产品去末煤系统,产率为1.05%,灰分为48.34%,总效益达到1 664.63万元。三锥角水介分选旋流器作为一种新型高效的粗煤泥分选设备,具有结构简单、占用空间小、入料粒度范围宽、适应性强、分选精度高和稳定可靠等优点。三锥角旋流器用于动力煤选煤厂粗煤泥分选,完善了动力煤选煤厂工艺流程,实现选煤效益最大化。

关键词:三锥角旋流器;动力煤;工艺流程;煤泥

中图分类号:TD94

文献标志码:A

文章编号:1006-6772(2019)01-0086-06

收稿日期:2018-12-17;

责任编辑:白娅娜

DOI:10.13226/j.issn.1006-6772.18121702

基金项目:国家自然科学基金资助项目(51474140)

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作者简介:崔广文(1963—),男,黑龙江宾县人,副教授,博士,从事煤炭分选工艺与设备研究工作。E-mail:13791958576@163.com

引用格式:崔广文,隋文浩.高效动力煤分选工艺研究[J].洁净煤技术,2019,25(1):86-91.

CUI Guangwen,SUI Wenhao.Study on the separation technology for high efficiency power coal[J].Clean Coal Technology,2019,25(1):86-91.

Study on the separation technology for high efficiency power coal

CUI Guangwen,SUI Wenhao

(College of Chemical Environmental Engineering,Shandong University of Science and TechnologyQingdao 266590,China)

Abstract:During the separation process of power coal,the clean coal usually re-mixed into the blended coal due to the dewatering of below 2 mm coal slurry.The process of Gaojialiang power coal preparation plant was investigated by analyzing the coal quality.Coal slime under 2 mm desliming screen was re-sorted into the triple-cone angle cyclone.By changing the structural parameters and operational parameters of the triangle angle cyclone,the optimal separation results were obtained,and the separation effect and economic benefits were analyzed.According to the test results of the separation of coarse slime,the ash fraction is 8% with the yield of 30.91%,the tailings yield of 17.41%,the ash content of 48.34%,and the fine slime yield of 51.68%.After increasing triangle angle cyclone,a part of coarse coal slime can be separated to get clean coal.154 100 tons of high calorific clean coal can be produced per year.The price of clean coal is 298 yuan per ton with ash content of 8%.The yield is 1.05% after removing other products from the final coal system,and the ash content is 48.34% with total benefit at 16.646 3 million yuan.As a new type of high efficient crude slime separation equipment,triangle angle water medium separation cyclone has the advantages of simple structure,small occupancy space,wide feed size range,strong adaptability,high separation accuracy and high stability and reliability.Triangle angle cyclone is used to separate coarse slime in power coal preparation plant,which improves the process flow of power coal preparation plant and maximizes the benefit of coal preparation.

Key words:triangle angle cyclone;power coal;technological process;coal slime

0 引 言

近年来,随着我国国民经济快速发展,对能源需求量不断加大,特别是对优质动力煤需求量增加,从而推动了我国动力煤分选快速发展。2016年我国动力煤入选量约13.6亿t,入选率超过56%,预计到2020年,我国原煤入选能力达到32亿t以上,原煤入选率达到75%,其中动力煤入选率超过70%,动力煤入选量约达到17亿t。发展动力煤选煤厂将成为未来选煤产业发展的主要方向。但要提高入选比例必须降低分选下限,由于细粒级筛分设备分级效率低,动力煤分选一般采用50(25)mm分级筛分级,块煤重介质浅槽分选、末煤重介旋流器分选、煤泥压滤回收工艺流程。选煤入选下限越低,产生煤泥数量越大,与低阶煤伴生的矸石易泥化,形成的煤泥灰分高、难脱水、热值低。国内外学者对动力煤分选工艺、分选入料粒度下限进行大量研究。建瑞革[1]通过分析宁东选煤厂梅花井分厂的选煤工艺状况,提出了动力煤选煤厂块煤浅槽+末煤重介工艺适应市场多元化要求。夏云凯等[2]通过分析现有湿法分选工艺处理动力煤存在的问题,提出了干法分选工艺以及一系列干选设备的工程应用。谭兴富[3]通过论述入料原煤不同粒度下的动力煤工艺优缺点及应用情况,提出了开发高效的浓缩分级浮选工艺和设备是动力煤选煤厂的发展趋势。郑均笛[4]分析了目前国内外动力煤选煤工艺,提出规模大型化、生产高效化、设计通用化和模块化是动力煤分选的发展趋势。曹建波[5]研究表明,生产和消费决定了我国煤炭运输“西煤东调,北煤南运”的格局,大量低热值动力煤的远距离运输造成动力资源的浪费,建议通过高效分选降低运输成本。

由于在煤炭深度筛分方面出现了驰张筛、交叉筛等设备,提高了细粒级原煤分级效果,使得原煤分级粒度控制在6 mm以下,动力煤干法脱粉工艺已得到普遍共识。为了减少煤泥量,提高企业经济效益,趋向于原煤采用3或6 mm分级筛干法分级,分级筛筛下物料直接作为末煤产品销售。分级筛筛上物料经脱泥分级筛(筛孔2 mm)脱泥后进入重介浅槽分选机分选出精煤和矸石产品销售。脱泥分级筛筛下小于2 mm煤泥直接进行分级脱水,粗颗粒掺入混煤中销售,细颗粒煤泥经浓缩压滤后成为煤泥。由于分级筛分级效率相对较低,造成分级筛筛上物料中限下率较高,2 mm脱泥分级筛负荷量增大;同时,重介浅槽分选机入选下限过低,势必影响重介浅槽分选效率及处理能力。此外,小于2 mm粒级煤泥直接掺入混煤,使部分精煤进入混煤中,未有效利用资源,影响企业经济效益。选煤工艺决定了选煤厂的产品结构、生产方式、经济效益,因