Ultrafine coal classification using 150 mm gMax cyclone circuits

A two-stage classification circuit using 150 mm diameter gMax cyclones was installed and evaluated in a coal preparation plant in an effort to achieve a clean coal product without the use of froth flotation. Particle size separations of around 37 μm were achieved while limiting ultrafine bypass to less than 10% in the circuit underflow stream. As a result, approximately 81% of the ash-bearing material in the circuit feed was rejected to the circuit overflow stream. The feed ash content was reduced from around 50% to values in the range of 22–30% in the circuit underflow stream with a mass recovery of about 30%. Further reductions in the coarse product ash content were limited due to the particle density effect and the remaining presence of a significant quantity of high-ash slime material in the coarse product. The typical D₅₀ for the coal particles was 40 μm while the estimated value for mineral matter was 17 μm. Based on the findings of the study, the use of classification to recover a low-ash, coarse fraction in the feed of a fine coal circuit is limited by the density effect regardless of the ability to eliminate ultrafine bypass.     

High capacity fine coal cleaning using an enhanced gravity concentrator

Recent research has shown that enhanced gravity separators provide the opportunity to effectively clean 1 mm x 37 micron coal. A detailed experimental program was performed on a continuous Falcon Concentrator, which was found to achieve separations at mass throughput capacity values in excess of 75 tonnes/hour. The apparent particle separation density for 1 mm x 75 micron coal was about 1.60 with relatively high efficiency (Ep = 0.12). Typical ash and sulfur rejection values of 85% and 70%, respectively, were achieved while recovering 85% of the combustible material. Metallurgical and efficiency data from the evaluation are presented in this publication.     

动力煤干选脱硫工艺研究现状

结合具体工程应用案例,介绍了混煤脱硫、末煤脱硫、双干脱硫和主再选脱硫四种干法分选脱硫工艺流程。生产实践表明,干选技术可适用于100 mm原煤的处理,不仅具有无需用水的显著优势,并且投资少,工艺简单,操作方便,效果稳定,如工艺设计和设备选型适当,可以达到与传统水洗方法相近的脱硫效果,为合理配置和有效利用高硫煤资源以及保护环境提供了一条有效的技术途径。     

两种浮游选煤精选工艺流程分析

梗阳选煤厂采用煤泥二次浮选、精煤泥两段回收工艺流程,潘一选煤厂采用煤泥全部精选工艺流程,结合生产检查数据,对0.045 mm和0.045 mm两个粒级的分选效果进行分析。数据分析表明:前者适用于0.045 mm粒级灰分较低的浮选物料分选,后者仅适用于高灰细泥产率高的浮选物料分选。     

浮精运输系统的优化

山西太原选煤厂浮选精煤运输系统经优化改造后,解决了运输瓶颈,消除了安全隐患,改善了生产劳动环境,节约了生产成本和投资.     

矿井煤质管理与煤炭洗选加工协作探讨

为提高煤质管理水平,通过分析煤炭生产、加工过程中各影响因素,得出每个环节对煤质的主要影响因素：一是开采过程中的杂物、水分、煤矸石;二是煤炭洗选加工过程中的洗选介质、水分。结果表明：矿井煤质管理与煤炭洗选加工具有相辅相成的关系,做好两方面工作有利于矿井与选煤厂的安全生产,在层级管理乃至社会层面会产生更大的效益。     

螺旋分选机分选细粒煤的试验研究

为研究螺旋分选机对细粒煤的分选效果,采用实验室BL600螺旋分选机对粒度级为0～1 mm古交矿区8#煤进行了分选试验,通过对其分选效果、影响因素分析,探讨了螺旋分选机分选此种煤的可行性。     

井下螺旋煤仓施工工艺

介绍了螺旋煤仓的结构特点和工作原理，阐述了井下螺旋煤仓的施工工艺。     

发展洗选加工 提高经济效益

通过加强洗选加工的技术改造工作 ,提高入洗能力 ,进而提高经济效益     

选煤厂工艺改造的研究

通过改造影响产量的主要工艺环节———精煤过滤系统 ,减化了工艺流程 ,取消了精煤冬季干燥系统 ,同时对影响增产的洗选设备和运输设备进行了必要的改造 ,使设备达到最佳状况 ,降低了生产成本 ,提高了日处理能力 ,取得了巨大的社会效益和经济效益     

优化选煤工艺 适应煤质变化

为了适应原煤煤质变化的需要,五沟煤矿选煤厂在对生产状况进行分析的基础上,确定了生产系统改扩建方案,并根据实际情况逐步推进工艺系统改造工作。在采取一系列改造措施后,生产系统的适应能力提高,选煤工艺更加灵活,经济效益、社会效益、环境效益均得到提升,改造成效显著。     

洗煤厂块煤防破碎技术改造

云驾岭煤矿洗煤厂针对运输线路各个转载点块煤破碎严重的现象,采取了一系列改造措施,收到了良好的效果.     

螺旋滚筒输煤特性的分析

建立了叶片作用于煤粒的力学和速度方程,分析了滚筒结构与运动参数对轴向输煤力和输煤速度的影响,并根据螺旋滚筒的装煤要求,导出了滚筒的临界转速和极限转速的表达式,指出了滚筒转速的控制范围和选择原则。     

应用旋流技术,降低块煤损失

为了降低煤仓的块率损失,对煤仓进行技术改造。为煤仓设计、安装了一套钢结构壁挂式外螺旋溜槽。将运输的原煤导入螺旋溜槽,煤体沿螺旋溜槽匀速旋转下落,控制了运行速度,减少了煤体互相撞击,从而减少了块率损失。     

螺旋溜槽在煤仓中的应用

介绍了螺旋溜槽的布置形式、煤炭防破碎原理及经济效益。     

浮游选煤精选作业工艺效果评定方法的探讨

对浮游选煤精选作业工艺效果评定方法进行学术性探讨,初步提出将精选完善指标作为主要评价指标,浮选精煤可燃体回收率和浮选精煤非可燃体脱除率作为辅助评价指标。依据数理统计分析,在一定条件下,精选完善指标和浮选精煤相对降灰率存在良好的正相关关系。     

主井井底清理撒煤系统选型设计的探讨

对多种清理撒煤方式分析比较,针对传统设计中存在的问题（系统复杂、硐室施工难度大、工程量大）进行剖析,并对选型设计作有益的尝试.     

大型动力煤选煤厂设计分析

结合国内五座大型动力煤选煤厂设计经验,详细阐述了大型动力煤选煤厂在工艺选择、总平面布置、工艺布置、装备配置四个方面应遵循的设计原则,为选煤工程设计人员和选煤厂建设者提供了可资借鉴的参考和经验。     

Performance optimization of Jameson flotation technology for fine coal cleaning

A performance optimization study has been conducted using a laboratory Jameson Flotation Cell, which resulted in the development of empirical models for four key response parameters, such as product ash content, product total sulfur content, combustible recovery and separation efficiency. The empirical models were utilized to identify an appropriate experimental region to achieve a target set of metallurgical performances from the treatment of a flotation feed sample. The separation performance obtained from the treatment of three additional coal samples used in this investigation indicate that a high positive bias factor of about 0.6, which translates to a wash water ratio of 2.5, is required to produce superior quality coal especially from the treatment of high ash coals. The separation performance obtained using the same orifice—downcomer combination with various size separation chambers indicate that the diameter of the separation chamber of the Jameson Cell can be potentially reduced without affecting the separation performance. In other words, more number of downcomers can be used with the same size cell, which will significantly improve the throughput capacity of the Jameson flotation technology without sacrificing the separation performance.     

刘河选煤厂降低介耗的实践

针对影响重介选煤厂介耗的主要因素,结合刘河选煤厂介质回收系统工艺流程及其生产实践,阐述了该厂降低介耗所采取的技术和管理措施,通过严把介质质量关,加强选煤厂日常生产管理,提高机械设备管理、使用以及维护水平等措施,实现了降低介耗的目的。