选煤厂磁选系统节能降耗的研究

一般动力煤选煤厂因块煤洗选,稀介质中煤泥含量极少,磁选机的磁选效率一直未受到足够的重视;通过研究磁选机入料浓度、入料流量等因素,较为全面地阐述了影响磁选机磁选效率的因素;提出动力煤选煤厂通过加强磁选机运行管理来提高磁选机磁选效率的可行性及改进方法。     

梁北选煤厂降低介质消耗的管理

介绍了梁北选煤厂介质回收系统工艺流程;论述了降低介耗的技术措施,从控制重选系统细粒煤含量、加强弧形筛和脱介筛脱介效果、提高磁选机磁选效率、控制磁铁粉质量和循环水浓度等方面,加强生产过程中的控制和管理,有效降低了选煤厂的介质消耗。     

降低重介浅槽分选机介耗的措施研究

阐述了重介浅槽分选机的结构和工作原理,说明浅槽分选机的介耗与这两者密切相关。通过对浅槽分选机介耗降低途径的研究,从稳定分选环境,采用胶管进行双层筛脱介,优化浅槽结构,加强磁选机管理以及保证入料性质5个方面介绍了降低介耗的技术措施;从加强跑冒滴漏管理和磁铁矿管理等方面介绍了降低介耗的管理措施。介耗是重介选煤厂成本中的重要组成部分,加强对介耗技术和管理的控制,对于降低生产成本,提高企业经济效益具有重要的现实意义。     

加强磁选机管理 降低介质损耗

针对重庆天府矿业公司磨心坡选煤厂磁选机操作管理中存在的技术问题,提出了加强对磁选机的操作维护管理,调整磁选机结构与性能参数,提高工艺效果等降低重介质消耗的措施和方法,取得了较好的效果。     

介休选煤厂降低介耗的实践

分析了介休选煤厂介耗偏高的原因,通过采取翻转弧形筛、调整脱介筛喷水、改善磁选机入料、合理调整原煤入洗量、新增磁选机和浓缩机等多项有效措施,加强了对介质消耗的管理,有效降低了介耗,取得了较大的经济效益。     

选煤过程中介耗的影响因素分析研究

基于我国重介质选煤厂介耗高的现状,总结影响重介质选煤厂介耗高的原因有：磁铁矿粉质量、入料煤性质变化、脱介筛和磁选机运行情况、生产管理四方面因素。同时从分选工艺选择、加强介质脱除与回收设备管理以及加强生产管理等3个方面提出减少重介质选煤厂介耗的技术措施。     

王坡选煤厂降低介耗措施的探讨

为降低选煤厂介耗,介绍了王坡选煤厂的介质循环系统,并从介质质量、原煤粒度组成、脱介筛运行工况、喷水效果、磁选机回收效率等方面分别阐述了王坡选煤厂降低介耗的具体措施。针对王坡选煤厂改扩建后介耗偏高的问题进行分析,并在管理上加强重介质密度和煤质的监控力度来减少介质管理流失,在工艺上增加一小型的中煤脱介筛加强介质回收来降低介质技术流失。     

凯达选煤厂降低介耗的措施

针对凯达选煤厂介耗偏高的问题,从技术损失和管理损失两方面分析了选煤厂介耗偏高的原因主要有原煤脱泥脱水效果不理想、脱介筛脱介效果差、磁铁矿粉质量不达标、磁选机磁选效率低、加介方式不合理、合介系统密度不稳定、筛面清理不及时、磁选机管理不到位等。通过优化磁选机工作性能,提高脱泥筛脱泥效率,提高脱介筛脱介效果,实现介质系统自动化控制,加强日常管理等措施对选煤厂进行改造。改造后选煤厂磁选机磁选效率明显提高,均达到99%以上;产品带介明显降低,介质系统趋于稳定,产品质量得到保障;介耗由改造前的1.99 kg/t降至1.10 kg/t,每年节省介质费用426万元。     

尼龙66树脂生产过程中尼龙66盐消耗过高原因分析

从减少聚合釜头尾料排量，降低头尾料比率，提高单釜产量，控制超长粒，改造包装设备，加强仓库管理等方面论述降低尼龙66盐消耗的几项技术措施。措施实施后，效果良好。     

提高磁选机介质回收率的方法

重介选煤厂介耗是重要的技术指标,也是重要的经济评价指标。介质损失大造成介耗高,污染环境,降低产品质量,介耗的高低对生产系统的稳定起着重要作用。磁选机是介质回收净化的关键设备,磁选回收率直接影响重介生产介耗。磁选机磁选效率受多因素影响,入料浓度、入料稳定性、磁系偏角等因素都对磁选效率产生影响。济三煤矿选煤厂重介车间采用12台圆筒式磁选机,由于入料系统,脱磁装置、矿浆浓度等因素制约磁选机性能,造成磁选效率不高,磁选尾矿带介偏高。通过改造重介车间磁选机,介耗由原来的2.8 kg/t,降至1.6 kg/t,效果明显。     

镇城底矿选煤厂降低介耗的措施

镇城底矿选煤厂针对介耗高达3.5kg/t的问题,对有关工艺环节能力进行了技术改造,采取了增加脱介筛、改进脱介筛喷水管路、增加磁选机、加强介质系统的生产管理等措施,取得了介耗低达1.35kg/t的显著效果,全厂洗煤成本大大降低。     

Siebklassieren

Sizing by sifting with screens. Viewed physically, screening comprises superposition of segregation, diffusion, and passage through the screen. Frictional and cohesive forces have to be overcome and the coarse feed material transported over the screen, primarlily by circular, elliptical, or linear vibration. The specific screening performance and the sharpness of separation prove to be a measure for the quality of screening. There are three uses for screening: protective screening with mean particle size D_m ? mesh w with a simultaneous wish for high screen performance; classification with D_m ≈ w with a desire for greater sharpness of separation; and dust removal with D_m ? w and the problem of deagglomeration, i. e. separation of fines from the screened material. The maximum screen performance can be calculated for the coarse range; it is attainable with most screening machines. A problem encountered in the medium to fine size range is prevention of blinding of the screening machine and deagglomeration of sieved material, with attrition phenomena deserving attention. A range of machines is available: casting, planar, tumble, agitator screening machines are available, as are those with deforming screens, those utilizing centrifugal forces, and, as the latest addition, flow screening. New developments concentrate on fine screening, e. g. screening machines with direct activation of the screen fabric, tumble screening machines, combinations of mechanical and pneumatic screening extending through to pure flow screening. Plastic screens made of polyurethane are of advantage for wet screening; they exhibit greatly reduced wear. Safety requirements are met by silenced and explosion-proof-screening machines.     

薛湖选煤厂分选工艺技术改造实践

薛湖选煤厂原工艺系统存在粗煤泥分级、分选效果差,跑粗严重等问题;采用国内外首创的"三产品旋流分级筛+TBS分选机+德瑞克高频振动细筛"组合工艺对煤泥水系统进行了技术改造,不仅实现了粗煤泥的高效分级和有效分选,同时为后序工艺创造了良好的粒度和浓度条件,提高了精煤产率,降低了生产用药剂、介质等材料消耗和电耗。     

In situ synthesis of orange rutile ceramic pigments by non-conventional methods

Different precursor-mixtures of orange Cr,Sb-TiO₂ ceramic pigment have been obtained by non-conventional methods (heterogeneous ammonia coprecipitation, urea homogeneous coprecipitation, PECHINI polyester method and an original aqueous–organic coprecipitation method in water–diethylenglycol medium) in order to produce in situ the pigment through the ceramic body firing. The pigmenting performances of powders were appraised in two cases: (a) as ceramic pigment for glazed porcelain stoneware and (b) as ceramic inks for screen printing of porcelain stoneware. Samples were characterised by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), UV–vis-NIR spectroscopy by diffuse reflectance method, CIE-L*a*b* colour parameters, BET specific surface area and crystallite size measured by the Scherrer method. The colouring performance of raw powders obtained by non-conventional methods in glazed porcelain stoneware improves that of the ceramic samples fired at 1100 °C used as reference. TEM observations indicate nanostructured powders with pigmenting performance depending on factors such as their specific surface area (BET), the crystalline phases detected by XRD (e.g. anatase–rutile presence) and their crystallite size (Scherrer measurements). Ammonia coprecipitated samples, both in water and in water–diethylenglycol medium without surfactant addition, or modified by the addition of sodium dodecyl sulphate as surfactant, stand out by their colouring performance.     

Mass transfer behaviour of a fixed bed electrochemical reactor with a gas evolving upstream counter electrode

Mass transfer rates were determined at a horizontal screen cathode stirred by oxygen bubbles evolved at a horizontal anode placed below the screen by measuring the limiting current of the cathodic reduction of ferricyanide ion from alkaline solution. Variables studied were oxygen discharge rate, ferricyanide concentration and number of closely packed screens forming the cathode. For a single screen cathode the data were correlated by the equation: J = 0.249 (Re Fr)^-0.25 The mass transfer coefficient was found to decrease with increasing the number of screens forming the cathode. Implications of the present work for improving the performance of the flow-through packed bed electrochemical reactor were highlighted.     

三产品重介质旋流器选煤工艺介耗小于0.6kg/t的生产实践

文峰选煤厂通过强化磁选机工艺效果评定和检测,采用两段磁选机(单段串联)为精煤脱介;对原煤泥水系统增加斜管浓缩机和精煤压滤机,实现了清水选煤;优化磁铁矿粉供应基地,强化脱介喷水效果,合理调整原煤入洗量,全厂磁性物回收率达到99.8%以上,三产品重介质旋流器选煤工艺平均介耗2006年达到0.55kg/t,生产成本大幅度降低。     

不连沟选煤厂降低介耗的措施

结合不连沟选煤厂工艺流程,分析了不连沟选煤厂介耗不稳定的原因。通过加强介质质量管理、改变介质添加方式、调整磁选机磁偏角、减小磁选机滚筒与槽体间隙、提高磁选机精矿挡沿、控制分流量、增加加压泵、清理维护固定筛、调整脱泥筛筛板筛孔尺寸等措施,不连沟选煤厂降低了磁选机尾矿带介量和产品带介损失,有效减少了-3 mm碎煤进入重介系统,减轻了磁选机工作负荷,改善了悬浮液不稳定的情况,有效平稳了合介桶位,分流量得到合理有效的控制。2010年11月—2011年4月,选煤厂介耗由1.26 kg/t降至0.18 kg/t,降低了85.71%。2011年4月,选煤厂介耗降至0.18 kg/t,已低于国内吨原煤消耗的最低值,节省介质费用高达60.6万元。     

Single-layer organic-light-emitting devices fabricated by screen printing method

Single-layer organic-light-emitting devices (OLEDs) have been fabricated by screen printing method. Using the screen printing method, a polystyrene (PS) film doped with NPB, Alq₃, and rubrene was deposited to have the thickness of 100 nm. The film was used for the fabrication of single-layer OLEDs. In order to estimate the performance of the devices, single-layer OLEDs of the same structure were also fabricated by spin coating and compared with those fabricated by screen printing. The spin-coated OLEDs were turned on at 10 V and reached a maximum brightness of 1,100 Cd/m² at 21 V. The screen-printed OLEDs showed the same turn-on voltage but with a maximum brightness of 110 Cd/m² at 14 V.