Effect of quarry dust addition on the performance of controlled low-strength material made from industrial waste incineration bottom ash

The performance of industrial waste incineration bottom ash in controlled low-strength material （CLSM） was investigated in this paper, as the quarry dust was added. CLSM mixtures were made from the industrial waste incineration bottom ash, quarry dust, and cement. Tests for fresh density, bleeding, compressive strength, shear strength, hydraulic conductivity, and excavatability were carried out. The com- pressive strength ranges from 60 kPa to 6790 kPa, the friction angle varies from 5°to 19°, and the cohesion is from 4 to 604 kPa. Most of the mixtures are found to be non-excavatable. It is indicated that the quarry dust addition increases the compressive strength and shear parame- ters, decreases bleeding, and increases the removability modulus.

Evaluating the Stability of Indigenous Akwadum Soil with Cassava Peel Ash and Quarry Dust

Cassava peels are produced as a waste from cassava, which are disposed into landfills. These become an environmental problem;therefore the use of cassava peel ash (CPA) as a soil stabilizer must be encouraged. This study investigates the effects of CPA and quarry dust (QD) on the engineering properties of Akwadum soil behavior, using compaction test, Atterberg limit, and California bearing ratio (CBR). These properties were compared with those of unstabilized soil (original) and soil stabilized with CPA and QD. The natural soil was obtained from a borrowed pit at Akwadum near Koforidua at an average depth of 0.8 m which is meant for road works. This soil sample was stabilized with CPA and QD at 5%, 10% and 20% respectively. The compaction, California bearing ratio and Atterberg limit test were performed on the stabilized soils to thoroughly evaluate them. The results indicate that increasing the percentage of CPA to the natural soil decreases the maximum dry density at increasing optimum water content. The addition of QD at higher percentage increases the maximum dry density at decreasing optimum water content. The results reveal that both QD and CPA improve the engineering properties of the soil with QD providing better results.

基于PLC技术的烧结除尘自动卸灰机器人设计

作为钢铁生产中的重要环节,烧结过程产生了大量粉尘,严重威胁了环境与工人的身体健康。因此,采用自动卸灰机器人对提高作业效率、减少环境污染、保证作业安全具有重要意义。作为自动控制的核心,可编程控制器具有灵活多变、可靠性高的特点,是实现上述目的的理想选择。详细介绍了基于PLC技术的烧结除尘自动卸灰机器人的设计与实施,包括除尘卸灰系统的工艺、控制原理、PLC系统的选型与配置、机器人的运动控制设计、传感器的集成与数据处理以及安全与应急处理机制,提供了全面的设计蓝图,旨在实现烧结过程中除尘效率的最大化。

卷烟工艺风力负压波动分析与对策

目前国内大多数卷烟厂采用模块化扁布袋除尘器实现集中工艺风力与除尘,除尘器配置的脉冲喷吹清灰系统周期性的喷射压缩空气进入除尘布袋,造成卷烟工艺风力负压规律性波动,影响烟支卷制质量。为了解决以上不足,通过优化改造,实现独立控制每列喷吹电磁阀的脉冲信号通断,使得两列同序号的电磁阀不同时工作,分时喷吹,每次喷吹时减少一半的压缩空气流量,从而降低脉冲喷吹对负压的波动幅度,保障烟支卷制质量的一致性。

基于烧结机头粉尘特性理论的电除尘器灰斗结块燃烧研究

某钢厂烧结机机头电除尘器除尘灰灰斗发生了结块燃烧现象,影响了机头电除尘器运行。针对烧结机机头电除尘器除尘灰的粉尘特性进行研究,通过检测分析粉尘的含水量、成分、含碳量及粒径分布等,明晰烧结机头电除尘器灰斗结块燃烧原因,并提出基于烧结机头粉尘特性理论的电除尘器灰斗结块燃烧解决措施。研究表明:除尘器灰斗粉尘中水碳成分、碱金属氧化物以及微细粉尘占比较高,且一电场到三电场含量都呈现递增态势,从而导致除尘器灰斗中出现结块燃烧现象。由此提出烧结配料控制湿度6%~8%之间以及电除尘器灰斗增加声波吹灰器的结块燃烧解决措施,可为治理机头电除尘器除尘灰灰斗结块燃烧提供借鉴。

酒钢复配除尘灰直接还原-磁选试验研究

除尘灰的处理一直是冶金领域的难点问题。为实现除尘灰的资源化利用,减少除尘灰中有害元素对周边生态环境的影响,对酒钢6种除尘灰复配设计,验证火法工艺处理除尘灰的可行性及有害元素脱除效率,并根据直接还原实验结果确定合适的窑渣磁选实验配料。实验结果表明,按照质量百分比复配,高炉布袋灰∶炼钢二次除尘灰∶堆存高炉布袋灰∶混合除尘灰∶高炉重力除尘灰∶炼钢OG泥=28.50∶7.50∶15.50∶6.50∶28.50∶13.50,配碳量30%,焙烧温度1100℃,焙烧时间60 min,焙烧后烧损率为36.62%,锌、钾、钠的脱除率分别为67.86%、75.56%、72.41%,铁品位为30.77%,焙烧物料经过细磨磁选后,得到的铁精粉铁品位为80.84%,铁回收率高达81.44%。多种除尘灰复配后直接还原-磁选回收金属铁的试验及机理分析,有望为除尘灰的处理开拓新途径。

高温复合滤筒除尘器输灰方案探讨

随着高温复合滤筒除尘器的引入,与之配套的输灰系统也面临着新的挑战。本文以乾县农林生物质焚烧发电项目为例,对仓泵式气力输灰系统和机械集中(冷却)+低正压连续气力输送系统两种不同的输灰方式从技术、经济角度进行比较,最终提出了高温复合滤筒除尘器下可行的输灰方式,供同行借鉴。

浅析制酸尾气堵塞对脱硫脱硝中制酸工艺的影响

介绍了高含尘量的烟气易造成设备积垢多,阻力增大,管道易堵塞。一旦管道堵塞,需要停机检修,造成生产停滞,成本增加。含有除尘灰的气体一旦进入制酸系统会对管道造成堵塞,对生产造成严重的影响,同时也给清理工作带来了巨大的不便。通过介绍邯钢360m^(2)烧结机的制酸工艺,在实践生产遇到的成品酸产量低的问题,通过假设并实际考察,发现制酸尾气管部分堵塞,气流不畅。这一问题在之前的检修中从未出现过,尝试各种方法后,通过增加旁通管道的方法解决,避免停机检查,减少成本支出。今后要加强对烟气杂质的控制,减少管道除尘灰的含量,有利于生产的稳定进行,设备的稳定运行。

大型袋式除尘器灰斗的2种设计方法

利用解析法和计算机软件MidasGen模拟分析的方法对袋式除尘器灰斗进行计算,对钢结构模型进行力学分析,为设计袋式除尘器灰斗提供依据。

PCC自寻优技术在气力输灰系统中的应用研究

虽然气力输送系统是一种清洁环保的运输系统,但压缩气体的能耗较高且输送易受物料料性和工况变化的影响,导致系统能耗较高、稳定性较差。为在保证系统运行稳定的同时节能降耗,采用料性法设计气力输送系统,根据物料的气力输送特性(PCC),利用智能控制技术对系统进行适时调整,使系统能够自动寻找最佳的运行状态点,从而使得系统既能稳定运行,又具有最优的节能效果。

电厂锅炉电除尘气力自动输灰优化改造方法研究

针对电厂锅炉电除尘气力输灰均匀性差、输灰管道极易出现堵塞现象的问题,开展电厂锅炉电除尘气力自动输灰优化改造方法研究。为实现对输灰偏差的控制,在输灰管道上设置压力传感器;利用控制算法自动调节输灰速度;通过增设缓冲罐、平衡流量计等措施,避免输灰管道的堵塞,同时保证多个管道在同一时刻的输灰量达到平衡。实例证明,应用新的改造方法后,电厂锅炉电除尘气力自动输灰均匀性显著提升,且有效减少了输灰管道堵塞现象的发生,提升了电厂锅炉的运行性能。

高炉喷吹焦炭除尘灰的研究与实践

为解决焦炭除尘灰带来的环境污染和难以高效低碳处理问题,结合其理化特性,设计了高炉喷煤配加不同比例焦炭除尘灰的性能对比实验,稳定烟煤比例45%,用焦炭除尘灰替换不同比例无烟煤的方式,研究了焦炭除尘灰对混合煤粉性能的影响。结果表明,焦炭除尘灰配加比例3%时,混合煤粉燃烧性能指数相对最佳;配加比例5%时,混合煤粉燃烧速率相对最佳;配加比例8%时,混合煤粉可磨性指数和灰熔点相对最佳。通过进一步开展工业试验,研究高炉喷煤配加不同比例焦炭除尘灰的冶炼参数与成本变化,明确高炉喷煤中配加焦炭除尘灰的效益最优配加比例为5%。通过高炉喷吹焦炭除尘灰的方式,不仅可以充分发挥焦炭除尘灰的价格优势,降低高炉燃料成本7.80元/t,而且可以有效解决焦炭除尘灰在储存、运输过程中衍生出的一系列环保问题,实现了焦化环节固废零排放,铁前工序单位产能,降低二氧化碳排放40.82 kg/年,取得了焦炭除尘灰高效低碳处理的效果。

火力发电厂除尘器灰斗防堵技术的设计选型探讨

火力发电厂作为能源产业的重要组成部分,其高效运行对环境保护和能源节约具有重要意义。灰斗作为电除尘器的关键部件,其加热防堵技术直接影响到除尘效率和能耗。本文旨在探讨和比较电加热、蒸汽加热以及免加热三种灰斗伴热技术,分析其技术经济性,为火力发电厂的节能减排提供参考。

Sustainable Construction—Use of Stone Dust as Plasticiser in High Strength SCC with Blended Cement

Extensive growth in the developing countries due to infrastructure development is resulting into massive consumption of concrete thereby increasing the demand on concrete materials. Quite large amounts of fine aggregates are required for concrete in developing countries thus shortages of quality river sand is putting pressure on availability of fine aggregates. To fulfill the high demand of fine aggregates, a search for alternative materials is in process. Stone crushing and processing industry is a large industry which generates large amounts of stone dust and slurry which is a waste produced from this process. Tons of such waste generated has no useful purpose except as landfill material. Some preliminary studies have been conducted into use of marble/ limestone waste for use in concrete [1] [2].?This study aims at using stone dust as partial replacement of sand in concrete to observe its effects on workability and other mechanical properties. This would result in useful consumption of this waste product thereby eliminating environmental issues related to its disposal. Partial replacement of 10% and 20% sand replacement with stone dust is carried out with the use of self-compacting concrete with blended cement. Blended cement used contains 50% rice husk ash and 50% Portland cement. Such high strength SCC with blended cement containing 50% rice husk ash and 50% Portland cement has already been tested to provide better quality concrete [3]. Wide ranging investigations covering most aspects of mechanical behavior and permeability were carried out for various mixes for compressive strengths of 60?MPa & 80?MPa. Compressive strengths of high strength SCC with blended cements and 10% and 20% replacement of sand with stone dust for 60?MPa and 80?MPa were observed to be higher by about 10% to 13% than the control specimen. Higher elastic moduli and reduced permeability were observed along with better sulphate and acid resistance. Better strengths and improved durability of such high strength SCC make it a more acceptable material for major construction projects thereby reducing the burden on environment and use of such waste product for a useful purpose promoting sustainable construction.

Sustainable Fly Ash Based Roof Tiles with Waste Polythene Fibre: An Experimental Study

The compressive stress-strain behavior and other characteristics of treated fly ash based roof tiles have been studied by several experimental tests. This paper attempts to presents the results and observations of a study and comparison based on the past reported experimental data. Based on the results and observations of the comprehensive experimental study, five “control points” have been identified. The new sets of experiment have been carried out to investigate whether it might be possible the use of fly ash in fly ash based roof tiles for residential construction. In the present study, treated fly ash (TFA) of C category was used with different materials as a replacement of clay for making treated fly ash stone dust roof tiles (TFASDRT). Treated fly ash stone dust roof tiles (TFASDRT) were studied at varying percentages of cement, coarse sand, and radish stone dust (RSD) along with the constant percentage of waste polythene fibre (WPF). A research program was undertaken to evaluate the suitability of such test for assessing the properties of treated fly ash stone dust roof tiles (TFASDRT). The result of this study recommends that the fly ash based roof tiles provides a sustainable supplement to the traditional clay roof tiles, they increase the efficiency of traditional roof tiles and significantly help to reduce the environmental issues associated with the disposal of these waste materials.

A Review on Stabilization of Expansive Soil Using Industrial Solid Wastes

In developing countries like India, Industrialization is rising rapidly, and also?a great paucity of land is there, the demand for exploitation of industrial?wastes?which coming from industries is increasing. From geotechnical perspective,?fly ash, granite and quarry waste, cement kiln dust, silica fume, rice husk etc.?are the waste materials?which?have effectual features requisites by an excellent soil stabilization admixture. Stabilization using solid wastes is one of the different?methods of treatment, to improve the engineering properties and make it?suitable for construction. This paper briefs about the recent trends in stabilization of expansive soil using industrial waste (granite and quarry waste, cement kiln?dust, silica fume, rice husk) as stabilizers for decreasing the environmental?hazards.

超声波处理炼铁系统粉尘团聚研究

钢铁冶炼过程尤其炼铁工序产生大量粉尘,严重影响生态环境,冶金粉尘循环利用成为行业研究热点。由于含有K、Na、Zn等有价元素,粉尘资源化利用途径愈加广泛。超声波技术应用于粉尘的处理可避免因化学试剂的添加而对水体和环境造成的污染。本文利用超声波技术处理某钢铁公司产生的烧结除尘灰和高炉除尘灰,通过声波的振动来消除粉尘间的团聚,提高粉尘粒度分布分析的准确性,明晰不同粒度区间的有价元素赋存量,实现有价元素的高效富集。结果表明,烧结除尘灰的粒度较大,粉尘处理难度小;高炉除尘灰的力度较小,粉尘处理难度大;通过超声波振动得到,烧结除尘灰中Na、K主要分布在75~150μm粒级,Zn主要分布在40~54.5μm粒级,高炉除尘灰中K、Na、Zn主要分布在2.1~13μm粒级。

邯钢公司焦化固体废弃物配煤炼焦试验研究

固体废弃物配煤炼焦试验是在40 kg试验焦炉上进行的试验研究,是在邯钢现有配煤比的情况下配入不同比例的固体废弃物,检测试验焦炉炼得焦炭性能随固体废弃物配比的变化情况,据此找出最佳的固体废弃物配入量。

除尘灰和粉煤灰等工业固废的利用现状及发展趋势

介绍了典型的大宗工业固废除尘灰和粉煤灰的形成与性质。针对除尘灰现有火法冶金处理工艺能耗大、尾渣易造成二次污染,湿法冶金成本较高;粉煤灰利用率不高且大多为低附加值产品等问题,唐山华纤科技有限公司与华北理工大学合作,基于高温重构理论,提出了除尘灰与粉煤灰协同处理制备硅酸铝陶瓷纤维的工艺。新工艺不仅回收利用了除尘灰中的铁和锌,而且炉渣也可用来制备硅酸铝陶瓷纤维,达到了无害化处理的目标,实现了除尘灰与粉煤灰的高附加值利用,具有很高的推广价值。

转炉干法除尘细灰堵塞处理技术应用研究

【目的】自安阳钢铁二炼轧作业部转炉干法除尘系统投产后,经常出现细灰堵塞现象,或有细灰外喷情况发生,导致工作环境恶劣,炼钢生产受到影响。为减少劳动强量,预防细灰堵塞,提高处理细灰堵塞的效率,避免浪费炼钢时间,有必要对此进行研究。【方法】通过提取细灰的输灰压力曲线,并根据正压气力输送公式推导,在PLC程序中设定输灰步骤参数、延长清堵时间进行调试。【结果】试验结果表明,1#仓泵憋压超过0.55 MPa、时间超过5 min以上可有效疏通细灰堵塞。【结论】通过增加缓冲斗圆锥形周侧壁氮气喷吹口,能有效减少缓冲斗仓壁沾灰和堵塞。当停炉时间较长时,为防止粉尘温度较低而结露产生堵塞,转炉开始炼钢时应尽快提高系统烟气温度,使静电除尘器的电场能保持较好的集尘效果,保证先提高粉尘温度再输灰的顺序,从根本上减少细灰堵塞的情况。通过增加现场监控、保证扇形刮灰器的电流稳定,可及时发现设备隐患,预防事故发生和扩大。