转炉煤气干法除尘技术在国内钢厂的应用

转炉干法除尘技术已在我国钢厂推广应用,该技术主要由蒸发冷却器、静电除尘器和煤气冷却器等组成。生产实践表明,该系统运行稳定,净化后的烟气含尘量小于10mg/m3,且运行费用低。     

浆滴参数对酸性烟气净化的影响分析

建立了SO2、HCl酸性烟气喷雾干燥净化的气相、颗粒相及传热传质数学模型,模拟了浆滴运行参数对酸性烟气净化的影响,研究了浆滴在塔内的位移随入口烟气速度的关系;实验分析了雾化加湿和浆滴浓度对烟气净化效率的影响.实验结果表明:喷雾干燥过程中加入雾化加湿水后,SO2、HCl的脱除效率都增加,SO2脱除效率增加明显;增加浆液浓度,SO2脱除率和HCl脱除率均略有下降,且SO2脱除率减小程度大于HCl.模拟结果表明:当入口烟气速度为5 m/s时,浆滴的位移范围较大;随着浆滴粒径的增加,浆滴的温度随着时间逐渐升高,30,60和9 0 μm粒径的浆滴温度分别在3,3,4 s时达到稳定;随着浆滴粒径的增加,脱除效率不断增加,30,60和90 μm粒径条件下 HCl的去除效率分别在1.5,1.7和2 s达到平衡,SO2的去除效率分别在2.5,3.5和4 s达到平衡,可以看出, HCl 与SO2相比,其达到最大脱除效率的时间更短;随着入口烟气温度升高,SO2和HCl的脱除效率都在增大,HCl脱除效率比SO2脱除效率达到稳定的时间更短.     

Hot Corrosion Mechanism of Steels Exposed to Heavy Metal Chlorides and Sulphates in SO<Subscript>2</Subscript> Environment

Copper flash smelting produces flue dust containing SO₂-rich exhaust gas, causing corrosion problems in the heat recovery boiler of the gas train. In order to understand the corrosion behaviour of boiler steels, conditions of the boiler were simulated in the laboratory. Corrosion damage occurred as chlorine reacted with steel surfaces forming chlorides which deplete the steels from their alloying metals. At the scale/dust deposit interface, where the highest sulphur partial pressures prevail, a sulphate layer covered the mixed oxide and chloride scale. Molten sulphate deposit reduced the metal loss of AISI 304 steel by preventing chromium chloride diffusion away from the steel surface. The Cr₂O₃ scales were quite stable under molten sulphates. The dust deposit melted partially due to the presence of ZnCl₂ in the deposit which initiated corrosion damage by producing a molten salt layer on the steel surfaces bringing it in contact with aggressive compounds in the copper smelter flue dust.     

浅谈玉钢转炉二次除尘及混铁炉除尘工艺

根据烟气的特性,分析烟气运行轨迹,在转炉炉前设置捕集罩,有效地捕集转炉烟气;在混铁炉兑铁口和出铁口设置捕集罩,对混铁炉兑铁水和出铁水产生的烟气进行捕集,烟气捕集率达到95%以上.经除尘净化后排放的烟气低于国家排放标准,岗位含尘浓度符合国家卫生标准.     

大功率密闭直流电弧炉冶炼钛渣烟气净化工艺研究

根据国内引进的第一台30MW密闭直流电弧炉钛渣生产线的工艺流程,对采用云南省钛铁矿冶炼钛渣过程中产生的烟气进行了气体及烟尘的流量、含量、化学成分等分析。由于产生的烟气具有温度高、含尘量大(1.75%~9.60%)、SO2含量低、CO含量高的特点,选择烟气净化设备时,除了处理能力要符合生产要求,还需要考虑粉尘粒径和烟气温度这两个因素,以实现烟气回收利用的目的。经过研究,烟气净化工艺首先对烟气进行直接水冷使烟气降温,然后选用德国进口涤气机对烟气进行精处理,除尘效率可以达到99.983%。处理净化后的烟气,热值高,气体性质稳定,净化后可安全用于无烟煤/钛渣干燥及渣包/铁包的烘烤,实现节能减排的目标;烟尘可以回收利用。     

黄磷电炉电尘浆提取镓的预处理

根据在电炉还原炼磷过程中,磷灰石中的镓在电尘浆中高度富集,成为可供利用的镓资源,提出了一种提取镓的预处理技术:用浓硫酸熟化电尘,将其中的镓先转化成水溶性化合物,再从预处理物料中浸出镓.考察了预处理过程中电尘的化学和矿物学变化以及影响镓提取率的因素,并给出了适宜的预处理条件;在最佳质量比电尘:水:硫酸=1:1:1,200℃下熟化2 h.实验结果表明,在优化条件下将预处理的电尘在80℃浸出1 h,镓的浸出率可达90%以上.     

铸造生产过程中的废弃物循环再利用

以铁合金铸件生产为例，详细分析了铁合金铸件生产过程中产生的废砂、废渣、粉尘和废气等废弃物的由来，以及其对环境的严重影响；认为铸造企业新建或技术改造时就必须同时考虑废弃物的综合利用，并指出此项工作应该从改造方案设计、采用先进设备、采用清洁生产工艺和采用铸造废弃物资源化处理新技术等六个方面进行；最后，介绍了一汽铸造有限公司对这些废弃物所进行的循环再利用经验。     

硅业工业硅电炉的收尘设计

根据二期工业硅电炉的烟气特性,设计采用表面冷却器、粗分离器、布袋收尘整套收尘工艺对烟气进行综合治理.结合实际生产运行的情况,阐述了收尘设计的主要参数及主要设备,分析了烟气治理的效果,提出了改进措施.     

CFD simulation on performance of new type umbrella plate scrubber

A new type of umbrella plate scrubber was developed to address the pollution due to the dust, dioxide sulfur and other harmful gases, which were emitted from coal-burning boilers. The performance of the new device was studied through computational fluid dynamics（CFD） simulation and experiment methods. Initial work included experimental measurement of inlet-velocity, and gas phase simulation using Reynolds stress model（RSM）. After gas phase was converged, particles were injected from the inlet of the new device. Discrete phase model（DPM） was used for particle trajectories determination. The pressure drop and the collection efficiency of the new device were predicted through simulation. The simulation results show that the pressure drop of the new devices is 230-250 Pa and the efficiency is 84%-86%, with the inlet velocity equal to 10.6 m/s and the dust concentration ranging from 2 to 22 g/m3. The CFD simulation results of the new device show good agreement with experimental data. The relative error of the pressure drop and the efficiency is approximately 4% and 10% respectively. The results obtained both from the numerical simulation and from the experiment demonstrate that CFD simulation is an effective method for this type of study.     

不锈钢电弧炉粉尘直接还原回收工艺研究

电弧炉粉尘巳被列为有害废物，直接还原回收粉尘中有价金属不仅可保护环境，而且可充分利用宝贵的金属资源。采用中频感应电炉模拟电弧炉冶炼工艺进行了A、B、C和D系列实验研究。通过气体成分的检测、钢锭和炉渣的成分分析，了解工艺参数对还原过程的影响，认为电弧炉粉尘直接还原回收工艺切实可行，不影响钢产品质量，为该新工艺的生产实践提供了依据。     

Removal of Boron in Silicon by H2-H2O Gas Mixtures

The removal of boron in pure silicon by gas mixtures has been examined in the laboratory. Water-vapor-saturated hydrogen was used to remove boron doped in electronic-grade silicon in a vacuum frequency furnace. Boron concentrations in silicon were reduced from 52?ppm initially to 0.7?ppm and 3.4?ppm at 1450°C and 1500°C, respectively, after blowing a H₂-3.2%H₂O gas mixture for 180?min. The experimental results indicate that the boron removal as a function of gas-blowing time follows the law of exponential decay. After 99% of the boron is removed, approximately 90% of the silicon can be recovered. In order to better understand the gaseous refining mechanism, the quantum chemical coupled cluster with single and double excitations and a perturbative treatment of triple excitations method was used to accurately predict the enthalpy and entropy of formation of the HBO molecule. A simple refining model was then used to describe the boron refining process. This model can be used to optimize the refining efficiency.     

酸再生机组超低排放关键技术分析及改进

盐酸再生系统是酸连轧工序的辅助系统,也是带钢生产过程中重要的环保系统。随着我国日益严格的污染物排放标准,现有的盐酸再生控制技术已经不能满足污染物超低排放要求。分析了奥地利Ruthner盐酸再生设备污染物排放不达标的原因是烟气排放温度高及氧化铁颗粒细小,通过优化一级文丘里预浓缩器、增加二级文丘里、设计冷却循环系统等方式,将烟气温度降低到50 ℃,烟气中HCl和Fe₂O₃的排放量均满足污染物排放浓度低于10 mg/m³的“双十”标准。     

Hot briquetting of flue dust

The operation of a 5-tph, fluid bed reactor pilot plant for briquetting blast-furnace flue dust is reported. The design considerations are discussed, and the elements of the machine—fluid bed reactor, cyclone heat exchangers, and briquetting press—are described in detail. The economics of this process—which can use flue dust, millscale, oxygen-furnace slag, and ore fines as feed—are compared to those of a sintering plant.     

50m~2立式电收尘器供电改造问题的探讨

本文对郑州铝厂水泥分厂50m~2立电收尘器供电系统的改造加以介绍,如提高变压器输出阻抗、加装保护电阻、增加火花放电频率、增加清灰作用、提高电场有效电晕功率等。结果,使除尘器除尘效率提高到99.5％,使出口排放浓度大幅度降至150～300mg/Nm~3。     

敞开式环型焙烧炉的综合测试分析

对敞开式环型焙烧炉进行了综合性的测试分析 ,测定了火道中的烟气成分 ,以及火道和阳极的升温曲线 ,估算了焙烧炉的热平衡。指出促使焙烧时热耗增大的主要原因是预热段空气的严重渗漏以及排烟温度的过高。测试分析的结果还显示 ,沥青挥发分若不能及时从阳极逸出到火道中燃烧将严重影响阳极的焙烧质量。     

Recovery of gallium from phosphorus industry flue

The flue dust generated during electric furnace production of elemental phosphorus was investigated for the recovery of gallium. Then the flue dust was slurried with water and blended with concentrated sulfuric acid, followed by ageing. The gallium in the dust was thereby converted to soluble sulfate. The factors affecting the dust curing were investigated to understand the process chemistry of the pretreatment. The optimal curing conditions are determined as follows: the mass ratio of dust to water and acid is 1 : 1 : 1, ageing temperature and time are 200℃ and 2h, respectively. Almost all the gallium available to acid dissolution in the dust, about 90% gallium, can be extracted by leaching the cured dust at 80℃ for 1h.     

汽车尾气三元净化催化剂的研究新进展

概述了同时治理CO、HC、NOx的三元催化净化技术的发展历史和国内外现状，分析了三元催化剂的活性组分、助剂与涂层及载体等各相关材料的性能。描述了汽车尾气三元催化净化技术在4个方面的发展动向，即贫燃条件下的三元催化剂、只含贵金属的催化剂、载体与催化层一体化催化剂、汽车尾气多元净化技术。提出了将低温等离子体技术与三元催化净化相结合的多元净化新思路。     

Removal of sulfur in coke oven gas by mixing ZnO-based additive into coal

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钼精矿及烟道灰中铼的测定

介绍了钼精矿及烟道灰中铼的酸溶-萃取光度测定法。对溶样、萃取分离、显色、测定等条件进行了系统的试验研究,确定了铼的最佳测定条件。运用此法进行钼精矿及烟道灰中铼的测定,相对标准偏差 (n=11)均小于3.5%。经与其他实验室不同分析方法 (ICP-AES标准加入法、碱熔-萃取光度法)进行数据比对,结果令人满意     

加热炉空气预热器结垢及腐蚀原因分析

空气预热器是加热炉出口烟气的换热设备,用于回收烟气热量,提高加热炉热效率。烟气中含有水蒸汽、硫、氮等腐蚀性物质,易造成换热器腐蚀及结垢。本文分析了某炼厂空气预热器结垢及腐蚀的原因,提出了相应的预防措施及解决方法。