一起水煤气中毒事故原因分析

1 事故发生背景 乙公司用甲公司生产的水煤气作补充原料生产甲醇,在正常生产时,甲公司通过管道向乙公司供应水煤气.一周前,由于生产故障,甲公司停止向乙公司供气,生产故障排除后,甲公司准备向乙公司继续供气,为防止水煤气中氧含量超标,一般先用氮气对管道气继续置换,然后用水煤气置换氮气,氮气放散管设在化产车间,放散管阀门开启及水煤气置换由化产车间负责,当水煤气合格后,并入生产系统,实现正常供气.中毒事故发生在对氮气进行置换的过程中.     

日产五吨海绵铁水煤气竖炉鉴定会在韶关钢铁厂召开

1977年9月广东省冶金局、科技局受中国科学院和冶金工业部的委托,在韶关钢铁厂召开了日产五吨海绵铁水煤气竖炉鉴定会。参加鉴定会的有广东省和全国其它一些省市的冶金局、工厂、学校、科研、设计单位等100多人。会议代表对海绵铁试验在韶关钢铁厂党委统一领导下,排除了“四人帮”的干扰,实行厂内外两个“三结合”,经过共同努力,在我国首先试验成功水煤气竖炉海绵铁工艺的成果,给予了肯定。经过一年多的试验,初步掌握了水煤气竖炉冶炼海绵铁的生产操作技术,积累和总结了技术资     

常压流化床水煤气炉的工业运行分析

常压流化床水煤气炉是一种将流化燃烧和流化气化组合在同一气化炉内，间歇制取水煤气的专利气化技术。该炉煤种适应性广，且通过加煤时间的改变，可调节煤气组分，以适应不同用途的需要，同时煤气生产过程中无焦油和酚类产生，便于达到环保要求，在生产煤气的同时副产水煤气，不需另设锅炉房，投资省，运行成本低，是目前我国冶金工业广泛采用的固定床发生炉的合适的替代炉型。     

正压水煤气立式余热锅炉流动传热特性

利用Fluent 2020R2软件,针对正压水煤气立式余热锅炉,重点研究了炉内流动传热特性。研究结果表明:炉内两直角转弯处流场均匀性变差;烟气流经膨胀节后流通截面减小,烟气流速增大,强化了换热;余热利用率随入口烟温上升呈现出先增大后减小趋势,最佳入口烟温为1 223 K;炉内横截面温度呈现Π型分布特征,会造成并列管束吸热不均。     

水煤气在纺织印染厂的应用

近年来,由于能源需要量的不断增长,我国的燃料结构也发生了相应的改变。以煤为主要燃料,节约原油的方针既经确定,煤的气化工作迅速发展起来。纺织印染正是在这种形势下,确定普及使用水煤气的。纺织印染厂原来已有少数单位使用水煤气,但规模较小,炉子结构简单,环境污染严重,劳动强度很大。为了适应纺织工业日益发展的迫切需要,水煤气的使用及发展,已经成     

常压流化床水煤气炉的开发与应用

常压流化床水煤气炉是一种将流化燃烧和流化气化组合在同一气化炉内 ,间歇制取水煤气的专利气化技术。该炉具有煤种适应性广 ,通过改变加煤时间可调节煤气组分 ,以适应不同用途的需要 ,同时煤气生产过程中无焦油和酚类产生 ,利于达到环保要求 ,在生产煤气的同时副产水蒸汽 ,不需另设锅炉房 ,投资省 ,运行成本低 ,可用作我国中小城市的民用煤气和中小化肥厂的原料气     

水膜除尘应用于水煤气生产中的实践

本文分析了江西铜业公司武山铜矿将水膜除尘系统应用于水煤气生产中所遇到烟囱变径炸裂现象的原因,介绍了对烟囱变径炸裂现象的技改实践以及取得的效果.     

铁基水煤气变换反应催化剂的还原与催化活性

将分别加入Cr(N03)3·9H2O,Ce(N03)3·6H2O,Nd(N03)3·6H2O或Y(N03)3·6H2O的Fe(N03)3·9H2O水溶液与NH3·H2O发生共沉淀反应,制备4种铁基水煤气高温变换反应催化剂.X射线衍射结果表明:4种铁基催化剂的主要化学成分为Fe2O3,此外还分别含有CeO2,(Cr,Fe)2O3或NdFeO3;在催化水煤气变换反应以后,催化剂主要化学成分由Fe2O3变化至Fe3O4oH2还原实验结果表明:在4种铁基催化剂中,Fe-Cr催化剂的还原效率最高.通过对变换出口气中H2,CO和CO2(体积分数)含量进行对比可知,Fe-Ce催化剂的水煤气高温变换活性优于其他3种催化剂.     

焦炭在H2O+CO2气氛中的溶损反应特性

 为了研究富氢高炉内焦炭的溶损反应特性,开发了连续进水的全自动焦炭反应性测定装置,分别利用CO₂和N₂载带不同比例H₂O(0%～30%)提供H₂O+CO₂(H₂O和CO₂混合气体)和H₂O+N₂(H₂O和N₂混合气体)的含水气氛进行焦炭溶损试验,通过红外气体分析仪实时记录出口气体中CO和H₂的摩尔分数,研究了焦炭在H₂O+CO₂气氛下的溶损反应过程以及碳溶反应(C+CO₂=2CO)和水煤气反应(C+H₂O=CO+H₂)的动力学过程。研究表明,随着H₂O+CO₂混合反应气氛中H₂O比例的增加,焦炭的碳素溶损率和溶损速率均逐渐增大,而且水煤气反应的溶损速率逐渐变大、碳素溶损率逐渐升高,但是碳溶反应的溶损速率则逐渐减小、碳素溶损率也逐渐降低,这说明H₂O+CO₂反应气氛中H₂O和CO₂同时与焦炭反应存在显著的竞争作用。通过分析碳素溶损率和水蒸气含量线性关系的拟合斜率发现,焦炭在H₂O+CO₂混合反应气氛中发生的碳溶反应和水煤气反应的斜率均小于单纯单一气氛下的碳溶反应和水煤气反应的斜率,并提出基于斜率差值的抑制因子α表征H₂O和CO₂对碳溶反应和水煤气反应互相影响程度,CO₂对水煤气反应的抑制因子α_<sub>CO₂/H₂O为0.253,H₂O对碳溶反应的抑制因子α_<sub>H₂O/CO₂为0.179,α_<sub>CO₂/H₂O为α_<sub>H₂O/CO₂的1.41倍,CO₂对水煤气反应的抑制程度强于H₂O对碳溶反应的抑制程度。     

评析除尘过热器的双效性与推广价值

在小化肥行业中,造气炉出来的水煤气的温度一般在450℃左右,通常采用废热锅炉来降低其温度,达到工艺上降温要求和利用余热的目的。但由于水煤气含尘量较高、尘粒度较大(一般含量在40克/米~3左右,尘粒度的当量直径为0.8毫米),对尾部设置的废热锅炉管内结灰和管端磨损是一个很大的不利因素。据了解,化肥厂每台造气炉所配置的废热锅炉除了经常要清除结灰外,2年就要更换一次,这样势必会影响造气系统的停运,     

煤制气-竖炉生产直接还原铁浅析

以国内磁选铁精矿为原料制备的氧化球团综合性能良好,可作为竖炉直接还原用氧化球团。国内适合于煤气化的褐煤和低变质烟煤资源储量较大,占煤炭资源总量的50%以上,可以满足煤化工发展的需求。综合煤种需求、生产能力、煤气品质以及能耗指标,选取适宜的煤气化工艺,形成以煤制合成气为还原剂,以竖炉为反应器的煤制气-竖炉直接还原炼铁新工艺,是煤资源丰富而天然气匮乏的中国发展直接还原铁生产、实现低碳高效炼铁的有效途径。     

Thermodynamics and kinetics of coal gasification in a liquid iron bath

The thermodynamics and kinetics of the Molten-Iron-Pure-Gas (MIP) process used for coal gasification have been analyzed. In the MIP process, oxygen, fine-grained coal, and fluxes are injected into a liquid iron bath to produce a high temperature gas consisting of CO and H₂ plus a liquid basic slag. The sulfur is transferred from the coal to this slag. Computer calculations bearing in mind test conditions were used to determine equilibrium conditions as well as mass and energy balances; these indicated that the MIP process is technically feasible. The kinetics of the gasification process have been investigated by analyzing and assessing the basic reactions for a bottom-blowing MIP reactor. A comparison of all relevant reactions reveals that the dissolution of carbon in iron is the rate-determining step of the process. The bath turbulence induced by the injected gas and by the product gas results in intense mixing and dispersion of the reactants and their intermediate products. These phenomena create extremely large mass-transfer surfaces and extend the retention time of the reactants in the liquid iron bath. This results in high conversion rates relative to the volume of the MIP reactor.     

Zinc smelting with coal as the principal heat source and reducing agent

Recent progress in fluidized bed coal combustion and gasification suggests possibilities for the substitution of coal for coke in metallurgical smelting processes. One such possibility was ex-plored in a laboratory study of zinc smelting with coal. A two-stage reactor was constructed, which gasified coal in the lower stage to produce a reducing gas mixture. In the upper stage, the reducing gas was passed through a fixed bed containing a mixture of ZnO and either coal or coke. The extent of reduction of the ZnO was measured as a function of reaction time, temperature, and gas composition. Temperature was found to be the most important variable. At temperatures of 1000 °C or higher in the fixed bed, more than 97 pct of the ZnO was reduced in a few hours. No difference was found between the uses of coal and coke in the fixed bed. An important remaining step in proving process feasibility is condensation of metallic Zn from the product gas.     

Optimization study of sodium hydroxide consumption in the coal demineralization process

Demineralization study on flotation tailings coal with an objective to minimize the consumption of sodium hydroxide was explored. In the present work, the effect of process parameters such as pulp density (PD) of coal slurry, alkali (NaOH) concentration and reaction temperature on the ash content of product coal and NaOH consumption was investigated. Optimum process conditions were selected based on the minimum loss of NaOH and maximum PD (so that reactor volume required per ton of raw coal treatment can be minimized) along with the desired level of ash reduction. Experimental results shows that the consumption of sodium (Na) per unit ash removal increases with increase in alkali concentration for a given PD and at the same time decreases with increase in PD for a given alkali concentration. Furthermore, it was observed that the amount of Na consumption per unit ash removal is directly proportional to the reaction temperature.     

水分对MSW热解产气特性的影响及解决途径

城市生活垃圾(MSW)的固定床热解实验表明,水分引起气体热含量降低,导致MSW的热解靠自身产气的热量难以进行.提出预干燥和掺煤热解两条有效解决途径,并指出MSW掺15%的煤混合热解,可以达到与干燥MSW热解气体相近的热解产气效果.     

Reaction rates for sulfur fixation with iron at 1100 to 1275 K

The rates of sulfidizing iron in a simulated coal gasification atmosphere were studied. Mixtures of H₂S and CO were passed through fixed beds of coal char and prereduced iron ore, and effluent gas compositions were measured as a function of time. These mixtures ranged from 2.5 pct to 10 pct H₂S at various flow rates, with temperatures from 1100 K to 1275 K and iron ore sizes from 10 mesh down to 100 mesh. Experimental conditions were established to form a steady state reaction profile in the fixed bed. Analysis of the exit gas provided a measurement of the profile. The slope of the profile was used directly as a measure of the reactivity of the solids in the bed. The development of this experimental technique and its experimental design requirements are discussed. The observed sulfidization rate of thein situ reduced iron ore is characterized by a single rate constantm (minutes^-1), which varies primarily with temperature and particle size and is substantially independent of gas flow rate, bed configuration, and H₂S content of the incoming gas. Accordingly, the rate constant m can be applied in the design of a combined sulfur fixation, coal gasification reactor to estimate the solids retention time, and the minimum mass of iron required per cross sectional area of reactor. CRAIG B. SHUMAKER, formerly a Graduate Student in the School of Materials Engineering, Purdue University     

缩聚-萃取法净化处理精苯废酸的试验研究

精苯废酸组成极为复杂,长期以来对精苯废酸的处理没有合适的解决方法。济钢采用缩聚-萃取法对精苯废酸进行了净化处理试验,结果表明:采用该法处理后的净化酸外观为淡黄色,硫酸浓度35%～45%,COD脱除率在85%以上,色度脱除率在95%以上,完全能满足硫酸铵生产要求;同时回收黑色粉状固体聚合物5%～25%,可用于配煤炼焦。根据中试试验情况,工业生产建议采用串联连续搅拌釜式反应器系统,反应器可采用搪瓷内衬,其他部位可采用钢衬塑料,管道可用加强塑料。     

A Kinetic study of leaching of coal pyrite with nitric acid

The leaching of coal pyrite with nitric acid has been investigated. The temperature ranged from 313 to 363 K, and the concentration of nitric acid was varied from 0.154 to 1.54 mol/l. A coal sample of 50 grams was leached in a reactor containing 500 ml of solution in an open system. It was observed that the leaching reaction could remove 47 pct of the pyrite sulfur in seven minutes and 88 pct in 30 minutes at 343 K with 1.54 mol/l of nitric acid. The reaction order with respect to hydrogen and nitrate ion activity was found to be first order. The activation energy for the initial stage of the reaction was determined to be 14.7 K cal/mol (61.5 kJ/mol). A mathematical model was developed on the basis of mixed kinetics (reaction zone model) to explain the leaching rates. Good agreement between experimental rate data and predicted rate curves by the developed model was obtained. Ultimate analysis was used to determine the extent of nitration of the leached coal. This nitration was found to be insensitive to the reaction temperature and acidity of the solution.     

铁精矿粉熔态还原炼铁与过程集成

以概念设计的方式,提出了一种新的使用铁精矿粉进行熔态还原炼铁的流程。设计了多级流化移动床预还原反应器和闪速熔态还原炉。放弃了炉内二次燃烧的概念,代之以能量最大回收的原则。通过与汽油合成装置或其他化工装置的集成,构造了一套冶金、化工集成生产系统,从原则上克服了熔态还原炼铁和由煤合成汽油存在的多种问题     

Reduction and foaming of FeO containing slag

Abstract

Smelting reduction processes being developed for producing liquid iron using coal and oxygen are attractive because they allow the use of ore fines directly and do not depend on coke. This paper presents a brief review of some aspects of smelting reduction and some results of an experimental investigation carried out on the reduction of 5–20 wt-% FeO in a synthetically prepared slag by various reductants in a plasma reactor. Some results of a simulation of the smelting reduction process by carrying out post-combustion with oxygen lancing over the slag surface are also presented. It has been possible to achieve a steady state condition, namely, 1–2 wt-% FeO in the slag with a slag height of 4–5 cm during periodic addition of a charge consisting of iron ore, coal, and flux. A kinetic analysis of FeO reduction with various reductants is presented in detail.