Coal blend moisture—a boon or bane in cokemaking?

A by-product coke making plant is required to supply sufficient coke of good quality and adequate gas of high calorific value for the integrated steel plant to be a going concern. The one element that influences the handling of coal and impacts the operation and efficiency of the plant is moisture. Compared to other important properties of the coal blend, moisture can be easily manipulated. The coal moisture can be increased simply by adding water through hose pipes. Also, it can be reduced to 5–6 mass percent using Coal Moisture Control (CMC) and 2–4 mass percent using Dry-cleaned & Agglomerated Pre-compaction System (DAPS). Moisture content is one among the many variables affecting the bulk density of coal blend and those controlling the coke qualities and yield. Increase in moisture reduces coal grindability, coking pressure and internal gas pressure; helps in dust suppression during charging and hence reduces jamming of ascension pipes and hydraulic main. Batteries charging coals with high moisture content are not troubled with roof carbon deposits. It was observed that when moisture content in coal blend of SAIL-Bokaro Steel Plant increased to more than 8.50%, the calorific value of coke oven gas improved. In the working moisture range of 9–11%, the increase of the yield of coke oven gas per 1% of working moisture is 5.2 m³. Studies have shown, however, that the increase in moisture content of coal beyond 8% hampers strong coke formation. Pre-carbonization preheating process generally showed an increase in the proportion of 40–80 mm coke, compared with wet charges. For SAILBokaro coke ovens, driving out 1% moisture from coal blend requires 125 Mega-calories of heat/oven. With lesser moisture, the emission of NO _x in atmosphere will also be low. On using dry to low moisture coal blend, the swelling of coke mass increases leading to difficulty in oven pushings. Hence, an optimum level of moisture content of charge coal needs to be maintained for improving coke oven productivity, coke quality and operational smoothness. The coke oven managers all around the globe maintain this optimum level according to their requirement, the operating conditions, the quality of product and by products, the oven health & age and the ease of handling.     

焦化废水处理技术的新进展

焦化废水是煤制焦炭、煤气净化及焦化产品回收过程中产生的废水,受原煤性质、炼焦工艺、焦化产品回收等诸多因素的影响,其成分复杂多变,属于难处理的工业废水。利用传统的方法和工艺处理焦化废水不能达到令人满意的效果。近年来,不断有新的方法和技术用于处理焦化废水。作者介绍了焦化废水的预处理、生化处理、深度处理过程中所用的新技术和新方法,以及这些技术和方法的研究应用情况,并对焦化废水处理的前景进行了展望。     

Effects of binder on recovery stamp charged coke making process

The optimum stability of coal cake is essential for producing good quality of coke in stamp charged coke making process. A suitable binder named as ‘X7’ was identified to improve the stability of coal cake, oven throughput, coke quality and reduce specific energy consumption for stamp charged coke making process. Laboratory results show that addition of ‘X7’ in coal blend up to 0.10–0.50 percentage, improved the mechanical strength of coal cake by 3.0–5.0 percentage. Six hundred kg pilot plant trials show that addition of binder in the base coal blend improved coke quality in terms of CSR, M ₄₀ and AMS significantly. Coke plant trials also show that ‘X7’ addition (0.10%) in base coal blend improved coke quality in terms of CSR (1.25 point), M ₄₀ (0.9 point) and AMS (1.70 mm). Addition of ‘X7’ increased Coke End Temperature up to 24°C during plant trials. The increased in temperature saved energy approximately 11 000 Gcal and reduce CO₂ emission by at least 10 000 T/Annum.     

物化法治理焦化废水的研究

焦化废水是煤制焦炭、煤气净化及焦化产品回收过程中产生的废水。受原煤性质、炼焦工艺、焦化产品回收等诸多因素的影响,其成分复杂多变,属于难处理的工业废水。着重介绍了焦化废水处理过程中所用的物化方法以及技术的应用情况。     

焦炉余热综合利用研究进展

煤炭是我国主要化石能源,大力发展煤化工具有重要的战略意义,而煤焦化作为煤化工领域的一种重要技术得到了广泛的应用。目前的煤焦化技术耗能巨大,除高温干馏所需能量和炉体散热外,其余绝大多数能量最终转换成红焦显热、烟道气余热和荒煤气余热等待回收的热量。充分回收焦化厂所产生大量余热是当前煤焦化技术的研究重点。本文简述了以上3种形式热量的回收技术研究进展,指出干熄焦技术发展已日趋成熟,可回收大部分红焦显热;采用煤调湿技术、热管技术等可基本实现烟道气余热的高效回收;而回收荒煤气所带高温余热尚未形成成熟、可靠、规模化的技术方案。青岛科技大学开发的基于洗涤精馏的荒煤气余热回收技术,可彻底去除荒煤气中所夹带的焦粉,实现煤气、重质焦油与高沸点洗油的分离,并产生43.5kg高压蒸汽,是解决集中式热量回收的新思路,指出了荒煤气余热利用的新方向。     

高硫气肥煤替代肥煤炼焦的研究和应用

对价格较低的高硫气肥煤进行了工业分析、煤质分析、岩相分析和40 kg小焦炉试验,并将其用于配煤炼焦。结果表明,高硫气肥煤部分替代肥煤炼焦是可行的,将其应用到生产实践,焦炭质量得到了保证,同时降低了配合煤成本。     

顶装炼焦改造为捣固炼焦的生产实践

介绍了JN43-80型焦炉由顶装炼焦改为捣固炼焦的改造工程,对比了改造前后炼焦用煤质量指标、配煤煤种和比例、用煤量、焦炭质量指标、化工产品回收率等。顶装炼焦改为捣固炼焦具有减少主焦煤配入量、增加气煤的配入量、提高焦炭产量等优势,通过改造,可使焦化企业降本增效。     

昆钢应用“风选＋调湿”备煤技术的研究

介绍了昆钢对国内外风选调湿备煤技术的调研情况及实验室研究情况,研究表明,风选调湿备煤工艺可提高焦炭强度和焦炭均匀系数,改善配合煤灰分的均匀化程度,提高焦炭质量,具有环保、节能、延长焦炉炉龄的潜能,并可降低成本。     

以无烟煤为主在捣固焦炉中生产冶金焦

清洁型热回收捣固炼焦技术在扩大炼焦煤资源、提高焦炭质量及保护环境等方面具有显著的效果。文中介绍了以无烟煤为主要炼焦煤,在清洁型热回收捣固焦炉中生产一级冶金焦的过程。同时还就清洁型热回收捣固焦炉的炼焦工艺、炉体结构、焦炉铁件和机械配置等方面作了介绍。     

适合于炼厂制氢的煤气化技术选择

阐述炼厂煤/焦制氢的必要性以及煤气化技术在制氢项目中的重要性,介绍国内外主要煤气化技术,并从气化压力、原料的适应性、产品的适应性、投资和操作费用等不同方面对粉煤气化技术和水煤浆气化技术进行了分析。重点分析了不同水煤浆气化技术对炼厂制氢项目的影响,分析认为单喷嘴水煤浆气化技术具有自己独特的优势,是炼厂制氢项目较为适合的技术。     

梅山焦炭质量预测模型的研究

结合炼焦配煤生产数据,从单种煤指标的加和性分析开始,利用回归方法建立适合梅山自身特点的焦炭灰分、硫分、M_(40)、M_(10)、CRI和CSR的预测模型,并对模型进行了检验。结果表明,所建立焦炭质量预测模型能够预测焦炭质量,优化炼焦配煤配比,满足生产需要,为稳定焦炭质量和降低配煤成本创造了条件。     

捣固炼焦值得关注的几个问题

叙述了捣同炼焦配煤与焦炭质量的关系及捣固强度与配煤的关联性.指出:焦炭质量的基础是配煤质量,不会因煤准备和炼焦工艺等有根本性的改变;捣固炼焦可多用低变质程度,高挥发分气煤类的炼焦煤生产出一定质量的焦炭;捣同炼焦配煤适当增加黏结性配煤比例可提高焦炭质量,但用接近顶装焦炉的配煤进行捣固炼焦将丧失其优势并引发问题.捣固焦炉的...     

常规焦炉上的完全型煤炼焦

简单介绍了型煤炼焦技术在国内外的发展情况。分析了型煤炼焦的优点,包括提高了非主流炼焦煤种的利用量;在降低入炉煤水分的同时,缩短了炼焦周期,降低了焦粉产率。但型煤炼焦也存在诸多问题,主要包括炉型小且适应性差,炼焦过程中对环境的污染严重,产出的炼焦产品质量不稳定。为了解决上述问题,研究了常规焦炉上的完全型煤炼焦技术。介绍了该工艺的流程,重点分析了其经济意义与技术可行性。结果表明:完全型煤炼焦可以提高不粘煤的配入比例,从而直接提高焦炭产量。在降低入炉煤成本的情况下,提高了焦炭品质。     

A semi-industrial scale study of petroleum coke as an additive in cokemaking

The addition of petroleum coke to a typical industrial coal blend used in the production of metallurgical coke was studied. Cokes were produced at semi-industrial scale at the INCAR coking plant, using petroleum coke of different particle size distribution as an additive. Special attention was paid to changes caused in the textural properties (porosity, pore size distribution, fissures at the interface between metallurgical coke and petroleum coke) which have been found to be responsible for variations in the metallurgical coke quality parameters (e.g., mechanical strength and reactivity towards CO₂). Variation in porosity was found to depend on particle size and the proportion of the additive. The decrease in the microporosity (i.e., pore radius<3.7 nm) of the metallurgical cokes observed when petroleum coke is added to the coal blend, is postulated to be one of the main factors responsible for the decrease in the reactivity of these cokes. The variation of the mechanical strength indices can be explained by the changes in porosity and the quality of the interfaces between petroleum coke and metallurgical coke.     

焦化能源流高效集成关键技术研发与应用

针对焦化能耗高、能效低的产业现状,基于冶金流程工程学理论,研发了一系列焦化余热余能回收关键技术。其中,自主研发的高压高温干熄焦余热回收技术,实现吨焦产540℃、9.81MPa的高品质蒸汽550kg,降低焦炭烧损率0.2%;研发的纳米多层复合结构温度可控的上升管一体化余热回收技术,实现了上升管出口的荒煤气温度由804℃降至552℃,实现吨焦产蒸汽119kg;研发的煤调湿技术降低了配合煤水分4%,降低工序能耗250.8MJ/吨煤;研发的导热油作热载体的能源高效利用技术,实现了脱苯能耗降低30.6%和蒸氨能耗降低21.4%,脱苯效率提高0.15%,过程无废水产生;研发的多塔连续粗苯萃取精制和高效复合萃取剂技术,实现了苯纯度达99.95%,甲苯纯度达99.8%以上,二甲苯流程控制在5℃以内,噻吩纯度达99.0%,还实现了全过程不消耗蒸汽。这些关键共性技术在河钢大型焦炉上的成功实施引领了我国焦化行业向能源利用高效化、资源利用深度化的可持续方向发展。     

7米焦炉优质焦炭的研究及生产

文章介绍了安钢4000级高炉投产前,为保证7米焦炉生产焦炭满足炼铁生产使用,焦化厂展开了7米焦炉配煤结构科学制定和焦炭质量的技术攻关。通过采取矿点配煤、完善技防手段,提高配煤比准确率和干熄焦工艺改进等措施解决了焦炭生产过程中出现的焦炭灰分、硫分和强度波动较大的问题,取得了不错的效果,对同类焦炉焦炭质量控制具有很好的指导作用。     

煤岩分析在配煤炼焦中的应用

介绍了煤岩分析在进厂原料煤的分类、混煤辨别、优化配煤方案以及和用单种煤反射率分布图合成配合煤反射率分布直方图来预测焦炭质量等方面的应用,用于指导配煤炼焦生产,取得了明显的效果。     

应用炼焦新技术,加强焦炉生产管理,提高焦炭质量

介绍了近几年我国发展较快的炼焦新工艺技术,分析了各新型炼焦工艺技术对焦炭质量的影响程度。结合包钢焦化厂近年来炼焦及相关技术的进步,总结了焦炭生产过程的管理经验;从技术、设备和管理多角度出发,探索科学、规范、高效的提高焦炭质量的途径。     

焦炉烟道气余热负压蒸氨成套装置技术

分析了传统蒸汽蒸氨技术的不足,介绍了近年来导热油蒸氨、管式炉蒸氨、负压蒸氨技术的进展情况,研究开发了焦炉烟道气余热负压蒸氨成套装置技术,将热管技术、焦炉烟气-剩余氨水换热器技术成功应用于80万t/a焦炭生产系统,焦化废水处理成本降低40%,蒸氨废水量减少25%,提高了处理水水质,为焦化废水实现资源化利用和零排放创造了有利条件。     

用试验焦炉优选配煤方案

介绍了在山焦JN60－89型大容积焦炉投产前,应用JZD－40kg模拟试验焦炉,对配煤炼焦的三种备选方案进行试验的过程。结果,选出了最佳配煤方案,指导大焦炉生产出优质冶金焦炭。