青海省二噁英重点排放行业现状调查及污染防治对策分析

文章针对青海省日益严重的持久性有机污染物污染现状,在客观调查的基础上,分析近年来青海省废弃物焚烧、铁矿石烧结、炼钢生产和再生有色金属生产四个二噁英重点排放行业的变化情况,有针对性地提出青海省二噁英重点排放行业污染防治对策及建议,力求使青海省社会经济发展与生态环境保护相结合,实现社会经济发展与生态环境保护协调发展,更好地推进青海省经济社会的可持续发展[1]。     

中美二噁英相关标准的比较

总结分析了中美两国二噁英有关标准的特点。我国二噁英相关的标准体系有待完善,主要集中在重点行业的烟气排放标准方面。美国二噁英相关标准体系较为完善,以风险评估为重点,二噁英排放源涉及的行业划分细致,排放标准分级明显,技术导向明显。通过对比分析指出,我国应继续深化重点行业的烟气排放控制的策略,加强二噁英风险评估的基础性研究工作,以减排技术为基础,强化分级管理的思路,并针对不同排放源细化二噁英的标准。     

钢铁工业NOx控制技术创新和应用

介绍了钢铁工业NOx排放现状及NOx排放新标准;阐述了5种钢铁工业NOx减排控制技术-EOS、LEEP、EPOSINT、区域性废气循环和烧结废气余热循环技术;分析了钢铁工业NOx减排控制技术存在的主要问题,指出采用综合性烧结污染物减排技术是实现烧结NOx减排的最佳途径.     

钢铁行业烧结烟气脱硫技术的发展

烧结烟气脱硫是钢铁行业减排的重点,减排形势日趋严峻。本文比较了各种烧结烟气脱硫方法的优劣势、适用范围,分析了目前烧结烟气脱硫技术的发展动态,指出了未来烧结烟气脱硫技术的发展方向。     

规流塔技术在钢铁行业烧结烟气脱硫中的应用

烧结烟气脱硫是钢铁行业减排的重点,减排形势日趋严峻。本文介绍了一种新型的烧结烟气脱硫技术及其特点与优势,指出FS-04脱硫塔技术在烧结烟气脱硫排放控制方面具有较好的应用前景。     

生活垃圾焚烧二噁英类烟气排放控制技术研究进展

二噁英类是焚烧烟气排放的重点控制物质,从头合成和前驱物合成是生活垃圾焚烧过程中二噁英类生的主要机理,基于焚烧线中二噁英生成与存在的环境,概述了减少二噁英类的初始生成、脱除烟气中排放二噁英类或提高二噁英类检测速率三类技术的研究进展,并对部分技术的技术要点进行了分析。为焚烧厂烟气中二噁英类的排放控制技术的选择提供参考。     

福斯近零排放技术在钢铁企业的应用

概括分析了在环保超低减排高压态势下钢铁企业烧结机烟气治理的现状;介绍了福斯近零排放技术(FOSS-D)的主要理念、工艺流程和系统构成;比较了该技术与烧结超低排放治理技术路线的异同;概括了FOSS-D技术在烧结烟气治理项目达到超净指标稳定运行的情况;展望了FOSS-D技术在烧结、钢厂自备电厂锅炉、加热炉等烟气治理场合的应用前景。     

含氯有机污染土壤热脱附过程中二噁英的生成机理及抑制措施

利用热脱附技术处理有机污染土壤时可能会生成二噁英,而目前国内外普遍接受的关于二噁英的生成机理主要来自垃圾焚烧过程,并没有针对有机污染土壤热脱附过程中二噁英生成机理的分析。详细介绍了二噁英相关的理化性质、生成机理及影响因素并结合热脱附技术处理含氯有机污染土壤过程中的具体条件,分析了有机污染土壤热脱附过程中二噁英的可能的生成途径及影响因素,为热脱附过程中二噁英的合成提供了几种可行的过程控制方法。     

西安市采暖季与非采暖季环境空气中二噁英类物质浓度特征变化研究

为研究西安环境空气中二噁英类物质的浓度变化特征，选择西安市采暖季和非采暖季开展持续22周监测工作，并使用高分辨气相色谱高分辨质谱法对样品进行分析研究。结果显示：该市采暖季和非采暖季二噁英浓度均低于国内其他城市；采暖季期间化石能源燃烧是二噁英毒性当量质量浓度升高的主要原因；17种二噁英同类物浓度在时间与空间上分布特征基本相同。在采暖季期间，二噁英主要存在于细颗粒物中；在非采暖季，低氯代二噁英及呋喃主要存在于气相中，高氯代二噁英及呋喃主要存在于颗粒物中。采暖季期间，可通过采用非化石能源燃烧和佩戴PM_2.5口罩减少二噁英对人体的危害。     

简述二噁英降解方法的研究进展

二噁英是一类剧毒的持久性有机污染物和一级致癌物质。脱氯降解是降低二噁英毒性的有效途径之一。本文首先介绍了二噁英的种类、来源和危害,其次对二噁英的降解方法包括光降解、光-Fenton降解、生物降解、热降解、化学降解脱氯作了简要评述,比较了各种降解方法的优劣。     

Utilising of the oiled rolling mills scale in iron ore sintering process

Up to 5% of steel is lost with the scale at hot rolling operation. This waste contains 69-72% of iron in the form of oxides. However, its recycling is confronted with presence of up to 20% of oil and 10% of water. E.g. when the oiled scale is introduced as an additive to the iron ore sintering mixture, incomplete combustion of liberated oil at heating during sintering process creates problems for gas cleaning and may even lead to damage of the equipment. A possibility to improve combustion of the scale's oil at the sintering process by preparation of a mixture with peat was shown in the laboratory experiments. Industrial trials demonstrate possibility to increase the oil combustion degree at sintering 2.7 times as much. Consumption of the oiled scale was increased from zero to 12.8 kg (in a form of scale-peat blend) per ton of sinter, which allows for closing the loop of this waste at the integrated steelmaking factory.     

流化床生活垃圾焚烧炉污染物排放监控管理

依据生活垃圾循环流化床燃烧热电厂竣工环保验收及例行环保监测数据,提出了影响生活垃圾焚烧过程特征污染物排放的主要因素是炉温和燃烧过程的喷钙与脱氯,建议增加炉温在线监测为生活垃圾焚烧污染物排放的管理措施,在例行监测项目中增加粉煤灰钙含量监测,保证生活垃圾的完全燃烧、较高脱氯效率,降低二噁英的产生与排放。     

Resources consumption and wastes emission analysis for two manufacture processes of siliconit

Silicon carbide (SiC) heating elements (siliconits) are widely used at high-temperature fields. The raw materials, manufacture process and application fields of siliconits are all related to heavy energy consumption and pollutions, and bring high environmental loads. The resources consumption and pollution emissions in siliconit manufacture process were quantificationally estimated by input/output method. Difference between two traditional techniques to produce siliconits in China was also compared and analyzed. The results show that siliconit manufacture processes consume large quantities of resources because the furnace is open to environment and too much thermal-protection materials are used. For the thick-end technique is more complicated and the thick-end siliconits have a bigger size and mass, there are more resources and energy consumptions and pollution emissions for thick-end process than that for equal-diameter process. Some suggestions were introduced to improve the traditional techniques and a new process was designed. It is the most important that the open furnace should be replaced by close vacuum furnace. Sintering and siliconizing process can be combined into one high-temperature process. As results of process simplification and vacuum sintering, resources and energy consumption and wastes emission can be decreased remarkably.     

Potential CO2 emission reduction for BF–BOF steelmaking based on optimised use of ferrous burden materials

Currently, the blast furnace (BF) to basic oxygen furnace (BOF) is the dominant steel production route in the steel industry. The direct CO₂ emission in this process system exceeds 1 t of CO₂/t of crude steel produced. Different ferrous burden materials, for instance iron ore and scrap, can be used in various proportions in this steelmaking route. This paper analyses how energy use, conversion costs, and CO₂ emissions can be influenced by the use of different ferrous burden materials when producing crude steel. An optimisation mixed integer linear programming (MILP) model has been applied for analysis. By the use of the optimisation model, it is possible to highlight some issues of special importance, such as best practices to increase production at low conversion cost, or best practices to increase production at low CO₂ emission. It is found out that more benefits will be gained when using the system-oriented analysis to the steelmaking process. Furthermore, a comprehensive view of the trade-offs between the objectives of Cost and CO₂ can provide useful information for decision makers to generate strategies under the future emission trading.     

双回路立式垃圾热解炉试验研究

利用双回路立式热解焚烧炉对某地区的城市生活垃圾进行试验研究,结果表明,焚烧炉的二燃室温度能够达到850℃,烟气停留时间超过2s,燃烧灰的热灼减率小于3%。在废气排放口测到的数据表明：常规烟气的各种有害气体成分含量均能满足标准的要求;二噁英的含量不仅满足我国标准的要求,也远远低于欧盟的标准限值。     

钢铁行业烧结烟气脱硫技术现状和发展趋势

钢铁行业烧结过程产生的二氧化硫占钢铁企业产生二氧化硫总量的一半以上,理应作为钢铁企业二氧化硫控制的重点。我国已建设多个烧结脱硫示范工程,并取得了良好的脱硫效果。在分析烧结烟气特点前提下,阐述了目前国内采用的几种脱硫工艺的优缺点,比较了密相干塔烟气脱硫、石灰乳脱硫、石灰石-石膏法脱硫、氨法脱硫、循环流化床脱硫、活性炭脱硫、双碱法脱硫等方法的优点与缺点,为烧结烟气脱硫技术选择提供了参考。     

Long-term global availability of steel scrap

Primary steelmaking involves CO₂-intensive processes, but the expansion of secondary steel production is limited by the global availability of steel scrap. The present work examines global scrap consumption in the past (1870–2012) and future scrap availability (2013–2050) based on the historical trend. The results reveal that (i) historically, the consumption of old scrap has been insufficient compared with the amounts of discarded steel, and (ii) based on historical scrap consumption, the future availability of scrap will not be sufficient to satisfy the two assumed cases of steel demand. Primary steelmaking is expected to remain the dominant process, at least up until 2050. Under the reference-demand case of 2.19 billion tons in crude steel production by 2050, the total production of pig iron and direct reduced iron could reach 1.35 billion tons. Consumption of old scrap could reach 0.76 billion tons. Because the availability of scrap will be limited in the context of the global total, it is important to research and develop innovative low-carbon technologies for primary steelmaking and to explore their economic viability if we are to aim for achieving large reductions in CO₂ emissions from the iron and steel industry.     

Strength and workability of masonry mortars manufactured with ladle furnace slag

Ladle furnace basic slag (LFS) is a by-product of the steelmaking process. It has rarely been recovered in the past and is usually disposed of in landfill sites. Despite containing stable chemical substances of great quality, some of which are potentially hydraulic, its practical applications have been limited. This paper discusses the attractive option of using LFS in the manufacture of masonry mortars for use in the construction industry, which requires an analysis of the principal characteristics of such mortars, i.e. workability and mechanical strength. It reports on a comparative study, using standard commercial admixtures, between conventional masonry mortars and mortars manufactured with LFS as a partial replacement for sand and cement, the results of which imply considerable economic savings in sand and cement, improvements in the properties of the mortars and in overall sustainability, by avoiding disposal and conserving natural resources.     

环保,高效,节能的天车通过式集烟罩

文章介绍了天车通过式电炉烟气捕集罩的原理及设计要点,与传统的屋顶罩相比,它投资低,能耗低,烟气捕集率高,是符合我国国情的较为理想的适用于大、中型超高功率电炉的烟气捕集罩,具有广泛的推广前景。     

Comprehensive Study Regarding Greenhouse Gas Emission from Iron Ore Based Production at the Integrated Steel Plant SSAB Tunnplåt AB

During the years 2001–2002, a comprehensive study regarding CO₂ emissions related to the steel production for the integrated steel making production route, was carried out. The study was financed by SSAB and carried out by a research group with members from SSAB, MEFOS and LTU. The aim was to study the emissions from the existing system and how these could be influenced by process changes and by process modifications. The calculations were made using a global spreadsheet model for calculating the CO₂ emissions, developed from an existing Energy and Process Integration model of the same system. The calculated cases included the existing BF/BOF route as well as integration of other processes, e.g., an electric arc furnace, DR processes, COREX and a new future smelting reduction process concept (Sidcomet). All new existing alternative ore based process technologies would increase the specific CO₂ emission from the system. A technology transfer to scrap based metallurgy would significantly decrease the emission level, but is not feasible for SSAB, due to the future product mix and the structure of scrap availability. In a 5–20 year perspective, the existing steel making process route with the use of magnetite ore for pellet production has the lowest specific CO₂ emission. In a long-term perspective, 20–50 years, alternative process routes, e.g., based on H₂ and DRI, could be of interest. Studies on such changes are, however, big projects and should be carried out as joint European and/or international efforts.