共查询到20条相似文献,搜索用时 15 毫秒
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The European stainless steel producers generate 20 -30 kg dust per ton of produced stainless steel.The dust formed during various stages of the production process contains valuable metals such as Cr,Ni and Mo.In general this dust is considered as a hazardous waste.If not taken care of the dust will be an environmental risk causing potential problems such as leaching of heavy metals into groundwater and pollution of land and air.By applying techniques for recycling the dust the problem is minimized and valuable metals are recovered and re-used as raw material in the steel making process,leading to a significant reduction of the consumption of natural resources to decelerate the climate change and ensure a sustainable development.One of the business segments of Befesa Zinc S.L.U.,a subsidiary company of Abengoa,is the recycling of dusts and other residues containing nickel,chromium and molybdenum from the stainless steel industry.The technologies applied are submerged arc reduction smelting(Befesa Valera S.A.S.,Gravelines,France) and plasma reduction smelting(Befesa ScanDust AB,Landskrona,Sweden).Stainless steel plant dusts,mill scale and other residues are delivered in closed containers and big bags by ship,rail or truck and stored.After a preparation of the residues and charging into the pyrometallurgical furnace,the metal compounds contained in the charge are reduced to metals in the presence of the carbon added.At Befesa ScanDust,the regularly tapped liquid metal is cast in the form of granules via the Granshot? granulation process.The granulated product has many advantages such as excellent preheating properties and fast melting when added to a metallurgical process.The granules size and shape also makes it very suitable to handle with most raw material handling systems.By granulating the so-called alloyed pig iron(API) a high metallic yield is achieved ensuring maximum recovery of metal and less new dust generation compared to a crushed material.The granules are redelivered to the stainless steel producers or sold on the open market. 相似文献
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中国转炉炼钢技术的进步 总被引:4,自引:0,他引:4
在分析国内转炉炼钢技术现状的基础上 ,总结了国内在铁水脱硫预处理、转炉长寿工艺与长寿复吹技术、高效冶炼工艺等方面的经验。转炉炼钢是中国目前最主要的炼钢方法 ,转炉炼钢技术的进步对我国炼钢生产技术的发展起到巨大的推动作用。近 5年来 ,铁水脱硫预处理工艺和以长寿复吹转炉高效复吹工艺为代表的转炉炼钢技术得到了迅速的发展 ,取得了明显的经济效益。今后要进一步发展完善铁水脱硫和转炉炼钢技术。 相似文献
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To efficiently recycle valuable metals such as chromium and nickel in stainless steel dust,self-reduction experiments were carried out to study the reduction mechanism of metal oxides in coal composite stainless steel dust hot briquette,which is defined as a CCSB here.Self-reduction of CCSB is proceeded by volatile matter and fixed carbon contained within CCSB.Experiments were performed to study the effects of temperature and carbon to oxygen(C/O_(Coal))ratio on self-reduction of CCSB.At 1 400 and 1 450℃,volatile matter in coal used for experiment could take the place of about 40% of fixed carbon in coal.Under the present experimental conditions,reduction product of chromium appears as FeCr_2O_4,Cr_2O_3,Cr_7C_3,and[Cr]in turn during reduction.To evaluate the formation of metal nuggets in self-reduction process of CCSB,metal nuggets containing chromium and nickel were observed in outside of reduction products under various conditions,and thermodynamic equilibrium calculation was carried out for possible products and formation of molten metal by fixed carbon.SEM and EDS analyses were made for metal nugget and slag in reduced product.The results reveal that it is reasonable to achieve the metal nuggets at 1 450 ℃,0.8 of C/OCoalratio and 20 min of reduction time.The nugget formation can indicate one innovative process for comprehensive utilization of stainless steel dust. 相似文献
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对莱钢50 t电炉特钢流程研究与应用铁水热装工艺进行了较为系统的介绍,经过实践获得了最佳的热装铁水比.对于以齿轮钢为代表的低碳钢,最佳铁水比为30%;对于以轴承钢为代表的高碳钢,最佳铁水比为40%.经过对该项技术的系统优化,使得电炉与连铸机的生产节奏匹配,提高了莱特50 t电炉流程的生产效率,缩短冶炼周期5~10 min,降低冶炼电耗80~110 kW·h/t,降低过程温降、中间包钢水过热度15~25℃,并且有效地稀释了钢中残余元素,提高连铸机连浇炉数至162炉,实现了电炉与连铸的小时产量匹配与均衡生产. 相似文献
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Hong‐Li Zhu Ji‐He Wei Guo‐Min Shi Jie‐Hui Shu Qing‐Yuan Jiang He‐Bing Chi 《国际钢铁研究》2007,78(4):305-310
Mathematical modeling of stainless steelmaking in an AOD (argon‐oxygen decarburisation) converter with side and top combined blowing has been preliminarily investigated. The actual situations of the side and top combined blowing AOD process were analysed. A mathematical model for the whole refining process of stainless steel has been proposed and developed. The model is based on the assumption that one part of the oxygen blown through a top lance reacts with CO escaping from the bath, another part of the oxygen oxidizes the elements in the molten steel droplets splashed by the oxygen jet, and the remaining oxygen penetrates and dissolves into the molten steel through the pit stroked by the jet. All the oxygen entering into the bath oxidizes C, Cr, Si, and Mn dissolved in the steel and also the Fe of the steel melt, but the FeO generated is also an oxidant of C, Cr, Si, and Mn in the steel. During the process, all possible oxidation‐reduction reactions occur simultaneously and reach their equilibria, respectively their combined equilibrium, in competition at the liquid/bubble and liquid/slag interfaces. In the simple side blowing after the top blowing operation is finished, the possible reactions take place simultaneously and reach a combined equilibrium in competition at the liquid/bubble interfaces. The overall decarburization rate in the refining process is the sum of the contributions of both the top and side blowing processes. It is also assumed that at high carbon concentrations, the oxidation rates of elements are mainly dependent upon the supplied oxygen rate, and at low carbon contents, the rate of decarburisation is primarily related to the mass transfer of carbon from the molten steel bulk to the interface. It is further assumed that the non‐reacting oxygen blown into the bath does not accumulate in the steel and will escape from the bath and react with CO in the atmosphere above the bath. The study presents calculations of the refining rate and the mass and heat balances of the system for the whole process. Additionally, the influences of the operating factors, including addition of slag materials, scrap, and alloy agents, the non‐isothermal conditions, the changes in the amounts of metal and slag during the whole refining process, and others have all been considered. 相似文献
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不锈钢AOD渣在冷却过程中由于晶格转变体积膨胀导致粉化,易造成粉尘污染。研究表明,出渣时喷入含硼改质剂能有效抑制AOD渣从β-C2S相向γ-C2S相的晶格转变,从而使粉化扬尘率降低90.1%。对无害化处理后的不锈钢AOD渣进行资源化利用探讨,结果显示,由于钢渣具有水硬胶凝活性,可作为水泥砂浆掺合料取代部分水泥,掺量范围应在0~30%之间。同时,对AOD渣及其水泥试块进行毒性浸出检测,结果表明,其中总铬、六价铬等浸出值均低于标准限值,不存在重金属浸出的问题,可进行后续资源化利用。 相似文献
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电炉直接利用Cr Ni不锈钢除尘灰的试验分析 总被引:2,自引:0,他引:2
Cr Ni不锈钢冶炼过程中每吨不锈钢产生30~40 kg的除尘灰,其中含有大量氧化铬、氧化镍、氧化铁等金属氧化物,研究回收除尘灰中金属元素的技术具有重要意义。在分析研究国内外除尘灰回收利用技术的基础上,通过热力学计算分析,提出将除尘灰压球后,直接装入电炉,利用碳硅还原除尘灰中的金属元素。对此技术在160 t电炉内进行前期试验研究,由试验结果可知,铁的回收率与试验熔清碳含量、硅铁加入量、渣碱度、温度等没有直接的关系,铬、镍的还原率受上述因素影响较大。 相似文献