不锈钢粉尘铬镍回收及含铬镍铁水氧化脱磷的实验研究

利用铁浴熔融还原的方法对300系及400系不锈钢粉尘进行还原回收利用,并对还原回收得到的含铬、镍铁水进行了脱磷处理。研究结果表明:Cr、Ni等元素均被高效回收,300系和400系粉尘中Cr的收得率分别达到98.13%和98.39%,Ni的收得率几乎为100%,说明铁浴熔融还原方法适用于不锈钢粉尘的高温回收。当后续工艺对磷含量要求不高时,Ca O基脱磷剂亦可达到脱磷工艺的要求。使用Ca O基脱磷剂已成为该含铬、镍铁水脱磷的主流,今后可进一步完善。     

低温分离、富集冶金粉尘中的Zn

系统地研究国内多家钢铁企业粉尘的基础特性,开发出一种低温分离、富集冶金粉尘中Zn等金属元素的新工艺。基于ZnO超细粉的还原挥发热力学分析和动力学实验,进行了粉尘的非熔态还原及Zn的回收、富集研究。结果表明:使用高纯度CO或H2为还原剂,在800~900℃可实现粉尘中ZnO(s)→Zn(g)的转变,气化脱Zn率可达99%;收集到的气态还原产物经水洗去除掉K、Cl等元素后,富集成含Zn量可达90%的富Zn物料。同时,较低的温度使得粉尘于非熔融状态下还原,固态还原产物中Fe的金属化率可达90%,可直接经物理分离获得固态高纯铁。     

赤泥中有价金属提取的进展

随着氧化铝工业的发展,赤泥的堆放及危害已成为日益严重的环境问题,如何有效地利用赤泥已刻不容缓。介绍了赤泥的基本性质,国内外赤泥在有价金属回收方面的研究进展,并通过火法和湿法两方面对赤泥的有价金属回收进行了阐述。火法中还原焙烧——磁选工艺和直接还原进行铁元素的提取;湿法中采用盐酸和硫酸酸洗浸出提取钪、钛、铁元素;以及近些年,通过高梯度脉动磁选机,直接磁选出赤泥中的赤铁矿,均为回收赤泥中的有价金属提供了有效途径。     

二氧化钛熔盐直接还原

目前钛由Kroll工艺生产，即TiO2氯化成TiCl4后由镁还原为海绵钛。50年来，尽管生产设备和工序不断改进，但由于生产热回收困难、生产效率低、成本高，其低成本生产方法的研究工作一直没停止过。以人造金红石作为原料，将TiO2直接转变成金属钛，且能连续生产的高能效还原工艺是当前的研发热点。     

平果铝矿溶出赤泥直接还原炼铁的研究

在试验条件下，用平果铝矿溶出赤泥直接还原焙烧后磁选，可以有效回收其中的铁。产品海绵铁含Ｆｅ８４．１７％，铁的回收纺为８６．９６％，金属回收率为９１．４９％，可以代替废钢作为炼钢的原料。该工艺可供从有色金属废渣中回收铁的参考与借鉴。     

生态炼钢—一种新型的电弧炉烟尘处理工艺

现在，由于环保的要求，全世界的钢厂都在加强开发电弧炉烟尘处理技术，目标是寻求一种新型的综合利用的废弃物处理型式和较高的经济效益，研究的课题主要集中在以材料的再循环和回收为基础的水法或火法冶金技术，首先是回收无论以金属，还是以氧化物形式存在的所有的Zn，接着回收来自电弧炉烟尘的Cr和Ni，因为冶炼不锈钢的电炉，烟尘中Cr和Ni组成较高。由意大利EngitechImpianti公司开发的Ezinex工艺，是以沉积在盐酸电解槽阴极的含有Zn的重金属有选择的革取为基础。电弧炉烟尘处理能力为1万t／a的一套Ezinex设备，已经在Pittini集团…     

从含铁粉尘中回收铁、镍、铬、锌日本钢铁厂回收金属的动态简介

一、从含铁粉尖中回收有用金属连上三个新台阶 日本钢铁厂产出的含铁粉尘、氧化铁鳞和酸洗沉渣等固体废物,每吨钢约合50-60千克,其中不仅含有铁、碳等有用成分,生产不锈钢的电炉粉尘中还含有镍、铬等高价金属成分.但由于近年来镀锌钢板的使用日益扩大,废钢中的含锌亦日益上升并在冶炼中进入含铁粉尘,以用废钢多的电炉粉尘为例,其含锌量竟高达12-22%,具体成分见表1.     

浅谈选择电弧炉炼钢还原期工艺

三相炼钢电弧炉传统工艺是三期:即熔化、氧化、还原期,且还原期曾长期被公认为保证钢水质量必不可少的工序,并是其它炼钢炉所难以达到的,老的还原期工艺特点是:合金回收率高,脱硫、脱氧效果好,成分容易控制等,但因还原时间长,带来的弊病则是:钢水气体含量增加,钢水夹渣增加,炉衬侵蚀严重,电耗增加,炉子利用率低等。随着工业技术的发展,钢液直接     

钢铁厂含锌粉尘处理技术和锌的回收

介绍了含锌粉尘处理的主要工艺,包括传统的填埋法、物理法、湿法、火法,以及微波法、真空法、氯化法、铝浴熔融法和火法-湿法联合工艺,分析了各种方法的优缺点。湿法工艺的应用较广泛,但也存在对原料要求高,与现存的钢铁厂工艺技术不匹配的问题,火法处理工艺更适合钢铁企业的粉尘处理,但其初期投资大,操作复杂,在中小型企业中无法推广。先采用火法工艺选择性还原钢铁粉尘中的铁酸锌,然后再通过浸出等工艺可有效实现锌铁的分离和回收。     

从失效催化剂中回收钌的研究进展

总结了从失效催化剂中回收钌的多种方法和工艺,重点介绍了常用的熔融氧化蒸馏法。熔融氧化蒸馏法由于工艺繁杂、步骤冗长、对设备要求高等缺点,近年来不同学者和行业专家先后提出了还原沉淀法、直接氧化法和活泼金属置换法等方法,但尚未有工业化应用的报道。简化工艺流程、提高钌的回收率是目前钌回收研究工作并实现其工业化生产的重点和难点。     

The microwave processing of electric arc furnace dust

An ideal treatment for electric arc furnace (EAF) dust is to cost-effectively process the dust on site to generate high-value products. Microwave heating has the potential to be the ideal approach. In this study, testing was conducted to evaluate the feasibility of treating EAF dust under microwave radiation to produce iron metal and zinc metal instead of zinc oxides as co-products. Microwave processing time and fixed carbon addition amounts were investigated. Different carbons with high fixed carbon contents were also tested and no significant influence was observed. Products of both metallic zinc-rich particles and metallic iron-rich residuals exhibited high purities, which satisfy recycling feedstock requirements.     

电弧炉粉尘球团直接还原的热传导模型

对电弧炉炼钢粉尘加上还原剂碳混合制粒成的球团还原过程的热传导行为进行了研究,根据实验推导了球团导热模型的结构参数,并试图建立热传导模型。     

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

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The flash reduction of electric arc furnace dusts

The flash processing of electric arc furnace (EAF) dusts is a promising method for recovering zinc and producing nontoxic slags for direct disposal. In order to reduce the zinc content of the dust particles and maintain the iron content in oxide form, a certain range of temperature and oxygen potential must be provided, as dictated by thermodynamic requirements. Experiments were conducted with EAF dusts at three levels of zinc concentration in an electrically heated flash reactor. The results showed that the CO:CO₂ ratio in the process gas was the most important parameter. The effects of zinc content in dust and O₂ in inlet gas on zinc recovery were secondary. Toxicity leach tests showed that the resulting slag, even at low zinc recovery, can be disposed safely as landfill.     

Modeling of thermal conductivity of stainless-steelmaking dust pellets

The thermal conductivity of stainless-steelmaking dust pellets, an important parameter for the direct recycling of the dust, is naturally of interest to metallurgists. The measurement of central temperature and surface temperature was taken in a furnace. The physical model and calculation model for the heating process were set up to check the thermal conductivity of the dust pellets. The physical structure parameters δ and γ of the basic unit are 0.92 and 0.45 based on the calculation. The temperature in the pellet can be expressed in a linear equation α5 Tp =α1TN α2TM α4. This is convenient to determine the central temperature of a pellet in the direct recycling process.     

Kinetics of the reactions of carbon containing zinc oxide composites under microwave irradiation

As a fundamental study for the recycling of EAF dust using microwave heating, the reduction rate of a zinc oxide composite by solid carbon under microwave irradiation was investigated. It was found that the reduction of zinc oxide by solid carbon under microwave irradiation was much faster than the conventional method, and the activation energy for the reaction under microwave irradiation was estimated to be 335 kJ/mol.     

Kinetics of isothermal reduction of stainless steelmaking dust pellets

The stainless steelmaking dust pellets were reduced in isothermal temperature condition simulating the direct recycling practice in the stainless steel production and the kinetics of the reduction process was investigated.The pellets were formed after mixing the dust with carbon as the reducing agent and dolomite as the binder and smelting flux. An electric furnace was used to heat the pellets and an electrical microbalance was used to check the mass of the pellets in the reduction process. The reduction rate was calculated according to the data of pellet mass change in consideration of the evaporation of moisture, zinc and lead at high temperature. The results of the experi-ments show that the reduction process is in two consecutive stages. The reduction kinetic models were set up for each stage and the kinetic parameters such as activation energy and frequency factor were determined. The apparent activation energy of the first stage is 21.69 kJ/mol, and this stage is controlled by chemical reaction. The apparentactivation energy of the second stage is 17.35 kJ/mol, and this stage is controlled by the diffusion of carbon monox-ide through the resultants of reaction.     

“2sDR”: Process Development of a Sustainable Way to Recycle Steel Mill Dusts in the 21st Century

Significant amounts of electric arc furnace dust originating from steel production are recycled every year by the Waelz process, despite the fact that this type of process has several disadvantages. One alternative method would be the recovery of very high-quality ZnO as well as iron and even chromium in the two-step dust recycling process, which was invented to treat special waste for the recovery of heavy metal-containing residues. The big advantage of that process is that various types of residues, especially dusts, can be treated in an oxidizing first step for cleaning, with a subsequent reducing step for the metal recovery. After the treatment, three different fractions—dust, slag, and an iron alloy, can be used without any limitations. This study focuses on the development of the process along with some thermodynamic considerations. Moreover, a final overview of mass balances of an experiment performed in a 100-kg top blowing rotary converter with further developments is provided.     

当代电炉炼钢工艺的发展

论述了电炉短流程生产蓬勃发展的原因，分析了电炉炼钢的特点，提出LFV是电炉钢厂实用的炉外精炼方法，连铸可最大限度地提高效率和效益，为发展我国电炉短流程炼钢提出了建议。     

焦炭过滤床电炉粉尘捕集特性的模拟研究

以超细二氧化硅微粒为模拟粉尘,研究了在冷态焦炭过滤床条件下的电炉粉尘捕集特性：即在固定床的实验条件下,当气流速度一定时,平衡状态下静态捕集量在过滤床纵轴方向上的分布状态变化较小;当焦炭颗粒以一定速度下移时,随粉尘供给速率的增大,整体的静态捕集量也随之增加,从上部到下部静态捕集量呈渐增趋势。本实验条件下,在综合考虑捕集量、捕集速率和捕集效率的基础上,气流速度应小于0.65 m/s。