含碳球团还原法处理含锌电炉粉尘的试验分析

为综合利用含锌电炉粉尘,提出运用含碳球团的还原处理方法,并进行了扩大性试验,得到了还原焙烧法的合理工艺条件.试验表明:配碳的碳氧比C/O=1.2、还原温度1 150 ℃、料层厚度30 mm、加热时间65 min可取得较好的效果;还原后的球团为半金属化球团,其w(TFe)为50%左右,金属化率60%～70%,球团的残Zn含量在2%以下,是较好的高炉原料;Zn的还原挥发率达到90%左右,收集粉中ZnO含量在90%左右;PbO含量在2%以下,已达到等级氧化锌的标准,实现了含锌电炉粉尘的无害化和资源化利用.     

FeCl2处理电炉炉尘的热力学计算

电炉炉尘中富含Zn、Pb、Cd等元素，简单地将这些炉尘倾倒野外或填埋，Pb、Cd等重金属元素的浸出会污染环境，而直接将炉尘返回钢铁厂内循环使用，Zn在高炉内富集会缩短炉衬寿命，而又这些元素向钢水的转移还会降低钢材品质。为减少电炉炉尘对环境的污染和实现其综合利用，必须寻求经济高效的新方法脱除炉尘中Zn、Pb、Cd等有害元素。通过热力学计算分析了采用FeCl2去除电炉炉尘中Zn、Pb的可能性，比较了不同反应条件下的作用效果。计算结果表明，在600-900℃下，炉尘中ZnO、ZnFe2O4、CuO、PbO和CdO几乎全部转化为气相氯化物。对于CaO含量较高的炉尘，添加SiO2有利于提高炉尘中有害元素的脱除效率，Zn的脱除率约96％-98％。当反应温度超过950℃，炉尘中Zn的脱除率有降低的趋势。     

Ultrasound effects on zinc recovery from EAF dust by sulfuric acid leaching

In this work, an ultrasound-assisted leaching process was studied for the recovery of zinc from electric arc furnace (EAF) dust, in which zinc was mainly present in the form of franklinite (60%). Hydrometallurgy is emerging as a preferred process for the recovery of a variety of metals, and the use of ultrasound could offer advantages over the conventional leaching process, especially for the dissolution of franklinite. Franklinite is a refractory phase that is difficult to leach and represents the main obstacle in conventional hydrometallurgy processing. Atmospheric leaching with different sulfuric acid concentrations (0.2-2.0 M) at two temperatures (323 and 353 K) was performed. The tests were conducted using both conventional and ultrasound-assisted leaching. After the leaching tests, the solid residues were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques, whereas the leach liquor was analyzed by inductively coupled plasma spectroscopy (ICP). The use of ultrasound facilitated the dissolution of franklinite at low acid concentrations and resulted in a greater zinc recovery under all of the investigated operating conditions.     

电弧炉粉尘直接还原炉渣氧化和脱硫能力计算热力学

电孤炉炼钢粉尘中含有多种重金属，若填埋弃置会对环境造成污染．将粉尘与还原剂碳粉混合制粒后返回电弧炉，并补充硅铁还原粉尘中难还原的金属，有价金属还原后回收于钢液中，不仅能生产不锈钢或特种钢，而且能保护环境．制粒时使用木质磺酸钙作为粘结剂，而木质磺酸钙中含有硫，可能影响钢材质量，影响程度取决于冶炼过程中炉渣的条件．经改变初始熔铁、球团、硅铁和石灰加入的量比关系进行实验，采用X射线荧光分析仪检测炉渣成分进行计算热力学研究，确定了1550℃时CaO-MgO-FeO-Fe     

氨法处理高炉瓦斯灰制取等级氧化锌研究

以氨-碳酸氢铵混合液为浸出剂浸出高炉瓦斯灰中的有价金属锌,经净化、蒸氨、煅烧得到等级氧化锌,对相关工艺参数进行优化选择。结果表明,最佳浸出条件为:[氨水]/[NH4HCO3]=2、液固比为4、总氨浓度为5mol·L-1,浸出时间为3h,此条件下锌浸出率为82.55%;最佳净化条件为:锌粉用量为1.5g·L-1、净化时间为2.5h,此条件下铅的脱除率为97.70%;最佳蒸氨条件为90℃下蒸氨至终点溶液pH值为6~7,此条件下蒸氨后锌的沉淀率可达99.95%。沉淀物在500℃下煅烧1h,得到纯度为96.03%的氧化锌粉末,达到了HG/T2527—94的一级标准。     

EAF steelmaking process with increasing hot metal charging ratio and improving slagging regime

A new electric arc furnace (EAF) steelmaking process with increasing hot metal charging ratio and improving slagging regime simultaneously was developed and applied in a 50 t electric arc furnace for more than a year at No. 1 Steelmaking Plant of Shanxi Taigang Stainless Corporation Limited. The essential fact of the new EAF steelmaking process was to charge hot metal in two portions or steps: firstly, 35wt%-40wt% hot metal was pretreated by blowing oxygen in a specially designed reactor for decar burization and improving hot metal temperature and melting premelted slag; secondly, 30wt% hot metal was charged into EAF with high basicity refining slags from ladle furnace (LF)-vacuum degassing furnace (VD) refining process. The results show that the hot metal charging ratio can reach to about 65wt%-70wt% for the new EAF steelrnaking process; meanwhile, the tap-to-tap time of a 50 t EAF can shorten by 5-10 min, the electricity consumption can decrease by 35-50 kW·h/t, the lime consumption can reduce by 10.5 kg/t of molten steel, and the content of harmful heavy metals in molten steel can be easily controlled to less than the upper limits of aimed steel specification or grade compared with the traditional EAF steelmaking process. In addition, the dephosphorization ability shows a slight strengthening, however, a small degree of lessening for desulphurization ability is observed for the new EAF steelmaking process, but the weakness of desulphurization ability cannot become an obstacle to its further application since a stronger desulphurization ability can be achieved during secondary refining of LF coupled with VD after EAF steelmaking process.     

A novel hydrothermal method for zinc extraction and separation from zinc ferrite and electric arc furnace dust

A novel hydrothermal process was developed to extract zinc from pure zinc ferrite (ZnFe₂O₄) nanopowder and zinc-containing electric arc furnace (EAF) dust using hexahydrated ferric chloride (FeCl₃·6H₂O) as a decomposing agent. The effects of solid FeCl₃·6H₂O to ZnFe₂O₄ ratio by mass (R_F/Z), hydrothermal reaction temperature, and time on zinc extraction were systematically investigated. In the results, when the hydrothermal reaction is conducted at 150℃ for 2 h with R_F/Z of 15:20, the efficiency of zinc extraction from ZnFe₂O₄ reaches 97.2%, and the concentration of ferric ions (Fe3+) in the leaching solution is nearly zero, indicating a high selectivity for zinc. In addition, the zinc extraction efficiency from the EAF dust reaches 94.5% in the case of the hydrothermal reaction performed at 200℃ for 10 h with the solid FeCl₃·6H₂O to EAF dust ratio by mass (R_{F/EAF dust}) of 15:10. Zinc and iron separation is achieved by adjusting the pH value of the leaching solution according to the different precipitation pH values of metal hydroxides.     

含锌电炉粉尘配碳球团的冶金特性

以某钢铁公司含锌电炉粉尘为原料,配入适当的无烟煤制成含碳球团,焙烧球团通过还原煤保护冷却至室温后进行化学分析·研究了1150℃～1300℃的范围内,温度、时间和内配煤量对锌、铁的还原速率以及球团抗压强度的影响·研究结果表明:锌、铁的还原率均随焙烧温度、焙烧时间以及内配煤量的增加而提高;抗压强度随焙烧温度、焙烧时间的增加而增高,但随内配煤量的增加出现极值点·焙烧球团最佳的工艺参数:焙烧时间为15min,内配煤量为13 04%,焙烧温度为1250℃·此时锌的还原率为98 43%,金属化率为94 51%,抗压强度为800 6N/球·     

底吹条件对电弧炉熔池表面突起高度的影响

用３０ｔ底吹电弧炉１：７水模型探讨了底吹喷嘴孔数，孔径，气体搅拌功率及熔池深度对液面突起高度及上升速度的影响；得到了液面突起高度液体上升速度与气体搅拌功率的关系分别为：Δｈ＝０．３６１，Ｗ＾０．６６４，ｖＬ＝８４．１４４．Ｗ＾０．３３２，液面突起高度与气体搅拌功率及熔池深度的关系为：Δｈ＝０．８１５．Ｗ＾０．６６４．ｈ＾－０．６５９。     

电弧炉底吹搅拌混合特性的水模型研究

用实炉为３０ｔ电弧炉，缩尺为１：７的水模型确定了底吹气体流量，喷嘴孔径及孔数，喷嘴布置方式，液体深度对溶液均匀混合时间的影响，结果表明，底吹气体搅拌能密度增大，溶液均匀混合时间短，二者间的关系可用回归方程ｒ＝ｋε＾－ｎ表示；搅拌能密度相同时，均匀混合时间随喷吹点的增加而缩短，最佳喷吹点为中心圆及电极圆４孔，最佳喷嘴孔径为１．０～１．５ｍｍ均匀混合时间随溶液深度的降低而缩短。     

Reduction-melting behaviors of boron-bearing iron concentrate/carbon composite pellets with addition of CaO

Although the total amount of boron resources in China is high, the grades of these resources are low. The authors have already proposed a new comprehensive utilization process of boron-bearing iron concentrate based on the iron nugget process. The present work de-scribes a further optimization of the conditions used in the previous study. The effects of CaO on the reduction–melting behavior and proper-ties of the boron-rich slag are presented. CaO improved the reduction of boron-bearing iron concentrate/carbon composite pellets when its content was less than 1wt%. Melting separation of the composite pellets became difficult with the CaO content increased. The sulfur content of the iron nugget gradually decreased from 0.16wt%to 0.046wt%as the CaO content of the pellets increased from 1wt%to 5wt%. CaO negatively affected the iron yield and boron extraction efficiency of the boron-rich slag. The mineral phase evolution of the boron-rich slag during the reduction–melting separation of the composite pellets with added CaO was also deduced.     

含氧化钛高炉型渣中氧化镁对氧化钙活度的影响

在1500℃,用碳还原锡吸收法测定了含氧化钛高炉型渣中氧化钙的活度α_(cao),确定了渣中 MgO 对α_(cao)的影响,在碱度不变的条件下α_(cao)随 MgO 含量的增加而增加,α_(cao)达到极大值后随 MgO 增加而降低.α_(cao)为极大值时,%MgO=8.1～8.6.     

底吹电弧炉水模型熔池内气液综合传质系数的测定

根据溶液的ｐＨ值与ＣＯ２溶解量间的关系，测定了３０ｔ底吹电弧炉１：７水模型中溶液的气液总综合传质系数（ｋ，Ａ）与液体表面的气液综合传质系数（ｋＬＡ）ｓ由此计算了气泡区综合传质系数（ｋＬＡ）Ｂ。结果表明，底吹ＣＯ２后气泡区与表面区均因发生吸气反应而使溶液ｐＨ值降低，综合传质系数（ｋＬＡ），（ｋＬＡ）Ｂ和（ｋＬＡ）Ｓ均随气体流量增大而增大，且回归得到了（ｋＬＡ）（ｋＬＡ）ｓ与气体流量Ｑ之间的关系分别为     

锗烟尘浸出过程热力学分析

贵州、云南锗烟尘主要含锌、铅、锗、银等有价金属。对锗烟尘酸性浸出过程进行了热力学分析，讨论了锗烟尘中主要物质在浸出过程的行为。     

高砷含锡烟尘直流矿热炉挥发的工艺

采用直流矿热炉挥发工艺对高砷含锡烟尘除砷的工艺进行研究,考察系统压力、焦炭添加量、(NH4)2SO4添加量、冷凝区域温度及渣型对工艺的影响,用XRD和SEM(EDS)等方法对样品和渣的微观结构进行分析.研究结果表明:在最佳条件下,当渣的酸碱度为0.8～1.3,渣液温度为1 450～1 478 K,系统负压为-5～0 Pa,焦炭添加量为1.0％～5.0％(质量分数),(NH4)2SO4添加量为0～5.0％,冷凝区域温度为473 K以下时,最佳脱砷率可达93.3％～95.0％,产品的最佳品级可提高至99.2％,而锡含量仅为0.027％.弱酸偏碱性渣的黏度低,流动性较好,经放渣、冷却、残余砷的二次挥发后,渣含砷降低至0.79％,而有价金属锡富集至21.37％,该金属锡的回收率达90.0％以上.     

铁酸锌气体还原的热力学分析

根据热力学原理,计算并分析了含锌冶金粉尘中的重要成分ZnFe2 O4在CO- CO2气体还原过程中的热力学行为. ZnFe2 O4的气体还原遵循逐级还原规律,且ZnFe2 O4很容易被CO还原到ZnO和Fe3 O4.较高温度条件下,ZnO的气体还原易于FeO的还原.随着反应温度升高,锌完全反应和挥发所需要的CO含量不断降低,当反应温度从1100 K升高到1400 K时所需的CO体积分数由0.4降低到0.01以下.要达到还原分离金属锌的目的,不必将铁氧化物还原到金属铁,而只需将铁氧化物还原到Fe3 O4或FeO,同时满足锌的还原条件即可.在高炉炉身中上部,由于发生锌的还原反应和内部循环,给高炉生产带来危害,因此应减少和控制高炉的锌负荷.     

矿热炉塌料过程中烟尘扩散的数值模拟

以铁合金生产车间为研究对象,利用Fluent软件对车间内矿热炉生产过程中塌料事故的烟尘扩散规律进行非稳态的数值模拟.对连续相和离散相,分别采用标准k～ε模型和DPM模型,分析不同风速和风向的烟尘扩散规律.研究结果表明:当风速在2 m/s以下时,南风能更有效地排除烟尘,并且风速越大,清洁作用越明显;当塌料事故结束时,不论何种风速或风向,车间内烟尘污染面积达到最大;在300 s且无风时最大烟尘质量浓度是风速为4 m/s时的36.6倍;车间内的死角是烟尘最难排出的地方,北风风速为0.2 m/s的最大停留时间长达4 800 s.     

转炉细灰对转底炉直接还原含碳球团性能的影响

将转炉细灰用于转底炉直接还原含碳球团造球试验。结果表明,转炉细灰对提高球团抗压强度和落下强度有一定效果,但要想获得理想的球团强度,须达到一定的添加量;添加一定量的转炉细灰,可以提高含碳球团的还原速率和金属化球团的TFe、MFe含量;用转炉细灰调节渣相碱度,在还原温度为1450℃时可实现渣铁良好分离,其脱硫效果好于同碱度下的石灰石。     

具有前馈环节的电弧炉电极升降自适应控制器

针对炼钢电弧炉电极调节系统的参数时变及三相间相互影响等特点，设计出一种简单且有效的电极调节控制方案。该控制方案通过引入前馈控制环节来减小三相电极间的相互影响，并在线通过累计实际输入炉内的能量值来间接地估算电弧放大系数，从而校正控制器参数。     

钛渣电弧炉中的多物理场和还原反应模型

针对电弧炉操作参数的选取与控制,建立了一个物料、钛渣、铁水三相传输与反应过程的三维多物理场模型.基于有限体积法,求解模型方程,结果表明:焦耳热、温度场和电压压降都主要集中在熔池表面接近电极的区域,表现出多物理场的强耦合性和不均匀性;熔池沿横向的扩张随着时间的推移而明显减缓,直至稳定在炉壁附近,形成挂渣层;料层内钛精矿和焦炭的质量分数影响还原反应发生的位置,使之不断向炉膛入料口移动;电炉入料量与反应速率拥有相似的变化趋势,当炉况趋于稳定时,钛渣生成速率为2.4kg·s^-1,铁水生成速率为1.5kg·s^-1,主料口、副料口和炉心料口的质量流量之比为20∶22∶9.