Relationship between copper content of slag and matte in the SKS copper smelting process

In the newly developed oxygen-enriched bottom-blowing copper smelting process(also known as the SKS copper smelting process), Cu loss in slag is one of the most concerning issues. This paper presents our research results concerning the relationship between the Cu content of the matte and slag in the SKS process; the results are based on actual industrial production in the Dongying Fangyuan copper smelter. The results show that the matte grade strongly influences Cu losses in slag. The dissolved and entrained losses account for 10%–20% and 80%–90% of the total SKS industrial Cu losses in slag, respectively. With increasing matte grade, the dissolved and entrained Cu losses in the SKS slag both increase continuously. When the matte grade is greater than 68%, the content of Cu in the smelting slag increases much more dramatically. To obtain a high direct recovery of copper, the matte grade should be less than 75% in industrial SKS copper production.

Physical Modeling of the Vacuum Circulation Refining Process of Molten Steel

The available studies in the literature on physical modeling of the vacuum circulation (RH, i.e. Ruhrstahl Heraeus) refining process of molten steel have briefly been reviewed. The latest advances made by the author with his research group have been summarized. Water modeling was employed to investigate the flow and mixing characteristics of molten steel under the RH and RH KTB (Kawasaki top blowing) conditions and the mass transfer features between molten steel and powder particles in the RH PTB (powder top blowing) refining. The geometric similarity ratio between the model and its prototype (a multifunction RH degasser of 90 t capacity) was 1:5. The effects of the related technological and structural factors were considered. These latest studies have revealed the flow and mixing characteristics of molten steel and the mass transfer features between molten steel and powder particles in these processes, and have provided a better understanding of the refining processes of molten steel.

Mathematical Modeling of the Vacuum Circulation Refining Process of Molten Steel

The available studies in the literature on mathematical modeling of the vacuum circulation (RH) refining process of molten steel have briefly been reviewed. The latest advances obtained by the author with his research group have been summarized. On the basis of the mass and momentum balances in the system, a new mathematical model for decarburization and degassing during the RH and RH KTB refining processes of molten steel was proposed and developed. The refining roles of the three reaction sites, i.e. the up snorkel zone, the droplet group and steel bath in the vacuum vessel, were considered in the model. It was assumed that the mass transfer of reactive components in the molten steel is the rate control step of the refining reactions. And the friction losses and drags of flows in the snorkels and vacuum vessel were all counted. The model was applied to the refining of molten steel in a multifunction RH degasser of 90 t capacity. The decarburization and degassing processes in the degasser under the RH and RH KTB operating conditions were modeled and analyzed using this model. Besides, proceeded from the two resistance mass transfer theory and the mass balance of sulphur in the system, a kinetic model for the desulphurization by powder injection and blowing in the RH refining of molten steel was developed. Modeling and predictions of the process of injecting and blowing the lime based powder flux under assumed operating modes with the different initial contents of sulphur and amounts of powder injected and blown in a RH degasser of 300 t capacity were carried out using the model. It was demonstrated that for the RH and RH KTB refining processes, and the desulphurization by powder injection and blowing in the RH refining, the results predicted by the models were all in good agreement respectively with data from industrial experiments and practice. These models may be expected to offer some useful information and a reliable basis for determining and optimizing the technologies of the RH and RH KTB refining and desulphurization by powder injection and blowing in the RH refining and for controlling the processes.

Exploration and Practice of Nitrogen Addition Process for LF Refining Ladle Bottom Blowing Nitrogen Steel Liquid

This article discusses and analyzes the law of nitrogen increase in liquid steel and the main factors affect-ing the nitrogen increasing of molten steel,through the way of adding nitrogen to molten steel by bottom blowing nitrogen gas in LF refining process.It is considered that the main factors affecting the nitrogen increasing instability of molten steel are the initial temperature of LF refining,nitrogen relative element,surface active elements[O]and[S]of steel liquid,and bottom blowing rate of ladle.The large-scale production practice shows that T[O]not more than 50×10-6 and[S]is not more than 0.020 in LF refining at the initial temperature of not less than 1570.The liquid steel nitrogen enrichment test is carried out by ladle bottom blowing nitrogen gas after 20 min of refining,the flow rate is set as(6.0~7.0)NL/min per ton,and it is turned to 2 NL/min at 6 min before the end of refining,the nitrogen increasing rate of liquid steel is basically stable at(5~6)×10-6 per minute.

Effect of gas blowing nozzle angle on multiphase flow and mass transfer during RH refining process

A three-dimensional mathematical model was developed to investigate the effect of gas blowing nozzle angles on multiphase flow,circulation flow rate,and mixing time during Ruhrstahl-Heraeus(RH) refining process.Also,a water model with a geometric scale of 1:4 from an industrial RH furnace of 260 t was built up,and measurements were carried out to validate the mathematical model.The results show that,with a conventional gas blowing nozzle and the total gas flow rate of 40 L·min^(-1),the mixing time predicted by the mathematical model agrees well with the measured values.The deviations between the model predictions and the measured values are in the range of about 1.3%–7.3% at the selected three monitoring locations,where the mixing time was defined as the required time when the dimensionless concentration is within 3% deviation from the bath averaged value.In addition,the circulation flow rate was 9 kg·s^(-1).When the gas blowing nozzle was horizontally rotated by either 30° or 45°,the circulation flow rate was found to be increased by about 15% compared to a conventional nozzle,due to the rotational flow formed in the up-snorkel.Furthermore,the mixing time at the monitoring point 1,2,and 3 was shortened by around 21.3%,28.2%,and 12.3%,respectively.With the nozzle angle of 30° and 45°,the averaged residence time of 128 bubbles in liquid was increased by around 33.3%.

SWRCH35K冷镦钢120tBOF-吹氩-LF-CC流程的冶炼工艺和质量控制

通过KR铁水预脱硫[S]≤0.008%,BOF预脱氧加铝量由0.010%-0.025%提高到0.020%-0.035%,LF精炼时加Fe-Ca丝由3.0 m/t增至4.0 m/t,LF精炼时间≥35 min,白渣≥15 min,改进中间包结构,控制中间包钢水温度1 520-1 540℃,M-EMS电流由160 A提高至200 A,改善二次段喷雾冷却,控制拉速2.2-2.4m/min等工艺措施,生产的SWRCH35K冷镦钢（/%：0.29-0.31C,0.07-0.11Si,0.69-0.71Mn,0.009-0.010P,0.008S,0.038-0.041A1）160 mm×160 mm铸坯的碳偏析指数≤1.06,Φ6.5-20 mm热轧盘条组织为P＋F,用其生产的8.8级及以上的标准件,免退火后模具损耗率仅约为8.5%。

SPHE-B钢BOF-RH-CC过程夹杂物演变分析

通过定量金相分析的方法,对涟钢210转炉厂SPHE-B钢水中夹杂物在BOF-RH-CC过程中的演变规律进行了研究,结果显示10μm以下的较小颗粒夹杂物数量在氩站进站至RH脱氧前过程中大幅下降,在RH脱氧过程中大幅上升,RH脱氧后至中间包过程又大幅下降,而10μm以上的较大颗粒夹杂物数量总体呈缓慢下降趋势。研究结果表明,合理的吹氩、RH及中间包操作制度对降低钢水中夹杂物和提高钢质作用十分显著。

低碳铝镇静钢精炼渣理化性能研究及动态调控

为提升低碳铝镇静钢水的可浇性,基于低碳铝镇静钢精炼渣的热力学计算,研究典型组分CaO/Al2O3(C/A)、SiO_(2)、FeO对精炼渣液相线温度、1650℃黏度和表面张力的影响规律,结合精炼渣理化性能(熔点和黏度-温度曲线)测试结果,建立吹氩直上精炼渣动态调控模型,并投入生产实践应用。结果表明:随着C/A增加,精炼渣熔点在渣中SiO_(2)质量分数为5%时单调升高,在渣中SiO_(2)质量分数为10%时先降后升,另随C/A的增加精炼渣黏度及黏度-温度曲线的转折温度升高;精炼渣组分范围为C/A 0.75~1.50、SiO_(2)质量分数0~10%、FeO质量分数2%~6%时,可获得较低的液相线温度、较高的黏度和表面张力。生产实践中应用建立的模型可实现造渣物料的动态加入,精炼渣理化性能的稳定性得到显著提升,精炼渣的C/A和全铁(TFe)质量分数标准差明显降低;液相线温度、1650℃时的黏度和表面张力平均值分别降低6.9℃、增加0.0206 Pa·s和0.0109 N/m;全氧(TO)质量分数均值由2.78×10(-3)%下降为2.25×10(-3)%,改进了19.1%,钢水的可浇性得到显著改善。

Physical simulation of bubble refinement in bottom blowing process with mechanical agitation

In order to increase the contact area and promote the mass transfer process of gas and liquid,the process of the bubble refine-ment in a metallurgical reactor with mechanical agitation was studied by physical simulation.Based on the capillary number,a prediction equation for the bubble refinement was established.The effects of the gas flow rate,the stirring speed and thestirring depth on the bubble refinement in the reactor were discussed in detail.The distribution of the bubble diameter in thereactor was obtained under different conditions.The results show that when the stirring speed reaches 300 r/min,the bubblediamcter mainly distributes in the range of 1-2 mm.A higher gas flow rate may increase the number of bubbles in the meltand promote the bubble refinement process.The mechanism of bubble refinement under mechanical agitation was analyzed.and the results indicated that the stirring speed.,the blade area and the blade inclination are the main influencing factors.

红土镍矿富氧侧吹生产镍锍的工艺浅析

镍作为重要的战略金属,广泛应用于三元动力电池等产业。在三元动力电池的高镍化发展对镍原料需求旺盛的大背景下,随着优质硫化镍矿资源日益匮乏,对红土镍矿资源实现绿色高效提取,可开辟新的镍产业布局,对于促进新能源产业可持续发展具有积极意义。火法冶炼工艺具有流程短,对原料适用性强等优势,现已逐渐成为红土镍矿主流处理工艺。简要介绍了还原熔炼制备镍铁和还原硫化熔炼制备镍锍,并分析存在的优缺点,重点阐述采用富氧侧吹还原硫化熔炼生产镍锍,对绿色高效提取红土镍矿资源提出可行性建议。

超低碳钢RH高效脱碳工艺优化

针对IF钢过程中RH精炼周期较长的问题,研究了强制脱碳吹氧时机及脱碳终点时机对冶炼时长的影响。结果表明,吹氧时机提前至碳氧反应剧烈阶段,吹氧开始时间由真空循环260 s提前至180 s,脱碳时间从943 s降至860 s,提高了脱碳速率,缩短了脱碳周期。脱碳终点处,CO+CO_(2)含量在0.8%~2.0%之间时,RH精炼废气中CO+CO_(2)含量与钢水中碳含量呈明显的线性关系,碳含量随CO+CO_(2)含量的降低而减小。在保证终点碳含量小于15 ppm的内控条件下,CO+CO_(2)含量由0.8%~0.9%增至1.35%~1.40%时,脱碳周期由860 s降至803 s。通过优化强制脱碳吹氧时机及脱碳终点时机,RH循环脱碳时长由943 s降至803 s,缩短140 s。经过编程移植,开发的脱碳时间智能化模型与RH炉自身所带的激光废气分析仪相结合使用,有效缓解了RH脱碳过剩,提高了脱碳效率,同时为实现自动控制脱碳打下基础。

氧气底吹炼铜多组元造锍行为及组元含量的映射关系

通过分析氧气底吹炼铜过程产生的高品位铜锍中Cu、Fe、S、Si O2等组元含量变化趋势,结合冶金过程原理,研究上述各组元造锍行为及组元含量间的映射关系。结果表明:Cu、Fe、S、Si O2等组元在铜锍中的造锍行为具有相互关联性,其中Cu、Fe、S相互之间的关联性较强,Cu-Fe、Cu-S、Fe-S含量之间线性相关系数R2分别为0.96、0.89、0.79,但Si O2与Cu、Fe、S之间的关联性较弱。构造了Cu、Fe、S组元含量复合映射模型,该复合模型预测精确度高于单因素模型的预测精确度,可为生产过程中高品位铜锍多组元含量的精细调控,及熔炼-吹炼过程热量精确分配提供指导。

钢包炉吹氩与夹杂物去除

为了掌握钢包炉的冶金功能和去除夹杂物的规律,分析了钢包炉的精炼功能和精炼过程中钢液的流动行为及其对夹杂物去除的影响。探讨了钢包炉吹氩时夹杂物颗粒的去除效率与搅拌功、均匀混合时间、氩气泡直径、夹杂物直径、透气砖数目、吹氩流量及吹氩时间之间的关系,提出了合理的钢包炉底吹氩制度,以满足钢液精炼的要求。

底吹冰铜吹炼炉中气-液流动状况的数学模拟

采用Eulerian-Eulerian模型描述了底吹冰铜吹炼炉内气液两相流行为,在模拟结果与实测结果一致的基础上,对双喷嘴在不同喷气角度下熔池内的气液两相流行为及气体含量进行模拟计算与比较.结果表明:随着喷吹角度的增大,喷溅情况相应有所减弱,在14°对喷角度下的喷溅现象最为严重.随着双喷嘴对喷角度的增大,射流轴线横向穿透距离增大,湍动能的分布区域也相应增大,气泡在容器中停留时间增加.但当夹角超过一定范围后,继续增大角度会使喷嘴口距离液面垂直距离减小,气泡在熔池中的停留时间反而减小,其中28°对喷角度下,熔池中的气体体积分数最大,而且湍动能分布范围最广.

对我国电镍生产工艺的分析与改进研究

对我国电镍生产主要工艺存在的问题进行分析,并提出工艺改进方案。在现有不溶阳极电积精炼工艺基础上,采用常压浸出渣添加焙砂加压选择性浸出固定硫、浸铜后渣电炉还原熔炼、产出的铜镍锍用返液及镍和铜电积的阳极液分段浸出等措施解决现有工艺的内在矛盾和缺陷,提高对原料成分波动的适应性,分阶段集中和提高各有价金属的回收率。

氧气底吹造锍过程中气泡行为的水模实验

通过底吹炼铜转炉水模型实验,研究底吹造锍转炉中喷嘴数量、喷嘴角度、喷嘴直径、气流速度等因素对转炉熔池气泡大小、气含率及液面喷溅的影响规律.结果表明:喷嘴直径的增大不利于气泡微细化,且加剧了液面喷溅现象;喷嘴角度的增大有利于减小喷溅,但气含率下降;气流速度的增大有利于气泡微细化,显著提高气含率,但喷溅比较剧烈.与单喷嘴喷吹相比,在总喷气量相同的条件下,双喷嘴喷吹具有明显的优势,两种方法的气泡微细化程度差别不大,但是双喷嘴的喷溅情况明显减弱;双喷嘴夹角44°时能获得最大的气含率,约为9%.

RH真空精炼系统气液两相循环流动的均相流模型

提出一种修正的均相流模型,即在模型的含气率守恒方程中引入气相水平滑移速度,该速度只存在于喷嘴附近的区域,其物理作用是将气体导入流体中.计算实践表明,修正的均相流模型能够解决侧吹装置中的气液两相流动问题.同水模型的实验观察比较表明,该模型模拟的气相分布特征同水模型观察结果符合较好.

LF钢包精炼过程中的脱氧

研究了钢包精炼过程中钢水流动现象及吹氩方式对钢液中固相脱氧产物去除行为的影响和不同脱氧条件下吹氩过程对钢中溶解氧的去除规律 ,指出合理的吹氩制度对钢液中固相脱氧产物的去除至关重要。当钢液不用铝脱氧时 。

不锈钢的侧顶复吹AOD精炼过程

综述了不锈钢侧顶复吹AOD精炼的发展现状;阐述了该工艺的基本原理、过程和效果;基于该工艺过程的物理模拟研究,分析了有关参数对精炼过程的影响。

工业硅炉外吹气精炼除硼研究进展

冶金法太阳能级多晶硅技术具有能耗低、成本低和环境友好等特点,正逐步取代投资大、成本高的化学法而成为全球研究的热点.硼是工业硅中最难去除的非金属杂质之一,本文阐述了工业硅的生产过程和吹气炉外精炼除硼的原理,综述了国内外工业硅炉外氧气、湿氢、湿氧、湿二氧化碳以及吹气-熔渣联合精炼等工艺技术,并对本课题组湿氧精炼除硼的研究进行了重点介绍,分析了吹气精炼过程硅的损失问题,最后指出吹气-熔渣联合法是冶金法炉外精炼的发展方向.