Production of pig iron from red mud waste fines using thermal plasma technology

Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite （fixed carbon, 99%） as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.Results: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P < 0.01) and action potential amplitude reduced(P < 0.01) in model group. Moreover, repolarization 50% and 90% increased(P < 0.01).Conclusions: There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

Effect of titanium content on the precipitation behavior of carbon-saturated molten pig iron

The use of iron ores bearing titanium as a raw material is an effective measure to prevent hearth erosion and prolong the life of a blast furnace. In this research, the effect of titanium content on the precipitation behaviors of high-melting phases of carbon-saturated molten pig iron were studied by confocal scanning laser microscopy. The results showed that, when the titanium content was less than 0.25 wt%,Fe_3C was precipitated as a single phase from the molten carbon-saturated iron. The growth rate of the precipitated Fe_3C crystals was very high, reaching 7387 μm^2/s. When the titanium content in the molten pig iron was greater than 0.47 wt%, TiC crystals precipitated first. The shape and size of the precipitated TiC crystals did not obviously change. After TiC was precipitated, the fluidity of the molten pig iron worsened. With a decrease in temperature, Fe_3C was also precipitated but the growth rate of Fe_3C was limited by the presence of the first precipitated TiC phase. The crystal size of the precipitated Fe_3C was much smaller than that of pure Fe_3C.

Technical analysis of producing low Ni pig iron with laterite in a blast furnace

As nickel is mainly used to produce stainless steel, the demand for nickel is increasing. With the steady decline of nickel sulfide ore reserves, laterite will become the main source of nickel. In regards to China＇ s current blast furnace method of producing pig low Ni iron with laterite, this study analyzed the technical characteristics and relevant problems of this process based on the discussion on the characteristics of laterite. The study aims to provide a reference for the better use of laterite in China.

Optimization of Chelation Process for Complex Microelement Iron Supplement Derived from Pig Blood by Response Surface Methodology

[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl_2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl_2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood.

Electrophysiological changes of Papillary Muscles in Guinea Pigs with iron deficiency anemia and heart failure

Objective:To investigate the changes of left ventricular papillary muscle action potentials in guinea pigs with iron deficiency anemia and heart failure.Methods:A total of 20 cases of iron deficiency anemia with heart failure were treated with experimental group and 10 normal guinea pigs as control group. Blood samples were collected to determine hemoglobin content, red blood cell number and whole blood iron index, and the changes of cardiac function and hemodynamics were detected by 6240 biological signal collection system to determine whether the model was successful or not, Intracellular microelectrode technique was used to determine the action potentials of the papillary muscles in the model group and the control group. the potential amplitudes (APA), overshoot values (APA), maximum depolarization rate (Vmax), 20 % of repolarization, 50 % and 90 % of repolarization (APD20, APD50 and APD90 ) and the average velocity of repolarization were measured. Compare statistical difference between the model group and the control group.Results: 14 cases of model group survived completely, compared with control group, APD50 and APD90 prolonged, and the average velocity decreased.Conclusions: the action potential repolarization duration in the guinea pig papillary muscle of iron deficiency anemia with heart failure is prolonged, and the average repolarization velocity is slow.

Oxidation of Silicon and Boron in Boron Containing Molten Iron

A new process of directly smelting boron steel from boron-containing pig iron has been established. The starting material boron-containing pig iron was obtained from ludwigite ore, which is very abundant in the eastern area of Liaoning Province of China. The experiment was performed in a medium frequency induction furnace, and Fe2O3 powder was used as the oxidizing agent. The effects of temperature, addition of Fe2O3, basicity, stirring, and composition of melt on the oxidation of silicon and boron were investigated respectively. The results showed that sili- con and boron were oxidized simultaneously and their oxidation ratio exceeded 90% at 1 400℃. The favorable oxidation temperature of silicon was about 1 300-- 1 350℃. High oxygen potential of slag and strong stirring enhanced the oxidation of silicon and boron.

Iron extraction from lead slag by bath smelting

A new bath smelting process was proposed to recover iron for solid wastes reduction.99.79%of iron metallization,99.61%of iron recovery,pig iron with93.58%Fe,0.021%S,0.11%P,1.38%C,0.22%Si,0.01%Pb and0.031%Zn were achievedafter the wastes were smelted at1575°C for20min under C/Fe molar ratio of1.6and basicity of1.2.The produced pig iron could beused in steel-making.This study provides a way for recycling iron from smelting slag and hydrometallurgical residue.

Selection of raw materials and control of trace elements for production of high-quality SG iron

During the production of SG iron, the selection of raw materials and control of chemical composition are most important. From the very early days of SG iron production, the effects of trace elements on graphite form and matrix structure have been studied, and the allowable concentration limits for their detrimental influence has been decreased year by year, during the last fifty years. This paper has reviewed some of the suggested SG iron trace elements in the literature and in several Chinese foundries. It was found that for most SG iron castings, rare earth elements are still required to neutralize the harmful effects of trace elements and improve SG iron quality. It also found that the use of high purity and ultra-high purity base iron melts enabled integrated, safety-critical and complicated SG iron castings of varying thickness, and heavy-section, to be produced successfully. These SG iron castings have surprisingly good structures, and their mechanical and dynamic properties are vastly superior to those specified in current international SG iron standards. Further study is required on the effects of using high purity and ultra-high purity base melts on the structure and properties of SG iron.

高铁赤泥涡流熔融还原提铁中试扩大试验

高铁赤泥中氧化铁含量在30%以上,是重要的铁资源来源。为了规模化、资源化、无害化消纳高铁赤泥,作者所在课题组在实验室进行了高铁赤泥涡流熔融还原试验,并得到了最佳工艺参数。本文在实验室研究基础上进行了中试扩大试验,采用工业试剂替代了实验室分析纯试剂,取得了较好的效果。在试验温度1500℃、配碳比1.3、保温时间30 min、搅拌转速125 r/min、碱度1.0、氟化钙添加量为氧化钙添加量的10%的试验条件下,可回收赤泥中97.12%的铁;获得的生铁产品中磷和硫的含量低,成分满足炼钢用生铁国标L03的要求;还原渣中的主要物相为钙铝黄长石、钛酸钙和霞石,是生产水泥熟料的有效组分。该中试放大试验为工业大规模应用提供了相关数据参考,有利于实现高铁赤泥的规模化资源化利用。目前该生产采用间歇式生产模式,未来可通过设计连续式反应装置实现连续加料、连续出渣和出铁。

V含量对钒钛生铁高温氧化性能的影响

为探究不同V含量对钒钛生铁高温氧化性能的影响规律,采用静态增重法绘制试样质量随时间变化的曲线,通过扫描电镜、能谱和XRD等分析手段研究了800℃下不同V含量钒钛生铁的高温氧化性能。结果表明:①钒钛生铁的氧化增重与时间呈线性关系;V的加人会提高试验铁的氧化速率;②随着V含量的增加,氧化后的试样铁表面孔洞数量增多且孔径变大后趋于闭合;③铁试样中V含量较高时会造成较强的内氧化并促进Ti的氧化,当V质量分数高于0.3%,氧化层中主要氧化物为Fe_(2)O_(3)、V_(2)O_(3)和少量的TiO_(2),铁水凝固物的氧化程度明显上升。

能源转型背景下全球镍资源供需形势分析

全球16%、中国22%的镍用于新能源汽车动力电池领域,使得该领域成为仅次于不锈钢的第二大消费部门,面对全球能源转型背景下镍在电池领域新的消费增长点,保障动力电池生产所需的镍资源可靠及可持续供应至关重要。中国是全球最大的镍资源消费国和进口国,分析全球镍资源供需及产业最新变化趋势对国家制定相关紧缺矿产资源产业链供应链稳定政策具有重要现实意义。根据全球新能源汽车产业用镍情况,分析原生镍消费结构、消费变化数据,运用部门分析法预测了2030年全球镍需求量。以全球镍储量、勘探预算变化、主要资源国资源储量变化、镍矿及镍中间品和原生镍生产,以及全球镍贸易总量数据为基础,开展全球镍资源供需和产业变化研究。研究结果表明:未来全球镍产量能够满足镍在电池领域的消费需求增长;硫酸镍和含镍生铁成为重要的原生镍产品;镍湿法冶炼中间品氢氧化镍钴和高冰镍取代镍豆和镍粉成为硫酸镍最经济的生产原料。据此提出加强镍资源供需走势研判、开展镍产品国家储备研究及资源回收利用技术研发等建议。

零价铁对猪粪发酵产甲烷和磷转化的影响

为解决猪粪发酵沼液中有机物和磷对环境造成的污染问题,提高清洁能源的生产率,通过在厌氧发酵系统中投加零价铁,采用傅里叶红外光谱仪(Fourier transform infrared spectrometer,FTIR)、X射线衍射分析(X-ray diffraction,XRD)、高通量测序等技术分析厌氧发酵过程中产甲烷量、磷的分布与形态、酶活性以及微生物群落等变化,研究零价铁对猪粪厌氧发酵产甲烷和磷转化的影响。结果表明,零价铁富集了Clostridun_sensu_stricto_1、Terripotobacter和Syntrophomonas等酸化菌,促进了水解酶的活性,使蛋白酶和β-葡萄糖苷酶的活性分别提高了0.6倍和2.4倍,增强了系统的水解酸化能力。并且零价铁还富集了产甲烷菌Methanosaeta,使产甲烷菌活性增强,最终提高了产甲烷11.1%。另外,零价铁富集了Ruminofilibacter和WS6_Dojkabacteria等相关磷转化的微生物,使酸(碱)性磷酸酶的活性增强26.3%左右,促进了系统内有机磷向无机磷转化。同时,零价铁显著提高了系统中溶解性Fe2+的含量,促进了水溶性磷向Fe结合磷化物的转化,最终固定在蓝铁矿等沉淀物中,显著地降低沼液总磷浓度。研究结果为提高猪粪厌氧发酵产甲烷和磷的固定提供了技术参考。

不同添加比例有机铁合剂对育肥猪生长性能和肉品质的影响

试验旨在研究不同添加比例有机铁合剂对育肥猪生长性能和肉品质的影响。选用(65.20±2.50)kg的杜洛克、长白猪和大白猪三元杂交育肥猪36头,随机分为3组,分别在对照组、试验Ⅰ组和试验Ⅱ组的基础日粮中添加0、500、1000 mg/kg的有机铁合剂。结果表明:与对照组相比,试验Ⅰ组、试验Ⅱ组的日增重、肌苷酸、谷氨酸和必需氨基酸含量均显著提高(P<0.05)。说明添加有机铁合剂具有提高育肥猪的生长性能和改善肉品质的作用,其中添加量为1000 mg/kg效果较好。

马钢300 t转炉快速修补渣面工艺实践

文章主要针对转炉的生铁块补渣面技术进行了阐述。通过理论和实践相结合,生铁块补炉工艺得到稳定应用,有效缓解加料作业对渣面炉衬的冲刷及机械磨损,解决了生产组织与炉体养护之间的矛盾,生产效能提升,经济效益显著增加。

不同来源铁添加剂对育肥猪生长性能、血清生化和抗氧化指标的影响

文章旨在研究不同来源铁添加剂对育肥猪生长性能、血清生化指标和抗氧化指标的影响。试验将120头平均体重(60.24±0.89)kg的三元育肥猪随机分为4组,每组5个重复,每个重复6头。试验为期72d,其中预饲期9d,正试期63d。分别向基础日粮中添加100mg/kg(以铁元素计)硫酸亚铁、甘氨酸铁、富马酸亚铁和复合氨基酸螯合铁。试验结果表明,日粮添加甘氨酸铁、富马酸亚铁和氨基酸螯合铁显著提高育肥猪的终末体重和平均日增重(P <0.05);日粮添加甘氨酸铁、富马酸亚铁和氨基酸螯合铁可显著降低育肥猪的料重比(P <0.05);此外,日粮中添加不同来源铁对育肥猪平均日采食量无显著影响(P> 0.05)。日粮添加甘氨酸铁可显著提高育肥猪血清白蛋白含量(P <0.05);显著降低育肥猪血清谷草转氨酶和谷丙转氨酶活性(P <0.05);日粮不同来源铁对育肥猪血清总蛋白、球蛋白和尿素氮含量无显著影响(P> 0.05)。日粮添加甘氨酸铁、富马酸亚铁和氨基酸螯合铁可显著提高育肥猪血清GPX活性和GSH含量(P <0.05);显著降低丙二醛含量(P <0.05);此外,日粮不同来源铁对育肥猪血清过氧化氢酶、总超氧化物歧化酶活性以及氧化型谷胱甘肽含量无显著影响(P> 0.05)。总之,在本试验条件下,日粮添加甘氨酸铁的饲喂效果明显优于其他铁源。

返矿冷固球团在榆钢2800m^(3)高炉的应用

简要阐明了烧结返矿的利用现状及返矿冷固球团人炉的可行性,重点阐述了榆钢烧结返矿冷固球团制备及2800m^(3)高炉人炉应用的技术攻关成果。烧结返矿冷固球团的抗压强度、热爆裂性能指数、低温还原粉化指数、还原性能及软熔性能等质量指标符合高炉炉料冶金性能要求。高炉生产实践表明,返矿冷固球团人炉,有利于改善高炉透气性,提高煤气利用率,炉况稳定顺行,可取得良好的经济效益和社会效益。与返矿冷固球团使用前相比,在冷固球团入炉比例为5%时,煤气利用率提高4%~5%,生铁成本降低10.2元/t。

利用X射线荧光光谱快速分析高锰生铁锰含量

高锰生铁(又称镜铁)是用锰矿石经过高温冶炼富锰渣时产生的一种衍生产物,其锰含量为6%~20%,本文将详细阐述检测中心利用X射线荧光光谱快速分析高锰生铁锰含量。

火花源原子发射光谱法测定钒钛生铁中微量元素的研究

为了及时、准确地测定钒钛生铁中微量元素的含量,采用火花源原子发射光谱法,分析钒钛生铁中的Si、Mn、P、S、V、Ti、Ni和Cr等微量元素。通过优化分析仪器条件,进行仪器的精密度、正确性实验,实现了直读光谱仪快速检测钒钛生铁中的微量元素。

原煤配加干熄焦除尘灰技术探究与应用

长钢炼铁厂采用烟煤和长焰煤混合喷吹技术,按挥发分质量分数为10%~15%进行配煤,多年来一直维持130 kg/t左右的经济喷煤比,仅通过进一步提高喷煤比、降低焦比来优化生铁燃料成本,难度较大。鉴于此,喷煤作业区利用焦化干熄焦除尘灰w(C)高(在80%以上)、挥发分低(质量分数在2.5%以下),且价格仅为同期烟煤价格的55%的特性,在原煤中配加一定比例的焦化干熄焦除尘灰,降低了煤粉的制备成本,为生铁低成本冶炼起到积极作用。