含锡锌铁精矿链篦机-回转窑法制备炼铁用球团矿的研究

以含锡锌复杂铁精矿(质量分数)(0.25%Sn,0.20%Zn)为对象,进行了含锡锌铁精矿制备炼铁用球团矿的研究。在分析预热、还原焙烧过程锡、锌化合物挥发行为的基础上,重点研究了链篦机预热条件和回转窑焙烧条件对预热球、成品球团矿强度及锡、锌脱除率的影响。热力学分析表明,锡、锌的挥发脱除主要发生在弱还原焙烧阶段。实验结果表明:在优化条件下,预热球抗压强度为495N/个,AC转鼓指数为3.85%,焙烧球抗压强度为2254N/个,ISO转鼓指数为96.16%;Sn和Zn的挥发率分别为70.8%和61.0%,球团矿中残余Sn和Zn的质量分数分别为0.073%和0.078%。制备的成品球团矿冶金性能良好,各项指标均满足高炉冶炼要求。     

X射线荧光光谱在矿石分析中的应用评介—总论

矿石因其种类繁多、成分复杂和元素含量差异悬殊而成为地质分析的一大难题。作者收集各类矿石分析方法文献726篇,在此基础上主要以列表方式按黑色金属、有色金属、稀有稀土稀散金属、能源矿产和非金属矿石5大类介绍了X射线荧光光谱(XRF)分析在数十种矿石中应用的文献概况,从分析方法研究的基础条件和各类矿石分析方法类型、特点和文献量等进行了介绍和评介,也依据XRF分析仪器及技术的发展和目前在我国矿石分析中的应用现状提出了XRF在各类矿石分析中更广泛应用的发展建议。其中的黑色金属矿石包括铁矿石、锰矿石、铬铁矿及钛铁矿石和钒钛磁铁矿石,涉及文献177篇;有色金属矿石包括铝土矿石、钴镍铜铅锌矿石、钨钼矿石、锡锑铋汞矿石和多金属矿石,涉及文献186篇;稀有稀土稀散金属矿石包括稀土、铌钽、锆石和稀散金属矿石,涉及文献67篇;能源矿产包括煤、煤灰、石盐和油页岩,涉及文献40篇;非金属矿石包括碳酸盐类、磷酸盐类、硫化矿及硫酸盐类、氟化物矿石、镁及硅镁酸盐类、硅及硅铝酸盐类、岩盐卤水类和宝玉石9类非金属矿石,涉及文献257篇。作为矿石分析总论旨在以文献为基础框架展现XRF分析技术在我国各类矿石分析应用的基本概况,给读者一个全貌。而对XRF在各矿种矿石分析中应用的更具体评介将陆续发表,XRF在铁矿石、铬铁矿石和铜矿石分析中的应用评介已于2019年刊于《冶金分析》。     

X射线荧光光谱在矿石分析中的应用评介—总论

矿石因其种类繁多、成分复杂和元素含量差异悬殊而成为地质分析的一大难题。作者收集各类矿石分析方法文献726篇,在此基础上主要以列表方式按黑色金属、有色金属、稀有稀土稀散金属、能源矿产和非金属矿石5大类介绍了X射线荧光光谱(XRF)分析在数十种矿石中应用的文献概况,从分析方法研究的基础条件和各类矿石分析方法类型、特点和文献量等进行了介绍和评介,也依据XRF分析仪器及技术的发展和目前在我国矿石分析中的应用现状提出了XRF在各类矿石分析中更广泛应用的发展建议。其中的黑色金属矿石包括铁矿石、锰矿石、铬铁矿及钛铁矿石和钒钛磁铁矿石,涉及文献177篇;有色金属矿石包括铝土矿石、钴镍铜铅锌矿石、钨钼矿石、锡锑铋汞矿石和多金属矿石,涉及文献186篇;稀有稀土稀散金属矿石包括稀土、铌钽、锆石和稀散金属矿石,涉及文献67篇;能源矿产包括煤、煤灰、石盐和油页岩,涉及文献40篇;非金属矿石包括碳酸盐类、磷酸盐类、硫化矿及硫酸盐类、氟化物矿石、镁及硅镁酸盐类、硅及硅铝酸盐类、岩盐卤水类和宝玉石9类非金属矿石,涉及文献257篇。作为矿石分析总论旨在以文献为基础框架展现XRF分析技术在我国各类矿石分析应用的基本概况,给读者一个全貌。而对XRF在各矿种矿石分析中应用的更具体评介将陆续发表,XRF在铁矿石、铬铁矿石和铜矿石分析中的应用评介已于2019年刊于《冶金分析》。     

Reduction roasting of high iron bearing zinc calcine for recovery of zinc and iron

High iron bearing zinc sulphide ore is an important resource for zinc, and the reserve is very great in the world. It is very difficult to effectively obtain zinc and iron from the source by traditional technology. In this study, a novel method was proposed for recovery of zinc and iron from high iron bearing zinc calcine, and the key procedure, reduction roasting, was investigated. The effects of CO concentration, CO₂ concentration, temperature and time on reduction roasting were studied respectively. The experimental results show that the content of soluble zinc and magnetic susceptibility reached 91·15% and 4·1×10^?4 m³ kg^?1 under the optimum conditions respectively. About 90%Zn and 9·5%Fe were dissolved from the reduction roasted zinc calcine by low acid leaching, and simultaneously, 84·3%Fe was recycled to the iron concentrate containing iron of 53·2% from zinc leaching residue by low intensity magnetic separation.

Le minerai de sulfure de zinc à haute teneur en fer est une ressource importante du zinc et il en existe une grande quantité dans le monde. Il est très difficile d’obtenir efficacement le zinc et le fer de cette source par la technologie traditionnelle. Dans cette étude, on propose une nouvelle méthode pour la récupération du zinc et du fer à partir de produit calciné de zinc à haute teneur en fer, et on examine la procédure clef, le grillage réducteur. On a étudié respectivement les effets de la concentration de CO, de la concentration de CO₂, de la température et de la durée sur le grillage réducteur. Les résultats expérimentaux montrent que la teneur en zinc soluble et la susceptibilité magnétique atteignaient respectivement 91·15% et 4·1×10^?4 m³ kg^?1 en conditions optimales. Environ 90% du Zn et 9·5% du Fe étaient dissous à partir du produit calciné de zinc de grillage réducteur par lessivage à acide faible, et simultanément, 84·3% du Fe était recyclé en concentré de fer contenant 53·2% de fer à partir du résidu de lessivage du zinc par séparation magnétique à faible intensité.     

The reduction of zinc from slags by an iron-carbon melt

An experimental investigation was undertaken to study the mechanism of reduction of zinc from slags in the presence of a carbon-saturated iron melt. Batch tests were performed at 1400 °C, and the variation of the zinc and iron concentration in the slag during reduction was determined by sampling the slag at intervals during the test. In graphite crucibles, zinc in slags containing iron was reduced faster than zinc in iron-free slags, both when an iron bath was present and when it was absent. Zinc was reduced faster from slags containing iron when an iron bath was present than when an iron bath was absent. The dominant mechanism of reduction of zinc from slags containing iron appears to be the reaction of Zn²⁺ ions with Fe²⁺ ions to form zinc vapor and Fe³⁺ ions. When an iron bath is present, the Fe³⁺ ions are reduced back to Fe²⁺ predominantly by reaction with iron from the bath. Mass transfer of Fe³⁺ ions in the slag appears to be the rate-controlling step. Reduction of iron from slag by carbon occurred in parallel with the reduction of zinc, and whether there was a net increase or decrease of iron in the slag depended on the relative rates of production and consumption of iron. Lead and copper in the slag were reduced to low levels. The lead volatilized and the copper dissolved in the alloy.     

Reaction mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust

Abstract

The experiments in this paper were performed to research the mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust. The reduction potential of zinc during cementation was determined to investigate the morphology of products. Residues after the cementation process from zinc sulphate solution were analyzed by SEM and EPMA to investigate the morphology of products. Different temperature will cause different structure of particles. The reaction mechanism of cobalt removal by zinc dust is thought to be as follows: first, the Co2+ forms Co–Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; second, the Co–Zn alloy continues reacting to Co with Co2+, which is the control process of the whole reaction.     

‘Waste recovery in ironmaking and steelmaking processes’ 13 and 14 December 2010

Abstract

In order to develop and utilise cheap iron ores with low quality for cost reduction, a hematite ore from Xinjiang province was investigated to determine the iron increase and silicon reduction using ore dressing process experiments. Results showed that iron concentrate with 61%Fe and iron recovery of 66% were achieved through the process flowsheet of grinding, high intensity magnetic separation, regrinding of coarse concentrate, clean concentration by high intensity magnetic separation, roughing reverse floatation and cleaning reverse floatation of the high intensity concentrate, with the tailings from this latter stage fed back into the roughing reverse floatation stage.     

高铝铁矿和高锰铁矿共还原行为的研究

高铝铁矿和高锰铁矿是两种储量丰富但又极难分选的铁矿资源,实现铁、锰、铝的高效综合利用具有重要意义.本文研究了这两种铁矿石工艺矿物学,考查了单矿种及两者的混合矿种的直接还原行为及还原过程中的矿物组成演变,揭示了相应的还原机理.结果表明:高铝铁矿难还原,其机理为经还原后仅部分铁氧化物转化为金属铁,其余的铁与铝、硅矿物形成难还原的铁橄榄石和铁尖晶石;高锰铁矿易还原,其中的铁氧化物大部分被还原成金属铁,锰氧化物与铝、硅矿物结合形成锰尖晶石和锰橄榄石,促进了铁氧化物的还原.而且在相同还原条件下,高锰铁矿球团金属化率比高铝铁矿高30个百分点,前者还原性明显优于后者.两种矿进行共还原,当高锰铁矿配比达到60%时,球团金属化率就可大于90%.锰氧化物的存在对高铝铁矿石中铁氧化物的还原具有显著的促进作用.     

Improvement of sintering characteristics by selective granulation of high Al2O3 iron ores and ultrafine iron ores

The worldwide steel companies are expected to use low grade iron ores such as pisolitic iron ores, high Al₂O₃ iron ores and ultrafine iron ores etc. in their sinter blends due to the depletion of high grade iron ores or for the economic reason. This study investigated the methods for improving sintering characteristics without deteriorating sintering productivity and sinter quality by blending mini-pellets comprising high Al₂O₃ pisolitic iron ores and ultrafine iron ores containing low alumina. The results showed that the blending of iron ore mini-pellets produced by selective granulation is an effective way to improve sintering productivity and sinter quality without increasing the Al₂O₃ content in sinter as well as to effectively utilise high Al₂O₃ iron ores and ultrafine iron ores in the sintering process.     

Rules of Assimilation of Single Ore and Mixed Ores

Assimilation behaviors of 7 kinds of iron ores from Australia, Brazil, India, South Africa and China were evaluated and analyzed. On the basis of that, four ore blending principles were proposed, and seven groups of iron ore powder blending schemes were designed. The ores of different types or from different places are shown apparently different in assimilation. The assimilation of hematite in Australia, Brazil and India is relatively high, but the assimilation of magnetite in South Africa and China and specularite in China is relatively low. The assimilation of the ores has negative correlation with MgO content and binary basicity, while the assimilation of the ores has positive correlation with porosity, SiO₂ and Al₂O₃ contents, and crystal water. The iron ores with smaller crystal size and microstructure looseness have relatively higher assimilation. Assimilation of mixed ores has relationship of linear, arch and “S” types to the ratio of single iron ore powder. When the charge ratio of ore is less than 25%, it possesses additivity, providing theoretical basis for optimization of ore matching.     

Correlation of BOS process variables with dust mass formation and zinc content

Abstract

The basic oxygen steelmaking (BOS) process typically produces a dust rich in valuable iron units and often contaminated with zinc. This paper takes a look at statistical correlation and multiple regressions of process variables with the quantity of dust and the zinc mass contained in the dust. A robust inline sampling system was designed and installed to isokinetically sample the primary BOS dust slurry from a 248 m³ capacity BOS converter at Tata Steelworks Port Talbot (UK). This system was used to measure the dust mass and composition changes against time for 12 large scale trial heats and to compare with the process information data for a statistical evaluation of the variables. Statistically significant Pearson linear correlations were measured for the total dust mass produced with the iron ore and for the zinc mass contained in the dust with the addition of waste oxide briquettes (WOBs). A multiple regression analysis model showed strong associated correlations between the zinc mass contained in the dust with the galvanised scrap and WOB additions and explained 73% of the zinc mass variance.     

Reduction of boron-bearing iron ore concentrate/coal composite pellet and kinetics analysis

Ludwigite is a complex iron ore containing boron and it is the most abundant boron resource in China. Boron-bearing iron ore concentrate is an intermediate product of the ore dressing process of crude low-grade ludwigite and extracting boron from it has great influence on the total boron yield. Pre-reduction of the boron-bearing iron ore concentrate is one of the important steps of the pyrometallurgical boron and iron separation process. In the present work, non-isothermal and isothermal reduction of boron-bearing iron ore concentrate/coal composite pellet was performed. The evolution of reaction fraction, carbon consumption, off-gas evolution, phase composition and microstructure were systematically revealed based on reduction experimental results in conjunction with X-ray diffraction, scanning electron microscope-energy dispersive spectrometer and electron probe micro analyzer analysis. The kinetics of the reduction of the composite pellet was also analysed. The reduction mechanism changed at a temperature around 1150°C. The rate of carbon gasification in the composite pellet during the reduction decreased mainly due to the chemical inhibition by B₂O₃ on the electron transfer.     

STRATEGIES FOR PROCESSING LOW-GRADE IRON ORE MINERALS

The conventional routes for making iron and steel require that the ore be upgraded through a series of physical separation processes in sequence. The unit operations involved include crushing, grinding, separation, dewatering, pelletization, blast furnace processing, and basic oxygen furnace processing. This complex sequence is not cost effective for many low-grade ores that are resistant to physical concentration. For example, many ores contain iron oxide in a nonmagnetic form and are so fine-grained that it is uneconomical to grind them to a fine enough size to separate the iron oxides from the gangue. Exploitation of these iron minerals needs to take a different approach, using fewer process steps than are required for conventional ironmaking. Results are presented showing that it is possible to produce metallic iron directly from low-grade ores. The metal is in a form that can be easily separated to produce a high-grade iron product, and the iron recovery is greater than can be achieved from difficult-to-process ores by conventional means.     

Reducibility of laterite ores

The reducibility of several types of lateritic nickel bearing ores was investigated. The ores were reduced with hydrogen over a temperature range of 673 to 1273 K and reaction times from 5 to 80 minutes. The fraction of nickel, iron, and cobalt reduced to the metallic state was determined by leaching the reacted samples with a bromine-methanol solution followed by atomic absorption analysis for the individual elements. The reducibility of nickel increased with increasing iron concentration of the ore. Increased reduction temperature greatly raised the amount of nickel reduced for ores with high iron concentrations. The cobalt reducibility decreased with increasing iron concentration of the ore. Changes in reduction temperature affected cobalt reduction less than nickel reduction. The observed changes in reducibility have been attributed to the formation of phases which incorporate nickel and cobalt. The major ore components were plotted on the ternary phase diagram of the SiO₂+(Al₂O₃)-MgO-FeO system. It is shown how this plot can be used to predict the reducibility of different types of lateritic ores. Formerly with the Department of Metallurgy and Materials Science, University of Toronto, Toronto, ON, Canada     

Investigations on Flowsheet Development for the Treatment of Niobium-Tantalum Bearing Cassiterite

Abstract

The paper presents the results of experimental investigations carried out for developing a flowsheet for the treatment of niobium-tantalum bearing cassiterite containing about 23%of mixed niobium and tantalum oxide. Three different approaches viz. direct smelting of cassiterite to tin metal and niobium-tantalum bearing slag, reduction roasting-acid leaching and alkali fusion-leaching to separate tin from niobium-tantalum followed by recovery of tin as oxide and finally carbothcrmic reduction to tin metal have been examined on laboratory scale. It has been observed that alkali fusion—leaching—tin oxide smelting is quite attractive to obtain a good purity tin metal and also recover niobium and tantalum as mixed oxides.     

内蒙古某铜锌复杂多金属矿石选矿试验研究

针对内蒙古某铜锌复杂多金属矿矿石性质,进行了浮选试验研究。通过采用优先浮选流程,即先选铜,再选锌,获得了较好的试验指标:铜精矿铜品位26.98%、铜回收率83.56%,锌精矿锌品位50.59%、锌回收率76.84%。     

Effect of alumina on slag–metal separation during iron nugget formation from high alumina Indian iron ore fines

Abstract

Iron nuggets can be obtained from ore–coal composite pellets by high temperature reduction. Alumina in the ore plays a vital role in slag–metal separation during nugget formation, as it increases the liquidus temperature of the slag. In this study, the effect of carbon content, reduction temperature and lime addition on slag–metal separation and nugget formation of varying alumina iron ore fines were studied by means of thermodynamic modelling. The results were validated by conducting experiments using iron ore fines with alumina levels ranging from 1·85 to 6·15%. Results showed that increase in reduction temperature enhances slag metal separation, whereas increasing alumina and carbon content beyond the optimum level adversely affects separation. Carbon below the required amount decreases the metal recovery, and carbon above the required amount reduces the silica and alters the slag chemistry. Optimum conditions were established to produce iron nuggets with complete slag–metal separation using iron ore–coal composite pellets made from high alumina iron ore fines. These were reduction temperature of 1400°C, reduction time minimum of 15 min, carbon input of 80% of theoretical requirement and CaO input of 2·3, 3·0 and 4·2 wt-% for 1·85, 4·0 and 6·15 wt-% alumina ores respectively.     

潘菲氏管分离氢化物-冷原子荧光光谱法测定锌精矿中微量汞

试样于潘菲氏管中加入还原铁粉 ,加热使汞与基体及共存元素分离 ;试验了氢化物 -原子荧光光谱法测定汞的最佳条件。汞的检出限为 0.0 5ng/mL ,线性范围为 0. 5～ 2 5 0ng/mL ,汞的回收率为 94%～ 10 1%。方法应用于锌精矿中汞的测定 ,取得满意结果     

The hydrometallurgical treatment of zinc silicate ores

A novel hydrometallurgical procedure is described for the recovery of zinc from zinc silicate ores which have high acid-soluble zinc and silica contents. The process is conducted in a continuous concurrent manner at atmospheric pressure and temperatures of 50 to 95°C. The ore is leached with spent electrolyte from an electrolytic zinc plant to a final pH of approximately 2 to dissolve zinc and the soluble silica. The pH of the leach solution is then raised to 4 to 5.5, using a neutralizing agent, to precipitate and coagulate the colloidal silica. Finally the coagulated silica is filtered from the solution and washed. The resulting filtrate is treated conventionally for electrolytic zinc production. This process solves in a simple way the difficult problem of precipitating large concentrations of colloidal silica(e.g. 25 g SiO₂ per liter) in a readily filterable and easily washed form. The process has been tested at up to the 5 tons per day scale on ores containing willemite and on a laboratory scale with ore containing hemimorphite and smith-sonite. D.ELSNER was Formerly Senior Research Officer, Risdon Diversion, Electrolytic Zinc Company of Australasia Limited, Melbourne, Victoria, 3000, Australia.     

Relationship between sinter properties and iron ore granulation index

Abstract

A range of iron ores were used in varying proportions to prepare 28 different ore mixtures. Each mixture was classified according to its granulation index and sintered in a pilot plant. The resulting sinters were characterised by chemical analysis, degradation during reduction in the blast furnace (reduction degradation index test), cold strength (tumbler test), coke consumption and process productivity. Sinter quality was assessed in relation to the granulation index of the ore mixture.