逆流浮选柱柱径及柱高的设计

论述了柱径与柱高对逆流浮选柱浮选过程的影响,提出了气阻、面积负荷的概念.通过研究矿化气泡的受力及运动,建立了表征矿浆运动的理论模型,并对模型的参数做了经验处理.给出了用矿浆流速确定柱径、用柱径和浮选柱容积来确定柱高的设计方法.通过对细粒钼铋矿物的回收实验表明,在同等实验条件下,无论是精矿品位还是回收率,按该方法设计的柱体浮选效果明显好于其他尺寸的柱体.     

Modelling of bubble size in industrial flotation columns

Abstract

One of the commonly used models to estimate the bubble size in flotation columns is the drift–flux model, initially proposed by Wallis in 1962, which estimates the bubble size based on experimental measurements of gas velocity J_g, gas hold-up ?_g and pulp downward velocity J_sl. The model has been considered as an alternative to estimate the average bubble size d₃₂ in flotation cells and columns, when this cannot be measured experimentally, which is usually the case. However, the model has been validated only at laboratory and pilot scale. This paper presents the results of an extensive experimental programme to test the model conducted at the industrial scale. The test programme involved measuring the gas dispersion parameters (J_g, ?_g and d₃₂) in flotation columns at five concentrators. The data collected were used to estimate the average bubble size using the drift–flux model. A good correlation was found between the bubble size estimated with the model and measured experimentally.

L’un des modèles fréquemment utilisés pour évaluer la taille de bulle des colonnes de flottation est le modèle à flux de dérive, proposé initialement par Wallis en 1962, lequel évalue la taille de bulle en se basant sur les mesures expérimentales de la vitesse du gaz (J_g), du volume mort (?_g) et de la vitesse de la pulpe vers le bas (J_sl). On a considéré le modèle comme solution de rechange à l’évaluation de la taille moyenne de bulle (d₃₂) dans les cellules et les colonnes de flottation, lorsque l’on ne peut pas la mesurer expérimentalement, ce qui est habituellement le cas. Cependant, le modèle a été validé seulement à l’échelle du laboratoire et à l’échelle pilote. Cet article présente les résultats d’un vaste programme expérimental pour évaluer le modèle à l’échelle industrielle. Le programme d’évaluation impliquait la mesure des paramètres de dispersion du gaz (J_g, ?_g et d₃₂) dans des colonnes de flottation à 5 concentrateurs. On a utilisé les données captées pour évaluer la taille moyenne de bulle en utilisant le modèle à flux de dérive. On a trouvé une bonne corrélation entre la taille de bulle évaluée avec le modèle et mesurée expérimentalement.     

基于列生成与线性规划的炼钢组炉优化算法

针对考虑钢级"以优充次"的炼钢组炉问题,构建了以炼钢成本最小化与炼钢余材最小化为目标的多目标优化模型,基于目标优先级不同,首先以降低炼钢成本为目标,利用列生成算法给出具有最低炼钢成本的组炉方案;在此基础上,建立余材优化线性规划模型,通过缩减炉重和增加合同量的方式,进一步降低炼钢余材,得到最终的组炉方案。实例表明,该算法具有良好的优化性能和实用性。     

钢铁炉窑协同处置冶金及市政难处理固废技术路线

 无害化和资源化仍然是当前固废处置的重要方向,尤其在当前全力实现“碳达峰、碳中和”目标的大背景下,“以废代碳”还是降低碳排放的重要途径。针对当前固废处置出现的处置成本高、资源化利用不充分、邻避效应严重的现状,提出了利用钢铁炉窑,特别是烧结球团工序协同处置冶金及市政难处理多源固废的思路,提出了建立多源固废物质属性、能源属性、毒害属性多维识别指标体系与最佳处置路径的生态化适配原则;基于钢铁工业窑炉特性及固废属性,构建了火法/湿法预处理耦合热工制度优化的冶炼主工艺协同处置固废的技术路线,及基于北斗-物联网的区域性固废协同处置智慧平台,为冶金及市政固废生态化协同处置提供方向指导和技术参考。     

燃煤型锌精馏炉的供热系统与能耗分析

介绍了一种年产2000吨精锌、以原煤为燃料的一炉两塔型锌精馏炉的供热系统，并对生产中的能耗进行了简要分析。     

神经网络与遗传算法预测充填配比的研究

为确定最优充填配比方案,在实验的基础上,基于神经网络遗传算法,预测全局最优充填实验条件,最优实验条件为灰砂质量比0.2024,养护时间5.863 d,溶度67.8%,最大充填体抗压强度0.6777 MPa,与实际最佳配比方案灰砂质量比1∶4、养护天数28 d、溶度75%、最大抗压强度5.48 MPa相差较大,预测结果不是很满意.说明该方法有较强的适用条件,神经网络的预测精度对遗传算法的极值寻优有影响,建议扩大样本的数量.     

浮选柱的发展和应用

本文概述了浮选拉的结构、原理、优点和30年来的发展概况，并略加评论。介绍了国同外应用浮选拉的若干实例，建议选矿技术界予以重视。     

Effect of particle size distribution on recovery of coarse chalcopyrite and galena in Denver flotation cell

Abstract

The flotation recovery by particle size of single mineral chalcopyrite and galena was studied in a Denver flotation cell, using sodium dicresylthiophosphate (DTP) and sodium isopropyl xanthate (SIPX) as collectors and polypropylene glycol (PPG) as a frother. The study was extended to very coarse particle size (up to 1·6 mm). Froth stability was also measured in parallel to the batch flotation tests, in a specifically designed froth stability column, following the Bikerman approach. It is shown that particles up to 850 μm can be floated successfully, provided they are liberated and hydrophobic. However, the recovery of both chalcopyrite and galena was strongly influenced by the overall particle size distribution, decreasing sharply as the fraction of fines (?106 μm) in the feed also decreased. Rheology measurements showed negligible differences in pulp viscosity, and therefore in the collection zone hydrodynamics, between the different conditions tested. Froth stability, on the contrary, decreased as the feed particle size distribution became coarser. Correlation was found between the amount of fines in the pulp, froth stability and flotation recovery. The recovery of mineral particles is critically dependent on froth stability, which in turn is highly influenced by the overall particle size distribution of the feed material. For these reasons, the study also suggests that it is not possible in batch flotation to determine the rate and recovery of the coarse particle size fractions floating them independently from the fine size fractions.

Dans une cellule de flottation de Denver, on a étudié la récupération par flottation en fonction de la taille de particule d’un minéral unique de chalcopyrite ou de galène, en utilisant du dicrésyle thiophosphate de sodium (DTP) et de l’isopropyle xanthate de sodium (SIPX) comme agents collecteurs et du polypropylène glycol (PPG) comme agent moussant. On a étendu l’étude à la taille de particule très grossière (jusqu’à 1·6 mm). On a également mesuré la stabilité de la mousse en parallèle aux essais de flottation discontinue, dans une colonne de stabilité de la mousse spécialement conçue, d’après l’approche de Bikerman. On montre que l’on peut faire flotter avec succès des particules ayant jusqu’à 850 μm, à la condition qu’elles soient libres et hydrophobes. Cependant, la récupération, tant de la chalcopyrite que de la galène, était fortement influencée par la distribution globale de la taille de particule, diminuant sévèrement à mesure que la fraction de particules fines (?106 μm) dans l’alimentation diminuait. Les mesures de rhéologie montraient des différences négligeables dans la viscosité de la pulpe et ainsi dans l’hydrodynamique de la zone de collection, parmi les différentes conditions évaluées. Au contraire, la stabilité de la mousse diminuait à mesure que la distribution de la taille de particule de l’alimentation devenait plus grossière. On a trouvé une corrélation entre la quantité de particules fines dans la pulpe, la stabilité de la mousse et la récupération par flottation. La récupération des particules minérales dépend, de façon critique, de la stabilité de la mousse qui, à son tour est hautement influencée par la distribution globale de la taille de particule du matériel d’alimentation. Pour ces raisons, l’étude suggère également qu’il n’est pas possible, en flottation discontinue, de déterminer la vitesse et la récupération des fractions de taille de particules grossières, en les faisant flotter indépendamment des fractions de taille fine.     

铅塔处理高铅镉和高品位高镉锌的工业试验

进行了含镉物料单塔处理一步产出粗镉的工业试验。采用1372大型铅塔处理含镉40%～90%的物料可使镉富集到98%左右,铅、锌及其它高沸点杂质金属的含量符合粗镉要求。     

铅塔处理高铅镉和高品位高镉锌的工业试验

进行了含镉物料单塔处理一步产出粗镉的工业试验。采用1372大型铅塔处理含镉40％-90％的物料可使镉富集到98％左右。铅、锌度其它高沸点杂质金属的含量符合粗镉要求。     

Structural and electronic properties of bastnaesite and implications for surface reactions in flotation

The structural and electronic properties of bastnaesite were studied by using the first-principles method based on the density functional theory(DFT).The geometry structure of bastnaesite was first optimized,and then the Mulliken populations,electron density and density of states were calculated and further analyzed in detail.The calculation results reveal that it mainly ruptures along the ionic Ce-O and Ce-F bonds during the cleavage of bastnaesite,leaving≡Ce~+,≡F~-and≡CO_3~-dangling bonds exposed on the cleavage surface of bastnaesite.Combined with contact angle measurement,surface complexation theory and XPS analysis,the implications of structural and electronic properties on bastnaesite flotation reactions were studied.The hydration of exposed strong ionic bond on cleavage surface results in hydrophilic surface.According to surface complexation theory,the formed surface groups are≡CeOH~0,≡CO_3 H~0 and≡FH~0 groups.The investigated metal ions and flotation reagents complex with surface≡CeOH~0 groups,while≡CO_3 H~0 and≡FH~0 groups are not involved in the complexation.The high activity of Ce atoms facilitates these surface reactions.     

Synergistic depression mechanism of Ca2+ ions and sodium silicate on bastnaesite flotation

Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation. Sodium silicate is commonly used to depress calcium-bearing gangue minerals, however it can also depress bastnaesite when Ca²⁺ ions exist in the pulp. In this study, the effect of Ca²⁺ ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation, zeta potential, fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. Micro-flotation results show that the combination of Ca²⁺ ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect. Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly. Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely. XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO₃ precipitate, which causes more serious depression on bastnaesite flotation.     

新型浮选机叶轮动力学性能及对粗颗粒浮选效果

为了进一步提高粗颗粒的浮选回收率,开发下一代浮选机叶轮是研究的重点之一。针对某钼矿粗粒级回收率低的问题,将一种新型浮选机叶轮应用到钼矿局部浮选流程中。通过开展浮选机动力学性能研究,对比分析新型浮选机叶轮的搅拌分散和分选效果。研究表明,新型浮选机叶轮提高了粗颗粒在槽体内的输送高度,从而促进了粗颗粒回收,在考查期内选厂钼总回收率增加了1.73个百分点。     

Optimisation of work roll shifting and bending to roll thinner gauge HR coils using genetic algorithm

Abstract

Rolling of thin gauge hot rolled (HR) coils demands stringent flatness tolerance. Thin HR coils (≤3 mm) are rolled towards the end of any rolling campaign. The profile and flatness of the strip depend on the profile of the loaded roll gap in the mill stands. There are five key factors that influence the loaded roll gap: initial roll surface profile, roll thermal expansion, wear of roll, deflection of roll stack and shifting of work rolls. This paper deals with all these factors individually for the formulation of an objective function in order to minimise the flatness error. The shifting and bending of rolls are the controllable parameters that require optimising. This has been accomplished using a genetic algorithm (GA) optimisation technique.     

Mechanism of phthalic acid collector in flotation separation of fluorite and rare earth

The mechanism of phthalic acid,a dicarboxylic acid collector,in flotation separation of fluorite and rare earth(RE)was studied in this paper.The experimental data of flotation show that phthalic acid,as the collector,can realize highly efficient separation of fluorite and rare earth under weakly acidic conditions.The adsorption mechanism of phthalic acid on the surface of fluorite and bastnaesite was analyzed in this paper by means of the zeta potential measurement,the Fourier transform infrared(FT-IR),the X-ray photoelectron spectroscopy(XPS)and the stability constant measurement of active metal ion and phthalic acid coo rdination complex.According to the zeta potential testing results,the surfaces of fluorite adsorb the collector phthalate ion with negative charge under weakly acidic conditions which,in turn,increases its electronegativity and results in the motion of its potential.After the reaction between phthalic acid and fluorite ores under weakly acidic conditions,the peak of the fluorite ores is found to have significant changes in the FT-IR results,indicating strong chemical adsorption on the surfaces of phthalic acid and fluorite ores.According to the XPS analysis,the peak of benzene ring of phthalic acid is as high as 2%on the surface of fluorite,while no obvious characteristic peak of benzene ring is found on the surface of bastnaesite.According to the pH potentiometric titration results,the stability constant Ktotal of calcium phthalate complex within the acid range is higher than the stability constant K’total of cerium phthalate complex,indicating that the complex generated between phthalic acid and Ca²⁺is more stable than the complex generated between phthalic acid and Ce³⁺.The possible reason is that Ca²⁺,with the highest reticular density,plays a prevailing role in the octahedron structure of fluorite amidst the acidic media.As the active point of flotation,Ca²⁺works with the carboxyl groups of the collector phthalic acid(-C=O-)to form polycyclic calcium phthalate complex.     

工业有线通信设备在冶金企业的应用与发展

阐述了工业有线通信设备的特点，介绍了自动指令电话、有线对讲、指令电话及相互通话等工业有线通信设备的功能和使用方法，通过分析这些设备的优缺点，提出了工业有线通信设备的选型原则。最后对几种工业有线通信设备的发展历程进行分析，预示了工业有线通信设备的发展方向。     

A neural network based model of sinter quality and sinter plant performance indices

Abstract

A prerequisite of a smooth operation of the ironmaking blast furnace is that the quality of the burden is stable. In blast furnaces where sinter is used as the (main) iron bearing material, its quality plays a crucial role in productivity and fuel economy. Simultaneously the corresponding factors must be considered for the sinter plant. The present paper studies the influence of three variables characterising the bedding piles and five sinter plant operation variables on sinter quality, sinter plant productivity, specific fuel consumption and share of cold return fines. Daily mean values for a period of five years of operation were used in the data driven modelling based on feedforward neural networks. The resulting models were found to describe the major changes in the outputs well. The input–output relations captured by the models were analysed by perturbing one input variable of the networks at a time and analysing the predicted behaviour of the outputs.     

Prediction of electrical resistivity of steel using artificial neural network

Electrical resistivity of commercially produced plain carbon manganese steel has been experimentally measured at room temperature (28–30°C) using four-probe method. Resulting data were used to generate both regression based and artificial neural network-based models for prediction of electrical resistivity from the chemical composition of steel. It was found that both models were capable of predicting the resistivity within ±5% error band. Analysis of data also indicated carbon to be the most influential element to increase resistivity followed by manganese and silicon. A comprehensive literature review indicates no such advanced resistivity prediction model is available in the public literature for commercially produced steel with wide variation in carbon content (0.03?0.85?wt-%), manganese content (0.35–1.50?wt-%) and silicon content (0.015–0.90?wt-%).     

Online prediction and monitoring of mechanical properties of industrial galvanised steel coils using neural networks

In galvanising line of cold rolling mill, mechanical properties, i.e. yield strength (YS) and ultimate tensile strength (UTS), are achieved by controlling the key process parameters within specified limits. In this paper, a feed-forward back-propagation artificial neural network (ANN) is proposed to predict the mechanical properties of a coil from its chemical composition, thickness, width and key galvanising process parameters. Principal component analysis is used to avoid redundancy and collinearity effects in input variables for the ANN. The model predicted the YS and UTS with an accuracy of ±10?megapascal (MPa) for 90% of the data. The model was implemented in the continuous galvanising line of Tata Steel, India. An online quality monitoring system was developed to monitor the predicted mechanical properties and process parameters of a galvanised coil. This system helps quality team in decision making.     

基于遗传BP网络的PID控制算法在无模拉拔温度控制中的应用

将遗传算法与BP神经网络结合,提出了一种利用遗传算法优化BP神经网络权值的智能PID控制算法,改善了系统的动态性能.通过实验采集数据,拟合出无模拉拔感应加热温度控制系统的数学模型.采用本文提出的方法进行了仿真实验,结果表明该算法具有较强的快速性和鲁棒性.