高强度铜闪速熔炼过程颗粒行为仿真研究

通过在Fluent中增加铜精矿颗粒燃烧模块,建立闪速熔炼仿真模型,对闪速熔炼炉冶金过程颗粒行为进行仿真研究。通过在给定工艺条件下对颗粒的运动速度及轨迹、存活时间、颗粒温度变化、氧化程度及颗粒在沉淀池分布状况进行模拟。研究表明,精矿颗粒在进入反应塔内平均存留时间较短,并不断偏离反应塔中央,闪速熔炼炉内颗粒温度受颗粒直径的影响,粒度越小,温度上升越快,20μm的颗粒受漩涡的影响程度比较大且易随烟气排出。     

闪速吹炼炉反应塔内颗粒的反应行为

为深入了解闪速吹炼炉反应塔内颗粒的反应行为变化,通过在不同位置取样,以及对试样进行XRD、XRF、SEM-EDS等分析,观察冰铜粒子在反应塔中的物理化学变化过程,解析冰铜在反应塔中发生着火、氧化脱硫、碰撞聚并、造渣、造铜等变化的规律,了解反应塔产物的特点及烟尘的生成条件。     

铜闪速吹炼炉烟道内气粒两相流动过程的数值模拟

为深入研究闪速吹炼炉上升烟道中烟气与烟尘运动特点,分析烟道内局部耐火材料损耗严重的问题,以闪速吹炼炉上升烟道为对象,开展了烟道内气粒两相流动过程的仿真计算,分析了上升烟道中烟气与烟尘的运动特点,并对上升烟道与余热锅炉连接处黏结快速形成的主要原因进行探究。研究表明,闪速炉烟道内烟尘颗粒尺寸较小,其运动轨迹主要受烟气流动过程带动,且在烟道底部以及烟道与锅炉连接处速度较大,易对炉体耐火材料产生磨损;另外,在烟道与锅炉连接处,由于该位置处烟气和烟尘温度仍相对较高,因此进入锅炉后受烟气速度减小和回流的影响,熔融态颗粒易停滞黏结;同时,由于上升烟道内气流的影响,易导致烧嘴出口处气流偏移,出现烟道与锅炉连接处东侧不易结块,而西侧容易结块的现象。     

旋浮吹炼炉冷修及改造实践

根据某厂悬浮吹炼炉生产运行情况,结合冷修时发现的反应塔水套、沉淀池渣线区耐火砖以及上升烟道顶部侵蚀严重的情况,介绍了该厂悬浮吹炼炉第一次冷修期间针对反应塔、沉淀池、上升烟道进行的结构优化措施,并提出了后续该厂悬浮吹炼炉可以进行的进一步优化措施。     

铜闪速炉悬浮熔炼反应过程机理的研究(Ⅰ)——反应塔中物料颗粒的取样分析

闪速熔炼是现代火法炼铜的主要方法,其主要反应是在反应塔内完成的,所以要研究闪速熔炼的机理,重点是对反应塔内反应过程的研究。本文详细描述了反应塔内工艺物料颗粒的高温急冷取样实验,并对试样进行了全面检验分析,作为悬浮熔炼反应过程机理研究的基础。得出如下结论:研究颗粒在反应塔中的反应过程采用快速急冷的颗粒取样方式是可行的;反应塔中颗粒分布极不均匀,在反应塔中央区域较集中;反应塔中粒子氧化程度极不均匀;大量游离二氧化硅未在反应塔内完成造渣反应;在矿相显微镜分析中发现了草莓状(或蜂窝状)的颗粒、部分粒子有孔洞和部分粒子呈现层状氧化,这些都是闪速熔炼过程中存在粒子分裂行为的有力证据;同时颗粒在反应塔中平均粒径长大了7倍多,说明粒子在反应塔中明显存在碰撞聚合过程。     

闪速吹炼炉改造设计研究

为不断提高闪速吹炼炉炉体的安全性和稳定性,结合国内某铜冶炼厂1台已运行4.5 a的闪速吹炼炉改造实例,分析闪速吹炼炉在实际应用过程中碰到的闪速吹炼炉沉淀池安全性薄弱、粗铜带渣、事故烟道口黏接等问题,并针对这些问题提出了优化方案。改造后,该闪速吹炼炉已投产运行多年,生产正常,投料量比改造前有增加,白冰铜处理量达到100 t/h。     

铜闪速吹炼炉操作参数优化的数值模拟研究

金冠铜业闪速吹炼炉自2013年投产以来,操作参数的持续优化对炉况运行稳定性的大幅提升起到了至关重要的作用。公司前期主要依托生产实践经验对参数进行优化,调控幅度和影响程度缺乏理论数据支持。为此,本文开展了闪速吹炼炉的数值仿真计算,同时,利用正交试验,研究操作参数的影响并寻找闪速吹炼炉最优操作参数。研究表明,工艺风速度越小、工艺风富氧浓度越高以及分散风流量越大,则上升烟道出口烟气中的氧气质量分数越低,反应越充分;与基准工况相比,正交试验得到的最优工况下,上升烟道出口烟气中氧气的质量分数从8.32%减少至6.37%,氧气利用率从88.96%提高至92.67%。     

肯尼科特闪速吹炼炉设计改进

2001年7月肯尼科特（Kennecott）闪速吹炼炉按计划停炉以实施设计改进,增强炉子完整性。新设计有以下特点：重新设计了所有的侧壁冷却元件,包括Hatch的冷却元件最新设计技术;重新设计了炉膛,包括炉子反应塔端部的运动场型炉膛和靠近炉子侧壁的台阶式炉膛;在反应塔周围增加了沉淀池顶平冷却元件;反应塔过渡元件换成新设计元件并改进了炉子冷却元件监控系统。总结了停炉以后所做的这些改进并给出了冶炼厂性能的最新数据。     

闪速吹炼炉旋流分布器的应用实践

闪速吹炼是一种高强度的悬浮铜冶炼工艺,具有高热、高集中、高氧势的特点。针对金冠铜业闪速吹炼炉出现炉况波动较大的情况,对闪速吹炼炉分布器进行理论研究,并将其改为旋流设计。改造后,提高了闪速吹炼炉的反应效率,保证炉况稳定性,还减少了阳极炉的氧化还原时间,降低了天然气单耗,对提高炉体安全也有积极作用。     

肯尼科特闪速吹炼炉设计改进

2001年7月肯尼科特(Kennecott)闪速吹炼炉按计划停炉以实施设计改进,增强炉子完整性.新设计有以下特点:重新设计了所有的侧壁冷却元件,包括Hatch的冷却元件最新设计技术;重新设计了炉膛,包括炉子反应塔端部的运动场型炉膛和靠近炉子侧壁的台阶式炉膛;在反应塔周围增加了沉淀池项平冷却元件;反应塔过渡元件换成新设计元件并改进了炉子冷却元件监控系统.总结了停炉以后所做的这些改进并给出了冶炼厂性能的最新数据.     

闪速炼铜中烟尘的形成过程

从工业闪速炉及其排烟路径上的不同位置在线提取烟尘试样分析,研究了烟尘形貌、粒度等的变化及烟尘的形成条件,发现烟尘不是反应塔中没有反应的细颗粒精矿粒子,而是反应塔中未沉降到沉淀池的、过氧化的、粒度很小的熔融球形粒子;石英砂和吹炼渣粒子很难成为烟尘;反应塔高度对烟尘率有较大的影响,提高反应塔高度有利于降低烟尘发生率。提出了工业闪速熔炼生产中烟尘形成的过程机理。     

Kinetics of the flash converting of MK (chalcocite) concentrate

The chemical kinetics and mechanism of the flash converting reaction of MK concentrate (approximately 93 pct chalcocite and 7 pct pentlandite) in oxygen-containing atmospheres were determined. The reaction path of individual particles undergoing flash oxidation in a laminar flow furnace was followed by observing the particle temperature and changes in apparent particle diameter with a fast response, two-wavelength pyrometer; and these observations were compared to the predictions of a mathematical model of a single reacting particle. Flash reaction products were examined under a scanning electron microscope to determine chemical composition and particle morphology. A dust generation mechanism was elucidated, whereby preferential evaporation of copper from the surface of the particle leaves it encased in a nickel-rich shell. Continued oxidation of sulfides and metallic copper leads to ongoing particle heating and the generation of gas (sulfur dioxide and copper vapor) which either vents through a rupture or causes catastrophic fragmentation of the nickel-rich shell.     

旋流燃烧器颗粒分散特征研究

建立闪速炉旋流燃烧器试验模型,通过冷模试验方法研究旋流燃烧器颗粒分布特征。结果表明,反应塔内颗粒分布受控于风幕风和内旋风射流综合作用,风幕风射流使颗粒集中分布于燃烧器正下方区域,内旋风射流使颗粒远离燃烧器正下方区域分布;同轴多通道射流切向动量矩与按半径加权的轴向动量矩之比M与颗粒质量偏析度p_x和中心区域颗粒质量分数x_1拟合后的无量纲关联式分别为px=5.71e~(-0.262M)-0.34 M、x_1=68.66e!(-0.264M)-4.05 M;p_x与x_1近似线性相关。     

Compositional Fragmentation Model for the Oxidation of Sulfide Particles in a Flash Reactor

A mathematical model to predict the size distribution and chemical composition of a cloud of sulfide particles during high-temperature oxidation in a flash reactor is presented. The model incorporates the expansion and further fragmentation of the reacting particles along their trajectories throughout the reaction chamber. A relevant feature of the present formulation is its flexibility to treat a variety of flash reacting systems, such as the flash smelting and flash converting processes. This is accomplished by computing the chemical composition of individual particles and the size distribution and overall composition of the particle cloud in separate modules, which are coupled through a database of particle properties previously stored on disk. The flash converting of solid copper mattes is considered as an example. The model predictions showed good agreement with the experimental data collected in a large laboratory reactor in terms of particle size distribution and sulfur remaining in the population of particles. The cumulative contribution and distribution coefficients are introduced to quantify the relationship between specific particle sizes in the feed and those in the reacted products upon oxidation, the latter of which has practical implications on the amount and chemical composition of dust particles produced during the industrial operation.     

闪速吹炼的生产实践

简要介绍了闪速吹炼的基本反应原理和炉体结构特点,阐明了闪速吹炼的渣型选择、炉渣结构、炉渣特性及铁酸钙渣对炉衬和炉体安全的影响,分析了入炉原料尤其是铜锍粉的成分与要求,强调了炉体安全是闪速吹炼炉生产控制中的重点。     

Mathematical modeling of sulfide flash smelting process: Part I. Model development and verification with laboratory and pilot plant measurements for chalcopyrite concentrate smelting

A mathematical model has been developed to describe the various processes occurring in a flash furnace shaft. The model incorporates turbulent fluid dynamics, chemical reaction kinetics, and heat and mass transfer. The key features include the use of thek-ε turbulence model, incorporating the effect of particles on the turbulence, and the four-flux model for radiative heat transfer. The model predictions were compared with measurements obtained in a laboratory flash furnace and a pilot plant flash furnace. Good agreement was obtained between the predicted and measured data in terms of the SO₂ and O₂ concentrations, the amount of sulfur remaining in the particles, and the gas temperature. Model predictions show that the reactions of sulfide particles are mostly completed within about 1 m of the burner, and the double-entry burner system with radial feeding of the concentrate particles gives better performance than the singleentry burner system. The model thus verified was used to further predict various aspects of industrial flash furnace operation. The results indicate that from the viewpoint of sulfide oxidation, smelting rate can be substantially increased in most existing industrial flash furnaces. Formerly Graduate Student, Department of Metallurgical Engineering, University of Utah.     

饱和磁性分析法快速测定闪速吹炼炉渣中磁性四氧化三铁含量

探讨了饱和磁性分析仪快速测定闪速吹炼炉渣中磁性四氧化三铁含量的方法。通过选择试验发现了采用自制四氧化三铁合成标准物质绘制校准曲线时适用的局限性,改用实际闪速吹炼炉渣标准样品系列绘制校准曲线,得到了很好的应用。研究了试样量、试样粒度、共存磁性物质等各种因素的影响,确定了最佳实验条件。方法测定闪速吹炼炉渣中磁性四氧化三铁的含量范围为2409%～6662%,方法检出限为014%,相对标准偏差（RSD,n=12）在064%～079%之间,样品的分析结果与X射线衍射分析法（XRD）结果吻合较好,能完全满足生产控制快速分析的需要。     

基于多线程通讯的铜闪速炉反应塔内衬蚀损红外监测系统设计

针对铜闪速护反应塔内衬蚀损状况检测的传统方法所存在的局限性，提出了一种基于红外点温仪在线扫描识别反应塔内衬蚀损的非接触实时监测的新方法，并设计了一套相应的监测诊断系统。仿真实验表明，该方法技术可行，系统易于实现且经济实用，能满足闪速护运行工况要求。本文重点讨论了系统的多线程串行通讯实现。     

Pyrometric temperature and size measurements of chalcopyrite particles during flash oxidation in a laminar flow reactor

A fast two-color pyrometer has been constructed and applied to simultaneous temperature and size measurements of individual chalcopyrite particles (CuFeS₂) during flash oxidation in a laminar flow reactor. The influence of different oxygen concentrations (0, 10, 20, 50, and 75 vol pct), gas temperatures (1073 and 1273 K), particle size fractions (53 to 74 μm and 74 to 150 μm), and reaction times (up to 0.17 seconds) on chalcopyrite particle temperature and size distributions was studied. The particle reaction rates were characterized by the sulfur mass in the solid reaction product. Particle temperatures ranged from the ambient gas temperature up to 2700 K. A strong correlation between the oxygen concentration and the median particle temperature was observed.