Fluidized Bed Selective Oxidation-Sulfation Roasting of Nickel Sulfide Concentrate: Part I. Oxidation Roasting

Two-stage oxidation-sulfation roasting of nickel sulfide concentrate in fluidized bed was investigated to generate water-soluble metal sulfates as an alternative process to smelting of the sulfide concentrate for the recovery of valuable metals. The first stage, i.e., oxidation roasting, was employed to preferentially oxidize the iron before performing sulfation roasting. A batch fluidized bed roaster was constructed for roasting tests. Roasting products from various roasting temperatures and different roasting times were analyzed by SEM/EDS, EPMA, XRD, and ICP-OES to investigate the oxidation roasting behavior of the nickel concentrate as a function of temperature and time.     

复杂铜精矿沸腾焙烧扩大试验研究

本文对含Zn、Pb、Sb的复杂铜精矿沸腾焙烧扩大试验进行总结,确定了试验方法,进行了烟气量及烟气浓度的计算,并且确定了沸腾焙烧扩大试验的试验参数。     

锌阳极泥—硫化锌精矿中锰锌分离的焙烧参数研究

通过锌阳极泥与硫化锌混合焙烧—热水浸出工艺对锌阳极泥中的锰进行了提取,研究了焙烧气氛、物料配比、焙烧温度、焙烧时间等对锰提取率的影响。结果表明：锌阳极泥与硫化锌精矿质量比1∶1.5,焙烧温度760℃,焙烧时间2 h,浸出温度80℃,浸出时间2 h,液固比5∶1,锰的浸出率在80%以上。     

Fluidized Bed Roasting Process for Desulphurization of Scheelite

Studies on roasting of sheelite concentrate have been carried out in fluidized bed to reduce its sulphur content to <5%. Initial investigations have been done using a 10 cm I.D. fluidized bed roaster and the data so generated was used for the design of a fluidized bed roaster of 50 kg/hr capacity. The experiences on roasting of sheelite concentrate with the fluid bed reactor and the methods for scale up to large size reactor are presented.     

锌精矿主要杂质成分焙烧过程中的反应行为

对锌精矿沸腾焙烧过程相关反应进行了热力学分析;并系统分析了锌精矿原料主要元素对某厂沸腾焙烧系统的产品质量、操作条件、运行周期等的影响。最后结合某厂生产实际情况,提出解决问题的具体措施。     

沸腾焙烧处理细粉锌精矿的工艺改进及应用

对提高沸腾焙烧处理细粉锌精矿能力等进行探讨,通过细粉锌精矿在圆筒干燥过程中实现结构较松散的微制粒,满足沸腾焙烧入炉锌精矿粒度要求、优化沸腾焙烧工艺操作控制等工艺改进,能够提高沸腾焙烧处理含铜、铟高有价金属及高铅、高硅等细粉锌精矿能力,确保沸腾焙烧炉高效稳定经济运行。     

Sulfation Kinetics of Low-Grade Nickel–Copper Sulfide Ore in the Sulfuric Acid Roasting Process

The enormous demand for and consumption of nickel in industrial applications has induced the depletion of high-grade nickel sulfide ore, which has inevitably led to the utilization of the substantial deposits of depreciated low-grade nickel-copper sulfide ore. In this work, the mineral phase transformation and sulfation kinetics of nickel, copper, iron, and magnesium in the roasting process were studied. The kinetic parameters of the metals were calculated by using the sulfation rates under different roasting temperatures, ratios of acid to ore and particle size of ore. The results showed that the sulfation process of metals is fit well by the kinetic function $$1 - {{text{2}} mathord{left/ {vphantom {{text{2}} 3}} right. kern-0em} 3}x - {{(1 - x)}^{{{{text{2}} mathord{left/ {vphantom {{text{2}} 3}} right. kern-0em} 3}}}} = kt$$ (G–B equation) over 0–20 min and 30–150 min for nickel, copper, and iron, as well as over 5–30 min in the case of magnesium. Furthermore, internal diffusion (three-dimensional diffusion, D4) was the restricting factor in the sulfation processes of the metals, as suggested by experimental data regarding the ratio of acid to ore and the particle size of ore.     

Roasting of Nickel Concentrates

The oxidation of three nickel concentrates from two Canadian smelters was studied by thermogravimetric analysis. Concentrate samples were heated to 1223 K (950 °C) in inert or oxidizing atmospheres to determine the reaction behavior. By recording the mass change as well as the SO₂ content in the outlet gas, the oxidation behaviors were quantified. Isothermal roasting tests were carried out on the concentrates over the temperature range of 673 K (400 °C) to 1123 K (850 °C). When heated in air, the samples gain mass as a result of sulfate formation at temperatures up to approximately 873 K (600 °C) to 973 K (700 °C), whereas at higher temperatures, the samples exhibit a large mass loss attributed to sulfate decomposition as well as direct SO₂ formation by oxidation. In a 4 pct O₂ gas atmosphere, significantly less sulfates were formed. Mixed reactions take place, in which some lead to mass loss and SO₂ generation, and others lead to mass gain and SO₂ consumption. The relative importance of the various reactions depends on the experimental conditions.     

沸腾焙烧炉沸腾层测温一次装置选型实践

本文介绍了以锌精矿为原料的沸腾焙烧炉沸腾层测温一次装置的选型经验,以及比较成功的选型方案及其应用实践。     

一水硬铝石型高硫铝土矿硫酸焙烧试验研究

研究了某一水硬铝石型高硫铝土矿的硫酸焙烧特性。试验结果表明:焙烧温度是影响铝、铁溶出率的主要因素;最佳焙烧工艺条件为焙烧温度350℃,硫酸与铝土矿的质量比2.75∶1,焙烧时间180min;最佳焙烧条件下铝溶出率超过83%,铁溶出率超过99%。     

白云鄂博铁精矿氢气流化还原试验

通过可视流化床研究不同温度和氢气流速下对还原白云鄂博铁精矿的影响。试验表明,同一温度下,氢气流速的增加有利于提高流化还原反应的还原效率,但这种作用在低温下更为明显。随温度的升高,流化还原效率提高,但高温下流化效率增长幅度小于低温。应用热重分析研究了不同温度下氢气还原白云鄂博铁精矿的还原动力学,结果表明:其反应的限制性环节为内扩散,活化能随还原时间呈现先下降后上升的现象,而表观活化能的降低更有利于反应的加速进行。在试验条件下,5~10 min时的还原反应速度较快。     

铬精矿的焙烧工艺研究

通过对铬精矿的焙烧条件和焙烧过程的ＳＴＡ分析研究,得到合适的焙烧条件为：白云石配入量为铬精矿的１．０－１．４倍,苏打配入量为理论量的１．０５－１．１５倍,焙烧温度１０５０－１１５０℃,焙烧时间６０－９０ｍｉｎ,焙砂的铬浸出率〉９５％,焙烧过程中,焙烧反应是苏打分解的氧化钠与铬精矿的直接化学反应,其在〈９７０℃的焙烧温度下,９０％的铬精矿就已反应完全。     

流态化还原铁精粉粘结过程试验研究

采用热态可视化流化床装置研究了铁精粉流态化还原过程,描述了流化床粘结失流过程的一些宏观表现和颗粒的微观变化.研究发现,失流后不同还原剂引起的料层膨胀程度明显不同,例如用H2作还原剂时料层膨胀40%左右,而用CO时膨胀会达到82%,而且颗粒问的粘结强度也与还原剂的种类有关.同时,适当降低还原温度可以延缓失流的发生也得到了...     

Application of Sulfide Copper Ores Oxidizing Roasting Products as Sulfidizing Agent During Melting Nickel Raw Materials To Matte

Metallurgist - X-ray fluorescence analysis, X-ray powder diffraction, electron microprobe analysis, scanning electron microscopy, and thermal analysis are used to evaluate the material composition,...     

Integrated Modeling of Anaerobic Fluidized Bed Bioreactor for Deicing Waste Treatment. II: Simulation and Experimental Studies

This paper examines the influence of bed segregation on the performance of an anaerobic fluidized bed bioreactor (AFBR) using both an integrated mathematical model previously described in Part I of this study, and experimental data obtained from a laboratory-scale AFBR continuous flow system and batch serum vial tests. Local hydrodynamics within the bed are shown to determine mixing intensities and patterns of bioparticles thereby controlling biofilm thickness and composition along the bed height. Results of the model simulations and the experimental data indicate that shallow biofilms that allow full substrate penetration are dominantly populated with faster growing micro-organisms. The internal mass transfer resistance in thicker biofilm significantly influences population distribution resulting in the increase of population of slower growing micro-organisms in a deeper layer of the biofilm. The serum bottle tests also confirm that microbial distribution inside a multispecies biofilm is determined by the hydrodynamic condition of the reactor. This study illustrates the importance of hydrodynamic regimes in the AFBR, and demonstrates the impact of bed segregation on bioparticle properties and total system performance.     

难处理金精矿固砷焙烧工艺研究

对含砷金精矿固砷焙烧工艺条件进行了研究。用石灰作固砷剂 ,在 (6 5 0± 2 0 )℃下焙烧 1 80 min,固砷率 >95 % ,硫脲浸金的浸出率≥ 88%     

硫精砂综合利用试验研究

针对铜陵铜官山铜矿硫精砂综合利用所进行的试验研究，采用了内热多段焙烧工艺，使硫精砂中的硫砷主要以元素硫，单质砷和硫砷化物的形式产出，大大减少了尾气中SO2和As2O3的含量，便于环保。试验中，硫、砷的脱除率分别达到了98．4％和99．1％，金浸出率达到84．1％，在实验室规模上实现了该硫精砂的综合利用。