Studies on Characterization and Beneficiation of Typical Low-Grade Goethitic Iron Ore Jharkhand,India

The present investigation aims at detailed characterization and beneficiation of the low-grade goethitic ore deposit of Gua iron ore mines from Jharkhand. The main purpose of this study is to determine the chemical and mineralogical properties for its utilization for economic purpose. Chemical composition of iron ore used in the present study comprises of 56.54% Fe, 5.71% silica, 5.18% alumina and 6.62% LOI, and further characterization studies such as X-ray diffraction, microscopic study, Fourier transform infrared spectroscopy, TG–DTA have been carried out to ascertain different minerals. After completion of characterization studies, an attempt has been made to beneficiate the low-grade iron ore fines by selective flocculation using amylopectin as a flocculant and using sodium silicate as a dispersant. Flocculation experiments have been performed by varying dosage of amylopectin and sodium silicate at a pH of 10. From the studies, it is possible to enhance the grade and recovery to 63.66% and 83.33%, respectively.     

锌焙砂还原焙烧工艺的试验研究

锌焙砂含有少量难溶的铁酸锌 ,通过还原焙烧可以降低铁酸锌含量。本文主要探讨还原焙烧温度、时间和煤粉用量对可溶锌含量的影响。     

球团矿氧化焙烧及还原过程中的强度变化

研究了球团矿在氧化焙烧和还原过程中抗压强度的变化规律.通过焙烧试验得到了球团矿必要的焙烧温度.通过还原反应后的高温抗压强度研究估算了球团矿焙烧中必要的强度.使用可调气氛高温抗压试验机研究了相应球团矿在氧化焙烧过程中的强度变化规律.球团矿在焙烧过程中有一个强度大幅下降的特定温度.如果该温度高于必要的焙烧温度,焙烧工艺是可行的.     

某低品位二氧化锰还原焙烧矿粉的浸出试验研究

二氧化锰矿经还原焙烧后用硫酸浸出特性的研究,是高效利用锰矿资源的基础性工作。试验在某研究院自主研制的还原焙烧设备中取得的二氧化锰还原率94.67%的矿粉,通过浸出试验研究,获得了该还原焙烧矿粉的最佳浸出条件:粒度-0.15 mm、酸矿比0.64~0.70、温度60~80℃、时间60 min。最后经条件验证试验,锰浸出回收率可达91%以上。     

含铬废渣还原焙烧-富集试验研究

针对提钒之后的含铬废渣,利用SEM、XRD分析和化学分析,并结合热力学分析,主要考察含铬废渣球团还原过程中的铁、铬等有价金属元素的迁移富集规律和物相变化规律。发现随着还原温度和碱度的提高,Fe、Cr、Mn、V等有价金属的回收率呈先逐渐增大而后减小的趋势。Fe、Cr主要进入金属铁相与铬铁合金相中,Mn和V分别逐渐富集于锰铁合金相和钒钛碳化物相中,随着还原温度的升高,Ti随钙钛矿相逐渐向钒钛碳化物相中迁移。试验研究表明,合理回收有价金属的温度为1 400℃、碱度为1.0、还原时间90 min。     

红土镍矿含碳球团还原焙烧-磁选试验

为提高红土镍矿金属品位及回收率,采用含碳球团还原焙烧-磁选分离工艺对镍品位为1．45％（质量分数,余同）的红土镍矿进行了处理,研究了还原温度、配碳量、还原时间以及磁选工艺对Ni、Fe品位和回收率的影响。试验结果表明：随着还原温度和配碳量的增加,Ni、Fe品位及回收率均会增加,其中温度的影响最大,配碳量次之,时间最小。1...     

Characterization and Reduction Roasting Studies of an Iron Rich Manganese Ore

The article presents the reduction roasting followed by low intensity magnetic separation studies of a low grade Mn ore assaying 27.7% Mn and 26.1% Fe in order to obtain a Mn rich non-magnetic concentrate. The reflected light microscopic studies followed by the liberation studies of the as-received sample using quantitative mineralogical evaluation by scanning electron microscope suggested a poor liberation pattern of the constituent Mn and Fe minerals owing to a complex association of the different phases present. The reduction roasting studies carried out while varying different process parameters such as ore particle size, temperature, reductant content and residence time ended up with products containing 45–48% Mn with a Mn/Fe ratio of 5–6 at a yield of ~ 60% with the optimum level of conditions such as temperature: 800–850 °C, time: 90–120 min and charcoal: 10–12%. The scanning electron microscopy–energy dispersive X-ray spectroscopy studies of the roasted product reported manganite as the major Mn bearing phase while magnetite was found to be the major iron bearing phase.     

还原焙烧-磁选分步回收针铁矿渣中的锌铟铁

针铁矿法常用于湿法炼锌工艺中的除铁,其产生的针铁矿渣含有铁、锌等有价金属,具有较高的回收价值。以广东某冶炼厂针铁矿渣为原料,提出了采用还原焙烧—磁选的方法分步回收其中的锌、铟和铁资源。首先进行了较为详细的工艺矿物学研究,查明了其中有价金属含量和主要物相组成;通过考察还原焙烧过程中的主要影响因素,得到优化后的还原焙烧条件为:碳粉添加量为针铁矿渣量的60%、焙烧时间4 h、焙烧温度1100℃,锌和铟的挥发率可分别达到93.63%和71.48%。还原焙烧后的渣进行强磁—弱磁磁选试验获得铁精矿产品,铁精矿产品产率69.46%、铁品位63.80%。     

回转窑还原焙烧锌冶炼污泥与烟尘回收研究

设计了处理能力为100t/d的回转窑,开展低品位锌冶炼废水处理污泥还原焙烧回收氧化锌烟尘的试验。结果表明,污泥含锌品位对回转窑挥发获得氧化锌烟尘的效果有显著影响;当污泥的锌品位为5.04%和8.34%时,表冷收尘系统回收烟尘含锌分别为19.4%和21.4%,对应的布袋收尘系统回收烟尘的含锌量高达50.2%和51.6%。水淬渣浸出液中重金属浓度均低于GB5085.3-2007危险废物的各项限值,可直接用于生产或堆存。     

赤泥还原焙烧脱铁试验研究

研究了采用还原焙烧法从赤泥中除铁。试验结果表明:铁去除率达80.68%,钪损失率为2%;在400～500℃条件下,Fe2O3转变为Fe3O4阶段的还原反应动力学与界面化学反应控制模型符合较好;550℃以上,反应由界面化学反应和气体内扩散混合控制。     

废三元锂电池碳热还原焙烧热解研究

以废三元锂离子电池正负极片为原料,采用碳热还原焙烧—水浸联合法,通过热力学、TG-DSC分析,结合XRD、SEM-EDS等表征手段,为正极活性材料与铜铝箔之间热解分离、有价金属(Ni、Co、Mn)的还原及Li的优先提取进行相关理论研究分析,并简单分析了P和F的走向。结果表明,正极活性材料有价金属碳热还原理论上是可行的,且经XRD、SEM-EDS表征,焙烧后有价金属Ni、Co、Mn主要以金属或金属氧化物形式存在,Li则以Li_2CO_3形式存在,且Ni、Co、Mn含量分布不均匀。在碳含量27.33%、焙烧温度650℃和焙烧时间2.5h的最佳条件下,Li的浸出率达到83.17%,但该条件下,正极活性材料与铜铝箔分离效果不是很好,给后续酸浸净化回收Ni、Co、Mn带来一定的麻烦;P和F的走向为原料→焙烧料→水浸渣。     

锰矿石还原脱砷试验研究

研究了锰矿石还原焙烧脱砷,通过对比试验,确定了脱砷工艺及最佳工艺参数。试验结果表明,通CO气体并加石油焦还原焙烧,脱砷效果最好;在物料粒度0．5～0．75 mm、焙烧温度1100℃、焙烧时间2 h、CO流量1．5 L/min、石油焦加入量20％条件下,砷脱除率为97．13％。     

大型预焙铝电解槽焦粒焙烧技术的改进

本文介绍了某铝业公司大型预焙铝电解槽焦粒焙烧技术的应用和发展,以及焦粒焙烧技术的一些实践经验。     

蛇纹石矿还原焙烧与磁选富集镍铁研究

以四川某蛇纹石为原料,考察添加剂对还原与磁选富集镍铁的影响。结果表明,加入硫酸盐和碳酸盐各15%在1 100℃还原120min,然后在磁场强度79.62kA/m条件下磁选,精矿中镍和铁品位分别为5.99%和53.84%,镍和铁的回收率分别达到87.59%和72.09%。     

大洋多金属结核金属化还原焙烧—磁选回收镍铜钴工艺研究

采用金属化还原焙烧-磁选工艺从大洋多金属结核中回收镍、铜、钴,考察了氟化钙添加量、还原焙烧温度、二氧化硅添加量、黄铁矿添加量、无烟煤添加量、还原焙烧时间等对还原焙烧-磁选工艺回收镍、铜、钴效果的影响。结果表明,最佳的焙烧工艺条件为：原矿添加4%的氟化钙、2.5%的二氧化硅、4%的黄铁矿、7%的无烟煤混匀造球,1 150 ℃恒温焙烧2 h。焙砂细磨后,经过160 kA/m磁选分离,得到含Ni 10.09%、Cu 7.86%、Co 1.59%的精矿,Ni、Cu、Co回收率分别达到96.72%、88.28%、95.81%,实现了大洋多金属结核中有价组分的高效回收。     

红土型镍矿还原焙烧回转窑整体炉衬的设计与优选

以还原焙烧回转窑炉衬设计为例,阐述了还原焙烧窑整体炉衬的设计理念以及整个炉衬的优选配置。生产实践证明:经过优化的炉衬设计完全满足焙烧工艺对衬体在材料、结构方面的要求,其经验为国内外同类炉型的炉衬设计与优选提供了参考的成功案例。     

Preparation of Chromium-iron Metal Powder from Chromium Slag by Reduction Roasting and Magnetic Separation

Chromium slag(CS)has become one of the most hazardous solid waste containing chromium and iron.Based on its characteristics,the technology of reduction roasting and magnetic separation was employed to treat CS.The major impurity element of CS is magnesium and it exists in magnesium ferrite phase,which is hard to recover iron in the absence of additives.During reduction roasting,additives(Al2O3and CaF2)could destroy the structure of magnesium ferrite and improve the iron grade and recovery.The final product,i.e.chromium-iron powder,contains 72.54% Fe and 13.56% Cr,with the iron recovery of 80.34% and chromium recovery of 80.70%.     

Recovery of Iron From High-Iron Red Mud by Reduction Roasting With Adding Sodium Salt

 Red mud is the waste generated during aluminum production from bauxite, containing lots of iron and other valuable metals. In order to recover iron from red mud, the technology of adding sodium carbonate—reduction roasting—magnetic separation to treat high-iron red mud was developed. The effects of sodium carbonate dosage, reduction temperature and reduction time on the qualities of final product and the phase transformations in reduction process were discussed in detail. The results showed that the final product (mass percent), assaying Fe of 90.87% and Al2O3 of 0.95% and metallization degree of 94.28% was obtained at an overall iron recovery of 95.76% under the following conditions of adding 8% sodium carbonate, reduction roasting at 1050 ℃ for 80 min and finally magnetic separation of the reduced pellets by grinding up to 90% passing 0.074 mm at magnetic field intensity of 0.08 T. The XRD (X-ray diffraction) results indicated that the iron oxides were transformed into metallic iron. Most of aluminum mineral and silica mineral reacted with sodium carbonate during the reduction roasting and formed nonmagnetic materials.     

废旧三元正极材料葡萄糖还原焙烧优先提锂工艺

以废弃三元锂离子电池正极材料(spent-NCM)为研究对象,葡萄糖(C₆H₁₂O₆)为焙烧剂,采用焙烧—水浸工艺实现锂的选择性优先浸出。结果表明,在600℃焙烧90 min、C₆H₁₂O₆与spent-NCM质量比25%、浸出液固比20 mL/g的条件下,spent-NCM中的有价金属元素转变为水溶性的Li₂CO₃和不溶性的Ni、Co和MnO,焙烧产物经水浸可选择性优先分离Li, Li的浸出率为95.62%。