利用澳大利亚Hawsons磁铁精矿生产氧化球团试验

通过对澳大利亚Hawsons磁铁精矿进行理化性能测定、矿物组成分析及颗粒形貌观察以及球团实验室试验,研究了Hawsons磁铁精矿的品质以及用作球团原料时的各项性能。结果表明,Hawsons磁铁精矿铁品位高达70.58%,w(SiO_2)为1.88%,w(Al_2O_3)非常低,仅为0.3%,其他杂质质量分数也很低。Hawsons磁铁精矿粒度100%小于0.045 mm,比表面积为1 910 cm~2/g,成球性好。膨润土配比为0.8%时,生球强度可以满足生产要求。1 230℃焙烧20 min,球团矿的抗压强度可达到3 000 N/球以上。球团矿铁品位为67.53%,w(SiO_2)为2.43%;而且还原度(RI)高、低温还原粉化指数(RDI)和体积膨胀指数(RSI)低,是一种优质的球团矿。     

转炉炼钢污泥冷固结成型实验研究

使用对辊压球机压团,对转炉污泥的冷固结成球性能进行了实验研究。结果显示,加糖浆和F粘结剂制成的球团抗压强度随粘结剂用量增加先增加后减小;用水玻璃作粘结剂时,球团抗压强度随粘结剂用量增加而增加。在一定水分含量下,球团抗压强度与膨润土添加量成正比。加糖浆、F粘结剂、水玻璃和膨润土四种粘结剂所制得的球团,其最大抗压强度分别为:1 214 N/个、1 094 N/个、1 268 N/个和976 N/个。四种球团的抗压强度都随成球压力的增加而增加,但变化趋势不尽相同。     

降低10m~2竖炉膨润土用量的生产实践

在铁矿资源日趋短缺的条件下,提高球团矿品位可在一定程度上降低炼铁成本,降低膨润土消耗是提高竖炉球团矿品位的途径之一。分析了河北敬业集团10 m2竖炉膨润土消耗偏高的原因,通过严格原料管理、工艺控制、加强对原料水分的控制、选用适合所用球团矿原料特点的膨润土等措施,吨矿膨润土用量由23 kg降低到16 kg,球团矿的品位达到了63.5%,高炉综合入炉品位提高0.255%。     

硫酸渣精矿的润磨造球实验研究

为了解决硫酸渣精矿成球性能和成品球质量差的问题,研究了配加膨润土润磨对硫酸渣精矿成球性能及球团矿质量指标的影响。结果表明,在膨润土配比为1.7%,混合料水分为15%,润磨时间6min,造球时间15 min,预热温度950℃,生球预热时间6 min,焙烧温度1 210℃,焙烧时间15 min的条件下,可获得抗压强度为3 650 N/个,RI为86.28%,RSI指数为8.16%的成品球团矿。采用润磨技术,有望改善硫酸渣精矿的成球性能及其球团矿质量指标。     

Application of artificial neural network model to predict reduction degradation index of iron oxide pellets

Abstract

The reduction degradation index (RDI) is an important metallurgical property of iron ore pellets used for the production of RDI from shaft furnace or for use in blast furnaces. In order to develop a control strategy, a neural network model has been developed to predict the RDI of pellets from 13 input variables, namely feedrate of green pellets, bed height, burn through temperature, firing temperature, specific corex gas consumption, bentonite, moisture and carbon content in green pellets and Al₂O₃, SiO₂, CaO, MgO and FeO in fired pellets. The RDI of pellets was more sensitive to variation in MgO, CaO, bentonite and green pellet carbon content. The predicted results were in good agreement with the actual data.     

某铜钼矿铜钼分离工艺试验研究

介绍了某铜钼矿石铜钼分离的药剂试验成果，在硫化钠用量15．5kg／t、水玻璃用量0．55kg／t，闭路试验指标：当铜钼混合精矿中含铜17．85％，钼0．251％时，获得的钼精矿品位46．77％，钼回收率85．72％，其中含铜0．205％，铜精矿品位17．93％，铜回收率99．995％。     

膨润土理化性能对球团性能影响的研究

根据国内的质量标准和检测方法测定了六种膨润士的理化性能,并将其与冀东铁精矿混合造球。进行球团焙烧试验。通过对试验数据进行回归处理,找到了膨润士理化性能与球团性能之间的关系。     

低铁高硅赤铁精矿对氧化球团性能的影响

为合理利用国内低铁高硅铁精矿、降低球团生产成本,研究了低铁高硅赤铁精矿对生球、预热球和焙烧球团性能的影响。结果表明,典型的低铁高硅赤铁精矿A较磁铁精矿有更好的润磨性能。赤铁精矿A的亲水性较磁铁精矿强,在保持生球水分不变且赤铁精矿配比较高的条件下(>10%),生球水分不足,生球质量随着赤铁矿配比的提高而变差。随着赤铁精矿A的配比由0提高到50%,预热球强度由588降低到196 N/个,焙烧球团抗压强度由3 425降低到1 368 N/个,赤铁精矿A配比不宜高于30%,适当提高焙烧温度有利于球团抗压强度的提高。配加低铁高硅赤铁精矿A的球团还原膨胀性能和还原性能均有一定程度改善。     

GF88精粉特性研究及工业应用试验

球团作为精料在中国高炉炉料结构中呈现增加的趋势,这使得高品位球团精粉的需求不断增加,以烧结粉矿制备的GF88赤铁精矿是一种填补球团精粉的缺口的有益补充。广东珠海裕嘉球团厂在120万t/年的链篦机-回转窑生产线上开展了GF88精粉工业应用试验,对其使用性能进行综合评估。工业应用结果表明,配加25%GF88精粉后,膨润土用量从3.4%降低至2.8%,生球落下强度从4.5 次/0.5 m提高到7.0 次/0.5 m左右,成品球团抗压强度从2 300 N/个提升到2 400 N/个以上,工序能耗从24.21 kg/t降至23.93 kg/t,成品球团铁品位提升0.25%,SiO₂质量分数从7.1%减小到6.3%,冶金性能良好,高炉冶炼燃料比降低。在珠海裕嘉球团厂的工业试验表明了GF88精粉具有降低膨润土用量、提高球团抗压强度、降低球团粉率、降低工序能耗等优点。     

The Effect of Calcined Colemanite Addition on the Mechanical Strength of Magnetite Pellets Produced with Organic Binders

Iron ore pellets must have sufficient mechanical strengths against degradation in all stages of pellet production. Low strength is also a problem for product pellets since they abrade during transportation to the reduction furnaces. The use of a binder is necessary to provide sufficient strength to the pellets and for better operation and handling of pellets. Bentonite is the standard binder in the industry; however, it is considered an impurity due to its acid oxide contents. Organic binders have been tested for many years as alternative binder to bentonite. They have been found to give sufficient wet pellet properties. However, they failed to provide sufficient strength to the preheated and fired pellets due to lack of slag bonding. It has been assumed that one possible effective method to improve the preheated and fired pellet strengths is addition of a slag-bonding constituent. In this study, calcined colemanite was added to the pellet feed to overcome the lower strength problem encountered with organic binder use. The strength of pellets produced with organic binders and calcined colemanite alone and in combination was comparatively studied against the strength of pellets made with standard bentonite binder in magnetite concentrate pelletizing. The results showed that addition of calcined colemanite into the pellet mixture improved the preheated and fired pellet strengths of pellets produced with organic binders.     

利用神经网络模型预测球团矿的冷压强度(英文)

建立了一个神经网络模型来预测球团矿的冷压强度,该网络模型采用三层前向BP神经网络,网络结构为12-12-1,12个输入变量分别为给料率、料层高度、焙烧温度、干透点温度、COREX煤气单耗、膨润土的添加量、生球水分、生球碳含量以及成品球的FeO、MgO、Al2O3含量和碱度;隐层含有12个神经元;输出为成品球团冷压强度;神经元激活函数选择双曲正切函数;神经网络学习算法使用的是带惯量项的误差反向传播学习算法(BP学习算法)。选取353组数据来训练和测试神经网络,其中247组数据用于训练网络,其余数据用于测试网络。测试结果表明,该网络的预测结果与实际结果的误差在3%以内,同时通过敏感性分析得出以下结论:①膨润土添加量、生球碳含量以及成品球的FeO、MgO、Al2O3含量和碱度对球团矿的冷压强度有重要影响;②增加膨润土添加量、成品球碱度、MgO含量、焙烧温度、干透点温度、COREX煤气单耗有助于改善球团矿的冷压强度;③增加FeO含量、生球碳含量、Al2O3含量、料层高度、给料率将使球团矿的冷压强度迅速下降;④增加生球水分会降低冷压强度;⑤提高球团矿冷压强度的参数设置(膨润土的添加量:0.86%～0.92%;wFeO<0.5%;生球碳含量:1.00%～1.10%;MgO含量:0.39%～0.44%);⑥在0.3～0.7范围内增加碱度不能显著改善球团矿的冷压强度。     

Replacement of bentonite in hematite ore pelletisation using a combination of sodium lignosulphonate and copper smelting slag

Bentonite is the most common binder used in iron ore pelletisation owing to its good bonding properties in green and dry pellets at both ambient and elevated temperatures. However, due to its high alumina and silica content, it increases the slag volume and energy consumption in downstream processes. Organic binders may be used to replace bentonite; however, they fail to provide strength at a high temperature (700–900°C) due to poor thermal stability during pellet induration. In the present study, an organic binder Na lignosulphonate (NLS) has been used along with copper smelting slag (Cu-SS). FeO in Cu-SS provides diffusion bonding at high temperature and maintains the strength of pellets even after evaporation/burning of NLS. It also enhances recrystallisation bonding at relatively lower temperature to provide good strength. The study has been carried out with hematite ore and varying amounts of NLS and Cu-SS. Copper smelting slag (1.0%) addition with 0.5%NLS has been found to be optimum to provide very good green properties and ～300?kg/pellet cold crushing strength (CCS) at 1250°C induration temperature. However, hematite pellets of similar basicity with 0.5% bentonite requires higher induration temperature (1300°C) to achieve a similar CCS. The developed pellet also shows better reducibility (80%), similar reduction degradation index (18%) and swelling index (10%) to the usual bentonite pellet. Thus, the induration temperature of hematite pellet has been lowered by 50°C using a combination of NLS and Cu-SS eliminating bentonite completely, which can provide a considerable energy and cost saving.     

武钢金山店高品位球团矿制备研究

对金山店铁矿弱磁精矿用武科大自行设计的磁聚机进行磁团素重选，精矿品位可以提高到68．15％。只配用常规的膨润土粘结剂便可得到铁品位高于65％的氧化球团矿；若配合使用武科大研制的WKD型粘结剂，铁品位提高更多，达到67．41％。     

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.     

内配碳红土镍矿球团制备工艺

以红土镍矿作为原料,煤粉作为还原剂,氧化钙作为熔剂,配加一定量的黏结剂和水,经对辊压球机压制成含碳球团.对红土镍矿的成球特性进行了研究,考察了还原剂、水分和黏结剂等因素对球团强度的影响.结果表明:红土矿粉本身具有较好的成球特性,在不加入黏结剂的条件下,球团仍具有一定的强度;较细粒度的煤粉会降低球团的强度,适宜含量的较粗粒度的煤粉能提高球团的强度;随着水分加入量的提高,球团的抗压强度逐渐提高,当水的质量分数为18%时,其抗压强度达到最大值,若水分继续增加,抗压强度呈现下降的趋势;球团的落下强度随着水量的增加而升高;随着膨润土用量的增加,球团强度有明显的提高,当膨润土的质量分数为2%时球团强度达到最大值,随着膨润土用量的进一步提高,球团强度略微下降,且膨润土中含有较高含量的SiO₂和Al₂O₃,会降低球团有用元素的品位,因此用量不宜过高.     

济钢球团使用钠基膨润土工业试验

为降低黏结剂用量、提高球团矿品位,济钢在球团竖炉进行了钠基膨润土替代2/3普通膨润土生产球团矿的工业试验。在生产稳定状态下,钠基土替代普通膨润土的替代比大约1.37倍,结果表明,球团矿品位提高0.37百分点,二氧化硅降低0.36百分点,球团矿强度、还原度指标基本不受影响,但竖炉产量约降低2%,返粉、除尘粉约升高15%,膨胀指数升高5.32百分点。按替代比1.37倍计算,使用钠基土年效益可达675.7万元。     

Application of Surface Chemical Fundamentals to Improving Industrial Filtration Rates

The throughput of any process is limited by the step with the lowest throughput. In iron ore processing, filtration is used to dewater the iron ore concentrate created during reverse flotation. The conditions of the reverse flotation of iron ore and the efficient filtration of iron ore concentrate are found to be at odds with each other. We show that optimizing the filtration conditions should reduce cation retention in the filter cake, which also improves pellet quality in laboratory scale work. Experimental work was performed to investigate potential implementations at plant scale. Based on data collected at operating magnetite concentrators, it has been found that adding CO₂ into the filter slurry can increase filtration rates dramatically. In plant scale work, filtration rates were increased by up to 23.7% with the addition of 0.54kg of CO₂/ton of feed. We compare these results with laboratory scale results on the same process and elaborate on the theory leading to this discovery, while considering its potential impact on final pellet and iron product quality.     

马钢一烧竖炉配用巴西PF精矿工业试验研究

在马钢-烧2座8m^2竖炉上进行了配用巴西PF精矿的工业性试验。试验结果表明,在膨润土用量不变的情况下,配用8％和15％巴西PF精矿替代巴西CVRD精矿,其生产操作和球团矿的常规质量指标变化不大。冶金性能检验表明,配用巴西PF精矿的球团矿,除低温还原粉化变差导致压差略有升高外,还原性、还原速率、还原膨胀、熔滴性能的变化不大。     

Does the Zeta Potential of an Iron Ore Concentrate Affect the Strength and Dustiness of Unfired and Fired Pellets?

We show how pelletizing additives affect the zeta potential, sedimentation and agglomeration behavior of a hematitic iron ore concentrate. When the additives stabilized the particle–water system—indicated by higher zeta potential, higher total suspended solids content and denser settled sludge—pellet strength increased and dustiness decreased. Conversely, when the additives destabilized the particle-water system—indicated by lower zeta potential, lower total suspended solids content and rarer settled sludge—pellets became weaker and dustier. Specifically, our results show that problems related to starch binders can be resolved using carefully selected dispersants, and starch-dispersant mixtures are better pellet binders than starch alone.

In general, our results suggest that sedimentation and zeta potential tests may be effective techniques for understanding pellet–water–binder systems; organic dispersants are good alternatives to bentonite for making low-silica binders; and understanding surface properties and water chemistry of the balling feed is necessary to understand its agglomeration behavior. We believe that understanding the interactions between the balling feed minerals, pore water, and binder will become more important as balling feeds become finer and process waters more complex.     

超声波强化铜钼浮选过程的研究

斑岩型铜钼矿具有矿石性质复杂、嵌布粒度细、辉钼矿与黄铜矿可浮性相近等特点,导致在浮选过程中铜钼分离困难。利用超声波改变矿浆性质、矿物表面性质及药剂溶液性质。通过对某铜钼矿石采用超声波技术处理强化铜钼浮选分离,纯矿物浮选研究表明,采用超声波处理可以有效实现黄铜矿与辉钼矿的分离。实际矿石分选表明:在磨矿浓度为66.7%、矿浆pH=10.0、石灰用量为450 g/t、水玻璃用量为1 kg/t、YC药剂+丁基黄药用量为160 g/t+50 g/t、2#油30 g/t、磨矿细度 < 0.074 mm占77.2%时,获得混合铜钼精矿钼品位为2.96%,钼回收率为87.44%;铜品位为0.76%,铜回收率为92.77%。对铜钼混合精矿,在矿浆浓度10%下,经超声功率2 000 W处理时间20 min,浮选条件为矿浆pH=10、煤油用量为80 g/t、2#油用量为15 g/t、硫化钠用量为300 g/t,获得最终钼精矿Mo品位为22.19%,作业回收率为95.95%,钼总回收率为83.90%;铜精矿Cu品位为11.88%,作业回收率为98.27%,铜总回收率为91.16%,实现了铜钼矿物良好分离。