碱熔—电感耦合等离子体原子发射光谱法测定红土镍矿中硅钙镁铝锰钛铬镍钴

建立了红土镍矿中Si、Ca、Mg、Al、Mn、Ti、 Cr、Ni、Co 9种元素的电感耦合等离子体原子发射光谱测定方法。红土镍矿样品用无水Na₂CO₃-H₃BO₃混合熔剂熔融,盐酸浸取、酸化, 选用高盐雾化器和旋流雾室,在选定的测量条件下,用电感耦合等离子体原子发射光谱法测定试液中9种元素含量。基体铁和处理样品时引入试液中的盐分对测定的影响可以通过基体匹配的方法消除。精密度试验结果表明,样品中各元素测定结果的相对标准偏差小于5%。用本法测定标准样品,9种元素的测定值与认定值基本一致。     

从红土镍矿中提取镍钴铁的新工艺研究

针对云南省元江红土镍矿的矿物组成特点,在比较国内外红土镍矿处理工艺的基础上,提出了还原—磨矿—选别—氧化浸出工艺处理该矿,并进行了全流程试验。首先进行了还原—磨矿—选别试验研究,主要考察了还原温度、还原时间、添加剂配比和还原剂配比对指标的影响;其次进行了综合试验。试验结果表明,还原—磨矿—选别可以抛弃红土镍矿中80%以上的脉石,同时实现镍钴铁富集,氧压浸出工艺可实现镍钴与铁的分离,并获得铁红产品。通过试验,获得的技术指标为:从原矿至氢氧化镍(钴)段,镍直收率大于75%、钴直收率大于70%和铁直收率大于80%;氢氧化镍产品镍的品位大于31%,氢氧化钴产品钴的品位大于0.70%,铁红产品铁含量大于62%,铁红达到铁精矿要求,可以作为铁精矿出售。该工艺实现了镍钴铁综合回收,资源利用率高,环境友好,为综合回收红土镍矿中镍钴铁提供一条新的工艺技术路线。     

云南红土抗剪强度指标的神经网络模型研究

以水泥加固红土的直剪试验结果为基础,运用人工神经网络理论建立起云南红土抗剪强度指标的神经网络模型。该模型的输入层向量包括水泥加入比例和试样养护时间两个影响因素,输出层向量为粘聚力和内摩擦角两个抗剪强度指标,隐层传递函数确定为正切函数,输出层传递函数确定为对数函数,隐层神经元数目确定为5。预测结果表明,该神经网络模型能够反映水泥加入比例和试样养护时间对红土抗剪强度的影响,预测的抗剪强度指标与实测值接近,预测效果较好。     

Effect of pre-roasting on leaching of laterite

The effect of pre-roasting on leaching of the gamierite laterite ore, obtained from Yunnan province, China, was investigated in this study. The phase transformation of laterite minerals roasted at different temperatures was investigated with X-ray powder diffraction (XRD). The roasting experiment results show that there are two phase transformation processes of dehydroxylation of goethite and lizardite at roasting temperatures of 277 °C and 610 °C, respectively, which accord with the result of DTA–TG analysis. Pre-roasting of the laterite not only alters its mineralogical composition but also increases its porosity and surface area, thus making it more amenable to leaching. Compared to the leaching result of raw ore and ores roasted at different temperatures, it indicates that increasing roasting temperature up to 300 °C appears to provide the optimum nickel recovery and further heating appears to be detrimental to the nickel recovery.     

镍红土矿处理工艺的现状和展望

随着镍需求量的不断增长和硫化镍矿资源的日益枯竭,对红土镍矿进行高效且低成本的开发处理对于满足镍的增长需求以及镍工业的发展有着重要的意义。据此,对当前镍红土矿的处理工艺进行了综述,重点对湿法工艺进行了分析展望,认为湿法工艺中的常压浸出工艺、微波加热-氯化工艺和生物浸出工艺都是颇具前景的提取技术,是未来的发展方向。     

红土型镍矿电炉还原熔炼工厂实验研究

本文采用1000 kVA的圆形电炉,研究了300 t红土镍矿的还原熔炼过程。通过调整焙砂还原煤的加入量来研究泡沫渣的形成机理,实验表明在干矿中加入还原煤少于4%(干基)会产生泡沫渣;还原熔炼过程镍铁产品的含镍量在16%~22%之间,降低还原煤的加入量,能够提高镍铁产品中镍的品位;电炉中镍的分配系数为100,镍的回收率为94.4%。电炉的能耗随着实验时间的延长而逐步降低。     

Pressure acid leaching of a Chinese laterite ore containing mainly maghemite and magnetite

The high pressure acid extraction of nickel and cobalt from a Chinese laterite containing mainly maghemite and magnetite was studied. X-ray diffraction (XRD) and scanning electron microscopy/X-ray energy dispersive spectroscopy (SEM/EDS) were employed to characterize the residues. The factors influencing the dissolution of maghemite and magnetite, nickel and cobalt extractions and iron precipitation were investigated. The results show that after 75 min at 270 °C with an acid/ore ratio of 0.55, maghemite and magnetite completely dissolved, liberating 98% Ni and 88% Co into the leach liquor. EDS analysis reveals that some nickel may be associated with the amorphous silica and/or basic ferric sulfate, resulting in a minor loss of nickel. The presence of a cobalt-containing phase in the residues, believed to be ringwoodite, is mainly responsible for the incomplete extraction of cobalt. Both maghemite and magnetite dissolved gradually with the increase in temperature from 200 to 270 °C. Maghemite dissolved more slowly than magnetite at 270 °C which also produced ferrous sulfate in the leach liquor and increased the total iron extraction. Increasing temperature and/or agitation accelerated the hydrolysis of ferric sulfate. The leaching of maghemite and magnetite corresponds to a dissolution-precipitation mechanism. In both high and low acidic environments, the precipitation of ferric sulfate proceeds through the initial formation of basic ferric sulfate and its conversion to hematite. The extent of conversion depends largely upon residual acidity and reaction time.     

CPE／红泥填充体系流变性能

通过测试一系列不同与配比的ＣＰＥ／红泥填充体系的流变性能，探讨了级分比、温度等对体系流动性的影响，表明该填充体系具有剪切变稀的非牛顿性质；体系的表现切粘度随填充红泥量的增加有不同程度的增大；温度升高，体系的表观切粘度下降，温度对体系流动性的影响随填充红泥量的增加而减少，随切变速率的增大而减少；在低切变速率条件下，红泥粒度对体系的流动性有影响。     

镍红土矿冶炼炉渣综合利用工艺技术试验研究

进行了镍红土矿电炉冶炼炉渣综合利用的试验研究,分析了影响镍红土矿冶炼炉渣制取无机矿物纤维的主要工艺技术参数,验证了工艺的可行性.     

某红土镍矿长距离矿浆管道输送工程的浓度方案研究

本文对某红土镍矿长距离矿浆管道输送工程的小型静态试验和半工业性矿浆环管试验进行了简要叙述,同时分析了红土镍矿的浆体特性,确定了长距离矿浆管道紊流输送的设计原则,并结合工艺条件和管线地形,对该长距离矿浆管道输送系统的工艺方案进行技术经济分析,确定了管道输送浓度.本文为红土镍矿长距离矿浆管道输送工程矿浆重量浓度的研究提供参考.