复合改性伊蒙土的疏水性变化及结构研究

利用十六烷基三甲基溴化铵和KH-570偶联剂复合改性伊蒙土(ISIC),利用IR、XRD、SEM和TGA研究ISIC改性前后结构变化和热稳定性变化。结果表明:改性后ISIC在水和石油醚中的分散性增强,亲水性降低。ISIC改性前后结构变化表明,十六烷基三甲基溴化铵可插入ISIC层间,层间距明显变大。复合改性剂覆盖于ISIC表面,其表面由亲水性变为疏水性。改性后ISIC有机化程度为11%,且不破坏ISIC的原有结构。     

四川某稀土矿选矿试验研究

针对四川某稀土矿选矿工艺存在的稀土回收率低的问题,开展了一系列选矿试验研究。试验结果表明,在矿浆质量浓度为30%,粗选NaOH用量为600g/t,水玻璃用量为3000g/t,EF1106用量为3500g/t,起泡剂用量为60g/t情况下,采用一粗、三精、两扫、中矿按顺序返回的选矿流程,可获得稀土REO的品位和回收率分别为66.32%和79.88%的稀土浮选精矿。与该选厂的生产指标相比,稀土回收率提高了13.93%。     

“冲突矿产”的国际监管及其应对研究

"冲突矿产"问题引起了国际组织的高度关注。本文对"冲突矿产"问题来源、国际社会对"冲突矿产"监管项目及其影响进行了分析。"冲突矿产"国际监管严格实施将对中国矿产勘探、冶炼甚至下游企业带来很大的冲击和挑战。我国需尽快建立政府主导的冲突矿产信息搜集和披露机制,加强国内相关企业的相互合作及沟通,建立企业参与"冲突矿产"监管通报机制,变被动为主动,尽快获得中国在"冲突矿产"监控方面话语权,维护中国大国形象。     

稀有矿产资源经济重要性评估

稀有矿产资源作为现代工业,尤其是战略性新兴产业的关键原材料,在国民经济中扮演着越来越重要的角色。本文在对18种稀有矿产资源界定的基础上,独立于矿种市场规模的大小、价格的高低,采用价值增值链的方法,根据稀有矿产资源的最终用途以及它们所流动部门的增加值来评估其对经济的重要性,同时,将资源替代纳入经济重要性的计算。计算结果表明:2016年我国稀有矿产锗、锆、铟、铍、稀土金属以及镉对经济重要性排序较为靠前,钴、石墨、钽、锂等次之,铌、铼则较为靠后。     

2022年全球矿业展望

展望2022年,世界经济"V"型反转后增速将逐步回落,全球GDP将突破百万亿美元大关.世界矿产勘查开发投资持续回升,铜金矿取得重要进展.原油、铁矿石、铜等大宗矿产价格震荡加剧,锂、钴等电池金属供应将持续紧张.矿业公司面临艰难选择,ESG风险亟需化解.关键矿产热度不减,重要矿产资源国权利金政策备受关注.     

Managing clay minerals in froth flotation—A critical review

Clay minerals are widely present in various ore deposits as gangue minerals. The processing of high-clay-content ores is becoming a significant challenge for the mining industry owing to the poor flotation performance caused by the presence of clay minerals. Different types of clay minerals are typically present in ore bodies, and they cause several detrimental effects to flotation that require different treatments. In this article, a comprehensive review of the studies on understanding and mitigating the negative effects of clay minerals in flotation is presented. It starts with a review of the classification and structures of clay minerals commonly occurring in ore deposits and their properties that determine the behavior of clay minerals in flotation. It is followed by a critical review of two main negative effects of clay minerals on flotation, the recent research findings mainly from The University of Queensland group. The first negative effect is the coating of clay minerals on the surface of valuable minerals that decreases the floatability of valuable minerals. The second negative effect is the formation of network structures in the slurry. Depending on the type and strength of the network structure, it can cause either high pulp viscosity or increased gangue entrainment, which reduces the flotation recovery and flotation product grade, respectively. In this section, the mechanisms and key factors behind each negative effect are presented and critically discussed. Then, the approaches and techniques developed to mitigate the different negative effects of clay minerals are reviewed. To conclude, future directions for a more complete understanding of mechanisms and problem solving are recommended.     

Pre-treatment for the extraction of manganese from mangano-argentiferous refractory tailings

A novel process was used to extract manganese from minerals that are refractory to cyanidation and ammonium thiosulphate. These minerals, known as mangano-argentiferous compounds, are principally composed of manganese, silver, and iron and exhibit low recovery. The mineral of interest was obtained from the leaching tails procured in Monte del Favor, Hostotipaquillo, Jalisco, Mexico. The tailings were characterised by X-ray powder diffraction (XRD), atomic absorption, and energy dispersive X-ray spectroscopy (EDS) microanalysis. After mineralogical characterisation, the tailings were screened through a mesh (mesh number 100, 0.147?mm); later, they were subjected to a reductive leaching process, where the solid–liquid ratio was varied from 2:1 to 10:1. A 5:1 ratio yielded the highest manganese content. With sulphuric acid and sodium sulphite as the reducing agents, 96.05% of Mn could be extracted during the first 3?h, with a head grade of 3.58% and an acid consumption of 49.31?kg/t. The sulphite consumption was found to be 9.81?kg/t.     

Adsorption behavior of radioactive cesium by non-mica minerals

We studied the adsorption behavior of radioactive cesium (Cs) by the non-mica minerals kaolinite, halloysite, chlorite, montmorillonite, mordenite, MnO₂, TiO₂, Al₂O₃, and FeOOH to elucidate the environmental behavior of radioactive Cs fallout from the Fukushima Daiichi Nuclear Power Plant in the Tohoku region of Japan. The adsorption and desorption experiments of Cs on the minerals were carried out at the Cs concentrations 1 × 10^?4, 1 × 10^?5, and 2 × 10^?9 mole L^?1 at pH 5.5. The desorption of Cs from the minerals was examined using 0.1 mole L^?1 LiCl, NaCl, KCl, RbCl, and CsCl solutions. The sequential desorption was examined using a 0.1 mole L^?1 LiCl solution, a 1 mole L^?1 KCl solution, and a 1 mole L^?1 HCl solution. The distribution coefficient (K _d) for the minerals at the Cs concentration 10^?9 mole L^?1 was in the order of mordenite > illite > montmorillonite, sericite, MnO₂, kaolinite, and halloysite > chlorite, TiO₂, Al₂O₃, and FeOOH, differing from the order observed at higher Cs concentrations. After the sequential desorption by the three reagent solutions, the residual fraction of Cs was higher at the Cs concentration 10^?9 mole L^?1 than at higher concentrations. Approximately 40%, 40%, 50%, and 25% of the adsorbed Cs were residual in montmorillonite, mordenite, MnO₂, and kaolinite, respectively, after the sequential desorption. These results strongly suggest that (1) radioactive Cs at 10^?9 mole L^?1 is more strongly associated with the non-mica minerals than at higher concentrations of 1 × 10^?4 and 1 × 10^?5 mole L^?1, and (2) the non-mica minerals montmorillonite, mordenite, kaolinite, and MnO₂ contributed to the fixation of the radioactive Cs fallout on Fukushima soil.     

Improving fire retardancy of medium density fiberboard by nano-wollastonite

The improving effects of addition of nano-wollastonite on some fire properties of medium-density fiberboard (MDF) were studied in this work. Nano-wollastonite was added at four levels (2%, 4%, 6%, and 8%). The size range of at least 70% of nano-wollastonite particles were 30 to 110 nm. The results showed statistically significant improving effect of nano-wollastonite on time to onset of ignition. The improving effect was primarily attributed to an increase in thermal conductivity of board containing nano-wollastonite. This increase in turn resulted in better curing of resin, and a higher integrity of fibers thereof. Moreover, nano-particles provided a surface with reduced combustibility and therefore, penetration of fire to the inner layers of boards was delayed, thus improving fire properties. High and significant correlations were found between thermal conductivity coefficients of boards with different fire properties. It was concluded that for applications where fire properties are of prime importance, nano-wollastonite content of 8% can be recommended. Moreover, further studies are needed to compare and standardize the results obtained from the apparatus used here with those obtained from internationally recognized apparatuses like cone calorimeter.     

Quantitative Elemental Analysis of a Single Cell by Using Inductively Coupled Plasma-Mass Spectrometry in Fast Time-Resolved Analysis Mode

The elemental composition of a single yeast, green alga, or red blood cell (RBC) was precisely determined by using inductively coupled plasma-mass spectrometry (ICP-MS) operating in fast time-resolved analysis (TRA) mode. The technique is known as single-cell (SC)-ICP-MS. Phosphorus, sulfur, magnesium, zinc, and iron were detected in the three types of cell. The elemental composition of yeast and green alga obtained by SC-ICP-MS was consistent with results obtained from conventional ICP-MS measurements following acid digestion of the cells. Slight differences were found in the measured values between SC-ICP-MS and the conventional ICP-MS results for RBC. However, the SC-ICP-MS results for S and Fe in RBC were closer to the estimated values for these elements that were calculated from the level of hemoglobin in RBCs. The data suggest that SC-ICP-MS is suitable for the analysis of various cell types, namely, fungus, plant, and animal cells.