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101.
《分离科学与技术》2012,47(10):1585-1590
The effects of different physical parameters such as pulp density, aeration conditions, and impeller speed on the performance of coal-oil assisted gold flotation were investigated in this study. The experiments were conducted using samples taken from an epithermal gold ore deposit. The results demonstrated that increasing the solid concentration in feed pulp slightly improves recovery of gold particles, but accompanied by significant decreases in concentrate grade. At low aeration conditions gold recovery was relatively low whereas at high aeration conditions the selectivity was poor. The use of higher level of agitation in the agglomerate re-formation stage brought about an increase in gold recovery; however, gold grade of the concentrates tended to decline. Gold grade of the concentrate was significantly increased by reloading of the coal oil agglomerates; on the other hand, substantial decreases were observed in total gold recovery after each successive cycle. 相似文献
102.
《分离科学与技术》2012,47(9):1420-1424
In this study the modified procedure of the oil agglomeration process was carried out, where the emulsion of dodecylammonium hydrochloride (DDAHCl) solution and kerosene was added to the mineral suspension. The aim of this work was to research the oil agglomeration of dolomite mineral by the contact angle, zeta potential and surface free energy measurements. The relationship between the investigated parameters and the oil agglomeration as well as shear flocculation was revealed. The mechanism of oil agglomeration of hydrophilic particles in cationic-anionic surfactant system has been proposed. It was concluded that oil droplets interact rather with aggregates of particles modified by anionic surfactant than the single mineral particles as was explained for naturally hydrophobic particles. 相似文献
103.
《分离科学与技术》2012,47(5):610-618
This paper describes the use of coal-oil agglomerates in flotation to increase the gold recovery from an ore containing fine gold particles. The effects of operating parameters on gold flotation recovery such as oil type, particle size of agglomerating material, agglomerate/ore and oil/ore ratios were investigated. The studies showed that petroleum oils are more effective than vegetable oils in oil agglomeration of Kozlu coal and coal-oil assisted gold flotation. Gold recovery can be increased using a higher amount of agglomerates in the process; however, gold grade of the flotation concentrates is reduced significantly. The use of bridging oil at high concentrations in the agglomeration process provides high-grade gold concentrates, but lower recoveries. The utilization of coarser coal particles in the coal-oil agglomeration stage leads to higher selectivity and recovery values for gold particles. 相似文献
104.
105.
Sung Hyo Hong 《Papers in Regional Science》2014,93(4):803-818
This study investigates the magnitude of localization economies by analysing the relocation pattern of Korean establishments in the manufacturing sector. Relocation of establishments is identified by their move across the border of wards, counties, or cities and distinguished between beyond and within their workers' commuting distance. It seems that relocation beyond commuting distance costs more than that within commuting distance since the former includes additional costs related with searching for, hiring, and training new workers. Key findings of this paper show that external benefits from agglomeration are large enough to be recognized by manufacturers through relocation beyond the border of their workers' commuting area. When the own industry's share of employment in all manufacturing industries becomes doubled through relocation, the probability for establishments to relocate over a long distance across the boundary of their workers' commuting area rises by 17 per cent. The results for sub‐samples divided by the age of establishments show that older establishments are more likely to relocate over a long distance to an area with disproportionate presence of establishments in the same industry. These results seem to fit product life cycle theory by Duranton and Puga. As the production process of the product becomes standardized, the firms producing that product tend to relocate to the specialized area where they can reduce the production costs by increasing dependence on the existing intermediate input suppliers, who are more likely to appear in a more specialized area. 相似文献
106.
文章基于产城一体理念,以其最核心的特征——职住平衡为基础,通过对职住平衡测量标准的研究提出了职住平衡比用以衡量职住平衡状况;根据各项用地与城市就业人口、居住人口的关系,推导出一种理性确定城市用地结构的计算方法,以期能为今后城市规划落实产城一体的理念提供一定的借鉴. 相似文献
107.
介绍了有关菱镁石焙烧和焙烧MgO的物理化学特性和实验研究结果。由活性MgO同含硼物料按一定比例组成的硼镁复合添加剂,是一种新的优质添加剂。报道了球团矿使用硼镁复合添加剂的实验效果。 相似文献
108.
109.
以我国大储量的高岭土为原料,采用化学沉淀法制备超精细的氧化铝粉末。通过对比试验和SEM等设备的检测结果.考察制备过程中溶液浓度,分散剂,防团聚技术对最终产品的影响,探索出了一套适合工业生产纳米氧化铝的工艺。 相似文献
110.
Stefan Vajda Randall E. Winans Jeffrey W. Elam Byeongdu Lee Michael J. Pellin Sönke Seifert George Y. Tikhonov Nancy A. Tomczyk 《Topics in Catalysis》2006,39(3-4):161-166
This contribution is devoted to study of the thermal stability and growth of gold nanoparticles supported on SiO2/Si(111) and Al2O3/SiO2/Si(111) as a function of initial cluster size, support material and level of surface coverage. Experimental evidence for
“flipping” of two dimensional cluster structures from vertical orientation to horizontal on the support is presented. 相似文献