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Chen W.,Changsha Institute of Mining Research
26th International Mineral Processing Congress, IMPC 2012: Innovative Processing for Sustainable Growth - Conference Proceedings | Year: 2012

The flotation efficiency of magnetic concentrate of the Anhui hematite ore, which includes a great quantity of iron-bearing silicates, has been studied through reverse flotation test with a new type of collector Fly-102. The results indicate that collector Fly-102 has a strong adaptability to the variation of temperature, when the flotation temperature is in the range of 10°C to 35°C, using collector Fly-102 can obtain good flotation indexes. Collector Fly-102 has a strong adaptability to the variation of the slime contents and grades of the flotation samples. When the content of slime and the grade of the flotation feeds are 30% and 55.63% respectively, under the condition that the temperature is 15°C, the open circuit flotation test was carried out with collector Fly-102. After one-stage roughing, one-stage cleaning and two-stage scavenging, a better result is got, the grade of iron concentrate reaches 67.12%, and the recovery of iron concentrate comes up to 84.15%.

He C.-S.,Changsha Institute of Mining Research
Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | Year: 2012

In this paper, to evaluate the cavability of ore rock comprehensively for guiding the block caving design, according to geological conditions exposed by engineering geological survey, the factors influencing the cavability of ore rock are studied by using multifactor comprehensive evaluation method. The results show that the comprehensive consideration on distribution law of the rock mass structure characteristics indexes can reflect the cavability of ore rock better. Finally, we classify the ore body cavability of one mining area in this paper, and find that the cavability of this mining area is between the levels of middle to better, which can provide an important guidance for the future work in mine.

Li S.-L.,Xiamen University | Tang H.-Y.,Changsha Institute of Mining Research
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

Experiments on acoustic emission (AE) characteristics of full-regime rock failure are carried out with stiffness test machine (MTS) under uniaxial loading, cyclic loading-unloading conditions to obtain the relations of stress-strain, stress-time-accumulative counts of AE, stress-time-AE rates. Based on the test results, the AE characteristics of loading process, unloading and reloading of loading-unloading process are analyzed. The results show that AE phenomena can apparently appear during the process of unloading. When being reloaded under the stress level not more than 50% of the peak stress, there are less or little AE counts occurring as long as the stress level is not more than the previous loading stress level, that means the Kaiser effect occurs. While reloading is made again on the stress-level of over 60% of the peak stress, there occurs obviously AE events, that is so-called the Felicity phenomenon. Rock samples show a large amount of AE events in the post-peak region for both loading and loading-unloading processes. And the results also show that there exists a relatively tranquil period phenomenon of AE for all samples of the style of AE abruptly increasing during middle stress stage.

Zhang Y.,Memorial University of Newfoundland | Liu Q.,University of Alberta | Li L.,Changsha Institute of Mining Research
Hydrometallurgy | Year: 2016

Iron removal is a common procedure in hydrometallurgy of non-ferrous metallic ores. Chemical precipitation and solvent extraction are currently the main methods employed for separation of iron from copper leach solution. However, chemical precipitation methods have the problem of producing large amounts of iron precipitates, and/or requiring high temperature and high pressure conditions for precipitation. The precipitates are difficult to separate from the solution. Emulsification is a general problem for solvent extraction, which causes loss of extractants and contamination of the electrolyte. A common problem for solvent extraction and chelating ion exchange processes is the difficult iron stripping process. Therefore, finding an efficient and environmentally friendly method for iron removal is of great significance. In this paper, new processes of using ion exchange resins to remove iron from copper leach solution have been investigated. Salicylic acid, amino carboxylic acid, amino phosphonic acid and hydroxy-oxime resins were employed to adsorb iron from a synthetic copper leach solution containing 40 g/L of Cu2 + and 36 g/L of Fe3 +. It was found that a hydroxy-oxime resin, named Z-Fe, has excellent adsorption selectivity on Fe3 +. Desorption behavior of the resin was studied by two step elutions using dilute H2SO4 and oxalic acid solution, respectively. After optimizing the adsorption-elution processes, the extent of removal of iron from the simulated copper leach solution using resin Z-Fe was 89.83%, while copper recovery could reach 100% in closed circuit processing. © 2016 Published by Elsevier B.V. All rights reserved.

Liu X.,Central South University | Yu T.,Central South University | Wei Q.,Central South University | Yu Z.,Central South University | Xu X.,Changsha Institute of Mining Research
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

Nanodiamond seeding is a well-established approach to enhancing the nucleation density in chemical vapor deposition (CVD) diamond growth. However, the effects of nanodiamond seeding are highly dependent upon the dispersion properties of nanodiamond particles, the solvent and the interaction between nanoparticles and substrate surfaces. Surface modification and fractionalization were employed to improve the dispersion of nanodiamond particles and separate those particles into a more narrow range of particle size. Mono-dispersed nanodiamonds with a ζ-potential and average particle size of -41.5mV and ~25.3nm, respectively, were then obtained. They can be charged on copper substrate without any contaminations. Two-dimensional self-assemblies of nanodiamond seeding were actualized. The density and homogeneity of nanodiamond particles which act as pre-existing sp 3 seeds shorten the incubation time of diamond nucleation to less than 30min. High quality of 750nm thick continuous diamond film was deposited on copper substrate in 60min. Furthermore, we calculated electrostatic interaction energy between nanodiamond particle and copper substrate by using the nonlinear Poisson-Boltzmann theory, and discussed interaction energy of nanodiamond-Cu substrate and nanodiamond-nanodiamond in the seeding process. © 2012 Elsevier B.V.

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