Leaching and dissolution of a pentlandite concentrate …
This reflects the partial amorphization and structural disordering in chromite. Mechanical activation has already been reported to amorphize mineral particles[10, 11]. Tromans and Meech[13,14 ...
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Physical Chemistry of Roasting and Leaching Reactions for …
A.M. Amer, I.A. Ibrahim, "Leaching of a low grade Egyptian chromite ore", Hydrometallurgy 43 (1996), 307–316. Article Google Scholar Z. Yang et al., "Effect of mechanical activation on alkali leaching of chromite ore", Transactions of Nonferrous …
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(PDF) Investigation of the Effect of Mechanical Activation …
Investigation of the Effect of Mechanical Activation on the Leaching of Malachite Ore with Ammonium Nitrate. ... Effect of mechanical activation on carbothermal reduction of chromite with graphite, Canadian Metallurgical Quarterly, Arzutug, M. E., Kocakerim, M. M., & Copur, M.,2004. Leaching of Malachite Ore in NH3-Saturated Water. Industrial ...
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Effects of Mechanical Activation on the Soda …
Yarkadaş and Yildiz (2009) studied the effect of mechanical activation on soda roasting of chromite and could improve the conversion from 18% (non-activated chromite) to 74% (120 min activated ...
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Mechanical activation of lead–zinc mine tailings as a …
Mechanical activation is a common pretreatment procedure for minerals to augment their reactivity through the following mechanisms: a) reduction in particle size and enlargement in the specific surface area can enhance the surface reaction, and b) decline in crystal size and increase in microstructure disturbance would lead to enhancements in ...
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Effect of mechanical activation on carbothermal …
Keywords: Carbothermal reduction, Chromite, Ferrochromium, Mechanical activation Introduction Chromite is the only mineral composed of metallic chromium, chromium compounds and other chemicals.
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Synergistic strengthening mechanisms of mechanical activation …
In addition, Apaydin et al. (2011) studied the effect of mechanical activation on carbothermal reduction of chromite with graphite, and found that the activation process led to amorphisation and structural disordering in chromite, and accelerated the reduction and metallisation in the mixture of chromite and graphite. Mechanical activation can ...
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EFFECTS OF MECHANICAL ACTIVATION ON THE …
The carbothermal reduction of mechanically activated chromite with metallurgical coke under an argon atmosphere was investigated at temperatures between 1100 and 1400°C and the effects of the mechanical activation on chromite structure were analyzed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). An increase in specific surface area resulted in more …
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Kinetic study on solid state reduction of chromite …
2014. Ferrochromium is one of the important alloying materials used in the production of stainless and high-alloy ferritic steels. The carbothermal reduction of chromite with graphite under argon atmosphere was studied by differential …
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Effect of Ball Mill Parameters' Variation on the Particles …
Effect of Ball Mill Parameters' Variation on the Particles of a Mechanical Activation‑Assisted Leaching: A Hydrometallurgical Mechanics ... on the MA eect on the alkali leaching of chromite ore. Their study shows that 97% recovery ratio was achieved when the chromium ore was mechanically activated, but
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Structural evolution of arsenopyrite and dearsenification by mechanical
The results of leaching kinetic studies showed that mechanical activation can enhance the efficiency of dearsenification of arsenopyrite, causing the leaching activation energy to decrease from 54.3 kJ·mol −1 (non-activated) to 33.18 kJ·mol −1 (grinding speed of 300 r·min −1). Furthermore, the influence of temperature on leaching ...
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Effect of mechanical activation on alkali leaching of chromite …
Mechanical activation was used to improve the extraction of chromium in molten NaOH. It is observed that the extraction ratio reaches 97% after leaching for 200 min when …
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Leaching of Valuable Elements from the Waste Chromite …
2.1. Effect of Mechanical Ball Milling. The effect of mechanical ball milling was studied. In the experiments, the w/w % H 2 SO 4 was 50%, the liquid–solid ratio (L/S) was 8 mL/g, the reaction temperature (T) was 373 K, and the reaction time (t) was 6 h. Figure Figure1 1 shows that a longer ball-milling time can result in a better leaching effect for the elements.
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Mechanical activation in hydrometallurgy | Semantic Scholar
Semantic Scholar extracted view of "Mechanical activation in hydrometallurgy" by P. Baláž ... Effect of mechanical activation on alkali leaching of chromite ore. Yang Zhang S. Zheng H. Du Hong-bin Xu Yi Zhang. Materials Science. 2010; 37. Save. Mechanical activation of solids in processing of minerals and wastes.
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Effect of mechanical activation on alumina extraction
The activation procedure led to amorphisation and structural disordering in chromite, and accelerated the degree of reduction and metallisation in the mixture of chromite and graphite. View Show ...
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Effect of mechanical activation on carbothermal …
The mechanical activation of chromite concentrate was performed in a Planetary Mono Mill Pulverisette 6 under the following conditions: the weight of the sample
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Enhancing lithium leaching by mechanical activation
leaching of chromite ore. Trans. Nonferrous Met. Soc. China, 20 (5), 888-891. ... Mechanical activation in order to improve lithium recovery from a lepidolite ore concentrate was investigated. The ...
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Mechanical–Chemical Activation of Cement-Ash Binders to …
The article demonstrates the effectiveness of the mechanochemical activation of a cement-ash binder by increasing the specific surface area of the ash and introducing a sodium fluorosilicate additive (Na2SiF6). It has been experimentally proved that the introduction of a Na2SiF6 additive makes it possible to increase the degree of cement hydration, as well as the …
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Effect of mechanical activation on alkali leaching of chromite …
In this study, changes in physicochemical properties and leachability of indium from mechanically activated hard zinc residue by planetary mill were investigated. The results …
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Impact of mechanical activation and mechanochemical activation …
For mechanical activation in the attritor, a rotation speed of 1200 rpm, ball-to-powder ratio of 40 and milling time of 75 min were ideal. Under these conditions, the specific surface area (S BET) could be increased from 1.7 m 2 /g, for the starting slag, to 59.4 m 2 /g. According to ANOVA, the most important factor is the rotation speed.
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Effect of mechanical activation on alkali leaching of …
The mechanical activation of chromite ore was performed in a planetary mill PuLuerisette 6 (FRITSH, Germany). 50 g of chromite ores were ground with 400 g
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Impact of mechanical activation on bioleaching of pyrite: A …
The study of mechanical activation, an important solid processing technology (Baláž, 2008, Godočíková et al., 2002), is a branch of mechanochemistry with a wide range of potential applications. It has been verified that the mechanical activation of minerals can accelerate their reactivity in subsequent processes, such as leaching and ...
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Preparation of Superconcentrate and Chromium Powder from Chromite …
Tests for mechanical activation were accomplished in a vibration mill type ML-30 with a capacity of 0.5–0.2 kWh and a rotation of 1500–2400 min –1. The dimension of original chromite concentrate before grinding was 0.074 mm (about 95%), and after grinding less than 10 μm. The capacity of the steel drum was 150 cm 3. The grinding bodies ...
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EFFECTS OF MECHANICAL ACTIVATION ON THE …
The mechanical activation of chromite concentrate was performed in a Planetary Mono Mill Pulverisette 6 under the following conditions: the weight of the sample was 10 g; the weight and diameter of tungsten carbide (WC) balls were 200 g and …
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Kinetics and mechanisms of the carbothermic reduction …
The approaches for enhancing the chromite reduction can be generally classified into four categories by addressing the above-mentioned kinetic limitations. (1) Pre-treatment of chromite to enhance its reactivity before reduction, including pre-oxidation or heat treatment [18–20], and mechanical activation of chromite by high-energy milling [21].
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Effects of Mechanical Activation on the Soda …
Structural changes in mechanically activated chromite were examined using X-ray diffraction analysis (XRD), surface area analysis (BET) and scanning electron microscopy (SEM).
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(PDF) C390: Mechanical Activation Strategies for Integrated …
In this study, the mechanical activation of lizardite ore from a chromite beneficiation plant waste by grinding in a stirred media mill was studied. For grinding studies, grinding times of 10-20-30 min and stirring speeds of 600-800-1000-1200 rpm were the parameters investigated, while the ball charge rate was 60% and the ore charge rate was ...
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Effect of mechanical activation on carbothermal reduction of chromite …
Abstract The carbothermal reduction of mechanically activated chromite with graphite under an argon atmosphere was investigated at temperatures between 1100 and 1400°C and the effects of the mechanical activation on chromite structure were analysed by X-ray diffraction, scanning electron microscopy and specific surface area measurement. An increase in specific surface …
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Pressure oxidative leaching of Indian chromite ore in …
According to Amer and Ibrahim (1996), mechanical activation of chromite ore particles with alkali liquor permitted to decrease the reaction temperature at an O 2 partial pressure of 1.0 MPa. However, the difficulty of mechanical activation on a large scale limits its industrial application.
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