Factors affecting nickel upgrade during selective grinding of low-grade limonitic laterites

Petrakis, Evangelos; Karmali, Vasiliki; Komnitsas, Kostas

doi:10.1080/25726641.2018.1521578

Cited by 12 publications

(9 citation statements)

References 48 publications

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“…It is also revealed that the smallest balls (12.7 mm size) are suitable for efficient grinding of slag (K ranged from 0.0017 to 0.1333), whereas the use of larger balls (40 mm) results in a much smaller breakage rate (K ranged from 0.0008 to 0.0614). So far, various attempts have been made to define the optimum grinding media size and improve the efficiency of ball milling [30,[56][57][58][59][60][61]. It has been found that the optimum ball size depends on several factors, including the feed/product size ratio, the mill dimensions, and the breakage parameters.…”

Section: Grinding Kineticsmentioning

confidence: 99%

Effect of Grinding Media Size on Ferronickel Slag Ball Milling Efficiency and Energy Requirements Using Kinetics and Attainable Region Approaches

Petrakis

Komnitsas

2022

Minerals

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The aim of this study is to evaluate the effect that the size of grinding media exerts on ferronickel slag milling efficiency and energy savings. A series of tests were performed in a laboratory ball mill using (i) three loads of single size media, i.e., 40, 25.4, and 12.7 mm and (ii) a mixed load of balls with varying sizes. In order to simulate the industrial ball milling operation, the feed to the mill consisted of slag with natural size distribution less than 850 μm. Grinding kinetic modeling and the attainable region (AR) approach were used as tools to evaluate the data obtained during the ball milling of slag. Particular importance was given to the determination of the specific surface area of the grinding products, the identification of the grinding limit, and the maximum specific surface area which could be achieved when different grinding media sizes were used. The results showed that, in general, the breakage rates of particles obey non-first-order kinetics and coarse particles are ground more efficiently than fines. The AR approach proved that there is an optimal grinding time (or specific energy input) dependent on the ball size used for which the volume fraction of the desired size class is maximized. The use of either 25.4 mm balls or a mixed load of balls with varying sizes results in 31 and 24% decrease in energy requirements, compared to the use of balls with small size (12.7 mm).

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Section: Grinding Kineticsmentioning

confidence: 99%

Effect of Grinding Media Size on Ferronickel Slag Ball Milling Efficiency and Energy Requirements Using Kinetics and Attainable Region Approaches

Petrakis

Komnitsas

2022

Minerals

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“…Hence, the results of the present study show that the usual industrial practice of using higher milling rate does not necessarily result in efficient separation between the different minerals of interest present in ores or concentrates. Thus, detailed grinding kinetics analysis is required in order to determine the optimum grinding conditions that maximize the breakage rate of the minerals of interest, as for example diaspore in this case, while minimizing the respective rate of the impurities [55]. Al2O3 grade increases marginally from 63.5 to 64 wt% with increasing fc from 5% to 10% and then drops to 62.6 wt% when fc was 15%.…”

Section: Al2o3 and Fe2o3 Content Of The Selective Grinding Productsmentioning

confidence: 99%

Grinding Behavior and Potential Beneficiation Options of Bauxite Ores

2020

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This laboratory study investigates selective grinding and beneficiation options for a Greek bauxite ore. First, a series of batch grinding tests were carried out in order to investigate the grinding behavior of the ore and the effect of the material filling volume (fc) on the distribution of aluminium- and iron-containing phases. Then, the ground ore was subjected to magnetic separation either as received or after reduction roasting in order to further explore potential beneficiation options. The results showed that grinding of the ore exhibits non-first order behavior, while the breakage rate varies with grinding time. Additionally, Al2O3 tends to concentrate in the coarser than 0.300 mm product fraction, while fc 10% and 2 min of grinding time are considered optimum conditions for good distribution of Al2O3 and Fe2O3. When different product fractions were subjected to magnetic separation, it was seen that the non-magnetic product obtained from the 0.300–1.18 mm fraction was more rich in Al2O3. In this fraction, the Al2O3 content increased from 58 wt% in the feed to 67.9 wt%, whereas the Fe2O3 content decreased from 22.4 wt% in the feed to 13.5 wt%. When the ore was subjected to a two-step treatment, involving reduction roasting followed by magnetic separation, the Fe2O3 grade decreased from 20.8 to 5.1 wt%, but in this case the recovery was very low.

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“…The ball mill is powered by a motor connected to a belt. The number of balls (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15), the duration of the grinding (5-15 minutes), and the rotation speed of the ball mill were the experiment's independent variables (8-16 rpm). The mass and diameter of each steel ball used in this study are shown in Table 2.…”

Section: Grinding Process Using Ball Millmentioning

confidence: 99%

“…Petrakis et. al., [8] used the population balance approach to examine the effect of the number of balls on particle size reduction in the ball mill during a selective grinding process on low-grade laterite. Based on the research that has been done, there hasn't been much discussion about optimization with the RSM (response surface method) in the grinding process of laterite ore using a ball mill.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Laterite Ore Grinding Process Using Ball Mill With Response Surface Method

Prameswara

Tyassena

Amin

et al. 2022

metal.

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Dependence and interaction between several operating conditions that affect the grinding process using a ball mill such as the number of balls, grinding duration, and rotational speed on particle size at 80% product mass (P80) and mineral liberation have been obtained in this study using a CCD (central composite design) of response surface method (RSM). The grinding process was carried out in a cylindrical ball mill with a diameter and length of 18.6 cm and 21.5 cm, respectively, as well as a steel ball with a diameter of 2.5 cm and a weight of 100 grams/ball. The optimum data for the grinding process was obtained with the smallest response value of P80. It was known that the number of balls and grinding duration have a significant effect on the reduction of the P80 value in the sample. The model that can describe the influence of process variables on the P80 value was obtained with good accuracy. The character of the mineral content of the sample was observed with the X-Ray Diffraction (XRD) pattern and the elemental concentration. Minerals that have a smaller hardness scale are easier to liberate and more exposed. The P80 value of the initial material was 1560.89 µm, while at the optimum condition the P80 grinding process was reduced to 513.29 µm.

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Factors affecting nickel upgrade during selective grinding of low-grade limonitic laterites

Cited by 12 publications

References 48 publications

Effect of Grinding Media Size on Ferronickel Slag Ball Milling Efficiency and Energy Requirements Using Kinetics and Attainable Region Approaches

Effect of Grinding Media Size on Ferronickel Slag Ball Milling Efficiency and Energy Requirements Using Kinetics and Attainable Region Approaches

Grinding Behavior and Potential Beneficiation Options of Bauxite Ores

Optimization of Laterite Ore Grinding Process Using Ball Mill With Response Surface Method

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