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Grindability characterization and work index determination of alluvial ferro-columbite deposits for efficient mineral processing

Nzeh Nnaemeka Stanislaus, Adeleke Abraham A., Popoola Patricia Abimbola

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 3

art. no. 170297

EN

This study emphasizes on the physicochemical and grindability characteristics and work index of an alluvial formed silica dominated ferro-columbite mineral from Rayfield-Jos minefields in Plateau state, Nigeria. Investigations were also carried out in order to determine the mineralogy of the mineral deposits and most essentially the actual energy consumed during comminution and milling of the mineral so as to achieve the liberation size prior to high efficient mineral processing or beneficiation and the extraction of value metals. The distribution of the mineral particles as well as their sizes was determined, with a mineral liberation size fraction range essentially established as -150+90 μm particle sizes. Mass percentage of each size fraction obtained from PSD analysis conducted before and after comminution was also determined, obtaining 80% passing for both the mineral feeds and comminuted products. Berry and Bruce modified Bond’s work index was therefore obtained, and was determined to be within the range of 2.0414 to 2.5667 kWh/ton. Hence, the energy consumed or required to comminute or grind the Fe-columbite mineral to 80% passing is expected to fall within the range of 0.3613 to 0.4543 kWh. Thus, it could be said that a low milling work index as well as moderately low energy is required for comminution and this can be attributed to the mineralogy, mineral source and alluvial formation of the mineral reserve. Therefore, the grindability/PSD result of the mineral sample indicates that its mineralogy is considered a class of moderately soft mineral type in terms of texture with easy grindability.

2

Leaching of coal by trioxoboric acid for coal clearing

Bilgin Oyku, Hacıfazlıoğlu Hasan, Sert Dilara

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 5

129--136

EN

Trioxoboric acid (H3BO3) is a white weakly soluble acid produced from boron minerals. This acid type was used for the first time in this study for ash and sulfur removal from coal. Ash and sulfur are the most important impurities in the content of coal and have significant effects on environmental pollution. It is possible to remove ash and sulfur by H3BO3 leaching. However, there have not been enough studies in this area and the performance of trioxoboric acid has not been fully demonstrated. In this study, leaching performance of trioxoboric acid and other strong acids (hydrofluoric, hydrochloric and sulfuric acids) has been demonstrated. Trioxoboric acid removed ash and sulfur from coal by 41.18% and 32.16%, respectively. This acid can compete especially with hydrochloric and sulfuric acid in sulfur removal. However, hydrofluoric acid provided the best results in ash and sulfur removal.

3

Kinetic grinding test approach to estimate the ball mill work index

Gharehgheshlagh H. H.

Physicochemical Problems of Mineral Processing

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2016

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Vol. 52, iss. 1

342--352

EN

The standard Bond method is the most acceptable method for designing and selecting ball/rod mills described by their basic parameter called work index (Wi). The standard Bond method is a tedious time consuming procedure requiring at least 7 – 10 grinding cycles, so that many researchers have tried to simplify this method to be able to perform a rapid calculation of a work index. This study aims to develop a new approach toward estimating the Bond ball mill work index (BBWI) by applying a series of kinetic grinding tests with Bond standard mill. Establishing a series of relationships between grinding parameters and Bond equation parameters, this approach is fast and practical due to eliminating laboratory control steps while reducing the number of milling steps. In this scope, thirteen ore samples were used to compare Wi values obtained by standard Bond method with those of the proposed kinetic approach. The kinetic periods were determined as 0.33, 1, 2, 4 and 8 minutes. The results of kinetic tests were found to be logical and acceptable as they were so close to the values obtained by Bond standard method, for all samples error was ≤ 2.60%. It was therefore concluded that the proposed approach could be considered as a simple yet practical alternative for the standard Bond method.