The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal

Dejene Amane; Melesse Alemayehu

doi:doi:10.11648/j.ijmpem.20261104.13

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The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal

Dejene Amane^*

, Melesse Alemayehu

Published in International Journal of Mineral Processing and Extractive Metallurgy (Volume 11, Issue 4)

Received: 25 September 2026 Accepted: 13 October 2026 Published: 29 October 2026

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Abstract

Ethiopia possesses considerable coal resources, but their low grade, marked by high ash and moisture, restricts industrial utilization. This work examined how run-of-mine coal from the Dedo deposit in Jimma Zone, south-western Ethiopia, responds to froth flotation, with the goal of raising its quality. Duplicate batch tests were run in a laboratory Wedag flotation cell to assess how particle size (−500+250 µm and −125+63 µm) and impeller speed (1500 and 2500 rpm) influence concentrate yield. Kerosene served as the collector and n-octanol as the frother, and the feed mass, conditioning time and reagent dosages were kept fixed. Proximate analysis, sulfur content and calorific value were used to characterize both the raw coal and the floated concentrate. Mean concentrate yield varied from 48.0% for the coarse fraction at 1500 rpm up to 66.5% for the fine fraction at 2500 rpm, which shows that, within the ranges tested, finer particles and a higher impeller speed improved flotation. Compared with the raw coal, the concentrate produced under the best conditions contained less ash (25.66% to 20.28%), moisture (13.63% to 11.06%), volatile matter (33.45% to 25.63%) and sulfur (0.36% to 0.25%), and had a higher calorific value (4806 to 5029.38 cal/g), while fixed carbon increased (27.26% to 43.03%). The findings suggest that froth flotation can give a cleaner, more energy-rich product from Dedo coal; however, the calorific value gain was small (about 4.6%), and only two levels of two variables were investigated. Before process conditions for industrial use can be defined, the effects of collector and frother dosage, solids concentration, pH, air flow rate and conditioning time, as well as the composition of the flotation tailings, still need to be assessed.

Published in	International Journal of Mineral Processing and Extractive Metallurgy (Volume 11, Issue 4)
DOI	10.11648/j.ijmpem.20261104.13
Page(s)	93-101
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2026. Published by Science Publishing Group

Keywords

Froth Flotation, Dedo Coal Deposit, Flotation Response, Particle Size, Impeller Speed, Coal Beneficiation, Low-Rank Coal

References

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[13]	Matis, K. A., Gallios, G. P., Kydros, K. A. Separation of Fines by Flotation Techniques. Separations Technology. 1993, 3(2), 76-90. https://doi.org/10.1016/0956-9618(93)80020-L
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Amane, D., Alemayehu, M. (2026). The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal. International Journal of Mineral Processing and Extractive Metallurgy, 11(4), 93-101. https://doi.org/10.11648/j.ijmpem.20261104.13

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ACS Style

Amane, D.; Alemayehu, M. The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal. Int. J. Miner. Process. Extr. Metall. 2026, 11(4), 93-101. doi: 10.11648/j.ijmpem.20261104.13

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AMA Style

Amane D, Alemayehu M. The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal. Int J Miner Process Extr Metall. 2026;11(4):93-101. doi: 10.11648/j.ijmpem.20261104.13

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@article{10.11648/j.ijmpem.20261104.13,
  author = {Dejene Amane and Melesse Alemayehu},
  title = {The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal},
  journal = {International Journal of Mineral Processing and Extractive Metallurgy},
  volume = {11},
  number = {4},
  pages = {93-101},
  doi = {10.11648/j.ijmpem.20261104.13},
  url = {https://doi.org/10.11648/j.ijmpem.20261104.13},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijmpem.20261104.13},
  abstract = {Ethiopia possesses considerable coal resources, but their low grade, marked by high ash and moisture, restricts industrial utilization. This work examined how run-of-mine coal from the Dedo deposit in Jimma Zone, south-western Ethiopia, responds to froth flotation, with the goal of raising its quality. Duplicate batch tests were run in a laboratory Wedag flotation cell to assess how particle size (−500+250 µm and −125+63 µm) and impeller speed (1500 and 2500 rpm) influence concentrate yield. Kerosene served as the collector and n-octanol as the frother, and the feed mass, conditioning time and reagent dosages were kept fixed. Proximate analysis, sulfur content and calorific value were used to characterize both the raw coal and the floated concentrate. Mean concentrate yield varied from 48.0% for the coarse fraction at 1500 rpm up to 66.5% for the fine fraction at 2500 rpm, which shows that, within the ranges tested, finer particles and a higher impeller speed improved flotation. Compared with the raw coal, the concentrate produced under the best conditions contained less ash (25.66% to 20.28%), moisture (13.63% to 11.06%), volatile matter (33.45% to 25.63%) and sulfur (0.36% to 0.25%), and had a higher calorific value (4806 to 5029.38 cal/g), while fixed carbon increased (27.26% to 43.03%). The findings suggest that froth flotation can give a cleaner, more energy-rich product from Dedo coal; however, the calorific value gain was small (about 4.6%), and only two levels of two variables were investigated. Before process conditions for industrial use can be defined, the effects of collector and frother dosage, solids concentration, pH, air flow rate and conditioning time, as well as the composition of the flotation tailings, still need to be assessed.},
 year = {2026}
}

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TY  - JOUR
T1  - The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal
AU  - Dejene Amane
AU  - Melesse Alemayehu
Y1  - 2026/10/29
PY  - 2026
N1  - https://doi.org/10.11648/j.ijmpem.20261104.13
DO  - 10.11648/j.ijmpem.20261104.13
T2  - International Journal of Mineral Processing and Extractive Metallurgy
JF  - International Journal of Mineral Processing and Extractive Metallurgy
JO  - International Journal of Mineral Processing and Extractive Metallurgy
SP  - 93
EP  - 101
PB  - Science Publishing Group
SN  - 2575-1859
UR  - https://doi.org/10.11648/j.ijmpem.20261104.13
AB  - Ethiopia possesses considerable coal resources, but their low grade, marked by high ash and moisture, restricts industrial utilization. This work examined how run-of-mine coal from the Dedo deposit in Jimma Zone, south-western Ethiopia, responds to froth flotation, with the goal of raising its quality. Duplicate batch tests were run in a laboratory Wedag flotation cell to assess how particle size (−500+250 µm and −125+63 µm) and impeller speed (1500 and 2500 rpm) influence concentrate yield. Kerosene served as the collector and n-octanol as the frother, and the feed mass, conditioning time and reagent dosages were kept fixed. Proximate analysis, sulfur content and calorific value were used to characterize both the raw coal and the floated concentrate. Mean concentrate yield varied from 48.0% for the coarse fraction at 1500 rpm up to 66.5% for the fine fraction at 2500 rpm, which shows that, within the ranges tested, finer particles and a higher impeller speed improved flotation. Compared with the raw coal, the concentrate produced under the best conditions contained less ash (25.66% to 20.28%), moisture (13.63% to 11.06%), volatile matter (33.45% to 25.63%) and sulfur (0.36% to 0.25%), and had a higher calorific value (4806 to 5029.38 cal/g), while fixed carbon increased (27.26% to 43.03%). The findings suggest that froth flotation can give a cleaner, more energy-rich product from Dedo coal; however, the calorific value gain was small (about 4.6%), and only two levels of two variables were investigated. Before process conditions for industrial use can be defined, the effects of collector and frother dosage, solids concentration, pH, air flow rate and conditioning time, as well as the composition of the flotation tailings, still need to be assessed.
VL  - 11
IS  - 4
ER  -

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Author Information

Dejene Amane

Ministry of Mines, Ethiopian Geological Institute, Addis Ababa, Ethiopia

Contact Email

http://orcid.org/0009-0006-6675-814X
Melesse Alemayehu

College of Applied Natural Sciences, Adama Science and Technology University, Adama, Ethiopia

http://orcid.org/0009-0008-7172-2891

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Amane, D., Alemayehu, M. (2026). The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal. International Journal of Mineral Processing and Extractive Metallurgy, 11(4), 93-101. https://doi.org/10.11648/j.ijmpem.20261104.13

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ACS Style

Amane, D.; Alemayehu, M. The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal. Int. J. Miner. Process. Extr. Metall. 2026, 11(4), 93-101. doi: 10.11648/j.ijmpem.20261104.13

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AMA Style

Amane D, Alemayehu M. The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal. Int J Miner Process Extr Metall. 2026;11(4):93-101. doi: 10.11648/j.ijmpem.20261104.13

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@article{10.11648/j.ijmpem.20261104.13,
  author = {Dejene Amane and Melesse Alemayehu},
  title = {The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal},
  journal = {International Journal of Mineral Processing and Extractive Metallurgy},
  volume = {11},
  number = {4},
  pages = {93-101},
  doi = {10.11648/j.ijmpem.20261104.13},
  url = {https://doi.org/10.11648/j.ijmpem.20261104.13},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijmpem.20261104.13},
  abstract = {Ethiopia possesses considerable coal resources, but their low grade, marked by high ash and moisture, restricts industrial utilization. This work examined how run-of-mine coal from the Dedo deposit in Jimma Zone, south-western Ethiopia, responds to froth flotation, with the goal of raising its quality. Duplicate batch tests were run in a laboratory Wedag flotation cell to assess how particle size (−500+250 µm and −125+63 µm) and impeller speed (1500 and 2500 rpm) influence concentrate yield. Kerosene served as the collector and n-octanol as the frother, and the feed mass, conditioning time and reagent dosages were kept fixed. Proximate analysis, sulfur content and calorific value were used to characterize both the raw coal and the floated concentrate. Mean concentrate yield varied from 48.0% for the coarse fraction at 1500 rpm up to 66.5% for the fine fraction at 2500 rpm, which shows that, within the ranges tested, finer particles and a higher impeller speed improved flotation. Compared with the raw coal, the concentrate produced under the best conditions contained less ash (25.66% to 20.28%), moisture (13.63% to 11.06%), volatile matter (33.45% to 25.63%) and sulfur (0.36% to 0.25%), and had a higher calorific value (4806 to 5029.38 cal/g), while fixed carbon increased (27.26% to 43.03%). The findings suggest that froth flotation can give a cleaner, more energy-rich product from Dedo coal; however, the calorific value gain was small (about 4.6%), and only two levels of two variables were investigated. Before process conditions for industrial use can be defined, the effects of collector and frother dosage, solids concentration, pH, air flow rate and conditioning time, as well as the composition of the flotation tailings, still need to be assessed.},
 year = {2026}
}

Copy | Download

TY  - JOUR
T1  - The Flotation Response of Dedo Coal Deposit, Jimma, Ethiopia: Implication to Improve the Quality of Coal
AU  - Dejene Amane
AU  - Melesse Alemayehu
Y1  - 2026/10/29
PY  - 2026
N1  - https://doi.org/10.11648/j.ijmpem.20261104.13
DO  - 10.11648/j.ijmpem.20261104.13
T2  - International Journal of Mineral Processing and Extractive Metallurgy
JF  - International Journal of Mineral Processing and Extractive Metallurgy
JO  - International Journal of Mineral Processing and Extractive Metallurgy
SP  - 93
EP  - 101
PB  - Science Publishing Group
SN  - 2575-1859
UR  - https://doi.org/10.11648/j.ijmpem.20261104.13
AB  - Ethiopia possesses considerable coal resources, but their low grade, marked by high ash and moisture, restricts industrial utilization. This work examined how run-of-mine coal from the Dedo deposit in Jimma Zone, south-western Ethiopia, responds to froth flotation, with the goal of raising its quality. Duplicate batch tests were run in a laboratory Wedag flotation cell to assess how particle size (−500+250 µm and −125+63 µm) and impeller speed (1500 and 2500 rpm) influence concentrate yield. Kerosene served as the collector and n-octanol as the frother, and the feed mass, conditioning time and reagent dosages were kept fixed. Proximate analysis, sulfur content and calorific value were used to characterize both the raw coal and the floated concentrate. Mean concentrate yield varied from 48.0% for the coarse fraction at 1500 rpm up to 66.5% for the fine fraction at 2500 rpm, which shows that, within the ranges tested, finer particles and a higher impeller speed improved flotation. Compared with the raw coal, the concentrate produced under the best conditions contained less ash (25.66% to 20.28%), moisture (13.63% to 11.06%), volatile matter (33.45% to 25.63%) and sulfur (0.36% to 0.25%), and had a higher calorific value (4806 to 5029.38 cal/g), while fixed carbon increased (27.26% to 43.03%). The findings suggest that froth flotation can give a cleaner, more energy-rich product from Dedo coal; however, the calorific value gain was small (about 4.6%), and only two levels of two variables were investigated. Before process conditions for industrial use can be defined, the effects of collector and frother dosage, solids concentration, pH, air flow rate and conditioning time, as well as the composition of the flotation tailings, still need to be assessed.
VL  - 11
IS  - 4
ER  -

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