The International Journal of Coal Science & Technology is a peer-reviewed open access journal. It focuses on key topics of coal scientific research and mining development, serving as a forum for scientists to present research findings and discuss challenging issues.
Coverage includes original research articles, new developments, case studies and critical reviews in all aspects of scientific and engineering research on coal, coal utilizations and coal mining. Among the broad topics receiving attention are coal geology, geochemistry, geophysics, mineralogy, and petrology; coal mining theory, technology and engineering; coal processing, utilization and conversion; coal mining environment and reclamation and related aspects.
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A forum for new research findings, case studies and discussion of important challenges in coal science and mining development
Offers an international perspective on coal geology, coal mining, technology and engineering, coal processing, utilization and conversion, coal mining environment and reclamation and more
Published with the China Coal Society
Open Access
Published: 02 May 2022
1 Accesses
International Journal of Coal Science & Technology Volume 9, article number 30, (2022)
1.
Department of Geology, Ekiti State University, Ado Ekiti, Nigeria
2.
School of Chemical and Energy Engineering, Universiti Teknologi Malaysia, Skudai, Malaysia
3.
Department of Geology, Obafemi Awolowo University, Ile Ife, Nigeria
4.
Centre for Applied Energy Research, University of Kentucky, Kentucky, USA
5.
National Centre for Petroleum Research and Development (NCPRD), Abubakar Tafawa Balewa University, Bauchi, Nigeria
In this article, Professor Nikki Wagner (Department of Geology, University of Johannesburg, South Africa) raised the following concerns in the data presented in Tables 1 and 2.
In Table 1, the sum of proximate data (ash + moisture + fixed carbon + volatile matter) which is far above 100% for Lamja2, Garin-Maiganga, Okaba and Lafia-Obi coal samples.
In Table 1, the sum of ultimate data (total sulphur + carbon, nitrogen + hydrogen + oxygen) is far below 50% for Enugu and Imiegba coal samples.
In Table 2, the sum of macerals (vitrinite + inertinite + lipnite + mineral matter) which is far above 100% for Enugu and Imiegba coal samples.
Corrections:
Table 1: Proximate analyses (as-received basis) and ultimate analyses (dry basis; C, H, N, total S, and O by difference). The derived values (O/C, H/C and VM/FC), heating value parameters (HHV and LHV) and mineral matter (MM) of coals.
Table 2: Macerals, subtotals of vitrinite submacerals (in italics), and totals of maceral groups and of minerals (in italics) along with the vitrinite maximum and random reflectances and the respective standard deviations of the reflectances. Note that the first column for each coal includes the minerals in the total and the second column is the mineral-free normalization of the maceral content.
Parameter | LBT | MBT | UBT | |||||
|---|---|---|---|---|---|---|---|---|
Enugu | Imiegba | Okaba | Lafia-Obi | Chikila | Lamja1 | Lamja2 | Garin-Maiganga | |
Proximate analysis (as-received basis) | ||||||||
Moisture (%) | 3.17 | 3.77 | 8.63 | 11.59 | 3.07 | 2.98 | 12.91 | 11.35 |
Volatile matter (%) | 21.74 | 24.10 | 40.03 | 46.04 | 35.27 | 35.15 | 32.04 | 39.14 |
Fixed carbon (%) | 19.55 | 15.38 | 43.65 | 35.16 | 53.80 | 53.76 | 43.11 | 45.39 |
Ash (%) | 55.54 | 56.75 | 7.69 | 7.21 | 7.86 | 8.11 | 11.94 | 4.12 |
Total | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
Ultimate analysis (dry basis) | ||||||||
Hydrogen (%) | 3.05 | 3.32 | 5.37 | 6.17 | 5.48 | 5.55 | 4.99 | 5.09 |
Carbon (%) | 32.18 | 26.37 | 62.73 | 61.80 | 74.04 | 74.20 | 57.51 | 63.07 |
Nitrogen (%) | 0.43 | 0.27 | 1.27 | 0.91 | 1.50 | 1.48 | 1.13 | 0.77 |
Total sulphur (%) | 0.20 | 0.68 | 0.74 | 1.74 | 0.67 | 0.67 | 0.49 | 0.37 |
Oxygen (%) | 8.60 | 12.61 | 22.20 | 22.17 | 10.45 | 9.99 | 23.94 | 26.58 |
O/C | 0.3 | 0.5 | 0.4 | 0.4 | 0.1 | 0.1 | 0.4 | 0.4 |
H/C | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
VM/FC | 1.1 | 1.6 | 0.9 | 1.3 | 0.7 | 0.7 | 0.7 | 0.9 |
MM | 60.1 | 61.7 | 8.7 | 8.7 | 8.9 | 9.1 | 13.2 | 4.7 |
HHV | 11.1 | 9.8 | 25.5 | 23.2 | 28.8 | 28.7 | 23.7 | 26.1 |
LHV | 10.4 | 9.0 | 24.2 | 21.7 | 27.6 | 27.5 | 22.3 | 24.8 |
Macerals | LBT | MBT | UBT | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Enugu | Imiegba | Okaba | Lafia-Obi | Chikila | Lamja1 | Lamja2 | Garin-Maiganga | |||||||||
Telinite | 13.4 | 22.7 | 12.5 | 51.4 | 8.2 | 8.3 | 8.9 | 9.5 | 10.3 | 10.5 | 8.7 | 8.8 | 23.6 | 23.9 | 15.8 | 15.8 |
Collotelinite | 6.6 | 11.0 | 4.2 | 17.1 | 19.5 | 19.6 | 21.6 | 22.9 | 64.0 | 65.6 | 71.1 | 72.3 | 47.2 | 47.8 | 8.1 | 8.1 |
Total telovitrinite | 20.0 | 33.7 | 16.7 | 68.6 | 27.7 | 27.9 | 30.5 | 32.4 | 74.3 | 76.1 | 79.8 | 81.1 | 70.8 | 71.7 | 23.9 | 23.9 |
Vitrodetrinite | 15.9 | 26.7 | 3.8 | 15.7 | 25.1 | 25.3 | 25.3 | 26.9 | 11.3 | 11.6 | 6.7 | 6.8 | 10.0 | 10.1 | 16.9 | 16.9 |
Collodetrinite | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Total detrovitrinite | 15.9 | 26.7 | 3.8 | 15.7 | 25.5 | 25.7 | 25.3 | 26.9 | 11.3 | 11.6 | 6.7 | 6.8 | 10.0 | 10.1 | 16.9 | 16.9 |
Corpogelinite | 3.8 | 6.4 | 1.7 | 7.1 | 3.7 | 3.8 | 3.7 | 4.0 | 3.1 | 3.2 | 0.4 | 0.4 | 3.2 | 3.2 | 2.2 | 2.2 |
Gelinite | 0.0 | 0.0 | 0.0 | 0.0 | 1.5 | 1.5 | 3.0 | 3.2 | 0.3 | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.7 | 0.7 |
Total gelovitrinite | 3.8 | 6.4 | 1.7 | 7.1 | 5.2 | 5.3 | 6.7 | 7.1 | 3.4 | 3.5 | 0.4 | 0.4 | 3.2 | 3.2 | 2.9 | 2.9 |
Total vitrinite | 39.7 | 66.9 | 22.2 | 91.4 | 58.4 | 58.9 | 62.5 | 66.4 | 89.0 | 91.2 | 87.0 | 88.4 | 84.0 | 85.0 | 43.8 | 43.8 |
Fusinite | 5.9 | 9.9 | 1.0 | 4.3 | 23.6 | 23.8 | 12.3 | 13.0 | 4.5 | 4.6 | 5.9 | 6.0 | 10.0 | 10.1 | 37.5 | 37.5 |
Semifusinite | 3.1 | 5.2 | 1.0 | 4.3 | 9.0 | 9.1 | 2.2 | 2.4 | 0.7 | 0.7 | 0.4 | 0.4 | 0.4 | 0.4 | 15.1 | 15.1 |
Micrinite | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 1.1 | 1.1 |
Macrinite | 0.3 | 0.6 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 0.4 | 0.7 | 0.7 | 0.8 | 0.8 | 0.0 | 0.0 | 0.0 | 0.0 |
Secretinite | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Funginite | t | t | 0.0 | 0.0 | 0.4 | 0.4 | 0.4 | 0.4 | 0.3 | 0.4 | 0.4 | 0.4 | 2.0 | 2.0 | 0.0 | 0.0 |
Inertodetrinite | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 0.4 | 1.1 | 1.2 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Total inertinite | 9.3 | 15.7 | 2.1 | 8.6 | 33.3 | 33.6 | 16.7 | 17.8 | 6.2 | 6.3 | 7.5 | 7.6 | 12.4 | 12.6 | 53.7 | 53.7 |
Sporinite | 4.8 | 8.1 | 0.0 | 0.0 | 3.0 | 3.0 | 4.8 | 5.1 | 0.7 | 0.7 | 2.4 | 2.4 | 0.8 | 0.8 | 1.1 | 1.1 |
Cutinite | 0.7 | 1.2 | 0.0 | 0.0 | 1.5 | 1.5 | 0.0 | 0.0 | 1.7 | 1.8 | 1.6 | 1.6 | 1.2 | 1.2 | 0.7 | 0.7 |
Resinite | 4.8 | 8.1 | 0.0 | 0.0 | 2.6 | 2.6 | 10.0 | 10.7 | 0.0 | 0.0 | 0.0 | 0.0 | 0.4 | 0.4 | 0.7 | 0.7 |
Alginite | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Liptodetrinite | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Suberinite | t | t | 0.0 | 0.0 | 0.4 | 0.4 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Exsudatinite | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
Total liptinite | 10.3 | 17.4 | 0.0 | 0.0 | 7.5 | 7.5 | 14.9 | 15.8 | 2.4 | 2.5 | 4.0 | 4.0 | 2.4 | 2.4 | 2.6 | 2.6 |
Silicate | 37.2 | 75.0 | 0.7 | 3.3 | 2.4 | 1.6 | 0.8 | 0.0 | ||||||||
Sulfide | 0.3 | 0.3 | 0.0 | 1.9 | 0.0 | 0.0 | 0.4 | 0.0 | ||||||||
Carbonate | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | ||||||||
Other | 3.1 | 0.3 | 0.0 | 0.7 | 0.0 | 0.0 | 0.0 | 0.0 | ||||||||
Total mineral | 40.7 | 75.7 | 0.7 | 5.9 | 2.4 | 1.6 | 1.2 | 0.0 | ||||||||
R max | 0.55 | 0.45 | 0.49 | 0.39 | 0.71 | 0.73 | 0.72 | 0.39 | ||||||||
Stdev | 0.05 | 0.05 | 0.03 | 0.02 | 0.04 | 0.03 | 0.03 | 0.03 | ||||||||
R random | 0.52 | 0.42 | 0.45 | 0.35 | 0.66 | 0.67 | 0.69 | 0.35 | ||||||||
Stdev | 0.04 | 0.04 | 0.04 | 0.03 | 0.05 | 0.05 | 0.04 | 0.03 | ||||||||
20 April 2022
https://doi.org/10.1007/s40789-022-00503-2
Springer
