Independent quality assessment of Kolmar coals
Joint-Stock Company Eastern Scientific and Research Coal Chemistry Institute (JSC VUHIN) has studied the beneficiation ability, qualita tive characteristics and coking ability of the coals extracted by open-pit (Western area of Chulmakan deposit) and underground mining (Denisovskaya mine and Inaglinskaya mine).
For the coals of each bed, LLC Sibniiugleobogascheniye carried out an in-depth study with particle size and fractional analyses on the basis of which potential (theoretical) and expected actual indicators of beneficiation products of the run-of-mine coals of the studied coal beds. Besides, a range of lab tests were carried out for the coals, including technical, element and petrographical analysis, determination of caking and coking indicators by Russian and foreign techniques, as well as determination of the chemical composition of the ash of the concentrates and their melting temperature.
Quality of ROM coals
| Quality indicators | Mine Denisovsklaya | Western area | Mine Inaglinskaya | |
|---|---|---|---|---|
| Bed K4 | Bed Д19 | Bed Д19 | Bed Д15 | |
| Analytical moisture (W3), % | 0,5 | 0,8 | 1,0 | 0,9 |
| Ash (Ad), % | 26,6 | 32,8 | 38,3 | 25,1 |
| Volatile yield (Vdat), % | 25,4 | 31,1 | 33,1 | 38,1 |
| General sulphur (Sdt), % | 0,29 | 0,30 | 0,20 | 0,24 |
| Calorific value (Qdat), ккал/кг | 8793 | 8677 | 7519 | 8100 |
| Hardgrove Grindability Index, unit | 77 | 72 | 60 | 65 |
It is seen from the table that the coals are char acterized by ash content (Denisovskaya mine, 26.6 %, Western area, 32.8 %, and Inaglinskaya mine, 25.1–38.3 %) and low sulphur content (0.20–0.30 %). Actual coal density (ddr) is directly dependent on their ash content and rang ing from 1.48 to 1.64 g/cm3.
The coals of all beds are characterized by high calorific value (QSdaf>31.5–36.8 MJ/kg), even run-of-mine coals.
In terms of Hardgrove Grindability Index (HGI) the coals are characterized by medium and low strength categories.