| Year ended | |||
| Note | 31 December 2021 | 31 December 2020 | |
| Cash flows from operating activities | |||
| Net profit/(loss) for the reporting period | 1 786 470 | (2 234 337) | |
| Adjustments: | |||
| Income tax in profit or loss | 12 | 368 163 | (369 212) |
| Depreciation/amortisation | 9 | 1 539 286 | 1 598 063 |
| Loss on change, sale and liquidation of property, plant and equipment and right-of-use assets | 35 253 | 34 890 | |
| Impairment losses on non-financial non-current assets | 30 124 | 3 410 154 | |
| (Gain)/loss on sale of financial assets | (5 892) | 17 964 | |
| Interest income | (17 547) | (14 743) | |
| Dividend income | (227) | (283) | |
| Interest costs | 160 017 | 241 823 | |
| Gain on measurement of financial instruments | (108 567) | (77 311) | |
| Impairment of financial assets at amortised cost | 15 825 | 144 014 | |
| Share of profit of associates and jointly controlled entities | (192 561) | 332 361 | |
|
Impairment of investments in associates and jointly controlled entities |
− | 129 208 | |
| Other adjustments | (40 338) | (26 779) | |
| Total adjustments | 1 783 536 | 5 420 149 | |
| Paid income tax | (526 612) | (300 100) | |
| Changes in working capital: | |||
| CO2 emission allowances | 40 | (330 919) | (1 153 931) |
| Inventories | 40 | 9 660 | 241 866 |
| Trade and other receivables | 40 | (1 271 094) | (50 875) |
| Trade and other payables | 40 | 2 607 735 | 431 129 |
| Employee benefit liabilities | 40 | (4 344) | 67 694 |
| Accounting for subsidies and road lighting modernisation services | 40 | 120 152 | 33 259 |
| Provisions for other liabilities and charges | 40 | 1 312 336 | 702 910 |
| Total changes in working capital | 2 443 526 | 272 052 | |
| Net cash flows from operating activities | 5 486 920 | 3 157 764 | |
| Cash flows from investing activities | |||
| Purchase of non-current tangible and intangible assets and right-of-use assets | (1 901 807) | (2 382 772) | |
| Proceeds from sale of non-current tangible and intangible assets and right-of-use assets | 3 324 | 9 841 | |
| Purchase of financial assets | 40 | (68 219) | (199 415) |
| Proceeds from sale of financial assets | 40 | 121 461 | 476 |
| Purchase of associates and jointly controlled entities | (707) | (1 700) | |
| Sale of associates and jointly controlled entities | 982 | − | |
| Received dividends | 227 | 283 | |
| Inflows concerning funds at Mine Decommissioning Fund bank account | (6 080) | (7 592) | |
| Received interest | 911 | 3 443 | |
| Other (outflows)/inflows from investing activities | (359) | 1 136 | |
| Net cash flows from investing activities | (1 850 267) | (2 576 300) | |
| Cash flows from financing activities | |||
| Credit and loans received | 1 275 | 2 308 | |
| Repayment of credit and loans | (217 154) | (176 371) | |
| Bond buy-back | (997 110) | (1 894 310) | |
| Dividends paid | (105) | − | |
| Repayment of lease liabilities | (41 128) | (52 154) | |
| Interest paid | (165 611) | (276 256) | |
| Other outflows under financing activities | (4 821) | (5 074) | |
| Net cash flows from financing activities | (1 424 654) | (2 401 857) | |
| Total net cash flows | 2 211 999 | (1 820 393) | |
| Cash at the beginning of reporting period | 25 | 1 941 554 | 3 761 947 |
| Cash at the end of reporting period | 25 | 4 153 553 | 1 941 554 |
| including restricted cash | 646 928 | 754 321 | |