7. Other operating income
| in PLN thousand | For the year ended 31 December 2017 | For the year ended 31 December 2016 |
| Compensations and fines received | 1 494 | 1 047 |
| Revenue from property, plant and equipment (including grants) | 6 635 | 7 042 |
| Reversal of doubtful debt allowance | 735 | - |
| Reversal of provisions (liquidation of tangible assets and reclamation) | 299 | 4 858 |
| Gain on sale of property, plant and equipment | 1 949 | 4 |
| Utilization of write-downs of fixed assets under construction | 293 | - |
| Other | 469 | 437 |
| 11 874 | 13 388 |
