| | | 12/31/2017 | | 12/31/2016 | | 12/31/2015 | | |||
| | | ThUS$ | | ThUS$ | | ThUS$ | | |||
| Raw material and supplies | | | (413,283) | | | (335,192) | | | (309,103) | |
| Types of employee benefits expenses | | | | | | | | | | |
| Personnel expenses | | | (172,159) | | | (162,335) | | | (127,556) | |
| Depreciation expense | | | (232,365) | | | (271,239) | | | (305,091) | |
| Amortization expense | | | (2,921) | | | (3,210) | | | (3,469) | |
| Small deposit amortization expense | | | (5,440) | | | (9,498) | | | (2,287) | |
| Inventory provision variation | | | (14,989) | | | (926) | | | 2,597 | |
| Operating leases | | | (96,094) | | | (90,325) | | | (62,599) | |
| Investment plan expenses | | | (13,956) | | | (16,624) | | | (17,574) | |
| Maintenance and repair | | | (5,306) | | | (6,051) | | | (3,956) | |
| Contractors, | | | (67,337) | | | (62,300) | | | (49,862) | |
| Mining concessions | | | (7,802) | | | (7,313) | | | (12,888) | |
| Operations transport | | | (54,057) | | | (45,864) | | | (37,809) | |
| Freight and product transport costs | | | (131,729) | | | (132,260) | | | (96,295) | |
| Packaging costs | | | (2,402) | | | (1,712) | | | (4,244) | |
| Purchases from third parties | | | (113,898) | | | (125,456) | | | (120,040) | |
| Insurance policies | | | (11,199) | | | (12,110) | | | (7,620) | |
| CORFO right | | | (46,274) | | | (41,962) | | | (23,155) | |
| Other expenses, by nature | | | (3,611) | | | (3,908) | | | (4,632) | |
| Total | | | (1,394,822) | | | (1,328,285) | | | (1,185,583) | |