v3.26.1
Information by business segment (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
IfrsStatementLineItems [Line Items]      
Net revenues $ 3,002,055 $ 2,766,481 $ 2,573,233
Cost of sales 2,289,159 2,228,410 2,274,357
Gross profit 712,896 538,071 298,876
Impairment loss of long-lived assets (91,706) 32,870 114,643
Other income and expenses, net (79,483) (33,511) (110,584)
Adjusted EBITDA 771,879 714,080 406,041
Change in fair value of energy forward contracts 9,608 81 (15,663)
Share in the results of associates 21,143 21,223 23,536
(Loss) income before income tax 331,749 (71,851) (296,084)
Other restoration obligations 6,960
Divestment and restructuring (7,736) (9,028)
Operating segments [member]      
IfrsStatementLineItems [Line Items]      
Net revenues 3,002,055 2,766,481 2,573,233
Cost of sales (2,289,159) (2,228,410) (2,274,357)
Gross profit 712,896 538,071 298,876
Selling, general and administrative (145,452) (127,328) (126,599)
Mineral exploration and project evaluation (81,696) (67,976) (99,612)
Impairment loss of long-lived assets 91,706 (32,870) (114,643)
Other income and expenses, net (79,483) (33,511) (110,584)
Operating (loss) income 497,971 276,386 (152,562)
Depreciation and amortization 288,996 330,198 310,475
Miscellaneous adjustments (15,088) 107,496 248,128
Adjusted EBITDA 771,879 714,080 406,041
Operating segments [member] | Mining Segment [Member]      
IfrsStatementLineItems [Line Items]      
Net revenues 1,569,883 1,349,666 1,090,276
Cost of sales (938,273) (1,011,742) (1,026,178)
Gross profit 631,610 337,924 64,098
Selling, general and administrative (73,365) (66,307) (61,690)
Mineral exploration and project evaluation (75,804) (60,939) (90,238)
Impairment loss of long-lived assets 91,706 (32,870) (109,347)
Other income and expenses, net (87,752) (41,714) (67,876)
Operating (loss) income 486,395 136,094 (265,053)
Depreciation and amortization 189,670 243,111 229,153
Miscellaneous adjustments (17,771) 84,866 196,529
Adjusted EBITDA 658,292 464,071 160,629
Operating segments [member] | Smelting Segment [Member]      
IfrsStatementLineItems [Line Items]      
Net revenues 2,057,071 1,997,341 1,946,661
Cost of sales (1,975,060) (1,799,773) (1,726,271)
Gross profit 82,011 197,568 220,390
Selling, general and administrative (72,158) (57,197) (61,097)
Mineral exploration and project evaluation (6,561) (7,887) (9,374)
Impairment loss of long-lived assets   (5,296)
Other income and expenses, net 11,859 7,984 (26,412)
Operating (loss) income 15,151 140,468 118,211
Depreciation and amortization 95,497 86,458 80,471
Miscellaneous adjustments 2,683 22,630 51,599
Adjusted EBITDA 113,332 249,556 250,281
Operating segments [member] | Adjustment [Member]      
IfrsStatementLineItems [Line Items]      
Impairment loss of long-lived assets 91,706 (32,870) (114,643)
Miscellaneous adjustments 15,088 (107,496) (248,128)
Changes in fair value of offtake agreement (44,243) (102) 2,268
Loss on sale of property, plant and equipment (1,649) (16,183) (3,734)
Asset retirement obligations remeasurement estimate (7,710)    
Change in fair value of energy forward contracts 9,608 81 (15,663)
Reversal of other restoration obligations 8,112    
Divestment and restructuring gains 7,736    
Dividends received in cash (23,835) (25,185)  
Remeasurement adjustment of streaming agreement (24,637) (21,084) (10,121)
Depreciation and amortization (288,996) (330,198) (310,475)
Share in the results of associates 21,143 21,223 23,536
Net financial results (187,365) (369,460) (167,058)
(Loss) income before income tax 331,749 (71,851) (296,084)
Impairment of other assets   (307)  
Aripuana ramp up impacts   (25,158) (15,494)
Asset retirement obligations remeasurement estimate   5,310 3,125
Other restoration obligations   (1,026) (6,960)
Divestment and restructuring   9,028  
Tax voluntary disclosure     (86,906)
Elimination of intersegment amounts [member]      
IfrsStatementLineItems [Line Items]      
Net revenues (669,298) (604,034) (468,250)
Cost of sales 669,298 604,034 468,250
Material reconciling items [member]      
IfrsStatementLineItems [Line Items]      
Net revenues 44,399 23,508 4,546
Cost of sales (45,124) (20,929) 9,842
Gross profit (725) 2,579 14,388
Selling, general and administrative 71 (3,824) (3,812)
Mineral exploration and project evaluation 670 850  
Other income and expenses, net (3,590) 219 (16,296)
Operating (loss) income (3,574) (176) (5,720)
Depreciation and amortization 3,829 629 851
Adjusted EBITDA $ 255 $ 453 $ (4,869)