Cost of sales, without considering depreciation and amortization (Tables)

12 Months Ended

Dec. 31, 2018

(a)

The cost of sales of goods is made up as follows:

	2018			2017			2016
	US$(000)			US$(000)			US$(000)

Beginning balance of finished goods and products in process, net of depreciation and amortization		37,640			58,633			69,932

Cost of production
Services provided by third parties		245,705			262,195			211,325
Consumption of materials and supplies		136,991			134,070			100,401
Direct labor		96,612			87,886			72,344
Electricity and water		51,226			44,345			41,989
Transport		24,805			16,254			10,880
Maintenance and repair		24,459			22,839			17,792
Rentals		31,156			26,591			10,852
Insurances		11,550			6,637			4,347
Provision (reversal) for impairment of finished goods and product in progress, note 8(c)		4,521			2,118			(7,581	)
Cost of concentrate purchased to third parties		-			439			2,958
Other production expenses		10,025			10,464			9,789
Total cost of production of the period		637,050			613,838			475,096
Final balance of products in process and finished goods, net of depreciation and amortization		(49,206	)		(45,038	)		(47,216	)
Cost of sales of goods, without considering depreciation and amortization		625,484			627,433			497,812

(b)

The cost of services is made up as follows:

	2018		2017		2016
	US$(000)		US$(000)		US$(000)

Direct labor		2,128		7,398		5,983
Consumption of materials and supplies		675		1,026		868
Maintenance and repair		543		946		217
Services provided by third parties		382		1,782		1,689
Electricity and water		249		586		633
Rentals		92		423		480
Insurances		86		246		212
Transport		50		98		213
Other		113		449		459

		4,318		12,954		10,754