Mining concessions, development costs, property, plant and equipment, net (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of detailed information about property, plant and equipment [text block]

Below is presented the movement in cost:

	Balance as of January 1, 2016		Additions		Disposals		Sales		Reclassifications of assets held for sale		Reclassifications and transfers		Balance as of December 31, 2016		Additions		Disposals		Sales		Reclassifications and transfers		Balance as of December 31, 2017
	US$(000)		US$(000)		US$(000)		US$(000)				US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)

Cost
Lands		22,454		162		-		(6)		78		270		22,958		-		-		-		(268)		22,690
Mining concessions		198,009		-		-		-		-		-		198,009		2		-		(15,000)		(31,138)		151,873
Development costs		541,763		82,865		-		-		31,192		(3,428)		652,392		69,335		-		(10,107)		431		712,051
Buildings, constructions and other		1,018,956		581		-		(20)		10,458		79,192		1,109,167		835		(387)		(28,751)		198,387		1,279,251
Machinery and equipment		827,225		46,152		(6,569)		(2,844)		9,425		112,643		986,032		2,579		(3,749)		(50,097)		(5,742)		929,023
Transportation units		10,649		174		(341)		(396)		357		(27)		10,416		11		(190)		(1,079)		788		9,946
Furniture and fixtures		13,429		89		(61)		(88)		359		319		14,047		31		(157)		(487)		468		13,902
Units in transit		26,291		15,797		-		-		-		(12,037)		30,051		2,822		-		-		(28,124)		4,749
Work in progress		68,123		210,915		(352)		-		1,037		(173,935)		105,788		173,333		-		(190)		(177,809)		101,122
Stripping activity asset (e)		106,838		17,631		-		-		-		(2)		124,467		18,282		(13,573)		-		1,271		130,447
Mine closure costs		187,603		34,532		-		-		25,754		-		247,889		10,594		-		(17,195)		-		241,288
		3,021,340		408,898		(7,323)		(3,354)		78,660		2,995		3,501,216		277,824		(18,056)		(122,906)		(41,736)		3,596,342
Accumulated depreciation and amortization:
Mining concessions		77,450		16		-		-		-		-		77,466		8		-		(13,845)		(23,390)		40,239
Development costs		199,211		18,225		-		-		25,596		(1,396)		241,636		30,886		-		(7,910)		(241)		264,371
Buildings, construction and other		381,441		65,050		-		(9)		8,598		598		455,678		73,314		(115)		(28,208)		6,168		506,837
Machinery and equipment		475,941		81,753		(5,378)		(827)		6,640		(68)		558,061		74,744		(2,662)		(41,595)		(6,099)		582,449
Transportation units		7,932		1,103		(250)		(365)		358		14		8,792		837		(114)		(1,057)		(68)		8,390
Furniture and fixtures		7,577		1,156		(60)		(22)		319		202		9,172		1,109		(152)		(236)		(13)		9,880
Stripping activity asset		12,916		5,813		-		-		-		-		18,729		16,343		-		-		6,623		41,695
Mine closure costs		99,993		22,417		-		-		19,335		(470)		141,275		25,254		-		(8,408)		-		158,121
		1,262,461		195,533		(5,688)		(1,223)		60,846		(1,120)		1,510,809		222,495		(3,043)		(101,259)		(17,020)		1,611,982
Provision for impairment of long-lived assets:
Mine closure costs		4,080		-		-		-		6,910		-		10,990		17,916		-		(8,785)		-		20,121
Development costs		3,803		-		-		-		5,684		-		9,487		2,864		-		(2,198)		-		10,153
Mining concessions, development costs, property, plant and other		3,372		-		-		-		6,533		-		9,905		840		-		(6,214)		-		4,531
		11,255		-		-		-		19,127		-		30,382		21,620		-		(17,197)		-		34,805

Net cost		1,747,624												1,960,025										1,949,555

Commodity price estimates for current and long-term periods [Text Block]

Estimates prices for the current and long-term periods that have been used to estimate future cash flows are as follows:

	2018			2019 - 2022
	US$			US$

Gold		1,300.00	/Oz		1,300.00	/Oz
Silver		17.00	/Oz		18.00	/Oz
Copper		6,000.00	/MT		6,000.00	/MT
Lead		2,250.00	/MT		2,250.00	/MT
Zinc		2,750.00	/MT		2,600.00	/MT

Minera Yanacocha S.R.L. [Member]

Disclosure of detailed information about property, plant and equipment [text block]

(a)

Below is presented the movement in cost:

	Opening								Final
	balance		Additions		Sales and disposals		Transfer/Other changes		balances
	US$(000)		US$(000)		US$(000)		US$(000)		US$(000)

Year 2017
Cost-
Land		9,459		-		-		-		9,459
Land improvements		36,454		-		-		-		36,454
Building and constructions		236,551		-		(42)		61,289		297,798
Machinery and equipment		379,164		-		(92,299)		-		286,865
Leach pads		1,670,835		-		-		51,951		1,722,786
Vehicles		11,024		-		-		-		11,024
Furniture and fixtures		2,556		-		-		-		2,556
Other equipment		57,773		-		-		-		57,773
Work in progress		483,225		51,624		-		(134,439)		400,410
Mining rights		37,521		-		-		-		37,521
Asset retirement and mine closure		409,797		97,326		-		-		507,123
Stripping activity asset		148,487		-		-		-		148,487
Mine development		701,156		-		-		21,199		722,355
		4,184,002		148,950		(92,341)		-		4,240,611

Accumulated depreciation and amortization
Land improvements		35,053		90		-		-		35,143
Building and constructions		235,340		5,020		(12)		-		240,348
Machinery and equipment		329,965		8,431		(88,421)		-		249,975
Leach pads		1,588,205		33,061		-		-		1,621,266
Vehicles		11,003		21		-		-		11,024
Furniture and fixtures		2,556		-		-		-		2,556
Other equipment		55,645		269		-		-		55,914
Mining rights		29,457		-		-		-		29,457
Asset retirement and mine closure		337,173		19,172		-		-		356,345
Stripping activity asset		142,170		1,082		-		-		143,252
Mine development		622,604		16,846		-		-		639,450
		3,389,171		83,992		(88,433)		-		3,384,730
Net cost		794,831								855,881

	Opening						Transfer/Other		Impairment		Final
	balance		Additions		Sales and disposals		changes		loss		balances
	US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)

Year 2016
Cost-
Land		11,521		-		-		201		(2,263)		9,459
Land improvements		41,909		-		-				(5,455)		36,454
Building and constructions		274,262		-		(26,410)		26,396		(37,697)		236,551
Machinery and equipment		511,942		-		(125,064)		22,865		(30,579)		379,164
Leach pads		1,890,823		-				15,276		(235,264)		1,670,835
Vehicles		15,198		-		(4,168)				(6)		11,024
Furniture and fixtures		2,556		-		-		-		-		2,556
Other equipment		60,462		353		-		217		(3,259)		57,773
Work in progress		476,353		78,609		-		(70,282)		(1,455)		483,225
Mining rights		49,544		-		(3,113)				(8,910)		37,521
Asset retirement and mine closure		452,145		351,798		-				(394,146)		409,797
Stripping activity asset		157,048		26,148		-				(34,709)		148,487
Mine development		814,563		-		-		5,079		(118,486)		701,156
		4,758,326		456,908		(158,755)		(248)		(872,229)		4,184,002

Accumulated depreciation and amortization
Land improvements		35,266		298		-		(511)		-		35,053
Building and constructions		196,515		61,530		(22,705)		-		-		235,340
Machinery and equipment		429,910		12,230		(112,175)		-		-		329,965
Leach pads		1,565,508		22,697		-		-		-		1,588,205
Vehicles		14,620		2,735		(6,352)		-		-		11,003
Furniture and fixtures		2,547		9		-		-		-		2,556
Other equipment		53,964		1,681		-		-		-		55,645
Mining rights		29,457		-		-		-		-		29,457
Asset retirement and mine closure		318,405		18,768		-		-		-		337,173
Stripping activity asset		138,178		3,992		-		-		-		142,170
Mine development		613,646		8,447		-		511		-		622,604
		3,398,016		132,387		(141,232)		-		-		3,389,171
Net cost		1,360,310										794,831

Commodity price estimates for current and long-term periods [Text Block]

Estimated prices for the current and long-term periods that have were used to estimate future revenues were as follows:

	Current		Long-term
	US$		US$

Gold (per ounce)		1,221		1,300

Sociedads Mineras Cerro Verde Saa [Member]

Disclosure of detailed information about property, plant and equipment [text block]

The changes in cost and accumulated depreciation accounts as of December 31, 2017 are shown below:

	January 1,										December 31,										December 31,
	2016		Additions		Adjustments		Disposals		Transfers		2016		Additions		Adjustments		Disposals		Transfers		2017
	US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)		US$(000)

Cost
Land		20,384		-		-		-		3,299		23,683		-		-		-		784		24,467
Buildings and other constructions		2,202,122		-		(11,114)		(5,633)		191,586		2,376,961		-		(13,532)		(1,169)		7,782		2,370,042
Machinery and equipment		4,203,431		-		11,114		(4,427)		232,062		4,442,180		-		13,532		(4,540)		102,336		4,553,508
Transportation units		19,627		-		-		(730)		213		19,110		-		-		(261)		1,708		20,557
Furniture and fixtures		950		-		-		(1)		-		949		-		-		-		-		949
Other equipment		24,728		-		-		(1,065)		1,008		24,671		-		-		(34)		340		24,977
Construction in progress and in-transit units		362,058		154,876		-		-		(428,168)		88,766		173,845		-		-		(112,950)		149,661	(a)
Stripping activity asset (see Note 2(j))		263,498		61,261		-		-		-		324,759		153,623		-		-		-		478,382
Asset retirement costs (see Note 12(b)		149,724		3,743		(16,091)		-		-		137,376		2,661		(3,710)		-		-		136,327
		7,246,522		219,880		(16,091)		(11,856)		-		7,438,455		330,129		(3,710)		(6,004)		-		7,758,870

Accumulated depreciation
Buildings and other constructions		60,903		88,925		(30)		(4,936)		-		144,862		86,391		(457)		(1,169)		-		229,627
Machinery and equipment		966,525		275,388		30		(3,964)		-		1,237,979		283,250		457		(4,349)		-		1,517,337
Transportation units		9,723		1,828		-		(686)		-		10,865		1,593		-		(237)		-		12,221
Furniture and fixtures		777		26		-		(1)		-		802		32		-		-		-		834
Other equipment		12,582		2,423		-		(1,052)		-		13,953		2,474		-		(27)		-		16,400
Stripping activity asset		111,552		97,513		-		-		-		209,065		76,262		-		-		-		285,327
Asset retirement costs		7,171		6,018		-		-		-		13,189		5,511		-		-		-		18,700
		1,169,233		472,121		-		(10,639)		-		1,630,715		455,513		-		(5,782)		-		2,080,446

Net cost		6,077,289										5,807,740										5,678,424