Source:
p. 1
Newmont, Buenaventura and Sumitomo completed the transaction June 20, 2018 in which Sumitomo paid $48 million for the ownership interest in Yanacocha. In December 2017, Yanacocha repurchased the International Finance Corporation’s (IFC) five percent stake which it held since 1992 when it provided debt financing for construction of the operation.
As a result of the transaction, Newmont and Buenaventura’s ownership interests in Yanacocha will revert to 51.35 percent and 43.65 percent, respectively, the proportion held prior to the repurchase of the IFC’s ownership stake in December. The transaction is structured as a new share issuance to Sumitomo, with the payment going towards Yanacocha’s cash balances.
The operation is a joint venture between Newmont Mining Corporation (51.35%), Minas Buenaventura (43.65%) and Sumitomo Corporation (5%).
Summary:
Yanacocha is an epithermal type deposit of high sulfidation hosted in volcanic rock formations. Gold is associated with ironoxides and pyrite.
The Yanacocha property consists of the following open pit mines: the La Quinua Complex, Cerro Yanacocha, the Carachugo Complex and Maqui Maqui.
The Yanacocha gold district is a 10x4km zone of altered rocks within a belt of tertiary volcanics that extends the whole length of Peru. Andesitic domes and dome complexes have been silicified and leached by epithermal gold-bearing solutions in at least nine distinct deposits. The mineralised sequences, which can also contain significant amounts of silver, are flanked by extensive argillitic alteration, and subsequent events have created siliceous breccia pipes with localised high gold grades.
Summary:
The Yanacocha property began production in 1993 and consists of the following open pit mines: the La Quinua Complex, the Yanacocha Complex, the Carachugo Complex and Maqui Maqui.
The La Quinua Complex is currently mining material from the La Quinua Sur and the Tapado Oeste Layback and is scheduled to finish mining operations in 2019.
The Yanacocha Complex mines material from the Yanacocha Layback and Yanacocha Pinos. The Yanacocha Complex is scheduled to finish mining operations in 2019. The Yanacocha Complex began operations in 1997 and has had limited mining operations in recent years.
The Carachugo Complex and Maqui Maqui mined material from multiple mines that are no longer in operation and only de minimis residual leaching of gold continues.
Yanacocha’s available mining fleet consists of two shovels, four excavators, two loaders and 43 haul trucks, which range from 140 to 240 tonnes.
Brownfield exploration and development for new reserves is ongoing, including the development of Quecher Main within the existing footprint of Yanacocha. This oxide deposit will extend the life of the Yanacocha operation to 2027, with an average of approximately 200,000 ounces between 2020 and 2025. Quecher Main received full funding approval from the Board of Directors in October 2017 and is expected to reach commercial production in the fourth quarter of 2019.
Processing Technologies
- Heap leach
- Agitated tank leaching
- Counter current decantation (CCD)
- Carbon in column (CIC)
- SART
- AVR cyanide recovery
- Merrill–Crowe
- Cyanide (reagent)
Summary:
Yanacocha has four leach pads, three processing facilities and one mill.
Yanacocha’s processing facilities (Pampa Larga, Yanacocha Norte and La Quinua) are located adjacent to the solution storage ponds and are used to process gold-bearing solutions from Yanacocha’s leach pads through a network of solution pumping facilities. The Yanacocha Gold Mill processes high-grade gold ore to produce a gold-bearing solution for treatment at the La Quinua processing plant. The Yanacocha Gold Mill commenced operations in March 2008, and it processes between 5.5 and 6.0 million tonnes per year.
Since the ore is porous, run-of-mine ore can be heap-leached without crushing and the solution treated by the Merrill Crowe process.
Production:
| Commodity | Units | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 |
|
Gold
|
koz
| ......  ^ | ...... | ...... | 918 | 970 | 1,017 |
All production numbers are expressed as metal in doré.
^ Guidance / Forecast.
- Subscription is required.
Operational Metrics:
| Metrics | 2017 | 2016 |
|
Annual processing rate
| ...... | 5.75 Mt of ore |
- Subscription is required.
Reserves at December 31, 2017:
| Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
|
Proven
|
Total
|
39,963 kt
|
Gold
|
0.89 g/t
|
1,147 koz
|
|
Proven
|
Total
|
29,417 kt
|
Silver
|
16.9 g/t
|
16,096 koz
|
|
Probable
|
Total
|
135,060 kt
|
Gold
|
0.62 g/t
|
2,683 koz
|
|
Probable
|
Total
|
132,470 kt
|
Silver
|
8 g/t
|
33,858 koz
|
|
Proven & Probable
|
Total
|
175,023 kt
|
Gold
|
0.68 g/t
|
3,830 koz
|
|
Proven & Probable
|
Total
|
161,887 kt
|
Silver
|
9.6 g/t
|
49,954 koz
|
|
Measured
|
Total
|
9,991 kt
|
Gold
|
0.47 g/t
|
148 koz
|
|
Measured
|
Total
|
9,806 kt
|
Silver
|
4.8 g/t
|
1,499 koz
|
|
Indicated
|
Total
|
124,329 kt
|
Gold
|
1.16 g/t
|
4,644 koz
|
|
Indicated
|
Total
|
119,519 kt
|
Silver
|
18.8 g/t
|
72,118 koz
|
|
Indicated
|
Total
|
102,868 kt
|
Copper
|
0.64 %
|
647,549 t
|
|
Measured & Indicated
|
Total
|
134,320 kt
|
Gold
|
1.11 g/t
|
4,792 koz
|
|
Measured & Indicated
|
Total
|
129,325 kt
|
Silver
|
17.7 g/t
|
73,617 koz
|
|
Measured & Indicated
|
Total
|
102,868 kt
|
Copper
|
0.64 %
|
647,549 t
|
|
Inferred
|
Total
|
166,513 kt
|
Gold
|
0.94 g/t
|
5,032 koz
|
|
Inferred
|
Total
|
7,771 kt
|
Silver
|
7.7 g/t
|
1,906 koz
|
|
Inferred
|
Total
|
4,995 kt
|
Copper
|
0.35 %
|
18,501 t
|
Heavy Mobile Equipment as of December 31, 2017:
| HME Type | Quantity |
|
Excavator
|
4
|
|
Loader
|
2
|
|
Shovel
|
2
|
|
Truck (haul)
|
43
|