Pyrites Plant

Ownership: 100% Fresnillo plc
Location: Zacatecas, Fresnillo District
Facilities: Leaching plant at the Saucito mine, flotation plant at the Fresnillo mine
Commercial Production: 2Q18 (phase I), 2H20 (phase II)
Anticipated Production: Annual average 3.5 moz silver and 13.0 koz gold
Capex: US$ 155 million

The Pyrites plant is expected to improve overall recoveries of gold and silver, and therefore maximise production in the Fresnillo district; expected to total an average of 3.5 moz silver and 13 koz gold per year once both phases are operating at full capacity. 

The second phase, a flotation circuit, will treat the ongoing and historical tailings from the Fresnillo mine to produce a pyrites concentrate which will be sent to a filtration plant and then on to the leaching plant at Saucito, the final part of the process to produce the precipitates. Commissioning of phase II of the Pyrites plant set for 2H 2020.

Pyrites Plant (Phase I)

 

2Q19

1Q19

% change

2Q18

Ore processed (t)

39,159

47,846

-18.2

11,745

         

Production

       

Silver (koz)

333

306

8.8

73

Gold (oz)

1,215

1,100

10.5

186

         

Ore grades

       

Gold (g/t)

352

267

31.8

452

Silver (g/t)

2.57

2.10

22.4

3.37

Overview and Key developments:

  • The project will improve overall recoveries of gold and silver by processing historical and ongoing tailings from Fresnillo and Saucito mines.

  • The plant will froth float pyrite concentrates that will be leached in a 2,000 tpd dynamic leaching plant and Merrill Crowe plant to produce precipitates.

  • First stage completed: commissioned leaching plant at Saucito on time (2Q18), following a US$54.6 million investment.

  • Second stage: Construction of the flotation plant at Fresnillo expected 2H20, delayed due to a longer than anticipated permitting process.

Highlights - 2Q19

  • The leaching plant of the pyrites plant at Saucito contributed 333 koz of silver and 1,215 oz of gold in 2Q19, up 8.8% and 10.5% respectively vs. 1Q19. This resulted from the higher than expected ore grades, which more than offset the lower volumes processed as the stock pile is depleted.

  • Plant commissioned mid-2018, thus comparable figures vs. 2018 are not relevant.

  • Expected silver ore grade for 2019 continues to be between 190-210 g/t.

  • Construction of the flotation plant at the Fresnillo mine (phase II) remains on track and is due to be commissioned in the second half of 2020. The assembly of the flotation cells and milling structure continued as well as the construction of the maintenance workshop and compressors.
  • The project is expected to improve overall recoveries of both gold and silver by processing historical and ongoing tailings from the Fresnillo and Saucito mines.

  • Once both phases are commissioned and operating at nominal capacity, this US$155 million project is expected to contribute an additional annual production of c. 3.5 moz of silver and c. 13 koz of gold.