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Mercury-Free�Processing System

Engr. Bernardo Bitanga

Chief - Engineer V, Metallurgical Technology Division�Mines & Geosciences Bureau - DENR

MFPS |

Minahang Bayan of Brgy. Casalugan,

Paracale, Camarines Norte

21 September 2024

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MFPS 1: Mercury-Free Processing System

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  • A centralized ore processing facility with a capacity of 2-4 metric tons of ores per day�
  • Aims to recover gold by at least 80% through combined metallurgical methods of improved gravity concentration and chemical leaching using cyanide-amino acid mixture as alternative to mercury amalgamation

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  • Construction completed in the first week of December 2023

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  • Testing and optimization completed in May 2024

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MFPS 1: Mercury-Free Processing System

3D Rendering of�MFPS Facility Layout

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Process Flow Diagram (Gravity Circuit)

Screening

Grinding with Cyclone

Crushing

Shaking Table

Smelting

Refining

Crushing

Gold Concentrates

Gravity Tails

Gold bullion

Run of Mine

Undersize

Oversize

Hydro-cyclone Underflow

Fluxes

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Process Flow Diagram (Leaching Circuit)

Refining

Smelting

Detoxification

Tailing Storage Facility (TSF)

Leaching

Gold Bullion

  • - Activated Carbon - Sodium Cyanide, Glycine, and Hydrated Lime

Loaded Carbon (Adsorbed gold in solution)

Final tailings

Leaching

Tails

Hydrocyclone Overflow

Sodium metabisulfate

Fluxes

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Latest Helicoidal Concentrator Commissioning Results

Trial

Feed

Feed dry wt kg

Conc dry wt kg

Gold feed assay gpt

Gold conc assay gpt

Unit process recovery

1

Amalgamation tailings

47.07

8.03

4.17

5.03

20.58%

2

Silt materials from dewatering of mine operation

36.68

10.63

1.40

4.17

86.29%

3

Mill discharged

42.21

3.83

3.20

23.97

67.87%

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Latest Leaching Circuit Commissioning Results

Loaded carbon (LC)

for ashing

Leached tailings impounded at TSF

Ore packed in sacks

Leaching in progress

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Ashing of LC

Smelting of ashed carbon

1.235 grams doré

Bullion at ~98% purity

Latest Carbon Ashing

and Smelting Results

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Gold Produced from Commissioning Activities

Figure A - October 2023 to January 2024 commissioning activities using fresh ore with calculated

overall recovery of 21.66%

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Figure B - Reprocessed tailings from previous commissioning with calculated�overall recovery of 33.67%

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Figure C - May 2024 commissioning activities using fresh ore with calculated�overall recovery of 79.52%

Figure A

Figure B

Figure C

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Thank you!�Together, we can make a world�of difference in small-scale gold mining.