Pit leaching, heap leaching, and cyanidation can all accommodate silver. If the silver content is high, the Merrill-Crowe process using zinc replacement can be employed to recover gold and silver. If the silver content is low, activated carbon is used.

Normally around 100 mesh, and if the permeability is good, slightly larger particles can also be used. The particle size for the crusher is generally 70-80 mesh and can be adjusted by changing the grinding time (or increasing the water level) to adjust the particle size, it’s recommended to keep it within 100 mesh.

Testing the leaching solution once or twice a day is adequate. Monitoring the difference in gold content between rich and poor solutions indicates the adsorption by the activated carbon; a significant difference suggests effective adsorption. The leaching solution should be tested diligently, with tests conducted 1-2 times daily for pH, reagent concentration, and gold-silver content. […]

In theory, the solution can be circulated indefinitely. However, in special cases where harmful substances are present in the ore, it is advisable to replace the solution regularly.

The water usage for pit leaching is approximately 1:10 with the ore, while for heap leaching, it depends on the actual situation. Consumption mainly consists of daily evaporation and rainfall. Excess recovered water can be stored in reserve ponds.