Gold and Silver precipitates

Gold and silver precipitates in the Merrill Crowe process

For the extractive metallurgic of gold and silver, the Merrill Crowe process is the one used the most. It is with this process that through leaching in piles, treatment to cyanide liquors obtained is given, and it is of fundamental importance the processing of the precipitates produced, with the goal of recovering the gold and silver metals they contain.

Precipitates stages

The main goal of the precipitate fusion is to obtain the coating with a good content of gold and silver, as well as the minimal content of impurity and precious metals in the waste. The process is divided into 4 stages:

Stage 1 Clarification: The rich on metals solution is bombed through a leaching pile so it can pass by a plates clarifier, which also has the function to retain the solid suspended particles, as this may hinder the next stages.

Stage 2 Deoxygenation: This process is done among towers, in which CO2 and oxygen are extracted by vacuum bombs, as these gases might be mixed in the rich solution.

Stage 3 Cementation: The solution goes through the vacuum tower to another tank in which value is recovered by adding zinc. When precipitating the dissolved values into the solution with the aid of zinc dust, this one replaces gold and silver so they can be settled into the bottom of the barrel as a solid.

Stage 4 Filtering: The gold and silver precipitates are retained in a press filter that forms a slim cape that will be removed in the next process (foundry or calcination). The solution with no values returns to the leaching process in piles, through pumps. The material with gold and silver precipitates dries and melts to recover the metals.

Merrill Crowe in gold and silver

The Merrill Crowe process is used to recover gold and silver when they are too much and the quantity of carbon necessary to absorb them would raise the costs a lot.

At DINCO, we manufacture under Merill Crowe vacuum towers under the ASME Code, which has been used in different projects around the world, this positions us as a world-class engineering business, which contributes to the success of metallurgic project and sector development, as well as regions in which important mining projects are developed.