Preparation of Mineral

The previous preparation of the mineral is a common practice in operations of this type before building the heap leaching. In the case of some areas, this stage did not present any major complications, due to the fact that the mineral was only submitted to one stage of classification using a Zaranda of 1” of opening. This operation allowed us to obtain two products: the minus net which was heap leached for a direct lixiviation and the plus net which will be crushed to afterwards be lixiviated.

An important aspect which will be necessary to take into account in the operations of mining, will be the use of an adequate technique of explosions with the purpose of avoiding  in as many ways possible the formation of material which could be too thick.

One of the characteristics of the mineral is referred to the fact that it is easily lixiviable, condition which is seen favorable for not presenting problems of impermeabilization besides containing a considerable quantity of fine material.

The necessary lime for the neutralization of the mineral was added in a form of lime bed. This solution  was made to circulate through the heap leaching before the cyanide of sodium is added to the solution of the lixiviant. With this operation the protective alkalinity of the environment was assured.

Loading the Mineral
In the diagram of flux one can observe the form of the heap leaching, we can say that it has the appearance of a truncated pyramid. As it was already mentioned, the loaded tonneage to the pilot heap leaching is of 1,000 TM, having a height of 2 m.; for the determination of the height the following factors were taken into account: permeability and content of oxygen in the circulating sollutions.

Concerning this, tests in collumns of 2 m. of height and 30 cm. of diameter have demonstrated good characteristics of percolation; in the same manner, the siae of the heap leaching and its form of construction assure us a good oxygenation. In consequence, it is a favorable condition for the dissolution of gold that the remnant of the dissolved oxygen in the lixiviant until such a solution goes through the whole heap leaching.

During the loading of the mineral no compacting whatsoever was produced which could difficult the lixiviation, due to the fact that such loading was effectuated with a frontal loader, with which its shovel reached a height of 2 m.