Evaluation in a Laboratory Scale

The importance of the tests of laboratory radicates in that they allow to determine in a general form the behavior of the mineral under ideal conditions of lixiviation.

It is important to mention, within these tests of laboratory the importance which the sample has in treating. It is important to know that the sample is representative of the body of the mineral and that, therefore, all information obtained starting from it is trustworthy.

The preparation of samples for effects of a bacerial lixiviation basically comprehends:

• - Determination of the potential of the sample to be lixiviated by the microorganisms, an analysis of the content of total sulphur is performed, which at the end will be turned to sulphuric acid.

Stot – H2SO4

H2SO4 theoretically available in kg/t exceeds to the amount that theoretically could produce the material, it can be considered as non producer of acid, therefore, this material will not be docile to the bacterial lixiviation (at least not directly, the adding of pyrite or sulphur could help to beat this problem).

• - If the consumption of acids is less than the acid produced by the material it will then be mentioning a material productor of acid, therefore, the waste will be an appropriate source for the bacterial lixiviation.

In consequence, once the possibility for the bacerial lixiviation has been determined, a series of tests of lixiviation must be effectuated to demonstrate its feasibility. The experience has shown that not all the sulphured minerals are docile to the microbiological attack.

There are, fundamentally, four methods of the study of the chamical-bacterian lixiviation at a level of laboratory.