Mineral Flotation of Auriferous Veins

The metallurgical advance of the extraction of gold, is being oriented in the present time to hydrometallurgical processes; nevertheless, one can still use the method of flotation to obtain concentrates and/or pre-concentrates mainly for minerals which proceed from veins.

Under this aspect, in the metallurgical laboratories of the INGEMMET, we are still investigating the field of flotation to recuperate gold as a main product or sub-product.

In the present work we will present two typical examples by flotation of gold. The first, direct flotation of auriferous values and, in the second case, selective separation of auriferous pyrrite and arseno-pyrrites.

Direct Flotation of Auriferous Values

Analysis of the Mineral Head
The samples conveniently prepared and pulverized were remitted to the chemical laboratory for its corresponding chemical analysis.

Of the results obtained one can deduce that the richest sample is the #330446, with law of Au of 9.75 g/TM while the sample #330409 throws only 0.43 g/TM.

In both samples the laws of Cu and Pb are low and will not be possible to recuperate them by the method of flotation as valuable elements; the sample # 330446 has 2.47% of Zn, for which we will study the possible recuperation of this element as a concentrate of zinc.

Grinding Tests
After having formed the two composites with a weight approximate of 100 grams each one, the first stage consisted in effectuating a series of test of grinding to determine the optimal time with which one can obtain the adequate liberation of the valuable element to respond efficiently to the process of flotation.