INTEGRATION OF STATISTICAL ANALYSIS OF GEOCHEMICAL DATA FROM HANDHELD XRF ANALYZER, ICP AND AAS WITH MINERALOGICAL TECHNIQUES (QEMSCAN ANALYSIS AND OPTICAL MICROSCOPY) TO CHARACTERIZE PARAGENESIS, HYDROTHERMAL ALTERATION AND MINERALIZATION IN A PORPHYRY COPPER-MOLYBDENUM DEPOSIT IN CHILE, SOUTH AMERICA

The exploitation of porphyry copper deposits in Chile, South America, allows the mining sector to stand out as one of the largest worldwide. The metal industry is a high risk area, and small variations in the economy produce a strong impact on exports, so it is necessary to make the mining process as optimal as possible. The integration of geological information contributes to improve the understanding of the geology of the deposit and allows establishing relationships between the nature of the material and processing features, where it is important to pay attention to gangue mineralogy, which determines the behavior of the rock during mineral processing. It helps to understand intrinsic characteristics of the geology of the deposit like: zoning of hydrothermal alteration, paragenesis, mineralization and lithological relationships.. There is a lot of information that is constantly generated in the geological survey such as chemical and geometallurgical analysis that can be integrated in ore deposits models.

Hydrothermal alteration and lithology are analyzed using data acquired by a Handheld XRF analyzer, AAS and ICP-OES, and qualitative and quantitative mineralogy of the rock is characterized via core logging, petrographic techniques and Qemscan in Fieldscan mode. Qemscan gives modal mineralogy of samples, ore characterization, estimated grain and particle size, mineral association and elemental distribution. The description of alteration and lithology present at the site, in conjunction with analyses of bulk geochemical assay data using univariate and multivariate statistical tools allows linking the geochemical distribution of elements and certain qualitative and quantitative characteristics of the rock. A multivariate study is done to define relationships of elements, using the Handheld XRF analyzer, a rapid and low cost technique. These geochemical contrasts and ratios are analyzed to indicate a change in hydrothermal alteration, mineralization and lithology, supported by the mineralogical description, integrating macroscopic, petrographic and automated techniques. It aims to set the usefulness of a variety of techniques in conjunction to approach a better model of the deposit and analyze the feasibility of using data from the Portable X-Ray Fluorescence in lithogeochemistry.