The new application of geometallurgy in deportment of gold and critical metals studies.

As an interdisciplinary approach, geometallurgy links geological, geochemical, and mineralogical characteristics with the metallurgical performance of an orebody. The aim of a geometallurgical program is to characterize and understand the metallurgical variability of an orebody, and to build a "geomet" model that can be used to assist in mine planning and to predict plant performance. Gold ores could be generally classified into two major categories: free-milling and refractory, according to the difficulty of processes. The reason of refractory ores can be mainly attributed to two factors: gold locking and gangue mineral influence. The geometallurgy of gold needs to reveal the gold deportment, including types of gold minerals and the reasons for the refractory ore, so as to provide guidance for mineral processing. The form of gold includes microscopic gold, submicroscopic gold or surface gold. To study the gold deportment, it is necessary to use an automated mineral analysis system to analyze microscopic gold minerals and cross check with a variety of metallurgy experiments. Combined with analyses of sub-microscopic gold of gold-bearing minerals, all the distribution of gold can be obtained. Different genetic types of gold deposits have different geometallurgical characteristics, and the geometallurgy research of gold can in turn provides the information for the genesis and evolution of deposits. This study briefly introduces some geometallurgical studies in hydrothermal deposits including porphyry, epithermal, iron oxide copper-gold ( IOCG), carlin and skarn gold deposits in recent years. Many new methods have been used in geometallurgy studies, such as VNIR-SWIR hyperspectroscopy and machine learning of geochemistry data. Critical metals are difficult to study due to the low content and fine-grained host minerals, but it has many similarities with the geometallurgy study of gold. Therefore, we proposed that the research procedure and new technical methods for the gold deportment study could be applied to the critical metal deposits. Based on this principle, in this study the standard research procedure and a normalized expression of the deportment of critical metals have been proposed, which further extends the content and application of geometallurgy.