Chemical Characterization of Auriferous Ores from the Brazilian State of Paraiba

Abstract

One of the most important problems facing the gold industry is that the placer and free milling gold ores are almost terminating. Hence, the use of refractory ores has been increased during the recent years. In general, gold refractory ores occurs in various types of deposits associated with a range of minerals. Among the refractory ores, the sulfide type is the most common. The methodology employed in the mining process depends on the mode of occurrence of the ore and on the particle size, shape and degree of purity of the auriferous species. We have undertaken a mineralogical investigation of a representative sample of a complex gold mining ore collected in the municipality of Princesa Isabel, Paraiba, Brazil, using X-ray fluorescence spectrometry, X-ray diffractometry, infrared spectroscopy, inductively coupled plasma-atomic emission spectrometry and the Fire Assay. The results showed that the arsenic content of the ore was closely related to the gold content, and that the occurrence of "invisible gold" was associated primarily with pyrite and secondarily with arsenopyrite. The sulfur content of the ore was directly related to its refractoriness. It is concluded that gold mineralization in the study area is mainly of the gold-quartz-sulfide veins (lode gold), while the gold found in the mini-fractures of the deposits is probably associated with the hydrothermal processes that occurred in the region.

Efficiency of Crude <i>α</i>-Cyclodextrin in Gold Recovery from Electronic Waste and Soil

“…Gold recovery during electronic waste recycling and mining activities especially the Artisanal miners employ toxic and pollutive solvents with a detrimental effect on human health and the environment. Cyanides are used by industries and often discarded without proper treatment [1]. The use of mercury in the amalgamation process has been reported in Artisanal gold mines in more than 50 countries [2].…”