Recovery of arsenic by flotation - A case study on the tailings of Cabeço do Pião

• Type: Article in International Conference Proceedings Book
• Date: 2018-02-06

Authors

Diogo Martins (Author) FEUP; Aurora Futuro Silva (Author) FEUP; Rui Sousa (Author) FEUP; Maria Cristina Vila (Author) FEUP; Maria De Lurdes Dinis (Author) FEUP; Alexandre Leite (Author) FEUP; Joaquim Góis (Author) FEUP; António Fiúza (Author) FEUP

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Technological sciences > Technology > Mining

Other information

Abstract (EN): Mining wastes with high concentration in heavy metals may produce serious environmental problems when stored as a tailings dam. Due to the less advanced mining and beneficiation technologies used in the past, the historical tailing deposits can potentially have high grades in minerals that can be extracted profitably with modern technology. Furthermore, the decrease in the total amount of wastes stored, as the result of its recycling by reprocessing, will contribute to the mitigation of the environmental impacts. The present work refers to the Cabeço do Pião tailings disposal, which stores tailings of a former Panasqueira Mine Processing Plant. The location of this old dam is close to the Zêzere river, one of the tributaries to the Tagus river, that is the major river in Iberian Peninsula. For these reasons and also considering the potentially high grades in some commodities, the main objective is to study a process to remine and reprocess the tailings, thus also recovering some tungsten. The new tailings produced by the reprocessing can be stored in another location using a safer update technology. One of the studied processes was the froth flotation of the tailings. The inclusion of this process comes from the necessity of recovering the majority of the arsenic which is present in the tailings with very high grades, representing the most harmful element. For this purpose, the following strategy was selected: floatation of arsenopyrite and pressure leaching of the depressed material. Preliminary tests were performed to identify the parameters to be considered in a factorial test for studying the arsenopyrite flotation. As a result two collectors were chosen with two different dosages using two different froth bed heights. It was shown that it is possible to float more than half of the material using the roughing and scavenging stages. The recovery of arsenic exceeds 70% in almost all the cases. The depressed material represents more than 60% of the total tungsten in almost all the cases.

Language: English

Type (Professor's evaluation): Scientific