Abstract

The need to sustainably produce raw materials encourages mining companies to develop and incorporate new economically and environmentally efficient processes. Therefore, there is a need to investigate the behavior and stabilization of hazardous elements present in effluents from metal recovery processes such as arsenic. This study evaluates the incorporation of an effluent solution from a copper smelter that is to be treated in a copper hydrometallurgical plant (heap leaching). The treatment is applied to recover compounds of interest such as copper, acid and water, in addition to confining impurities as stable residues in the leach residues. Here, we assess the capacity of the mineral to retain arsenic. To do this, a mixed solution of effluent and process solution was prepared, with a concentration of 1 g/L of arsenic. The solution was irrigated in leach columns loaded with a heap mineral with varying pH levels (0.8; 1.5 and 2) and solution potentials (510 and 540 mV). The concentrations of arsenic and iron in the solution and in the solid residues were measured to determine the capacity of the mineral to retain arsenic and how it was retained. The pH level plays an important role since, at a higher pH, the presence of arsenic and iron in the solution decreases, therefore increasing in the solid residue. Finally, a retention of 57% of arsenic is reached at pH 2. The characterization of the residues by scanning electron microscopy (SEM) confirms that arsenic is associated with Fe, S and O, forming ferric arsenates, while an X-Ray analysis identifies the arsenic compounds as crystalline scorodite.

Highlights

  • Mineral processing and metallurgical operations have taken a new turn according to the type of copper production being used

  • It is expected that the copper, acid and water, that are currently lost due to the high arsenic content, can be recovered and that the arsenic can be fixed in a stable form in the heap leaching residue, allowing for its disposal in a confined and environmentally safe area

  • The mineral sample came from the operations of Minera Lomas Bayas

Read more

Summary

Introduction

Mineral processing and metallurgical operations have taken a new turn according to the type of copper production being used. Precipitation of As+5 with lime at room temperature results in the formation of various calcium arsenate compounds, including Ca4 (OH) (AsO4 )2 ·4H2 O, Ca5 (AsO4 ) OH and Ca3 (AsO4 ) , as well as CaHAsO4 ·xH2 O and Ca5 H2 (AsO4 )4 These compounds depend on the concentration and oxidation state of arsenic, calcium and SO4 2− and/or HSO4 −. This research analyzes the feasibility of incorporating the effluent solution from a metallurgical flue dust treatment plant (PLS-P) from a copper smelter to a copper hydrometallurgical plant In this way, it is expected that the copper, acid and water, that are currently lost due to the high arsenic content, can be recovered and that the arsenic can be fixed in a stable form in the heap leaching residue, allowing for its disposal in a confined and environmentally safe area

Materials and Methods
Sample Characterization
Column Leaching Test
Arsenic
Percentage weight precipitates with arsenic content
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call