Mineralochemical characterization of calcines and flue dust produces by neutral roasting of arsenic copper concentrates in a pilot plant

WILKOMIRSKY, I.; PARRA R.; PARADA, F.; BALLADARES, E.:
Proceeding of Conference of Metallurgist, The Canadian Institute of Mining, Metallurgy and Petroleum, Canada, 28 de septiembre-1 de octubre 2014.

Abstract

The neutral roasting of As bearing copper concentrates is confirmed well established and promising option for the treatment of this type of complex concentrate. The As elimination by volatilization allows subsequent treatment of the calcines produced in a conventional pyrometallurgical process, by blending this product with standard concentrates.

Several tests were performed using the fluidized bed pilot plant at the University of Concepción with different types of concentrates. Calcines, fines from two hot cyclones and flue dust from the ESP were collected. These materials were characterized using QEMSCAN® and the results used for the development of a mass and energy balance which took into consideration the specific chemical transformations that occurred in the reactor.

A physico–chemical/kinetic model is proposed to explain the formation of bornite, chalcopyrite and magnetite. The mechanism involves solid–gas reactions between chalcocite, pyrrhotite and gaseous sulfur that without the mineralogical characterization would not have been possible to propose.

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