DBPapers

DISSOLUTION OF FINE PARTICLE CHALCOPYRITE CONCENTRATE IN ACIDIC POTASSIUM DICHROMATE SOLUTION

AUTHOR/S: G. UCAR, M. BOYRAZLI, S. AYDOGAN
Sunday 1 August 2010 by Libadmin2007

7th International Scientific Conference - SGEM2007, www.sgem.org, SGEM2007 Conference Proceedings/ ISBN: 954-918181-2, June 11-15, 2007

ABSTRACT

This paper presents a study for leaching kinetics of chalcopyrite concentrate in
acidic potassium dichromate solution. For this purpose effects of stirring speed
in the range of 100-400 rpm, sulphuric acid (H2SO4) concentration in the range
of 0.1-0.5 M, potassium dichromate (K2Cr2O7) concentration in the range of
0.02-0.1 M, leaching temperature in the range of 20-90°C, particle size fractions
of 212x106, 106x75, 74x45, 45x38 and minus 38 μm and solid/liquid ratio in
the range of 10-200 g/L on copper dissolution were investigated. The rate of
chalcopyrite oxidation by potassium dichromate in sulphuric acid was directly
proportional to stirring speed, sulphuric acid and potassium dichromate
concentrations and leaching temperature. On the other hand, it increased with
decreasing particle size and solid/liquid ratio. The kinetic study showed that the
dissolution of copper from the concentrate is well represented by a shrinking
core model controlled by diffusion through a porous layer, 1-2/3X-(1-X)2/3.
The activation energy obtained was 22.44kJ/mol for the temperature range 20-
90°C.

Keywords: Chalcopyrite, sulphuric acid, potassium dichromate, shrinking core
model.