The leaching of iron oxides in boehmitic bauxite by hydrochloric acid (EN)

Patermarakis, G (EN)

Paspaliaris, Y (EN)

The leaching of iron oxides from boehmitic bauxite with hydrochloric acid has been investigated by means of optical microscopy, electron microscopy and electron microprobe analysis methods. Similar rectangular parallelepiped-shaped bauxite specimens were used for the leaching experiments. The experiments were carried out in a magnetically-stirred spherical reactor, thermostatically controlled at different temperatures and concentrations of hydrochloric acid. The kinetics of iron removal were followed by measuring the width of the reacted shell which was formed around the bauxite specimens during leaching. The experimental results suggested that the shrinking unreacted core model applies. The kinetic equation y = k C t2 3 was found to fit the experimental results satisfactorily. An activation energy of 19.6 kJ mol-1 was found, supporting the idea that the slow stage of the overall reaction is the diffusion of hydrochloric acid through the pores formed mainly by dissolution of hematite phases. In all leaching conditions employed the complete removal of iron did not occur. The residual iron in the reacted layer did not appear to be significantly affected by variation of the leaching conditions for which the proposed model applies. © 1989. (EN)

journalArticle (EN)

Hematite (EN)

Chemical Reactions--Reaction Kinetics (EN)

Activation Energy (EN)

Metallurgy & Metallurgical Engineering (EN)

Boehmitic Bauxite (EN)

Iron Oxides--Removal (EN)

Bauxite Ore Treatment (EN)

Hydrometallurgy (EN)

National Technical University of Athens

Digital Library of National Technical University of Athens | Dspace@NTUA

Κεντρική Βιβλιοθήκη Ε.Μ.Π.

Ιδρυματικό Αποθετήριο

Δημοσιεύσεις μελών Δ.Ε.Π. σε περιοδικά

Hydrometallurgy (EN)

English

1989 (EN)

http://hdl.handle.net/123456789/10121

77 (EN)

23 (EN)

1 (EN)

ISI:A1989AX25300006 (EN)

0304-386X (EN)

90 (EN)

ELSEVIER SCIENCE BV (EN)