INVESTIGATION OF DISSOLUTION KINETICS OF A NIGERIAN COLUMBITE IN HYDROFLUORIC ACID USING THE SHRINKING CORE MODEL

Authors

  • O Sanda DEPARTMENT OF CHEMICAL ENGINEERING, OBAFEMI AWOLOWO UNIVERSITY, ILE-IFE, OSUN STATE NIGERIA.
  • EA Taiwo DEPARTMENT OF CHEMICAL ENGINEERING, OBAFEMI AWOLOWO UNIVERSITY, ILE-IFE, OSUN STATE NIGERIA.

DOI:

https://doi.org/10.4314/njt.354.1177

Keywords:

columbite, tantalum, leaching, shrinking core model, PIXE

Abstract

A study of the kinetics of the dissolution of a Nigerian columbite in hydrofluoric acid has been examined and an investigation on the quantitative leaching of the mineral was also carried out. The effects of some parameters such as acid concentration, contact time and temperature were investigated. Elemental analysis of the ore was done using Particle-induced X-ray Emission (PIXE) spectroscopy with 2.5 MeV protons and this showed the major elements in the ore to be Si (8.82 %), Fe (10.74 %), Mn (4.72 %), Ta (6.80 %),Nb (28.90 %) and W(2.61%), with K, Ni, Zn, Sr and Y occurring in traces. Experimental results indicate that the dissolution rate is chemical reaction controlled, with reaction order of 0.57. Dissolution of over 90 % of the columbite was achieved in 5 h, using 20 M HF at 90 oC with 100 µm particle sizes. Activation energy, Ea of 15.70 KJ.mole-1 was obtained for the process.

 

http://dx.doi.org/10.4314/njt.v35i4.19

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Section

Chemical, Industrial, Materials, Mechanical, Metallurgical, Petroleum & Production Engineering

How to Cite

INVESTIGATION OF DISSOLUTION KINETICS OF A NIGERIAN COLUMBITE IN HYDROFLUORIC ACID USING THE SHRINKING CORE MODEL. (2016). Nigerian Journal of Technology, 35(4), 841-846. https://doi.org/10.4314/njt.354.1177