Investigation of Dissolution Kinetics of A Nigerian Tantalite Ore in Nitric Acid

Abstract

A study of the kinetics of the dissolution of a Nigerian tantalite ore in Nitric acid has been examined. A detailed investigation on the quantitative leaching of the mineral was also carried out. The effects of some parameters such as acid concentration, contact time, temperature, particle size and the stirring rate on dissolution action have been investigated. Experimental results indicate that the dissolution rate is diffusion controlled via hydrogen ion [H + ] action, with reaction order of 0.64. About 81.3% of tantalite ore was dissolved within 120min., using 8.06M HNO 3 solution with <0.040mm particle size. Activation energy, Ea, of 22.37kJ/mole was obtained for the process. However, elemental analysis by inductively coupled-plasma mass spectrophotometry showed that the major elements in the ore are Ta(39.9%), Fe(24.9%), Ti(4.03%), S(12.4%) and Mn(2.39%). The x-ray diffractometry also confirmed the ore to exist in a single phase with tantalite characteristics peaks at 3.31A 0 , 2.55A 0 and 1.74A 0. The ore is not radioactive by its virtue of its very low thorium and uranium contents.

Quantitative leaching of a Nigerian chalcopyrite ore by nitric acid

“…From Figure 3, while the dissolution of chalcopyrite with the samples of particle size -90 + 75µm was between 30 -80% after 120 minutes, the dissolution decreased to about 20 -55% for the particle size above -90 + 75µm. This may be attributed to increase in surface area for the finer size chalcopyrite ore (Baba et al 2012;Baba et al 2007;Aydogan et al 2005).…”

Development of a combined pyro- and hydro-metallurgical route to treat spent zinc–carbon batteries

“…The concentration which gave the highest percentage of dissolution (4 M) was used for the optimization of other parameters such as temperature, particle size, and stirring speed. The activation energy was estimated from the Arrhenius plot [28,30,31]. In all cases, the fraction of ashed sample dissolved were calculated from the initial difference in weight of the amount dissolved or undissolved at various time intervals up to 120 min, after oven-dried at about 60 • C. The residue at the optimal conditions was subjected to X-ray diffraction analysis (XRD, PHILIPS Scientific) using Cu ␣1 target, 1.541 Å (40 kV, 55 mA).…”

Kinetics of Leaching Process of Sella Uranium Ore Material, South Eastern Desert, Egypt

“…The dissolution study of various ores in inorganic acids has been investigated in details ( Morse and Arvidson, 2002;Liang et al, 2005 andBaba et al,2007). Kinetic leaching of bastnaesite concentrate, rutile ore, and ukpor clay by using hydrochloric acid were represented by shrinking core model with diffusion through a porous product layer (Bian et al,2011 ;Alafara et al,2009 ;Regina and Okechukwu,2012).…”