Journal of Minerals and Materials Characterization and Engineering, 2012, 11, 730-734

Published Online July 2012 (http://www.SciRP.org/journal/jmmce)

Model for Prediction of the Concentration of Extracted

Tin during Leaching of Cassiterite in Potassium

Hydroxide Solution

Onyedika Gerald1*, Ugwu Priscilla1, Ogwuegbu Martin1, Ejike Emmanuel1,

Nwoye Chukwuka2, Jiann-Yang Hwang3

1Mineral Processing Unit, Department of Chemistry, Federal University of Technology, Owerri, Nigeria

2Department of Metallurgical and Materials Engineering, Nnamdi Azikiwe University, Awka, Nigeria

3Materials Science and Engineering, Michigan Technological University, Houghton, USA

Email: *gonyedik@mtu.edu

Received May 8, 2012; revised June 19, 2012; accepted July 10, 2012

ABSTRACT

Model for prediction of the concentration of tin extracted during potassium hydroxide leaching of cassiterite has been

derived. The model: A = Nt1.53, indicates that the concentration of tin extracted is dependent on the residence time. It

was found that the validity of the model is rooted in the expression LogA = Log(Nt1.53). Tin extraction per unit time as

obtained from experiment and derived model are 2.6666 and 2.6268 mg/min respectively. The maximum deviation of

the model-predicted concentration of dissolved tin from the corresponding concentration obtained from the experiment

was found to be less than 8%, which is quite within the acceptable deviation limit of experimental results and hence,

impacting about 92% confidence coefficient on the model.

Keywords: Model; Tin; Potassium Hydroxide; Cassiterite; Leaching

1. Introduction

Tin presently finds extensive use in industrial and do-

mestic applications. As a result of this, extraction of tin

from ores has continued to attract considerable attention.

Extraction of metals from their ores and recovery from

their various industrial wastes are a major step towards

judicious utilization and conservation of our mineral re-

sources. Various works have been done to extract metals

from their ores [1-4]. Cassiterite, otherwise known as tin

ore is the only tin mineral from which tin can be ex-

tracted in a commercial quantity. Matell [5] studied the

extraction of tin from its ores by reduction of cassiterite

to tin metal and then extracting the tin with aqueous in-

organic acids.

Models are of central importance in many scientific

contexts, useful for testing, analysis or training where

real-world systems or concepts can be represented by a

model [6,7]. One of such models as reported by Hwang

et al. [7] is a numerical simulation of heat transfer during

the microwave heating process of a two dimensional,

magnetic dielectric, magnetite, subjected to heat conduc-

tion, convection and radiation. The heat transfer process

was modeled using an explicit finite difference approach

and the temperature profile for different heating parame-

ters was generated through developing a code in mathe-

matica 7.0.

The derivation of models for the evaluation of the

concentration of some metal values leached in some ores,

concentrates, calcine or other solid materials containing

metal(s) in some aqueous solutions of acids, bases, com-

plexing agents, etc has gained very wide interest among

researchers in recent time. Many models have been evalu-

ated involving the use of different acids for the leaching

of some ores. One of such works as reported by Nwoye

[8] is the model for the computational analysis of the

solution temperature during leaching of iron oxide ore in

hydrochloric acid solution. The model is expressed as:

N

Te

(1)

8.9055

Te

(2)

where T is the solution temperature (˚C) during leaching

of iron oxide ore using hydrochloric acid; N = 8.9055 (pH

coefficient for hydrochloric acid solution during leaching

of iron oxide ore) determined by Nwoye et al. [9];

is

the final pH of the leaching solution at the time t when the

solution temperature is evaluated.

Nwoye [10] also derived a model for computational

analysis of the concentration of dissolved haematite and

*Corresponding author.

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