Review paper

Potential Technologies for Removing Thallium from Mine and Process Wastewater: An Abbreviated Annotation of the Literature

L.G. Twidwell¹* and C. Williams-Beam<sup>2

1</sup> Metallurgical and Materials Engineering, Montana Tech of the University of Montana
Butte, MT, USA 59701

² Former Graduate Student (Deceased), Montana Tech of the University of Montana
Butte, MT, USA 59701

Received 21 June 2001; accepted 08 January 2002



ABSTRACT

Thallium is more toxic to humans than mercury, cadmium, lead, copper or zinc. Its chemical behavior resembles the heavy metal lead and the alkali metals (K, Rb, Cs). It occurs almost exclusively in natural waters as monovalent thallium (Tl⁺¹).The solubility of thallous compounds (e.g., thallous hydroxide) is relatively high so that Tl⁺¹ is readily transported through aqueous routes into the environment. The major sources of thallium are the base metal sulfides and precious metal bearing sulfides. Therefore, it has been shown to be a contaminant constituent in waters emanating from heavy metal sulfide bearing deposits.
A comprehensive survey of the thallium literature was conducted to answer two questions:

• Is thallium contamination in mine and effluent wastewater a significant problem and, if so,

• What technologies are available for removing thallium from the waters to achieve current U.S. effluent discharge regulations?

* Corresponding author
   E-mail : Ltwidwell@mtech.edu