Design and construction of an activated carbon thermal regeneration kiln for small scale gold operators :

Abstract

The economic feasibility of processes using granular activated carbon for the recovery of precious metals or the purification of water and waste-water is contingent upon re-use of the carbon in multiple adsorption regeneration cycles. Different techniques, both chemical and physical have been used and developed to restore the activity of a spent (exhausted) activated carbon. Various chemical methods can effectively restore the activity of spent carbon from which only single or defined adsorbates need to be removed or recovered. In such cases, appropriate solvents and/or chemicals are used to specifically desorb the adsorbates in question. However, chemical regeneration can restore only partial activity to carbon that is loaded with a heterogeneous mixture of adsorbates such as those normally present in industrial process streams or effluents. (Rogans & Director, 2012) have pointed out that, while chemical regeneration may restore sufficient activity to the carbon for a few cycles of effective operation, comprehensive thermal regeneration must be applied at regular intervals to restore complete activity. Thermal regeneration effectively restores the activity of carbons loaded with organic adsorbates. Thermal regeneration is very expensive in Uganda, making it hard for small scale gold processing operators to access it. Currently in Uganda, there is no facility that is totally committed to regeneration of exhausted activated carbon for gold processing companies. In this case, these people have resorted to rudimentary ways of regeneration. These methods are totally inefficient, time consuming and unsafe to the operators. This project will be limited designing and constructing an exhausted activated carbon thermal regeneration kiln that is efficient, cheap, clean and time friendly so as to solve this problem that has hindered gold production in Uganda.