Activated carbons prepared from refuse derived fuel and their gold adsorption characteristics

Abstract

Activated carbons produced from refuse derived fuel (RDF), which had been prepared from municipal solid waste have been characterized and evaluated for their potential for gold adsorption from gold chloride solution. Pyrolysis of the RDF produced a char, which was then activated via steam gasification to produce activated carbons. Steam gasification of the char at 900°C for 3 h yielded 73 wt% activated carbon. The derived activated carbon had a surface area of 500 m² g⁻¹ and a total pore volume of 0.19 cm³ g⁻¹. The gold adsorption capacity of the activated carbon was 32.1 mg Au g⁻¹ of carbon when contacted with an acidified gold chloride solution. The gold adsorption capacity was comparable to that of a commercial activated carbon tested under the same conditions and was well in the range of values of activated carbons used in the gold industry. Demineralization of the RDF activated carbon in a 5 M HCl solution resulted in enhancement of its textural properties but a reduction in the gold adsorption rate, indicating that the metal content of the RDF activated carbon influenced its gold adsorption rate.

Keywords:

• pyrolysis
• municipal solid waste
• activated carbon
• gold adsorption

Acknowledgement

The support of the Ghana Government via a Ghana Education Trust Fund (GETFund) Scholarship is gratefully acknowledged.