Carbon-in-Leach Gold Recovery from Fungi-treated Carbonaceous Ore: Effect of Entrained Biomass on Activity of Activated Carbon
Grace Ofori-Sarpong,
Charles Ebenezer Abbey,
Nelson Akuoko Sarpong,
Richard Kwasi Amankwah
Issue:
Volume 5, Issue 4, August 2020
Pages:
71-78
Received:
30 June 2020
Accepted:
20 July 2020
Published:
30 July 2020
Abstract: The ability of the fungus, Phanerochaete chrysosporium to reduce preg-robbing of carbonaceous matter (CM) in gold ores has been confirmed by many researchers, and studies are ongoing to minimize the effect of entrained biomass on subsequent gold leaching and adsorption processes. This paper presents a study on gold extraction from surrogate carbonaceous gold ore (CGO), and fungal-treated CGO to ascertain the influence of entrained biomass on the downstream carbon-in-leach (CIL) process. The surrogate CGO was prepared by adding 3% anthracite-grade CM to free-milling gold ore (FGO). The main minerals in the FGO were quartz, feldspar and sericite, with 8.4 g/t gold, 0.18% sulphide sulphur and 0.06% organic carbon. Aside biotreatment of the CGO with cell-free liquor of P. chrysosporium, anthracite and activated carbon (AC) were also contacted with P. chrysosporium to confirm the direct effect of biomass on the CMs’ ability to preg-rob aurocyanide. Preg-robbing effect of the as-received anthracite and AC were 95% and 80% respectively, and these reduced to 81% and 13% respectively. Water-washing, acid-washing and alkaline-washing of the treated CMs returned respective preg-robbing effects of 88%, 92% and 85% for AC and 32%, 38% and 28% for anthracite. Scanning electron microscopy and Raman spectroscopy of anthracite revealed a decrease in the degree of orderliness in the structure required for gold adsorption. The FGO and the prepared CGO gave cyanidation gold recoveries of 94.5% and 54.8% respectively. Following cell-free treatment of the CGO, direct cyanidation recorded 88.3% solution recovery, which was increased to 91.3% in CIL. The overall recovery onto activated carbon in CIL was 81%, which improved to 82% and 85% respectively after washing the fungal-treated CGO with water and NaOH. The results here affirm that thorough washing of fungal-treated CGO assists in removing some entrained biomass. However, the results also call for additional studies on purification of the cell-free liquor to further minimize the biomass effect, and sustainability of the enzyme activity during pretreatment to enhance the overall gold recovery.
Abstract: The ability of the fungus, Phanerochaete chrysosporium to reduce preg-robbing of carbonaceous matter (CM) in gold ores has been confirmed by many researchers, and studies are ongoing to minimize the effect of entrained biomass on subsequent gold leaching and adsorption processes. This paper presents a study on gold extraction from surrogate carbona...
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Challenges and Determinants of the Use of Renewable Energy, Special Reference to the Selected Woreda of Assosa and Metekel Zones, Benishangul Gumuz Region
Issue:
Volume 5, Issue 4, August 2020
Pages:
79-82
Received:
12 June 2020
Accepted:
24 July 2020
Published:
10 August 2020
Abstract: The Known importance of renewable energy in the discussion of a reliable and sustainable energy future, it is imperative to understand its main determinants and hindering factors and to draw result implications for energy policy and to overcome the challenges. This Research surveys about the determinants and challenges of the use of Renewable Energy, with Special Reference to, Benishangul Gumuz Regional State selected zonal Woredas (Assosa Zone and Metekel Zone). Using HOMER SOFTWARE and the EXCEL spread sheet, for a period covering 2008-2016, the results suggest that the community under study mainly relay on the Energy source of hydropower covers mostly 58.59% of the total energy consumption of the inhabitants. Also the finding indicates the inhabitants mostly relay on gas oils for energy sources with the percentage of 20%, for modified biomass 17.56% and for solar energy dependence only 3.8% which is the least amount. From the finding the relative price where the most determinant factor and also the community where sparely distributed which hinders the distribution of renewable Energy with the required speed. This article does not shows the region potential for developing renewable energy such as wind, biomass, solar and hydropower, dispersed throughout the Region, this potential has not been explored.
Abstract: The Known importance of renewable energy in the discussion of a reliable and sustainable energy future, it is imperative to understand its main determinants and hindering factors and to draw result implications for energy policy and to overcome the challenges. This Research surveys about the determinants and challenges of the use of Renewable Energ...
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