Microanalysis study of Al-Amar rock and leaching behavior of its tailings for recovery of gold and silver

• Autorzy: Mahmoud M. H. H. , Awad H. M. , Altalhi T.

Identyfikatory

DOI

10.5277/ppmp1852

• Języki publikacji: EN

Abstrakty

EN

Some Saudi gold ores, such as that at Al-Amar mine, suffer from low leaching efficiency using the toxic cyanidation process. Only about 60% of the gold and 26% of the silver in the feed ore can be extracted at 0.2% CN– after 24 h and the rest percentages of these metals remained in leaching residues (tailings). These tailings contained 1.1 ppm Au and 4.3 ppm Ag. Reprocessing of tailings serves both for economic and environmental reasons. A petrography analysis of the mineral constituents indicated that the rock samples consisted primarily of sphalerite, chalcopyrite, pyrite and galena in decreasing order of abundance. An electron probe microanalysis quantitatively showed that gold and silver were finely distributed in the grain boundaries and within sphalerite, chalcopyrite, pyrite, and quartz. The dissemination of gold and silver in these hard minerals may be the main reason for their low recovery by cyanidation. Open air roasting of the tailings can release amounts of the disseminated gold and silver which can be extracted during leaching with the harmless thiosulfate ion S2O32–. After studying the different parameters, we found that the maximum possible extraction of gold and silver from the tailings roasted for 2 h at 400°C reached about 50% at 0.2 M ammonium thiosulfate, 0.3 M ammonium hydroxide, solid–liquid ratio ½ for 24 h. These achievements represent a possible exploitation of the accumulated 1.65 million Mg tailing waste containing significant amounts of gold and silver valued at about $73 million.

Słowa kluczowe

EN

gold; silver; tailings; mineralogy; extraction; thiosulfate

• Wydawca: Oficyna Wydawnicza Politechniki Wrocławskiej
• Czasopismo: Physicochemical Problems of Mineral Processing
• Rocznik: 2018
• Tom: Vol. 54, iss. 2
• Strony: 527--537
• Opis fizyczny: Bibliogr. 19 poz., rys., tab.

Twórcy

autor

Mahmoud M. H. H.

• Chemistry Department, College of Science, Taif University, Taif, Saudi Arabia
• Central Metallurgical Research and Development Institute, P.O. Box 87, Helwan, Cairo, Egypt

autor

Awad H. M.

• Biotechnology Department, College of Science, Taif University, Taif, Saudi Arabia
• Ceramic Department, Natural Resources Division, National Research Center, Cairo, Egypt

autor

Altalhi T.

• Chemistry Department, College of Science, Taif University, Taif, Saudi Arabia

Bibliografia

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Uwagi

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2019).