Details:

Personal Author:
Bhakta, P. ; Langhans, J. W. ; Lei, K. P. V. (Kenneth P. V.)
Bhakta, P. ; Langhans, J. W. ; Lei, K. P. V. (Kenneth P. V.) Less -
Corporate Authors:
United States. Bureau of Mines.
Description:
"The U.S. Bureau of Mines developed an alkaline oxidative pretreatment leaching procedure to increase the recovery of gold from arsenopyrite (feass) ores. The best solution compositions for arsenopyrite dissolution were determined using cyclic voltammetry and chronocoulometry. Initial arsenopyrite dissolution occurred at - 0.20 V versus standard hydrogen electrode (she) in a sodium hydroxide (naoh) solution. Leaching of a high-grade arsenopyritic ore containing, in percent, 28.2 As, 25.3 Fe, 19.9 Total s, and 1.0 Sb and, in troy ounces per short ton, 1.6 Au and 5.5 Ag resulted in > 90 pct as extraction at 100 deg c, 40 psig o2, 4 h, and 2 m naoh solution in a 2-l autoclave. Cyanidation of the leach residues resulted in 90 to 93 pct au and 60 to 80 pct ag extractions, compared with only 5 and 15 pct, respectively, without the pretreatment. The procedure was further tested by leaching a low- grade gold ore and a bulk sulfide flotation concentrate prepared from it. Cyanidation of the leach residues resulted in 70 pct au and 31 pct ag extraction. The naoh leachate was partially regenerated by precipitating the arsenate as calcium arsenate [ca3(aso4)2] and the sulfate as barium sulfate (baso4)." - NIOSHTIC-2

NIOSHTIC no. 10007261


Subject:
[+]
Gold -- Metallurgy.
Leaching.
Oxidation.
Sodium Hydroxide.

Series:
Report of investigations (United States. Bureau of Mines) ; 9258
Document Type:
Report
Collection(s):
National Institute for Occupational Safety and Health
Main Document Checksum:
[+]
urn:sha256:303ee60f3c5a66f616462b3dec35fd8ab492260af2f404745ff9e52664086465
File Type:

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