Specialized metallurgical processes – compositions for use therei – Processes – Free metal or alloy reductant contains magnesium
Patent
1997-03-11
1998-05-12
Simmons, David A.
Specialized metallurgical processes, compositions for use therei
Processes
Free metal or alloy reductant contains magnesium
75711, 75710, 75392, 420501, C22B 1100
Patent
active
057499403
ABSTRACT:
The known method comprises the following steps. (1) the de-copperized anode slime is chlorination-leached with HCl and H.sub.2 O.sub.2. (2) Na.sub.2 CO.sub.3 is added to the chlorination-leach residue of (1). (3) NH.sub.3 is added to the residue of (2). (4) Distillation of NH.sub.3 to remove NH.sub.3 contained in the ammonia leach solution of (3). (5) Distillation residue is washed with water to yield refined AgCl. (6) Conversion of AgCl to Ag.sub.2 O. (7) Reduction of Ag.sub.2 O to Ag. In order to enhance the purity of the reduced silver, the present invention provides the following improvements (a) to (d). (a) Dechlorination (2) with the use of Na.sub.2 CO.sub.3 is carried out at ambient temperature. (b) After dechlorination, the residue is washed with hot water. (c) Sulfuric acid is added instead of carrying out distillation (4). (d) Prior to conversion (6), the chlorination is again carried out.
REFERENCES:
patent: 2060539 (1936-05-01), Spies
patent: 4094668 (1978-06-01), Yannopoulos et al.
patent: 4229270 (1980-10-01), Subramanian et al.
Elve M. Alexandra
Nippon Mining & Metals Co., Inc.
Simmons David A.
LandOfFree
Method for producing high grade reduced silver does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing high grade reduced silver, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing high grade reduced silver will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-975824