Metal recovery process
AssigneeEastman Kodak Company
InventorMichel G. Lamisse
Life of this patent
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Abstract
A method for recovering a metal from a solution containing ions of the metal and a complexing agent for the ions is disclosed. The method involves contacting the solution with another metal more electropositive than the metal to be recovered in order to bring about a metal-metal exchange reaction which will yield a precipitate of the metal to be recovered. The precipitate is then separated from the solution. In order to maximize the yield of the metal-metal exchange reaction, the redox potential of the solution is measured during the course of the reaction, and the precipitate is separated from the solution as soon as the redox potential substantially reaches a predetermined minimum value.
Claims12
In a method for recovering a first metal from an aqueous solution containing ions of said first metal and a complexing agent for said ions, said method comprising:
- (a) contacting said solution with a second metal that is more electropositive than said first metal to thereby provide a metal-metal exchange reaction to form a precipitate of said first metal, and
- (b) separating said precipitate from said solution;
- the improvement comprising:
- (c) measuring the redox potential of said solution during the course of said exchange reaction, and
- (d) initiating the separation of said precipitate from said solution when said redox potential is substantially at a predetermined minimum value.
In a method for recovering a first metal from a solution containing ions of said first metal and a complexing agent for said ions, said method comprising:
- (a) contacting said solution with a second metal that is more electropositive than said first metal to thereby provide a metal-metal exchange reaction to form a precipitate of said first metal, and
- (b) separating said precipitate from said solution;
- the improvement comprising:
- (c) measuring the redox potential of said solution during the course of said exchange reaction,
- (d) generating a signal when said redox potential is substantially at a predetermined minimum value, and
- (e) initiating the separation of said precipitate from said solution in response to said signal.
In a method for recovering silver from an aqueous solution containing silver ions and a complexing agent for silver ions, said method comprising:
- (a) contacting said solution with iron to thereby provide a metal-metal exchange reaction to form a silver precipitate from said silver ions, and
- (b) separating said silver precipitate from said solution;
- the improvement comprising:
- (c) measuring the redox potential of said solution during the course of said exchange reaction, and
- (d) initiating the separation of said silver precipitate from said solution when said redox potential substantially equals a predetermined minimum value.
In a method for recovering silver fron an aqueous solution containing silver ions and a complexing agent for silver ions, said method comprising:
- (a) contacting said solution with iron to thereby provide a metal-metal exchange reaction to form a silver precipitate from said silver ions, and
- (b) separating said silver precipitate from said solution;
- the improvement comprising:
- (c) measuring the redox potential of said solution during the course of said exchange reaction,
- (d) generating a signal when said redox potential is substantially at a predetermined minimum value, and
- (e) initiating the separation of said silver precipitate from said solution in response to said signal.
Dependencies are inferred from the claim text.