Recovery of metal values from manganese deep sea nodules using ammoniacal cuprous leach solutions

Claim 2

A process for treating manganese nodules to enable at least one metal values selected from the group consisting of copper, nickel, cobalt and molybdenum to be recovered therefrom comprising the steps of: a. grinding the nodules; b. contacting the ground nodules with an ammoniacal solution containing cuprous ions to reduce the manganese oxides in the nodules and enable the metal values to be recovered to be leached from the nodules into the leach solution; and c. separating the leach solution containing the metal values to be recovered from the reduced nodules.

Claim 3

The process as set forth in claim 1 wherein copper values are recovered from the leach solution.

Claim 4

The process as set forth in claim 1 wherein nickel values are recovered from the leach solution.

Claim 5

The process as set forth in claim 1 wherein copper and nickel values are recovered from the leach solution.

Claim 6

The process as set forth in claim 1 including the step of washing the reduced nodules with a wash leach solution after the separation which takes place in step (c) to remove entrained metal values from the reduced nodules and recovering the metal values to be recovered from the wash leach solution.

Claim 7

The process as set forth in claim 1 wherein step (b) the ground nodules are contacted with cuprous ions in an ammoniacal solution containing from about 60 to 140 grams per liter ammonia.

Claim 8

The process as set forth in claim 6 wherein cuprous ions are formed in the ammoniacal solution by reducing cupric copper to cuprous copper.

Claim 9

The process as set forth in claim 7 wherein cupric copper is reduced to cuprous copper by bubbling a reducing gas through the ammoniacal solution.

Claim 10

The process as set forth in claim 8 wherein the cupric copper is reduced to cuprous copper by bubbling a reducing gas containing carbon monoxide through the ammoniacal solution.

Claim 11

The process as set forth in claim 9 wherein the nodules reduced in step (b) are washed with an ammoniacal washleach solution to remove entrained metal values from the nodules and in step (c) the wash-leach solution is separated from the washed nodule residue and the metal values are recovered from the wash-leach solution.

Claim 12

The process as set forth in claim 10 wherein the ammoniacal solution used to reduce the nodules in step (b) is separated from the reduced nodules and is recycled to contact ground nodules.

Claim 13

The process as set forth in claim 6 wherein in step (b) the nodules are contacted with the ammoniacal solution to produce a slurry containing from about 2 to about 20% by weight solids.

Claim 14

The process as set forth in claim 12 wherein cuprous copper is regenerated in the leach solution by reducing cupric copper to cuprous copper by bubbling a reducing gas containing carbon monoxide through the slurry.

Claim 15

The process as set forth in claim 1 wherein in step (b) the temperature of the leached solution is between the range of 40° - 70° C.

Claim 16

The process as set forth in claim 14 wherein in step (b) the ground nodules are leached for a period of time between the range of 45 minutes to 2 hours.

Claim 17

A continuous process for treating manganese nodules to enable metal values selected from the group consisting of copper, nickel, cobalt and molybdenum to be recovered therefrom comprising the following steps: a. contacting and intimately mixing a cuprous ion containing ammoniacal solution with the manganese nodules to form a slurry, the contacting and mixing of the cuprous ions and nodules reducing the manganese in the nodules as the cuprous ions form cupric ions; b. contacting the slurry with a reducing gas to reduce cupric ions to cuprous ions and thereby maintain a continuous supply of cuprous ions; c. separating the reduced nodules from the ammoniacal solution; d. washing the reduced nodules obtained in step (c) with a wash solution to remove entrained metal values therefrom and yield a wash effluent containing the metal values to be recovered; and, e. recovering metal values from the wash effluent.

Claim 18

A continuous process for treating manganese nodules to enable metal values selected from the group consisting of copper, nickel, cobalt and molybdenum to be recovered therefrom comprising the following steps: a. contacting and intimately mixing a cuprous ion containing ammoniacal solution with the manganese nodules to form a slurry, the contacting and mixing of the cuprous ions and nodules reducing the manganese in the nodules as the cuprous ions form cupric ions; b. contacting the slurry with a reducing gas to reduce cupric ions to cuprous ions and thereby maintain a continuous supply of cuprous ions; c. separating the reduced nodules from the ammoniacal solution; d. washing the reduced nodules obtained in step (c) with a wash solution to remove entrained metal values therefrom and yield a wash effluent containing the metal values to be recovered; and, e. recovering metal values from the wash effluent.

Claim 19

The process as set forth in claim 16 wherein the manganese nodules are ground prior to being mixed with the ammoniacal solution.

Claim 20

The process as set forth in claim 17 wherein the ammoniacal solution separated from the reduced nodules in step (c) is recycled back to the slurry formed in step (a).

Claim 21

The process as set forth in claim 17 wherein in step (a) the manganese nodules are contacted with a cuprous ion containing ammoniacal solution containing from about 60 to about 140 grams per liter ammonia.

Claim 22

The process as set forth in claim 19 wherein in step (a) the nodules are mixed with the ammoniacal solution to produce a slurry containing from about 2 to about 20 weight percent nodule solids.

Claim 23

The process as set forth in claim 20 wherein in step (b) the slurry is contacted with a reducing gas containing carbon monoxide.

Claim 24

A continuous process for treating manganese nodules to enable copper, nickel, cobalt and molybdenum values contained therein to be recovered therefrom comprising the steps of: a. contacting a copper containing ammoniacal leach solution with a reducing gas in a vessel to reduce the copper and produce an ammoniacal leach solution containing cuprous ions; b. contacting the ammoniacal leach solution containing cuprous ions prepared in step (a) with ground manganese nodules to form a slurry and reduce the manganese oxides in the nodules; c. separating the reduced nodules in the slurry from the leach solution to leave a pregnant leach solution containing copper, nickel, cobalt and molybdenum metal values; d. washing the nodule residue with an ammoniacal-ammonium carbonate wash solution to remove entrained metal values from the nodule residue and yield a wash effluent containing copper, nickel, cobalt and molybdenum values; and e. recovering metal values from the wash effluent.

Claim 25

A continuous process for treating manganese nodules to enable copper, nickel, cobalt and molybdenum values contained therein to be recovered therefrom comprising the steps of: a. contacting a copper containing ammoniacal leach solution with a reducing gas in a vessel to reduce the copper and produce an ammoniacal leach solution containing cuprous ions; b. contacting the ammoniacal leach solution containing cuprous ions prepared in step (a) with ground manganese nodules to form a slurry and reduce the manganese oxides in the nodules; c. separating the reduced nodules in the slurry from the leach solution to leave a pregnant leach solution containing copper, nickel, cobalt and molybdenum metal values; d. washing the nodule residue with an ammoniacal-ammonium carbonate wash solution to remove entrained metal values from the nodule residue and yield a wash effluent containing copper, nickel, cobalt and molybdenum values; and e. recovering metal values from the wash effluent.

Claim 26

The process as set forth in claim 22 wherein the pregnant leach solution separated from the reduced nodules in step (c) is recycled back to the vessel.

Claim 27

The process as set forth in claim 23 wherein in step (b) the ground nodules are contacted with an ammoniacal leach solution containing from about 60 to about 140 grams per liter ammonia and copper as cuprous ion.

Claim 28

The process as set forth in claim 24 wherein in step (b) the ground nodules are contacted with the leach solution to produce a slurry containing from about 2 to about 20 weight percent nodule solids.

Claim 29

A process for treating manganese deep sea nodules to enable metal values selected from the group consisting of copper, nickel, cobalt and molybdenum contained therein to be recovered comprising the following steps: a. loading a plurality of vessels connected in series with an ammoniacal leach solution containing cuprous ions; b. grinding manganese nodules; c. introducing the ground nodules into a vessel loaded in step (a) to form a slurry in which the manganese in the nodules is reduced by the cuprous ions to enable metal values in the nodules to be solubilized in the ammoniacal leach solution while the cuprous ions form cupric ions; d. contacting the slurry in the series of vessels with carbon monoxide to convert cupric ions to cuprous ions; e. cascading the slurry in one vessel to the next vessel in the series of vessels; f. withdrawing the slurry from a last vessel in the series of vessels; g. separating a pregnant leach solution from the nodule residue; h. recycling the pregnant leach solution to a vessel as pregnant leach solution recycle; i. washing the nodule residue with wash liquor to remove entrained pregnant leach liquor from the nodule residue and to produce a pregnant wash liquor, and j. recovering metal values from the pregnant wash liquor.

Claim 30

A process for treating manganese deep sea nodules to enable metal values selected from the group consisting of copper, nickel, cobalt and molybdenum contained therein to be recovered comprising the following steps: a. loading a plurality of vessels connected in series with an ammoniacal leach solution containing cuprous ions; b. grinding manganese nodules; c. introducing the ground nodules into a vessel loaded in step (a) to form a slurry in which the manganese in the nodules is reduced by the cuprous ions to enable metal values in the nodules to be solubilized in the ammoniacal leach solution while the cuprous ions form cupric ions; d. contacting the slurry in the series of vessels with carbon monoxide to convert cupric ions to cuprous ions; e. cascading the slurry in one vessel to the next vessel in the series of vessels; f. withdrawing the slurry from a last vessel in the series of vessels; g. separating a pregnant leach solution from the nodule residue; h. recycling the pregnant leach solution to a vessel as pregnant leach solution recycle; i. washing the nodule residue with wash liquor to remove entrained pregnant leach liquor from the nodule residue and to produce a pregnant wash liquor, and j. recovering metal values from the pregnant wash liquor.

Claim 31

The process as set forth in claim 26 wherein in step (b) the nodules are ground to yield particles with a size in the range of between minus 60 mesh to about minus 120 mesh.

Claim 32

The process as set forth in claim 27 wherein in step (i) the nodule residue is washed with an ammonia-ammonium carbonate wash liquid having an ammonia concentration of about 60 to 140 grams per liter.

Claim 33

In a process for recovering metal values from a complex manganese ore in which the metal values to be recovered are bound within the ore by manganese oxides, the process being of the type in which the manganese ore is reduced to enable the metal values contained therein to be solubilized in a leach solution wherein the improvement comprises contacting the manganese ore with an aqueous solution containing cuprous ions to reduce the manganese oxides in the ore and enable the metal values to be leached therefrom.

Claim 34

In a process for recovering metal values from a complex manganese ore in which the metal values to be recovered are bound within the ore by manganese oxides, the process being of the type in which the manganese ore is reduced to enable the metal values contained therein to be solubilized in a leach solution wherein the improvement comprises contacting the manganese ore with an aqueous solution containing cuprous ions to reduce the manganese oxides in the ore and enable the metal values to be leached therefrom.

Claim 35

The process as set forth in claim 29 wherein the manganese oxides are reduced with an ammoniacal aqueous solution containing cuprous ions.

Claim 36

The process as set forth in claim 30 wherein the cuprous ions form cupric ions after reducing the ore and in which cuprous ions are regenerated by reacting cupric ions with a reducing gas to convert the cupric ions back to cuprous ions.

Claim 37

The process as set forth in claim 31 wherein the cupric ions are reduced with a reducing gas containing carbon monoxide.

Claim 38

The process as set forth in claim 32 wherein the ore is reduced with an aqueous solution of cuprous ions containing 60 to 140 grams per liter ammonia.

Claim 39

The process as set forth in claim 33 wherein the ore is ground prior to being reduced to result in particles with a size within the range of minus 60 to about minus 120 mesh.

Claim 40

The process as set forth in claim 32 wherein the manganese ore is reduced by cuprous ions in a vessel and cuprous ions are regenerated in the same vessel by bubbling carbon monoxide into that vessel.

Claim 41

The process as set forth in claim 32 wherein cupric ions are reduced to cuprous ions in a first vessel by bubbling carbon monoxide into the first vessel and wherein the cuprous ions formed in the first vessel are passed into a second vessel to reduce the manganese oxides in the ore.

Claim 42

The process as set forth in claim 32 wherein carbon monoxide is introduced into an ammoniacal liquor in a first vessel, with the ammoniacal liquor absorbing the carbon monoxide, the ammoniacal leach solution containing the absorbed carbon monoxide being passed into a second vessel containing cupric ions to reduce the cupric ions to cuprous ions and the ammoniacal solution containing the cuprous ions being passed into a third vessel into which manganese ores are introduced to reduce the manganese oxide in the ores.

Claim 43

The process as set forth in claim 28 wherein the ore is leached with an ammoniacal leach solution after the manganese oxides in the ore have been reduced and wherein the copper and nickel values are extracted from the leach solution by a liquid ion exchange extractant capable of extracting copper and nickel values from ammoniacal leach solutions.

Claim 44

The process as set forth in claim 38 wherein the copper and nickel values are stripped from the ion extractant and are recovered by electrowinning.

Claim 45

The process as set forth in claim 39 wherein the temperature during the reduction of the manganese oxide in the ore is between the range of 40° - 70° C.