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1. WO2020113264 - METHOD AND APPARATUS FOR MINERAL PROCESSING

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[ EN ]

CLAIMS

1. A chemical processing apparatus comprising:

at least one vessel comprising:

an inlet for a liquid process stream;

an outlet pipe for a liquid process stream to exit the vessel; and

a zone at least partially occupied by a gas

wherein the zone at least partially occupied by a gas communicates with the outlet liquid process stream pipe for removing accumulating gas from the zone to the outlet liquid process stream.

2. The chemical processing apparatus of claim 1 , wherein said zone communicates with the outlet pipe for the liquid process stream through an excess gas port or duct.

3. The chemical processing apparatus of claim 1 or 2, wherein said outlet pipe extends through the interior of the vessel or externally to the vessel.

4. The chemical processing apparatus of claim 3, wherein said vessel includes agitator impeller(s).

5. The chemical processing apparatus of any one of the preceding claims, wherein said liquid process stream is a slurry of ore or concentrate and a process liquor such as a leachant.

6. The chemical processing apparatus of any one of the preceding claims, wherein said apparatus includes a plurality of vessels, preferably autoclaves.

7. The chemical processing apparatus of any one of the preceding claims, wherein at least one said vessel is vertically disposed.

8. The chemical processing apparatus of any one of the preceding claims, wherein said feed inlet of the liquid process stream or slurry is disposed at the top or upper portion of said at least one vessel and said outlet for the liquid process stream or slurry is disposed at the bottom, or in a lower portion of said at least one vessel; and a duct communicating with said outlet, whether internally or externally of said at least one vessel, directs the slurry up to at least to the desired level of the excess gas and liquid process stream interface.

9. The chemical processing apparatus of any one of the preceding claims, wherein said feed inlet of the liquid process stream or slurry is disposed at the bottom or lower portion of said at least one vessel and said outlet for the liquid process stream or slurry is disposed at the top, or in an upper portion of said at least one vessel; and a duct communicating with said outlet, whether internally or externally of said at least one vessel, directs the slurry up to at least to the desired level of the excess gas and liquid process stream interface.

10. The chemical processing apparatus of claim 8 or 9, wherein an excess gas port is provided at said interface in the case of an internal outlet slurry pipe; or an excess gas duct connected to the vessel is provided in the case of an external outlet slurry pipe.

1 1 . The chemical processing apparatus of any one of the preceding claims, wherein said vessel is an autoclave with one or more compartments.

12. The chemical process of claim 1 1 , wherein the vessel is a vertical autoclave with staggered injection points for injecting a reagent or process stream to said one or more compartments.

13. The chemical processing apparatus of any one of the preceding claims, including a series of vessels, wherein excess gas duct(s) bypass individual vessels.

14. The chemical processing apparatus of any one of the preceding claims, including a series of vessels, wherein the excess gas duct of the last of said series of autoclaves is directed to a liquid/gas separation vessel.

15. The chemical processing apparatus of any one of the preceding claims, wherein a plurality of excess gas duct(s) are connected to said outlet slurry pipe at different levels of said vessel or autoclave.

16. The chemical processing apparatus of any one of the preceding claims, wherein an excess gas duct is connected to the outlet slurry pipe at a level higher than the connection point of said outlet slurry pipe to said vessel.

17. The chemical processing apparatus of claim 16, wherein said slurry pipe includes a loop of the pipe rising above the height equivalent to the head loss of the mineral slurry through the vessel or autoclave and outlet slurry pipe.

18. The chemical processing apparatus of claim 17, wherein a pipe diameter of the loop is sufficiently large to allow excess gas to disengage from the mineral slurry such that only gas proceeds to the outlet slurry pipe.

19. The chemical processing apparatus of any one of claims 3 to 18 as dependent on claim 2, wherein said excess gas duct includes a control valve.

20. The chemical processing apparatus of claim 7 as dependent from claim 6, wherein a last vertical autoclave in said plurality of vertical autoclaves feeds a flash tank via a control valve or pressure letdown station, with a pressure drop that is higher than over one vertical autoclave and the last vertical autoclave has separate slurry and gas flow controls.

21. The chemical processing apparatus of any one of the preceding claims, wherein said at least one vessel includes supplementary gas venting means, operated manually or automatically.

22. The chemical processing apparatus of any one of the preceding claims, wherein said outlet pipe includes a heat exchanger.

23. The chemical processing apparatus of claim 22, wherein said heat exchanger is an indirect heat exchanger.

24. The chemical processing apparatus of claim 23, wherein said heat exchanger comprises circular profile channels surrounded by a heat exchange medium.

25. The chemical processing apparatus of claim 22, wherein said heat exchanger is a heat pipe heat exchanger.

26. The chemical processing apparatus of claim 25, wherein said heat exchanger transfers heat between a first process stream and a second process stream through the medium of a heat transfer fluid and comprises: at least one first process stream passage; at least one second process stream passage; and a shell enclosing said plurality of first and second process stream passages within a volume, said volume being, as a result of a heat transfer process, fully filled with both vapour and liquid phases of said heat transfer fluid wherein said at least one first process stream passage and said at least one second process stream passage are spaced by a disengagement zone enabling separation of said vapour and liquid phases and limiting accumulation of liquid phase heat transfer fluid about said at least one first process stream passage.

27. A chemical processing method comprising:

conducting a chemical processing operation in at least one vessel comprising

an inlet for a liquid process stream;

an outlet pipe for a liquid process stream to exit the vessel; and

a zone at least partially occupied by a gas and communicating with the outlet liquid process stream pipe;

directing a liquid process stream entraining the gas to an inlet of a vessel, at least a portion of the gas being directed to and partially occupying a zone of the vessel;

directing an exit liquid process stream through an outlet pipe; and

removing accumulating gas from the zone to the outlet pipe.

28. The method of claim 27, wherein said zone communicates with the outlet pipe for the liquid process stream through an excess gas port or duct.

29. The method of claim 27 or 28, wherein said liquid process stream has a propensity to scale, and a flow of this stream or slurry is maintained through the excess gas duct or port at a velocity sufficient that the slurry erodes the scale formation without eroding the excess gas pipe.

30. The method of any one of claims 27 to 29, wherein peak temperature of the vessel is controlled by allowing vapour to be vented.

31. The method of any one of claims 27 to 30, wherein vessel temperature is controlled by injection of cold streams.

32. The method of any one of claims 27 to 31 , wherein said chemical processing operation is conducted in a series of vessels and temperature is controlled by controlling the pressure in the last vertical autoclave.

33. The method of any one of claims 27 to 32, wherein said chemical processing operation is a leaching process.

34. The method of any one of claims 27 to 33, wherein said chemical processing operation is an oxidation process.