Bubble collector guide and use thereof

Abstract

The invention concerns a bubble collector guide for use in an electrolysis process, which comprises a plurality of guide members arranged at a distance from each other, the guide members comprising a lower side. The guide members can be arranged horizontally on the vertical surface of an electrode so that the lower side of the guide member forms a downwards facing surface that is substantially orthogonal to the vertical surface of the electrode, so as to collect bubbles of gas generated at the electrode.

Claims

1. A bubble collector guide, where the bubble collector guide comprises a plurality of guide members arranged at a distance from each other horizontally along the length of a rectangular vertical surface of a plate-like electrode, the vertical surface orthogonal to opposed edge surfaces of the electrode, each of the guide members comprising a lower side and each having a proximal end and a distal end, and wherein the guide members are arranged so that the lower side of the guide member forms a downwards facing surface that is orthogonal to the vertical surface of the electrode, so as to collect bubbles of gas generated at the electrode, and wherein the bubble collector guide includes a first support member arranged along a first of the opposed edge surfaces and which connects the proximal end of a first one of said plurality of guide members with the proximal end of a second one of the plurality of guide members, and a second support member arranged along a second of the opposed edge surfaces and which connects the distal end of said first one of said plurality of guide members with the distal end of the second one of said plurality of guide members.

2. The bubble collector guide according to claim 1, where the guide member extends at least half the width of the vertical surface of the electrode.

3. The bubble collector guide according to claim 1, where the guide member is sealably attachable to the vertical surface of the electrode.

4. The bubble collector guide according to claim 1, where the guide members are arranged at an equal distance from each other.

5. The bubble collector guide according to claim 1, where the guide members are arranged at non-equal distances from each other.

6. The bubble collector guide according to claim 1, where the guide members are of the same size and depth.

7. The bubble collector guide according to claim 1, where the guide members are identical in at least one of size and depth.

8. The bubble collector guide according to claim 1, where the downwards facing surface formed by the lower side of the guide member has a linear shape.

9. The bubble collector guide according to claim 1, where the downwards facing surface formed by the lower side of the guide member has a sawedged shape.

10. The bubble collector guide according to claim 1, where the downwards facing surface formed by the lower side of the guide member has a cogged shape.

11. The bubble collector guide according to claim 1, where the guide member comprises at least one of an orifice and an aperture.

12. The bubble collector guide according to claim 1, where the support member extends farther away from the vertical side of the electrode than the guide members so as to prevent other parts of the electrolysis system from touching the guide members.

13. The bubble collector guide according to claim 1, comprising one or more spacers for keeping electrodes at a correct distance from each other.

14. The bubble collector guide according to claim 1 capable of use in an electrowinning process.

15. The bubble collector guide of claim 14 in combination with at least one of an acid mist suppressant chemical, a diaphragm bag or a hood.

16. An electrowinning process comprising: using a bubble collector guide to reduce acid mist in the electrowinning process, the bubble collector guide comprising a plurality of guide members arranged at a distance from each other horizontally along the length of a rectangular vertical surface of a plate-like electrode, the vertical surface orthogonal to opposed edge surfaces of the electrode, each of the guide members having a proximal end and a distal end, and wherein the bubble collector guide includes a first support member arranged along a first of the opposed edge surfaces, and which connects the proximal end of a first one of said plurality of guide members with the proximal end of a second one of the plurality of guide members and a second support member arranged along a second of the opposed edge surfaces, which connects the distal end of the first one of said plurality of guide members with the distal end of the second one of the plurality of guide members; and further reducing acid mist in the electrowinning process beyond that reduced by the bubble collector guide.

17. The process of claim 16 where said step of further reducing acid mist comprises using at least one of an acid mist suppressor chemical, a diaphragm bag, and a hood.

18. A bubble collector guide comprising first and second elongate vertical support members generally parallel to each other and a plurality of spaced apart horizontal guide members arranged at a distance from each other along the respective lengths of the elongate vertical support members, the guide members comprising a lower side and each having a proximal end and a distal end, the first support member connecting the proximal end of a first one of said plurality of guide members with the proximal end of a second one of the plurality of guide members, and a second support member arranged along a second of the opposed edge surfaces and which connects the distal end of said first one of said plurality of guide members with the distal end of the second one of said plurality of guide members, the first and second elongate support members together with the first one and the second one of the plurality of guide members defining a space capable of selectively receiving a plate-like electrode having a rectangular vertical surface so that the lower side of the guide member forms a downwards facing surface orthogonal to the vertical surface of the electrode and which collects bubbles of gas generated at the electrode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The accompanying drawings, which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention. In the drawings:

(2) FIG. 1 is a side view of a bubble collector guide comprising a plurality of guide members arranged on the vertical side of the electrode,

(3) FIG. 2 shows examples of possible shapes or profiles of the downwards facing surface formed by the lower side of the guide member,

(4) FIG. 3 shows a bubble collector guide comprising a plurality of guide members arranged on the vertical side of an electrode,

(5) FIG. 4 demonstrates an embodiment of the bubble collector guide comprising a plurality of guide members and support members,

(6) FIG. 5 is a close-up of the bubble collector guide shown in FIG. 4, and

(7) FIG. 6 shows experimental measurements of acid mist generated in a test system.

DETAILED DESCRIPTION OF THE INVENTION

(8) Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

(9) For reasons of simplicity, item numbers will be maintained in the following exemplary embodiments in the case of repeating components.

(10) FIG. 1 shows a side view of a bubble collector guide according to the invention. An electrode 1 is shown in dotted line. The electrode is attached to an electrode hanger bar 2 (also in dotted line). The bubble collector guide comprises a plurality of guide members 3 which are arranged on the vertical side of the electrode 1. Bubbles of gas (shown as circles) generated at the electrode are collected below the lower side 4 of the guide members 3. The arrows demonstrate how coalesced bubbles move from underneath the lower side of the guide members to the electrolyte and to the electrolyte surface.

(11) FIG. 2 shows examples of possible shapes or profiles of the guide members of the invention and/or the downwards facing surface formed by the lower side of said guide members. FIG. 2A shows a guide member 3 and its lower side 4 which have a linear shape; 2B shows a guide member 3 and its lower side 4 which have a saw-edged shape; and 2C shows a guide member 3 the lower side 4 of which forms a downwards facing surface that has a cogged shape.

(12) FIG. 3 shows another view of a bubble collector guide comprising a plurality of guide members 3 arranged on the vertical side of the electrode 1. The electrode 1 is attached to an electrode hanger bar 2 (in dotted line). The bubble collector guide up to the uppermost guide member may be sunk below the electrolyte surface.

(13) FIG. 4 demonstrates an embodiment of the bubble collector guide arranged on an electrode 1 attached to an electrode hanger bar 2. The electrode has a rectangular shape and comprises two broad and two narrow vertical surfaces. The bubble collector guide comprises a plurality of guide members 3 arranged on the vertical surface of the electrode 1 and support members 5 which connect the ends of the guide members on the two sides of the electrode. The support members 5 are arranged on the two narrow vertical surfaces of the electrode. In the embodiment shown in this figure, the support members 5 extend farther away from the broad vertical surface of the electrode than the guide members so as to prevent other parts of the electrolysis system, such as cathodes loaded into the system, from touching the guide members. The embodiment shown in this figure comprises several spacers 6 that keep other electrodes and other parts of the electrolysis system apart from the guide members and the electrode. The spacers 6 are attached to the support members.

(14) FIG. 5 is a close-up of the bubble collector guide shown in FIG. 4 from a different angle. This close-up clearly demonstrates how the support members 5 extend farther away from the broad vertical surface of the electrode than the guide members 3 so as to prevent other parts of the electrolysis system, such as cathodes loaded into the system, from touching the guide members 3. The upper ends of the support members 5 taper towards the upper part of the electrode 1.

(15) It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described above; instead they may vary within the scope of the claims.

Example 1

(16) Bench scale copper electrowinning experiments were carried out to demonstrate the effect of the invention.

(17) A transparent cell with ca. 30 cm long and 15 cm wide electrodes (lead alloy anode, 2SS 316 cathodes) with a hood was used to determine the effect of bubble collector guides to reduce acid mist. The cell system was able to collect all the acid mist evolved. The experiments were done with and without bubble collector guides that comprised guide members that had a linear shape and a depth of 1 cm. The hood contained an orifice on the top, from which acid mist was suctioned with a pump, collected and measured. The experiments were carried out at two temperatures: 40 and 50 C. The cathodic current density used was 300 Am.sup.2 and electrolysis time 6 h. The same electrolyte was circulated during the experiment. Acid mist was suctioned at 3-4.5 L/min. The sulfuric acid concentration was 1865 g/l and the copper concentration was 373 g/l at the end of the experiments.

(18) The results are shown in FIG. 6. The acid mist reduction was considerable with the bubble collector guides (bubble guides), over 75%. In a similar manner, the amount of copper in the mist was also reduced. The amount of collected acid and copper had the same ratio as the electrolyte, as expected.

Example 2

(19) Similar experimental setup was done as in Example 1, with the exception that the electrolysis time was 4 h and only one experiment was done with the bubble collector guides at 40 C. In addition, an acid mist suppressant chemical was added into the electrolyte with the concentration of 10 ppm. The results are given in FIG. 6. The acid mist reduction together with the acid mist suppressant and the bubble collector guides was 96%.