WO2020069539A1

WO2020069539A1 - Cascade of processing vessels

Info

Publication number: WO2020069539A1
Application number: PCT/ZA2019/050061
Authority: WO
Inventors: Ruan KUKARD; Abraham Barend SMIT; Barend Jacobus BEYLEFELD; Charl Jan DU PREEZ
Original assignee: Kukard Ruan; Smit Abraham Barend; Beylefeld Barend Jacobus; Du Preez Charl Jan
Priority date: 2018-09-26
Filing date: 2019-09-26
Publication date: 2020-04-02

Abstract

A cascade of processing vessels (10) each having an inlet (24) at its lower part and a launder (28) at its upper part, each vessel (10), other than the first, having a feed pipe (34) leading from a launder (28) of the previous vessel (10) to the inlet of the next vessel (10) characterised in that there is a feed pump in each feed pipe (34) other than the feed pipe (34) in the last vessel (10).

Description

CASCADE OF PROCESSING VESSELS

[0001] This invention is concerned with a cascade of processing vessels in ore recovery plants. The vessel can be used as a leach vessel, an adsorption vessel, an agitated solution or slurry vessel, a flotation vessel, etcetera. The vessel can be used on its own or in series with any number of vessels.

[0002] The invention is concerned with a cascade of processing vessels of the kind comprising a plurality, normally one to six, vessels connected in series and each comprising either an inverted frustoconical mixing chamber located above and coaxial with a cylindrical inlet chamber and leading to a launder there above, or the whole vessel could be a cylindrical shape . The vessels are connected together by a feed conduit leading from the outlet of each launder of one vessel to the inlet chamber of the next vessel in the cascade. Such a cascade is hereinafter called "a cascade of the kind set forth".

[0003] In known cascades of the kind set forth an inlet feed pipe is provided leading to the inlet chamber of the first mixing chamber and an outlet from the launder of the last vessel of the cascade is connected to the next stage of the recovery plant. The vessels are arranged at different heights so that the liquid can pass by gravity down from the launder of an earlier vessel to the inlet chamber of the next vessel. Usually the earlier vessel is about a half to one metre higher than the other. Thus, it is necessary for the earlier tanks to be supported on a steel or civil structure to make allowance for the required cascade height. [0004] According to the present invention there is provided a series of vessels of the kind set forth wherein a pump is provided in at least some of the inlet feed pipes, and preferably in each inlet feed pipe, so that as the launder overflows the liquid passes into the feed conduit where it is engaged by the pump to be forced down under pressure into the inlet chamber of the next vessel and such pressure forces the liquid upwards through the vessel into the launder there above. With such an arrangement the vessels can be arranged at the same height which will avoid the necessity of the expensive steel or civil structures required where the vessels are at different heights.

[0005] A cascade of the prior art and an embodiment of the invention will now be described with reference to the accompanying drawings.

[0006] In the drawings:

Figure 1 is a side view of a cascade of processing vessels of the prior art; Figure 2 is a similar view of a cascade of processing vessels of the invention;

Figure 3 is an isometric view of a cascade of processing vessels of the invention; and

Figure 4 is a plan of a cascade of processing vessels of the invention.

[0007] Referring now to Figure 1 there is shown a cascade of processing vessels

10.1 to 10.5 arranged in accordance with the prior art. Each processing vessel 10 comprises an inlet chamber 12 above which is the mixing chamber 14 that is in the shape of a frustum of an inverted cone and above which is a launder 16 extending out outwardly and having an ear (not shown) projecting towards the next processing vessel 10. A feed pipe 18 leads from an opening in the ear to the inlet chamber of each vessel. The feed pipe 18.1 leading to the first vessel 10.1 is fed with slurry from a feed box (not shown) or from a pump leading to the feed pipe 18.1. The feed box is higher than the first processing vessel 10.1 so that slurry can be delivered to the vessel by hydraulic head. This transfers the slurry in the vessel 10.1 to the launder.

The slurry then passes to the feed pipe at 18.2 leading to the inlet chamber of the second vessel and so on up to the fifth vessel 10.5. At the fifth vessel 10.5 the outlet 17 from the launder 16.5 leads to the next process. Because the slurry has to be moved forwardly by hydraulic pressure, the vessels must be at different heights. The first vessel is typically between half a metre to a metre higher than the second and so on to the fifth vessel. The feed box is also between half a metre to a metre higher than the first vessel. With such an arrangement a very expensive steel or civil structure (not shown) is necessary to support the vessels.

[0008] In the arrangement of the invention as shown in Figure 2, Figure 3 and

Figure 4 the horizontal cascade (series) 20 again comprises six processing vessels 22 each comprising an inlet chamber 24 above which is a mixing chamber 26 that is in the shape of the of a frustum of an inverted cone. [0009] Above the mixing chamber 26 is a launder 28 (best shown in Figure 3) which has an opening 30 in the vertical wall 32 of the launder 28 at the closest portion between that vessel and the next. Below this opening 30 is a feed pipe 34 which leads to the inlet chamber 24 of the next vessel. A pump (not shown) is provided in the feed pipe. The pump is driven by an electric motor 42 there above.

[0010] Above the launder 28.1 of the first vessel 22.1 there is a feed box 38 from which slurry is led to the second feed pipe 34.1 and the pump there above which pumps the slurry from one vessel to the other under sufficient pressure to drive the slurry upwardly in the next vessel to its launder. Thus the vessels are all on the same level. This means that it is unnecessary to provide the steel or civil structures for supporting the vessels.

[0011] Each launder 28 has a base which is an annular base coaxial with the vessel.

There is a slightly triangular shaped enlargement to the launder base (best shown above the fifth vessel in Figure 4). This provides additional space for a bypass valve for the slurry flow to the next vessel’s launder if required.

The outlet 36 from the fifth launder 28.5 leads the slurry to discharge.

[0012] A small steel supporting structure 40 is provided to support the bottom end of each feed pipe.

[0013] The launder of the last vessel has an outlet pipe leading to discharge. [0014] As mentioned above because the horizontal cascade (series) comprises all the vessels at the same level it is unnecessary to have the steel or civil structure for supporting the vessels, which significantly reduces the cost of manufacture of the cascade system.

[0015] The invention is not limited to the precise pump, vessel shape and

constructional details hereinbefore described and illustrated in the drawings.

Claims

1 A cascade of processing vessels each having an inlet at its lower part and a launder at its upper part, each vessel, other than the first, having a feed pipe leading from the a launder of the previous vessel to the inlet of the next vessel characterised in that there is a feed pump in each feed pipe other than the feed pipe in the last vessel.

2 A cascade is claimed in claim 1 characterised in that each vessel comprises a body and inlet below the body, and a launder above the body.

3 A cascade is claimed in claim 2 characterised in that the body is the shape of the

frustum of an inverted cone, the inlet comprises a cylinder connected to the lower part of the body and there is a launder connected to the upper part of the body.

4 A cascade is claimed in any one of the preceding claims wherein the vessels are located at the same level.

5 A cascade is claimed in any one of the preceding claims characterised in that the cascade comprises six vessels.

6 A cascade is claimed in any one of the preceding claims wherein there is a motor on top of each feed pipe to drive the pump in that feed pipe.