Patent Application
20060289301
This invention relates generally to smelting of ores and more particularly to edge protectors for cathodes.
Electro-deposition is used for the refining of many minerals including copper. Copper is extracted from the ore using large metal sheets made of titanium or stainless steel. These sheets are suspended in tanks containing the copper ore, a 5%-10% solution of sulfuric acid, plus other chemicals.
In Solvent Extraction-Electro Winning (SXEW), the copper is leached out of the copper bearing ore using sulfuric acid. The acid containing the copper drains to a collection system (pumps, pipes), ending up in tanks containing the large metal plates.
Low voltage/high amperage direct current electricity is applied, using lead as the anode, and the titanium/stainless steel plate as the cathode. The copper is electro-deposited (plated) on the metal to a pre-determined time/thickness.
Removal of the deposited copper requires the “peeling” of the copper from the cathode using a “knife” arrangement. Should the copper become deposited around the edge of the cathode, then its removal is significantly encumbered.
There is a significant need to provide for a mechanism which curtails depositing of the copper into a defined area. To this end, a variety of techniques have been developed including the use of various edge strips of CPVC, HDPE, Sponge/Spring combinations, etc.
All too often though, the edge strips break due to rough handling, copper getting underneath the strips, impact, age, etc. Protection such as wax, silicone, etc., must be re-applied each cycle; these are messy and create occupational and safety hazards, increase production costs.
Another problem associated with traditional edge strips is that when they are exposed to the high temperatures of their working environment, the maters used in the edge strip tend to degrade or unduly expand; this creates gaps in the seal between the edge protector and the cathode (allowing copper to be deposited in these gaps).
Gaps in the seals are also created during the grinding process to clean the cathode for subsequent uses. This narrows the width of the cathode; hence, the edge protector (designed for a particular width cathode) does not seal as well as it previously did.
When the edge strips break or fails to form a proper seal around the edge of the cathode, removal of the deposited copper is a major problem.
It is clear there is a need to provide secure edge protectors.
The invention is a edge protector in which the edge protector is configured to encircle an edge of a cathode.
While the present discussion relates to cathodes used in the electrowinning process, those of ordinary skill in the art recognize that the present invention is useful in a variety of situations where an edge of a material is to be protected from physical damage and also in the fields where electro-deposition of metals is to be curtailed along an edge of a plate.
The edge protector of the present invention is configured to encase an edge of the cathode. This is accomplished by sliding or slipping the edge of the cathode into an internal channel established within the edge protector. As such, in the preferred embodiment, once the cathode has be placed on the cathode, a pair of lips on the edge protector address opposing faces of the cathode and the edge of the cathode is contained within the edge protector.
In the preferred embodiment, the internal channel is shaped in a “triangular” arrangement. In this embodiment, the widest portion of the triangular shape is closest or proximal to the lips with the narrowest portion distal from the lips. The narrowest portion has a width which approximates the width of the cathode. This arrangement provides a “gripping” or engagement relationship between the edge protector and the cathode.
In another embodiment of the invention, the triangular shape of the internal channel is reversed; that is, the widest part of the channel is distal from the lips.
A key is provided and is secured to the cathode. In the preferred embodiment of the invention, the key fits on both faces/sides of the cathode and is secured through holes in the cathode to each other. In an alternative embodiment of the invention, the key is secured to a single side of the cathode.
The key is configured to substantially fill a void between the cathode and walls of the internal channel. This configuration of the key creates optimal contact between the elements so that the edge protector is firmly secured to the cathode.
In the preferred embodiment, where the widest part of the internal channel is proximal to the lips, the key is shaped with its widest part proximal to the lip; in the alternative embodiment where the internal channel is widest at a distal point from the lips, the key is widest at the distal location from the lips.
In this manner, the key is configured to mimic the internal channel's configuration.
To further increase the amount of physical contact between the edge protector, key, and cathode, in the preferred embodiment, the edge protector includes an externally accessible slot located at the far side away from the lips. An expansion pin is inserted into this externally accessible slot which acts as a “lever” arrangement on the edge protector and forces the edge protector to contract around the lips region. This provides an action which encourages the edge protector to fully engage both the key and the faces of the cathode.
The invention, together with various embodiments thereof, will be more fully explained by the accompanying drawings and the following descriptions thereof.
Referencing
Further, edge protector 10A has an externally accessible channel 15A located at a location opposite lips 9.
Electrode 11A is equipped with hole 18 through which pin 17 from key 12A is inserted to engage with key 13A as illustrated by arrows 16B. Ideally there are a series of holes with associated pins for attaching key 12A and key 13A to each other so that key 12A and key 13A are secured to opposing faces/surfaces of cathode 11A. These additional holes are not visible from this angle.
Note, key 12A and key 13A are shaped to mimic the walls of the internal channel 19.
Once key 12A and key 13A are fully secured to cathode 11A, edge protector 10A is placed over the keys 12A and 13A as illustrated by arrows 16A (typically by sliding edge protector 10A over keys 12A and 13A), resulting in the state illustrated in
Once edge protector 10B is placed over keys 12B and 13B, expansion pin 14A is inserted into externally accessible slot 16B. The diameter of expansion pin 14A is greater than the width of externally accessible slot 15B, resulting in a force illustrated by arrows 16C which create a compression force illustrated by arrows 16D. This compression force 16D causes edge protector 10B to fully engage keys 12B and 13B together with forcing lips 9B to engage the faces of cathode 11B.
Once fully assembled, the combination of edge protector 10C, keys 12C and 13C, and expansion pin 14B, fully engage cathode 11C.
Referencing
Another shape for the internal channel is shown in
Still another shape for the internal channel is shown in
In this embodiment of the invention, key 32 is located on one surface of cathode 30. Edge protector 31 encircles key 32 and, on the opposing face, fully contacts the surface of cathode 30.
This embodiment provides for enhanced contact between the edge protector and the cathode.
It is clear that the present invention provides for a highly improved and secure edge protector.
