Apparatus and Process for the Improved Economic Extraction of Metal from a Metal-Bearing Material

Abstract

The present invention relates to an improved apparatus for economically extracting metal from a metal-bearing material. In particular, the present invention relates to an improved apparatus for extracting metal, including inter alia base metal (i.e. copper) and gold, from a metal-bearing ore, concentrate or other metal-bearing material. The present invention further extends to a process for the extraction of such metal which is carried out in accordance with the aforementioned apparatus. According to a first aspect thereof, the present invention provides an apparatus for extracting metal from a metal-bearing material, said apparatus, including a feed receptacle for receiving a metal-bearing feed stream; a reaction vessel; at least one pump means for delivering the metal-bearing feed stream to the reaction vessel; a means for introducing leaching agents, in the form of a leaching agent solution, to the reaction vessel; a means of agitation by circulating the metal-bearing feed stream and leaching agent solution in the reaction vessel so as to allow for a combination of agitation (tank) leaching and vat leaching to take place; a means for achieving liquid/solid separation; and a means for extracting a metal containing product; —wherein said apparatus is re-locatable and transportable in order to allow the apparatus to be assembled easily on site without being geographically bound to one specific site.

Description

FIELD OF APPLICATION OF THE INVENTION[0001]The present invention relates to an improved apparatus for economically extracting metal from a metal-bearing material. In particular, the present invention relates to an improved apparatus for extracting metal, including inter alia base metal (i.e. copper) and gold, from a metal-bearing ore, concentrate or other metal-bearing material. The present invention further extends to a process for the extraction of such metal which is carried out in accordance with the aforementioned apparatus.BACKGROUND TO THE INVENTION[0002]The economics of metal extraction are not only dependent on the quality of the ore and the cost of extraction, but also depend on the market price and demand. In addition hereto, it is possible to improve the technology of metal extraction so as to enable companies to produce greater quantities of metal from metal-bearing ore than was previously possible and to even utilise low grade ores previously discarded or not considere...

AI Technical Summary

Benefits of technology

[0082]An advantage of the process of the present invention is economical in that multiple process steps usually carried out in dedicated equipment are performed in a single apparatus operated in a batch or semi-batch nature. Additionally, multiple leaching and separation approaches can be performed using the same equipment, allowing cost-effective implementation of processes tailored to specific ore types and grades.

[0083]The presently disclosed invention thus affords a significant reduction in capital by combining the multiple process steps into a single-stage process concomitant with simplifying the design of the reaction vessel with a view to reducing construction time on site significantly.

[0084]In addition hereto, a single plant will thus be used for treating several metal ore deposits by virtue of the fact that the present apparatus is easily re-locatable and transportable (and thus not geographically bound) to more than one site.

[0085]The present invention advantageously provides the following benefits, namely that it has a compact, modular construction thus achieving a smaller site footprint; the respective modules are largely pre-assembled in workshops / factories for ease of site establishment; reduced construction time of the plant concomitant with reduced erection costs; and the apparatus is easily dismantled and re-assembled to ensure quick site relocation.

[0086]A further advantage exists in utilising this invention for “debottlenecking” current hydrometallurgical operations. Ideally all hydrometallurgical operations want to operate at the limit of the refining capacities (for in example, the limit of their tank house plating capacity when considering electrowinning). It is quite common that the leaching and solid / liquid separation process becomes the bottleneck and results in an under-utilised tank house hence lower than expected production. This invention provides the ability to “fill” the available tank-house capacity by producing PLS from concentrates decoupled from the existing operation.

[0087]The presently disclosed subject matter will now be described more fully hereinafter with reference to the accompanying Figures and Example, in which a representative embodiment is shown.

Problems solved by technology

Unfortunately, this process is taught as requiring finely ground ores and increased temperatures in order to reach useful efficiencies.

It is wide known in the art that the economics of current mining and recovery methods often hinder or even prevent the mining of metal ore deposits that either contains insufficient metal values or requires extensive site preparation or operating expenses.

In particular, low grade copper deposits of typically 1.5 to 2.0% Cu with a life of mine of approximately two years are generally not exploited due to the significant upfront capital requirement and lengthy installation and erection time which render the process uneconomical.

This is especially the case in most of Africa where the traditional capital requirements are greater and construction abnormally delayed relative to similar projects on other continents.

It is quite common that the leaching and solid / liquid separation process becomes the bottleneck and results in an under-utilised tank house hence lower production.

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