The technology developed by BacTech using the technology of Kings College London (First Technology) relates to a process for recovering base and/or precious metals from sulphide materials comprising bacterial leaching the sulphide material with an aqueous solution at a temperature of 25°C to 55°C. The aqueous solution contains a thermotolerant bacterial culture which has an optimum growth temperature of 40°C to 45°C, and is capable of promoting oxidation at a temperature of 25°C to 55°C. The oxidized residue is separated from the aqueous liquid and metal is recovered from the residue and/or aqueous solution.
The technology purchased from VistaTech (Second Technology) relates to a process for recovering precious metals from particulate sulphide materials comprising bacterial leaching the sulphide material with an aqueous solution at a temperature of 45°C to 90°C. The aqueous solution contains a facultative or obligate thermopile capable or promoting the oxidation of the sulphide material. The oxidized residue is separated from the residue and/or aqueous solution. The bioleaching is carried out at a temperature of at least 45°C, and in the presence of nutrients to oxidise the mineral sulphide and liberate the precious metal.
The First and Second Technologies are the subjects of patent applications and registrations in a number of countries as follows:
In Australia, the original patent application 652231 with respect to the First Technology was subject to an opposition by Billiton South Africa Limited ("Billiton") and an opposition by Technological Resources Pty Ltd. The patent application was refused. The decision does not prevent BacTech from using its technology for gold or base metals. BacTech (Australia) Pty Ltd has filed a Divisional Application with respect to Application 652231. This has allowed BacTech to file more detailed data on the base metals applications within the Patent Application that the company believes are still patentable The commercial application of the First Technology is dependent upon trade secrets and other proprietary information in addition to the patents.
BacTech and Mintek have jointly applied for patents for improvements to copper bioleaching in a number of Central and South American countries.
In addition BacTech has access through its agreement with Mintek to technology for the bioleaching of chalcopyrite that has been patented in a number of countries and has applications pending in others.
BacTech has submitted patent applications for its two development reactors in a number of South and Central American countries and in Australia as PCT applications.
BacTech has submitted patent applications for a method of improving heap leaching using high temperature bacteria in a number of South and Central American countries and in Australia as a PCT application.
Of equal or greater value to patents is the knowledge that BacTech and Mintek have gained from testing, piloting, and commercially applying the technology to over 300 sulphide ores and concentrates for precious and base metals. In all of its processes BacTech has developed proprietary methods for base metals over the past 16 years. Bactech and Mintek have adapted the bacteria to create a vast number of differing inoculums applicable to many ores and concentrates. This repository is an extremely valuable component of BacTech and Mintek's intellectual property. It represents a significant barrier to entry for competitors. In addition BacTech and Mintek have developed detailed methods for utilizing the technologies. These methods are part of the intellectual property of BacTech and Mintek, although the nature of the methods may be such that they would not substantiate the granting of a patent.