MetaLeach Limited formed to own AmmLeach® and HyperLeachTM intellectual property

Date Posted:  Tuesday, 26th February 2008
Alexander Mining plc
26th February 2008
 
Significant developments in hydrometallurgical mineral processing technology with new HyperLeach™ process patent filed MetaLeach Limited formed to own AmmLeach® and HyperLeach™ intellectual property.
 
Alexander Mining plc (“Alexander”, the “Company”), the AIM-listed mining and mineral processing technologies company announced today:
  • In discussion with over 25 companies, including international majors, about proprietary mineral processing technologies.
  • Eleven companies have signed confidentiality agreements, with more anticipated.
  • Seven companies have committed to metallurgical test work programmes.
  • MetaLeach Limited is the new name for Alexander’s wholly owned mineral processing technology business.
  • HyperLeach™ is MetaLeach’s new proprietary ambient temperature and pressure process for the leaching and extraction of base metals from sulphide ores and concentrates.
 
MetaLeach now owns the intellectual property to two hydrometallurgical technologies where provisional patents have been filed, namely AmmLeach® and HyperLeach™. These can be summarised as follows:
 
 

AmmLeach®

A proprietary ammonia based process for the leaching and selective extraction of base metals from high acid consuming and complex ores under ambient (i.e. atmospheric) temperature and pressure conditions.
 
Although initially developed for copper, the Company has also developed its AmmLeach® process for the treatment of zinc oxide deposits. Test work results indicate a new solvent extraction and electro-winning (SX-EW) process for producing high purity zinc metal at the mine. This process leaches common zinc oxide minerals with very high extraction efficiencies and offers a potentially economic processing route for many zinc oxide deposits that are currently economically unviable.
 
The Company believes that this technology will be of considerable commercial interest to both mining companies and zinc metal producers because it has the potential to be a highly competitive economic alternative to the processing technologies currently available.
 
 

HyperLeach™

A proprietary ambient temperature and pressure process for the leaching and extraction of base metals from sulphide ores and concentrates.

Martin Rosser, CEO, said:
“With Alexander’s exciting development of the HyperLeach™ process, which complements its AmmLeach® technology, the creation and branding of MetaLeach Limited is an important step in our marketing efforts to provide innovative cost effective solutions to the international mining industry.”
 
“Because most base metal sulphides are processed to produce a concentrate at the mine site, with the associated selling costs and payment terms involved, there is considerable scope to do more on site processing to generate higher returns for mine owners. Indeed, in many cases miners may receive payment for as little as 60% of the in situ metal content of the concentrate. We believe that MetaLeach Limited, with its AmmLeach® and HyperLeach™ technologies, has a tremendous opportunity to develop a substantial new business.”

MetaLeach Limited

After its ongoing research and development work on processes for the hydrometallurgical extraction of base metals from ore deposits and concentrates, the Company has made significant progress. In order to maximise the commercial potential, and more properly reflect the broadening range of its mineral processing technologies, the Company has renamed and rebranded its wholly owned AmmLeach Limited subsidiary MetaLeach Limited. MetaLeach Limited has been formed to commercialise Alexander’s proprietary new mineral processing technologies that have the potential to revolutionise the extraction processes for many base metal deposits.
 
In support of these marketing efforts, a new website reciprocally linked to Alexander’s own, http://www.metaleach.com/ has been created.
 
In addition, to its AmmLeach® process, MetaLeach Limited has developed a second new innovative leaching technology - HyperLeach™, for which a provisional patent application has been made. HyperLeach™ has been developed for the extraction of base metals from sulphide ores and concentrates. This is potentially a major breakthrough for the global mining industry.
 
 
HyperLeach ™ process
The HyperLeach™ process is a new proprietary process for the extraction of base metals, especially copper, zinc, nickel and cobalt from sulphidic ores and concentrates and has been developed by Alexander’s wholly owned technology subsidiary company, MetaLeach Limited. The process utilises a chlorine based oxidant to oxidise the sulphide, thereby allowing the metals to solubilise.
 
Unlike previous chlorine based processes, HyperLeach™ does not require chlorine gas to operate; the oxidant can be generated on‑site via industry standard chlor‑alkali technology. A key feature of the HyperLeach™ process is that it operates at ambient temperatures and pressure and is eminently suitable for heap leaching as well as tank leaching.
 
HyperLeach™ technology is suitable for both low grade heap leaching and higher grade tank leaching; the choice is dictated by the grade and deposit economics. Polymetallic deposits can be readily handled using standard solvent extraction and solution purification techniques.
Key Features:
  • leaches base metal sulphides including chalcopyrite, bornite, chalcocite, millerite, pentlandite, pyrrhotite, violarite, sphalerite and enargite
  • ambient temperature
  • ambient pressure
  • heap leach or tank leaching
  • rapid kinetics
  • selective for sphalerite over galena
  • selective for nickel-sulphides over pyrite
  • low reagent consumptions
Mining economics
Currently, nearly all base metal sulphides are concentrated on‑site using a physical process such as gravity or flotation before being shipped off site to a smelter and refinery for further processing. The costs involved in selling an ore concentrate include road transport, shipping, smelter and refinery charges and can include penalty costs imposed by the smelter that are deducted from the payable metal in the concentrate supplied. In addition in many situations mine owners may not be paid for valuable metal by‑products contained in the concentrate. Taken altogether these charges and costs can amount to as much as 40% of the value of the contained metal produced from a mine.
 
There is considerable scope to do more on‑site processing to add value using hydrometallurgy to generate higher returns for mine owners. The HyperLeach™ process has been developed to produce high value metal products on‑site at competitive operating costs and relatively low capital costs.
 
The technology and how it works
The technology consists of three major stages; leaching, separation/concentration and recovery. The leaching can occur either in a heap or tank and involves contacting the ore/concentrate with a hypochlorite solution at an appropriate concentration. Solvent extraction is used to separate and concentrate the metal(s) from solution whilst also changing from a mixed chloride/sulphate media to acid sulphate media, from which most metals can be directly electrowon using industry standard unit operations.
 
One of the key benefits of the HyperLeach™ process is that, unlike some other technologies, it requires no special purpose built equipment, only the addition of an appropriate leaching circuit or leach pads and collection ponds.
 
Potential applications
The following metals and applications are particular targets for the HyperLeach™ process:
  • low grade nickel sulphide ores
  • nickel sulphide concentrates
  • nickel mattes
  • low grade copper sulphide ores
  • low grade native copper ores
  • copper flotation concentrates
  • arsenical copper ores
  • arsenical gold ores
  • gold bearing sulphides
  • concentrate cleaning.
The use of HyperLeach™ for potential applications with platinum group metals (PGM’s), molybdenum sulphides and uranium leaching is also currently being investigated.
 
Indicative costs
Whilst still at an early stage, it is possible to give indicative operating costs for the HyperLeach™ process to produce various metals, these are shown below:
 
Mineral
Range of HyperLeach™ operating costs
US$/lb metal produced
Copper
chalcopyrite CuFeS2
0.45‑0.90
Nickel
pentlandite (Ni,Fe)9S8
0.60‑1.20
Zinc
sphalerite ZnS
0.40‑0.80
Nb: These indicative costs are based upon chlorine costs of between US$300‑$600 per tonne and power costs of between US$0.04-0.13 per KWh.
 
 

For further information please contact:

 
Martin Rosser
Chief Executive Officer
Mobile: + 44 (0) 7770 865 341
 
Matt Sutcliffe
Executive Chairman
Mobile: +44 (0) 7887 930 758
 
 
 
Alexander Mining plc
1st Floor
35 Piccadilly
London
W1J 0DW
 
Tel: +44 (0) 20 7292 1300
Fax: +44 (0) 20 7292 1313
Email: mail@alexandermining.com
 
 
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