News

MMS Refractory Gold Process to be used at Banro's Twangiza Project in the DRC

Banro corporation recently announced in its press release that it will be adopting Maelgwyn Mineral Services proprietary Leachox™ process to enhance the recoveries in its 43-101 compliant Feasibility Study. According to the press release the flow sheet comprises the following main steps:

• Production of sulphide concentrates by flotation (conventional process)
• Fine-grinding the flotation concentrate
• Contacting the fine milled product with oxygen in Aachen reactors™ (proprietary equipment) to effect the partial oxidation of sulphides, which will in turn liberate the refractory gold making it amenable to conventional cyanidation.

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Maelgwyn Minerals Expands Further into Australia

The international presence of Maelgwyn Minerals took another giant step forwards in June 2009 with the appointment of Dr Mike Adams to head up Maelgwyn Minerals Australia.
Mike has over 25 years diverse experience in the development and assessment of metallurgical projects covering precious, base and rare metals.

Mike completed BSc(Hons) and MSc degrees at Witwatersrand University in Johannesburg, South Africa in 1983 before joining Mintek in 1993. He completed a PhD in 1989 on the chemistry of the CIP process for gold recovery. In 1999 he joined Lakefield Oretest and was there until 2004. Mike then formed his own company Mutis Liber to consult to the wider minerals industry. He was awarded a DSc(Eng) degree in 2009 covering his work in several gold-processing advances not used in his previous theses and spanning some twenty years.

Mike is a Chartered Professional (Metallurgy) and has published numerous technical publications including editing the book "Advances in Gold Ore Processing" which has rapidly become a standard reference amongst gold metallurgists.

Mike has recently arranged for the setting up of test work facilities in Perth, Australia to provide pilot plant testing and laboratory test work to clients with a 65 litre Leachox pilot plant installed in January 2010.

Maelgwyn Minerals Services Managing Director Mike Battersby commented "we are very excited to have such a well respected and qualified metallurgist as Mike joining our team. His appointment is a direct reflection of demand for MMS technology in Australia and Mike's appointment combined with the setting up of the laboratory facilities in Australia demonstrates our commitment to further serving the Australian mining industry".

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Maelgwyn at World Gold Conference 2009 - South Africa

Three Maelgwyn Minerals employees attended the World Gold Conference held in the Misty Hills Conference Centre in the Cradle of Mankind, South Africa. The employees were Mike Battersby, Adrian Singh and Hennie Stallknecht.

Adrian Singh delivered a presentation on MMS technologies and their specific applications in gold processing. The paper was very well received and promoted a considerable amount of discussion amongst delegates both at the time and afterwards "over a beer".

Maelgwyn Minerals were also one of the sponsors for this conference.

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Maelgwyn at Flotation 09 -South Africa

A number of Maelgwyn Minerals employees from the UK, South Africa, and Germany recently attended the MEI Flotation 09 conference held at the Vineyards hotel in Cape Town, South Africa. Maelgwyn Minerals were also one of the conference sponsors and manned a stand at the associated exhibition. At the stand the team demonstrated the principles of Pneumatic flotation with the aid of a 0.65m diameter Perspex G-cell. This formed a focal point for many delegates and promoted a great deal of interest and discussion .

Dr Rainer Imhof gave a paper at the conference entitled "Pilot plant testing and the successful commercial installation of Imhoflot G-cell pneumatic flotation for molybdenum concentrate cleaning at Los Pelambres in Chile".

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Official Opening of Maelgwyn Africa New Offices and Test work Facility

Maelgwyn Mineral Services Africa (MMSA) recently celebrated the opening of their new offices and test work facilities in Roodepoort, Johannesburg with an open day for their customers. The opening took the form of a tour around the extensive metallurgical facilities followed by a spit roast barbeque and refreshments.

Hennie Stallknecht - Head of flotation technology enthusiastically guided visitors through the test work facilities which include bulk sample preparation i.e. crushing and milling, flotation, Leachox™ evaluation, rolling bottle leach tests and cyanide destruction test work using MMS's CN-D process.

Adrian Singh - Chief Operating Officer and Director of MMSA welcomed guests and gave a detailed presentation of MMS's proprietary technologies including Imhoflot Pneumatic flotation cells, Leachox and the recently developed cyanide destruction process.

The new facilities are located at:
Corner of Spokeshave Road and Staal Road
Stormill Extention 2, 1709
Roodepoort, Johannesburg, South Africa

MMSA Offices

MMSA Pilot Plant

MMSA Flotation Laboratory

MMSA Leachox Laboratory

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Maelgwyn Mineral Services Africa Supply Aachen Reactor™ Technology to West Africa

MMSA is please to announce the installation and operation of twelve Aachen Reactors at the Loulo Mine in Mali. The Loulo Mine is 20% owned by the Mali government and 80% owned by Randgold Resources Limited who are managers of the mine. Randgold Resources is an African focused gold mining and exploration business listed on the London Stock Exchange and Nasdaq. They are one of the world’s largest gold producers. The supply of Aachen Reactors under a lease maintenance and service agreement is part of the MMSA collaboration with Air Liquide and in this case being managed by Air Liquide MALIGAZ in Mali. As part of the arrangement Air Liquide supplied an on-site oxygen plant.

The Loulo Mine is situated in the west of Mali, close to the Senegal boarder. The Loulo plant treats approximately 230,000 tons per month of ore. As part of the Air Liquide supply oxygen capacity at the plant has been increased from 5t/day to 15t/day. Despite this, before the installation of the Aachen Reactors, the dissolved oxygen levels in the CIL circuit remained low at around 1.5ppm. The twelve REA400 Aachen Reactors have now been installed to run with approximately 9t/day of oxygen. After installation dissolved oxygen levels immediately jumped to over 20ppm, demonstrating the higher oxygen utilisation possible with the Aachen Reactor Technology.

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Maelgwyn Mineral Services Africa Develops Strategic Alliance with Air Liquide for Africa

Maelgwyn Mineral Services Africa has entered into strategic alliance with Air Liquide to jointly pursue and develop projects that require both MMSA’s mass transfer technology and Air Liquide’s gas supply. The non-exclusive agreement, facilitated through Air Liqude (Pty) Ltd in South Africa, covers mining projects in sub-Sahara Africa. The alliance blends MMSA’s proprietary equipment into Air Liquide’s ALDOC system (Air Liquide Dissolved Oxygen and Control).

Air Liqude is a world leader in the supply of industrial gases and gas manufacturing equipment. MMSA offers proprietary MMS technology to Africa such as Aachen Reactors, Leachox and the Maelgwyn Cyanide Destruction Process (CN-D Process) that all utilise oxygen. MMSA’s Technical Director, Adrian Singh comments “As a result of this collaboration, it has become possible to offer to the mining industry a package deal that incorporates gas supply, Aachen Reactor injection technology, and dissolved oxygen measurement”. The first contract of this nature will shortly be concluded for a West African gold mine.

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Knowledge Transfer Partnership (KTP)

Maelgwyn Mineral Services in conjunction with Cardiff University’s Engineering Department has been awarded a grant to fund a Knowledge Transfer Partnership (KTP) and to employ a graduate mineral processing engineer. The KTP is to undertake fundamental research into the MMS Leach Column around which the Leachox refractory gold and the MMS cyanide destruction processes are based. The partnership has employed Andrew Molloy to undertake the work. Andrew has BSc in Applied Geology and an MSc in Minerals Engineering from Camborne School of Mines.

The general objective of the KTP is to facilitate the transfer of knowledge and the spread of technical and business skills; provide company based training for graduates and stimulate and enhance business relevant research undertaken by the knowledge base.

Pictured are Dr Arun Vathavooran (Company Supervisor) Andrew Molloy (KTP Associate), Prof. Tony Griffiths (Lead Academic), Prof. Keith Williams (Academic Supervisor) and Mike Battersby (KTP Chairman & Project Facilitator).

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Maelgwyn Mineral Services Internal Conference, Franschoek, South Africa

Maelgwyn Mineral Services recently completed a very successful four day Internal Conference for its stakeholder metallurgists held in beautiful Franschhoek in the Western Cape, South Africa. The objective of the conference was to exchange information, experience and ideas on the group’s proprietary mineral processing technology. Present were representatives of MMS companies in the UK, Germany, South Africa and Russia together with its partner companies in South America. It was calculated that the group has a combined total of well over 350 years of mineral processing experience!

Pictured standing from left to right are; Alejandro Sanchez Pino, Hennie Stallknecht, Dave Jordan, Mark Battersby, Arun Vathavooran, Heiner Sprenger, Andrew Molloy and David Imhof.

Sitting from left to right are Mike Battersby, Sam Sanchez Pino, Rainer Imhof, Adrian Singh, Joseph Chifamba and Alexander Bakulin.

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MMS Licences its Leachox™ Refractory Gold Process to Vasilkovskoye Gold Mine in Kazakhstan

Maelgwyn Mineral Services Ltd (MMS) announces that it has licenced its proprietary Leachox refractory gold recovery process to JSC Vasilkovsky MMC for use at the Vasilkovskoye gold mine near Kokshetau in Northern Kazakhstan. The Leachox plant, with a nominal capacity of 50 tons per hour of gold contained in sulphide concentrate, will be one of the largest refractory gold treatment plants in the world and will have a throughput over 50% greater than the largest gold bio-oxidation plant currently operating worldwide. The MMS Leachox process is a major breakthrough in the treatment of difficult to process refractory gold ores. It offers a low capital and operating cost process route but with high gold recoveries, comparable to bio-oxidation. The Vasilkovskoye gold mine is a joint venture between Floodgate Holdings BV and the Kazakhstan state-owned Ministry of Finance of the Republic of Kazakhstan. The mine has one of the largest undeveloped gold reserves in the world however the gold is mostly contained in hard to recover refractory gold ore. Commissioning is planned for later in 2009.

Aachen Reactors in manufacture for Vasilkovskoye

The Leachox process, which has been patented world-wide, has been jointly developed over a number of years by MMS and Maelgwyn Mineral Services Africa (Pty) Limited. It utilizes proprietary MMS Aachen Reactor™ technology in conjunction with a specific process flowsheet that includes ultra fine grinding. The process has previously been trialled by MMS Africa over a number of gold operations in the Mpumalanga greenstone belt of South Africa.

The Vasilkovskoye operation will initially mine 5 million tons per year of a pyrite/ arsenopyrite refractory gold ore. The Leachox plant has been designed to treat 7800 tons per week of a gold contained in sulphide concentrate with over 93% leach recovery expected. Vasilkovskoye chose the Leachox process after extensive pilot plant testwork in South Africa as it gave high gold recoveries with low capital investment cost and low predicted operation cost compared to bio-oxidation, pressure oxidation and other processes. The Vasilkovskoye flowsheet is one of the most innovative in the gold industry where, apart from the introduction of Leachox, it also utilizes high pressure grinding rolls in the comminution circuit and a differential pyrite/ arsenopyrite flotation circuit.

The Leachox process involves the ultra fine grinding of mineral concentrate followed by low pressure partial oxidation of sulphides using a series of Aachen Reactors in a proprietary flowsheet configuration including MMS Leach Columns. The Leachox process can also be designed to treat carbonaceous “preg robbing” ores. One of the issues that had previously been encountered in trying to treat refractory gold ores by ultra fine grinding has been that, almost universally with such ores, there comes a point where further ultra fine grinding results in an appreciable drop in gold recovery. It is thought that this is due to passivation of the gold at extremely fine sizes. A further major problem encountered with the treatment of sulphide ores at grind sizes generally less than 20 microns is that the consumption of reagents required to leach the gold - typically cyanide, lime and oxygen, increases exponentially in open tank leaching. This may be so high as to make the process uneconomic even at the current high price of gold. The Leachox process negates both the passivation effect and the great increase in reagent consumption making the process economically attractive.

Vasilkovskoye Leachox plant building and construction

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