Atoll Mining & Metals
Technical Consultant
Dr Peter Scott
Peter Scott obtained the degrees of BSc, BSc (Hons), MSc (Eng), PhD (Eng) from the University of the Witwatersrand. His postgraduate research was done in the field of uranium hydrometallurgy as a bursar of the National Institute for Metallurgy (NIM now Mintek). He went on to conduct research and development at NIM in the field of base metal leaching and PGM refining.
He then spent 10 years in the Gencor group in field of hazardous waste treatment and waste recycling, during which time he obtained a B Com degree from UNISA. That was followed by 5 years trading in chemicals and minerals in the Chemical Services group (an AAC subsidiary). He returned to Mintek in 1992 and spent 9 years as Marketing Director responsible for commercializing its technology.
In 1999 he was the co – founder of Atoll with Basil Smidt of Titaco and became CEO of the Atoll group in 2001. He led the growth of the BOO metal from slag recovery and DC EAF fines and dust smelting businesses until late 2009 when he retired. Peter has offered his experience and expertise to the new owners of Atoll.
History: Our Journey Through Time
Since its formation in 1999, Atoll Metal Recovery (“Atoll”) has built, owned and operated (BOO)11 major gravity metal-from-slag and mineral recovery plants in Southern Africa, capable of processing between 120 and 200 t/h of feed using unique pneumatic jigs and classifiers. It has also constructed a 100 t/h plant for Sweden, 60 t/h plants for France, Romania, Georgia, Turkey and the USA and has supplied 10 t/h to 35 t/h mobile jigging plants to clients throughout the world.
Most of the plants recovered metal from ferroalloy slag, initially by toll processing for clients but more recently Atoll has begun to recover metal and slag for its own account – the metal is sold to steel and alloy foundries while the slag is sold as construction and remediation material. Atoll still operates the plants in Romania, Turkey as well as one plant in South Africa. The other plants have been sold to the slag owners.
Although metal from slag recovery remains a key focus, Atoll is turning more of its attention to the beneficiation of minerals by jigging, particularly manganese and iron ores and coal.
Atoll was also a major participant in Mogale Alloys that used a unique process in a 40MVA DC furnace to smelt Stainless Steel EAF dusts to form a FeNiCr alloy and an inert slag. The BOO processing of SS EAF dusts and SS pickling acids is another major focus for Atoll.
Atoll continually strives to introduce innovative but proven technology to its clients on a BOO basis, reducing the risk to the client while providing cost effective services.
Innovations in Metal Recovery: Metal from Slag
A need to recover the metal from slags was first identified by the South African metallurgical research institute, Mintek, in the 1970s, due to the rapid growth of the ferroalloy industry in South Africa.
Attempts by the mining industry at this time to use physical separation techniques such as dense media separation (DMS), spirals, tables, magnetic rolls and diaphragm jigs proved inefficient and it was not until the late 1980s that Mintek identified pneumatic jigging as the technology most suitable for metal recovery from ferralloy slags.
Initially a Batac jig was modified to achieve higher recoveries and grades of metal. At about the same time Titaco identified a need in the market for better metal-from-slag recovery technology and approached Mintek with a view to developing a complete product / process package for the market. The Titaco / Mintek joint venture (JV), formed in 1992, grew out of this interaction.
Since its formation, the JV has built 18 major metal-from-slag recovery plants in Southern Africa capable of processing between 120 and 200 t/h of slag. It has also constructed a 100 t/h plant for Sweden, 60 tph plants for France, Romania, Turkey and the USA and conducted BFS’s for 6 major plants (200 t0 300 tph) in Eastern Europe. In line with the JV’s commitment to the ongoing improvement of its technology, continual development has taken place. Initially, pneumatic jigs were only used to recover metal from coarse (+6 – 25 mm) slag fractions while diaphragm jigs were used for fine (+1 –6 mm) fractions.
In the mid 1990s, however, the Batac jig was abandoned in favour of the Apic jig, the technology for which was sold to Titaco by FCB of France and which was a development of the original patented Pic pneumatic jigs. Building on the advantages of the Apic jigs, Titaco / Mintek developed a fines (+1 –6 mm) Apic jig to complement the coarse (+6 –25 mm) jigs.
Since 1998, the Apic fines jig is now standard on all Titaco / Mintek Metal Recovery Plants (MRPs) and two of the major plants were retrofitted with these circuits. In a further development, the Apic classifier was developed for ultrafines and was commercialised at Middelburg Ferrochrome in November 2000 and Transalloys Silicomanganese in April 2002.
The success of the technology was recognized by the Associated Scientific and Technical Societies who awarded Mintek and Titaco their national trophy for ‘outstanding contributions to science’ or the application of science in 1999. As the MRP business developed, the need of many clients for a build, own, operate (BOO) service emerged and Titaco / Mintek therefore formed the Apic Toll Treatment (Pty) Ltd joint venture company (Atoll) to provide BOO services.
Atoll has operated a 170 t/h plant at Transalloys, a 250 t/h plant at Middelburg Ferrochrome, a 150 t/h plant at Hernic Ferrochrome, a 30 t/h plant at Metalloys, a 60 t/h plant at SA Ferrochrome, an 80 t/h plant at International Ferrometals and an 80 t/h plant at ASA Metals in South Africa, a100 t/h plant at Vargön Alloys in Sweden and 60t/h plants at Boulogne-Sur-Mer, France; Tulcea, Romania; Zestafoni, Georgia; Antalya, Turkey and Johnstown, USA.
Most of the RSA plants and the Swedish and French plants were toll operations. However, the Romanian, Georgian, Turkish and USA plants all sell both metal and slag for their own account.
The Titaco/Mintek JV built a manganese ore pneumatic jigging beneficiation plant in Otjosondo, Namibia. Atoll had a manganese ore toll processing BOO pneumatic jigging plant at Burke Mining near Kathu, RSA. Atoll has conducted several pilot plant pneumatic jigging campaigns on both RSA and Brazilian iron ores. Two Apic iron ores jigs have been sold to Brazilian iron ore producers, several to Indian iron ore producers.
The pilot plant development done by the JV led to the first major pneumatic jigging iron ore beneficiation plant in RSA at Beeshoek. Based on its pneumatic jigging experience, the JV built a major pneumatic iron ore jigging plant in RSA for Kumba. Atoll also ran a toll processing BOO on coal at Mooifontein during 2002.
Titaco merged with Bateman Engineering in 2000 and in 2006 the AIM listed Bateman Engineering N.V. (BENV) bought Mintek’s share in the South African part of the Atoll group and consolidated the Atoll companies under the BENV mantle. In 2008 Atoll was rebranded as Bateman Mineral Recovery.
A year or so after the financial crash in September 2008 which led to a collapse of commodity prices, BENV sold its interest in Atoll to the current owners who are entrepreneurs with extensive experience in the quarrying and metal recovery industry.
Atoll Metal Recovery
BOO Metal from Slag Recovery Plants using pneumatic jigging gravity separation technology provides:
- High, cost-effective recovery of saleable metal: coarse metal (<2 % slag) at >95 % recovery, fines (<2 % slag) at >95 % recovery and ultrafines (<10 % slag) at >70 % recovery
- Recovery of a wide range of metal alloys from slag dumps and other waste streams: ferromanganese (FeMn), ferronickel chrome (FeNiCr), ferrochrome (FeCr) and silicon manganese (SiMn)
- Environmental benefits: removal of unsightly stockpiles, potential reduction in pollution and low energy usage
- Beneficiation of coal, ores and industrial minerals
- Services provided on a build, own and operate (BOO) basis
BOO Mineral Beneficiation Plants, using pneumatic jigging gravity separation technology:
- Production of on specification iron and manganese ores and coal
- Highly competitive operating costs
Contracting Models
With its principal activity being the recovery of metal alloys, mostly FeMn, FeNiCr, FeCr and SiMn, from slag dumps and other waste streams, the company operates through the following business models:
- On a build, own and operate (BOO) basis:
- With metal recovered either by toll treatment (BOOT) at a fixed fee per ton
- Or in joint venture (JV) with the client
- Operation of plants with the sale of the products for its own account
Past Collaborations
Credibility Statement
During the rapid growth of the ferro alloy industry in South Africa in the seventies, Mintek identified the need for recovery of metal from slags. Attempts by industry to use physical separation techniques such as DMS, spirals, table, magnetic rolls and diaphragm jigs proved inefficient and were often not cost effective due to low recoveries and poor grades of metal.
During the late eighties Mintek identified pneumatic jigging as the technology most suitable for metal recovery from ferroalloy slags. Initially a Batac jig was modified to achieve higher recoveries and grades of metal.
At about the same time Titaco became aware of the need in the market for better metal from slag recovery technology and approached Mintek with a view to developing a complete product / process package for the market.
The Titaco / Mintek joint venture grew out of this interaction. Since its formation in 1992 it has built eleven major metal from slag recovery plants in Southern Africa capable of processing between 120 and 200tph of slag. It has also constructed a 100tph plant for Sweden, a 60tph plant for France, a 50tph plant for Romania and has supplied 10 – 35tph mobile jigging plants to clients throughout the world. A reference list is attached.
The Titaco / Mintek technology has been developing ever since its inception. Initially, pneumatic jigs were only used to recover metal from coarse (+6 – 25mm) slag fractions while diaphragm jigs were used for fine (+1 –6mm) fractions.
The Batac jig was abandoned in favor of the Apic jig in about 1996. Apic jig is a development of the original Apic pneumatic jigs. FCB of France has sold the technology to Titaco.
Building on the advantages of the Apic jigs Titaco / Mintek have developed a fines (+1 –6mm) Apic jig to complement the coarse (+6 –25mm) jigs. Since 1998 the Apic fines jig is now standard on all Titaco / Mintek MRP’s and two of the major plants have been retrofitted with these circuits. Recently, a new device, the Apic classifier, has been developed for ultrafines and it was commercialised at Middelburg Ferrochrome in November 2000 and Transalloys silicomanganese in April 2002. It replaces spirals because it gives better recoveries and grades and is easier to operate.
Mining, crushing, screening, slimes handling and water reticulation form part of the process.
Slimes that are washed out on the screens, are removed by the desliming cyclone. After thickening the slimes are dewatered and the supernatant water is returned to the gravity separation circuit. All products of the process are managed in an environmentally safe fashion.
The process design has been based on success achieved and lessons learned from the many plants that the Titaco/Mintek JV have built in the past. It is a state-of-the-art solution to ensure optimum economic recovery of ferroalloys from the slag.
The process design is based on process development expertise, design and project engineering capability and Atoll’s extensive operating experience that lead to optimum capital and operating costs for high recovery of on-specification ferroalloy from the slag.
The success of the technology was recognized by the Associated Scientific and Technical Societies who awarded it their national trophy for ‘outstanding contributions to science or the application of science in 1999’.
As the MRP business developed it became apparent that many clients required a build own, operate (BOO) service rather than their own plant and Titaco / Mintek decided to form the Apic Toll Treatment (Pty) Ltd joint venture company (Atoll) to provide BOO services.
Atoll’s clients enjoy the benefit of the high recoveries of cost effective MRP plants which produce saleable coarse metal (<2% slag) at >95% recovery, saleable fines (<2% slag) at >95% recovery and ultrafines (<10% slag) at >70% recovery.
Ultrafine metal concentrates produced by Atolls MRP’s are usually not saleable. Although these concentrates are often recycled to clients existing ferroalloy furnaces, Atoll has been able to use Minteks patented DC arc furnace technology to remelt and refine such materials. Ulltrafine baghouse dusts and other ultrafine wastes from the ferroalloy industry present environmental and health threats.
Mintek’s Enviroplas DC arc furnace technology converts these ultrafines into valuable ferroalloys. Atoll is using this technology at Mogale Alloys where a 40 MVA DC furnace produces a Fe, Ni, Cr alloy from stainless steel EAF dust and chromite fines. A photograph of one of the furnaces used appears on the front cover.
Titaco merged with Bateman in 2000 and in 2006 the AIM listed Bateman Engineering NV (BENV) bought Mintek’s share in the RSA part of the Atoll group and consolidated all the Atoll companies under the BENV mantle.