Exploration Orbite VSPA recently announced it had successfully extracted alumina from samples of Guinean bauxite using an in-house, patented process developed and tested over the past few years. According to the Quebec, Canada-based company, internal laboratory tests and reviews by independent engineers confirmed the potential of the process—a development Orbite claims “opens the door to an immense new market” for the company.
In a press statement issued in July, Orbite said laboratory tests at its Cap Chat facility were conducted by processing bauxite under the patented process, and the rate of alumina extraction obtained with the tested bauxite compared well with that of high-alumina clay from Orbite’s Grande-Vallée deposit under similar conditions. The quality of the extracted alumina and the application of the Orbite process on bauxite, according to the statement, prompted management to believe Orbite’s process has the potential to become a viable substitute for the traditional Bayer process, which has remained virtually unchanged since its invention in 1887 by Karl Josef Bayer.
Orbite owns exclusive mining rights on the 6,441-hectare Grande-Vallée property, the site of an aluminous clay deposit located 32 km northeast of Murdochville, and a scale facility in Cap Chat, both in the Gaspé region of Quebec. The latest NI 43-101 report issued has identified an Indicated Resource varying between 800 million and 1 billion metric tons (mt) of aluminous clay in part of the deposit.
“These positive lab tests offer the potential for Orbite’s unique alumina extraction process to become a substitute for the Bayer process currently used by the bauxite industry,” said Dr. Joel Fournier, vice president of technologies. “The latest extraction tests demonstrate the possibility of adapting Orbite’s patented alumina extraction process to the broader global bauxite market. This would give alumina producers around the world access to a more affordable and environmentally friendly alternative to the Bayer process.”
Citing various industry research sources, Orbite stated that on average, 4 to 5 mt of bauxite are required to create 2 mt of alumina, from which 1 mt of aluminum can be produced. Each metric ton of alumina produced creates approximately 1.5 mt of red mud. With more than 70 million mt of red mud residue generated annually from bauxite processing, the environmental cost of producing alumina with the Bayer process is significant.
As explained in a company white paper (available at www.orbitealuminae.com), the process begins with the clay being mechanically crushed and acid-leached at room temperature. It is then acid-leached at higher temperature, followed by distillation of the leachate and recovery of more than 90% of the acid. Iron is precipitated out of the concentrated high-pH leachate, leaving an aluminum-rich liquid, the pH of which is lowered before being refined by liquid-liquid extraction to yield metallurgical alumina; further processing yields high-purity alumina. As the process specifically adjusts pH level to selectively extract different elements in solution, it can potentially harvest other economically attractive elements present in the clay ore, including gallium and rare earth elements, and it can also selectively extract iron separately from silica, unlike the Bayer process.
The solid waste remaining after the extraction of alumina can be chemically neutralized, avoiding the caustic nature of the red mud which results from the extraction of alumina from bauxite, and Orbite has identified potentially attractive markets for this waste product.
“Many of today’s aluminum producers are looking for new ways to reduce their environmental footprint, and the world is becoming increasingly concerned with the impact of red mud resulting from the Bayer process, particularly since the deadly spill in Hungary last year,” said Richard Boudreault, CEO of Orbite.
“Considering that Orbite’s alumina generates higher purity alumina without producing the harmful and toxic red mud, we feel confident in our ability to establish relationships with major producers. This new development of extracting alumina from bauxite using the patented Orbite process may result in the possible licensing of our exclusive technology to numerous bauxite refiners worldwide,” Boudreault said.
Inmet Upsizes Grinding Mills for Cobre Panama Project
Process equipment supplier Metso Mining and Construction Technology recently announced Minera Panama S.A. has revised its original order for Metso grinding mills to be installed at the company’s Cobre Panama copper-gold-silver project. The grinding mill order, announced in 2008, now calls for two 40-ft (12.2-m) diameter SAG mills and four 26-ft (7.9-m) diameter ball mills. This change, said Metso, resulted from detailed throughput modeling conducted as part of the project’s Basic Engineering phase and will provide a reasonable design margin over the targeted nominal throughput of 150,000 dmt/d. Delivery will be completed by the end of 2013. The revised contract is valued at at €54 million ($77.4 million), according to Metso.
The Cobre Panama project, owned by Canada-based Inmet Mining Corp., is located approximately 100 km west of the Panama Canal in the Republic of Panama. Construction is slated to begin in 2012, with project start-up tentatively scheduled for the end of 2015 and shipment of first copper in 2016. Once the mine is in full operation, the concentrator will be capable of processing ore at a rate of 150,000 dmt/d over the first 10 years of operation. According to figures included in a March 2010 front end engineering and design (FEED) report, average annual metal production rate over the first 16 years is estimated at 289,000 mt of copper, 108,000 oz of gold, 1.544 million oz of silver and 3,600 mt of molybdenum. Mine life is currently targeted at 30 years.
Outotec’s Recent Plant Orders Exceed $400M
Outotec has won two sizable contracts to provide concentrator equipment to a pair of Russia’s largest metals producers, plus another to build what it says will be the world’s largest pelletizing plant in Brazil.
The company announced in mid-July that it signed a contract with ZAO Miheevsky GOK, a subsidiary of Russian Copper Co., for design and delivery of a new copper concentrator for the Miheevsky porphyry copper project located in Chelyabinsk, Russia. The €60-million-plus ($86-million) contract includes the process design and engineering package for the entire concentrator along with delivery of the main process equipment for flotation and dewatering, including 12 TankCell 300 flotation machines, Proscon automation, instrumentation, electrification, spare parts and training and site supervision services for installation and start-up. The equipment deliveries will take place during 2012 and 2013. The Miheevsky concentrator is designed to treat 18 million mt/y of copper ore and is expected to be commissioned by the end of 2013.
“Outotec has been a long-term strategic partner for Russian Copper, which is the third largest copper producer in Russia. We have designed and delivered their two concentrators at Aktogai in Kazakhstan. Our cooperation continues now with this project in Russia, where Russian Copper already operates two smaller concentrator plants, a metallurgical plant at Novgorod, and a solvent extraction and electrowinning plant at Polevskoy, all delivered by Outotec,” said Pertti Korhonen, president and CEO of Outotec.
Also in July, Outotec said it was awarded a contract for delivery of concentrator technology for the Malomyr gold mine in the Russian Far East. The €25-million ($35.9-million) contract was signed with LLC Malomyrskiu rudnik, part of the Petropavlovsk Group, Russia’s third largest gold producer, and follows another transaction between the two parties for pressure leaching process technology announced in May 2011. The most recent order includes flotation, thickening, filtration and process automation technology for the concentrator. The equipment package, part of Petropavlovsk's process technology development plans for processing sulphide ore, will be delivered during the next eight months.
Outotec also struck a €200-million ($288-million) deal with Samarco Mineração S.A. for turnkey delivery of what it claims will be the world’s largest-capacity iron-ore pelletizing plant. The new plant will be built at Samarco’s iron ore port in Ponta de Ubú, Espírito Santo, Brazil. When it becomes operational at the end of 2013, the facility will process 9.25 million mt/y of iron ore using an 816-m2 traveling grate indurating machine. Outotec’s scope covers all process technology, conceptual and detailed engineering, project management, supply, construction and start-up of the pelletizing plant.