Article from minnigmagazine Very nice article about Orbite
https://www.miningmagazine.com/reports/refining-alumina-extraction
Mining Magazine > Reports > Refining alumina extraction
Refining alumina extraction
Reports
Publishing Date29 Mar 2012 11:31am GMTIssue/SupplementMM Apr 2012Author Mining Magazine
Processing
Orbite Aluminae owns the mining rights to the Grande-Vallée property, a 6,441ha site with a homogenous aluminous clay deposit in the Gaspé area of Québec, Canada. In one sector of it, Orbite has identified an indicated resource (in compliance with Canadian National Instrument 43-101) of one billion tonnes of aluminous clay, containing Al2O3, SIO2, Fe2O3 and MgO.
To develop the resource, Orbite has patented a unique, low-cost technology, which enables the extraction of alumina and other valuable and marketable by-products from a variety of sources, including aluminous clay, bauxite, kaolin, nepheline and other aluminium-containing ores.
The continuous process does not generate the infamous and caustic ‘red mud’ associated with the long-established Bayer process for extracting alumina from bauxite. This red mud typically requires long-term storage in holding ponds to protect the environment and human life.
By contrast, Orbite’s process conforms with the highest standards of sustainability; separating the individual components of the clay sequentially and recycling the acid used to leach out the metals. The firm has also assembled a consultative committee in the Gaspé region to inform local communities on the project’s ongoing status, and to gain their input on the region’s key challenges and needs.
The process
The main challenge in extracting alumina from aluminous clay is to eliminate iron and other impurities in an economically viable and eco-friendly manner. The uniqueness of Orbite’s alumina-refining process resides in its proprietary sequence of steps in combination with leaching temperature, concentration of hydrochloric acid, acid-to-clay ratio and quantity of reagents.
Unlike the Bayer process, Orbite’s technology enables the processing of low-quality bauxite, nepheline and other high-silica ores. In addition, the capital and operational costs are expected to be lower than for the Bayer process, while avoiding the iron-rich, high-pH toxic red mud waste that is such a serious liability. The expense of rehabilitation for these muds is typically not accounted for in the Bayer process’s operational costs.
Annual production from the first of a series of smelter grade alumina (SGA) plants (planned for full commissioning in early 2014) is estimated at 540,000t of alumina, 189,000t of pure hematite and 1.2Mt of high-purity silica.
Using Orbite’s proprietary process – which incorporates an efficient and eco-friendly hydrochloric acid, closed-loop system – the proposed plant’s annual production will also yield other value-added by-products.
Intellectual property
Orbite has protected its proprietary process for extracting alumina, and also filed a provisional US patent application for the use and extension of its processing technology to extract other by-products.
The company’s intellectual property portfolio includes three delivered patents, and 17 more filed in ten countries. These address process enhancements to improve productivity through higher yields and lower production costs, the extraction of two rare-earth elements and the production of hematite.
History to present
Throughout the 20th century, as demand for aluminium soared during wartime and economic prosperity, and high-quality bauxite reserves became depleted, researchers sought alternative sources and methods of extracting alumina.
Aluminous clays were long targeted because of their high prevalence in North America and other parts of the world. While several sintering and acid-extraction methods have been investigated over time, an economical, industrial-scale process has never been fully realised.
This set the stage for Orbite’s research into a novel extraction process, which took place from 2005-07, in partnership with the Centre d’études des procédés chimiques du Québec (CEPROCQ).
This work led to the design of the first pilot plant for extracting alumina from aluminous clay, which was built with the support of private and government organisations. The pilot plant successfully proved the technology at the laboratory level by extracting over 95% of the alumina from the clay and recycling the acid solution. In addition, the pilot plant produced small quantities of 99.8% pure alumina, leading to the first patent application in 2007.
From 2008 through 2010, Orbite conducted geological exploration campaigns covering less than 5% of its land claims. The 2010 campaign, supported by results from the pilot plant’s operations, led to a 43-101 compliant indicated resource of one billion tonnes of aluminous clay, at an average grade of 23.37% alumina. This indicated resource could potentially supply all the alumina requirements of Quebec’s nine aluminium smelters for many years.
In February 2011, Orbite successfully commissioned its industrial-scale pilot plant, and has since produced high-quality SGA and high-purity alumina (HPA). The 2,600m2 full-scale pilot plant will be re-equipped in the first half of this year, to initially produce HPA at a rate of 1t/d, eventually ramping up to 5t/d. This plant should enable Orbite to generate positive cash flow rapidly, as its production costs will be among the industry’s lowest.
Orbite will thus be in an ideal position to capture a portion of the growing demand for HPA in coming years, primarily driven by the increasing global penetration of LED lighting.
The pilot plant’s operation has produced a range of ancillary benefits beyond just product. Chiefly, it has enabled the optimisation of Orbite’s patented process, along with equipment design and layout, and the end characteristics of the value-added products that can be manufactured by the projected full-scale SGA plant.
A preliminary economic assessment (PEA) by GENIVAR, an independent engineering consultancy, estimates that Orbite’s production cost for SGA will occupy the lowest industry quartile. Once production costs are spread across all products generated by the plant, the alumina production cost actually becomes the industry’s lowest – about half the current lowest total cash manufacturing costs calculated by CRU International.
A bankable feasibility study for the first SGA plant should be complete by mid-2012 and, pending permitting requirements, commissioning is planned for late 2013. In the meantime, the firm is pursuing licensing opportunities for its technology with global players in the aluminium industry.
Markets
CRU International forecasts that the SGA market to increase from about 80Mt in 2010 to 120Mt by 2016, growing at a compounded annual growth rate (CAGR) of 6.6%. It also forecasts higher demand for alumina production capacity of about 4.6Mt/y, which will continue until 2035, in order to maintain market balance.
Quebec is the third-largest aluminium producer after China and Russia, with nine smelters producing about 3Mt/y. When the capacity of other smelters accessible via the St Lawrence seaway are added (chiefly in northeastern US and Iceland), the total demand for SGA from Orbite’s targeted customers reaches 8Mt/y; growing at a CAGR of 6.5% until the end of the decade.
Shipping costs to Quebec for alumina and bauxite are significant, and are expected to increase as fuel costs rise. Importing these materials by ship also emits large quantities of CO2 equivalent greenhouse gases into the atmosphere.
The vast majority of the alumina requirements for Quebec, northeastern US and Iceland are currently filled by imports from sub-tropical countries. This incurs significant direct costs (freight and logistics), and indirect costs in the form of carbon credits and greenhouse gas emissions.
In addition, Quebec’s aluminium producers have encountered impurity issues with overseas alumina extracted from bauxite. Beryllium, which is found in imported alumina made from bauxite, is a particular health concern for the industry.
According to the International Committee for the Study of Bauxite, Alumina and Aluminium (ICSOBA): “Alumina refineries [the] world over presently generate more than 100Mt/y of red mud, which is likely to increase with the setting up of new production facilities and decreasing ore quality. Less than 5% of red mud is being utilised in the world, with the remainder disposed in ponds.”
Red mud is toxic and highly caustic, with potential for serious water and land pollution. Red mud has been cited as, by far, the most serious environmental problem associated with the aluminium industry. The environmental and social costs associated with bauxite mining and with the Bayer process are generating opposition to the development of new alumina capacity in several key countries.
HPA (purity greater than 99.9%) is used for a variety of applications, including the manufacture of artificial sapphires and rubies for fibre-optic communications, integrated circuit substrates, ultra-pure nanomaterials, and especially for the fast-growing domestic and industrial LED market.
According to various sources, the LED penetration rate is expected to grow from about 1% to about 50% by 2020. This trend will create an estimated gap in demand of about 6,000t/y of HPA by 2015.
Conclusion
Orbite’s technology has the potential to become a new reference standard in alumina refining. Not only does it solve the serious environmental issues associated with the current process, but it also turns out to be among the most cost-competitive.
Orbite estimates that it is the lowest cost process when all marketable by-products extracted by the technology are factored into the capital investment and ongoing operating expenses. As aluminium demand is widely forecast to double from 2010-20, additional alumina will consequently be required.
Orbite’s technology represents one of the most eco-friendly and economical options for meeting the future demand in alumina, and for reducing the expense for aluminium producers.