Resource World Magazine

MINI NG Orbite Aluminae defies history with new alumina technology by David Forest H uge ore deposits just won't be denied. The latest example comes from Québec's Gaspé Peninsula, where Orbite Aluminae Inc. [ORT-TSX] is just months away from production of one of the world's largest alumina deposits. Despite the fact that short years ago, no technology existed capable of processing this spectacular aluminum endowment. Just as geology drove process technology development in places like Nevada's Carlin Trend – where Newmont spent millions to develop roasters and proprietary bio-oxidation techniques to unlock huge resources of refractory gold – the development of Orbite's Grande-Vallée aluminous clay deposit required the company to start in the lab rather than the field. Although Grande-Vallée has long been known to host massive alumina resources (over a billion tonnes, as it turns out), the geol- Construction of Orbite Aluminae's high purity alumina plant at Cap-Chat, ogy is unconventional. Most alumina, globally, is produced from Québec is nearly complete, with first production expected in Q1 2013. Photo courtesy Orbite Aluminae Inc. bauxite, a rock created by intense weathering that leaves behind a surface crust of highly immobile aluminum along with traces of iron, titanium and silica. Orbite's Grande-Vallée deposit, however, top-level scientists to chart a new course for the aluminum indusis hosted in clay called kaolinite – the stuff bauxite looked like try. The mission: find a way to slough off troublesome impurities in clay ore. Acid seemed like a possible answer. But the new probefore weathering set in. Grande-Vallée's clay mineralogy presents a century-old chal- cess had to avoid the pitfall of ending up with unusable alumina lenge. In 1887, Austrian chemist Karl Bayer noticed something slop as a final product. The quest for answers started in a university laboratory, at strange about alumina. When treated with acid, alumina turned to a hard-to-handle jelly. But when an alkaline solution was used, nearby Laval. In 2004; researchers there began stitching together it resulted in neat, crystal alumina. The "Bayer process" became process technologies in innovative arrangements. This chemical the world standard in alumina production, one which still domi- Frankenstein was jolted to life in 2006 and 2007 by the Centre d'études des procédés chimiques du Québec (CEPROCQ), which nates today. But despite its prominence, the Bayer process has its drawbacks. Orbite contracted for final design of a pilot-scale testing scheme. Blueprints turned to brownfields in 2009 when Orbite began For one, it's messy. Aluminum dissolves, but other elements like iron and titanium remain solid, having to be filtered out of the constructing a large-scale pilot plant. It was partly paid for by circuit, forming a toxic by-product known simply as "red mud". aluminum; Aluminerie Alouette, operator of North America's Even in bauxite deposits where weathering has scoured impuri- largest aluminum smelter in Sept Isles, Québec, was intrigued ties like silica, Bayer processing still produces up to two pounds enough by the project to kick in $1 million in the form of a promissory note, repayable in alumina. of red mud for every pound of saleable alumina. The bet paid off. In 2011, the pilot plant successfully produced Treating Grande-Vallée's less-weathered clays by Bayer's process would dump out an untenable waste pile. At a time when a tonne of alumina processing material taken from Grande-Vallée, toxic, red mud has become a hot-button issue, following a 2010 previously thought untreatable. The secret turned out to be deft accident at a Hungarian aluminum plant, where a million cubic manipulation of acidity. By starting with an acid solution, the metres of the waste was released. Add to this environmental chal- process dissolved iron and titanium, getting rid of the toxic solids lenge the fact that high volumes of silica in clay would gum up that create red mud. Later, these metals could be isolated and prea traditional Bayer circuit, and it was clear a new approach was cipitated as potentially valuable by-products. This pinpoint control over pH levels also solved Bayer's probneeded to unlock Grande-Vallée's expansive alumina riches. Undeterred by prevailing process trends, and spurred on by lem of ending up with alumina Jell-O, the challenge that had the substantial metal resource at Grande-Vallée, Orbite enlisted stumped chemists for over a century. By rapidly moving from low 50 www.resourceworld.com DECEMBER 2012/JANUARY 2013

• Cover