June/July 2010

Historical Metallurgy

The beginnings of mineral processing research in Canada (Part 5)

By F. Habashi

Academic, industrial and government research

When Université Laval was created in 1852, it comprised the four faculties of theology, medicine, law and arts. The humanities and sciences were taught under the arts faculty. At that time, engineering was not regarded as a subject suitable for a university whose primary mission was to advance the faith.

The first teacher of chemistry, mineralogy and elements of metallurgy in the Faculty of Arts was Thomas Sterry Hunt. A Yale University graduate, he was employed from 1847 to 1852 as a chemist-mineralogist at the newly founded Geological Survey of Canada in Montreal. He was hired by Laval University in 1856. In 1862, he taught chemistry at Morrin College in Quebec City, which was affiliated with McGill University in Montreal. In 1868, Hunt returned to the United States to become a professor of geology at the Massachusetts Institute of Technology. He served two terms as the president of the American Chemical Society.

The Hunt-Douglas Process

In 1862, German chemist Max Schaffner found that copper oxide was soluble in a ferrous chloride solution, an observation that drew Hunt’s attention. Hunt contacted his friend James Douglas, a theologian-turned-medical-doctor, in Quebec City. He suggested that Douglas apply Schaffner’s discovery to treat the low-grade copper oxide ore at his family’s Harvey Hill Mine in Leeds Township, south of Quebec City.

Douglas tested the process at the mine and found it to be promising. Becoming deeply interested in mining and metallurgy, he abandoned theology and medicine. By 1869, Hunt and Douglas had developed a new hydrometallurgical process to treat copper ores and filed a Canadian patent for their process.

In 1870, Arthur Lewis, an English investor visited the Harvey Hill mine works and was impressed with what he saw. At the same time, Juan Stewart Jackson applied for a patent in Chile on behalf of Douglas. Jackson was the president of the Chilean Compañia de Minas de la Invernada, a limited liability corporation founded in Valparaiso in 1870. He arranged for Hunt and Douglas to visit Chile to apply their process at the Invernada, about 48 kilometres northwest of Santiago. Accordingly, Douglas arrived in Chile aboard the S.S. Panama on February 21, 1871. Hunt could not travel with him because of his engagements.

At the Invernada Mine, the leaching agent was prepared by treating a commercially available ferrous sulphate solution (copperas) with an excess of sodium chloride (salt) and crystallizing as much of the sodium sulphate formed as possible according to:

FeSO4 + 2 NaCl → FeCl2 + Na2SO4

The leaching of copper oxide by ferrous chloride solution could be represented by:

CuO + Fe2+ + H2O → Cu2+ + Fe(OH)2

The dissolving action was due to the acid generated by the hydrolytic action of the ferrous ion:

Fe2+ + H2O → FeOH+ + H+
FeOH+ + H2O → Fe(OH)2 + H+
CuO + 2 H+ → Cu2+ + H2O

The ferrous hydroxide thus formed was known to be a gelatinous precipitate difficult to filter. The leaching action of ferrous chloride could have succeeded for copper oxide ore containing silicate gangue, but not for carbonates like limestone. Any carbonate present would compete with cupric oxide (CuO) and immediately react with the acid present, leading to the precipitation of ferrous hydroxide. Thus, the reagent was lost and the process did not function. The Hunt-Douglas process was a failure because it was not based on sound chemistry. However, it represented the first attempt to use a hydrometallurgical process to leach ores in Canada.

Pyrometallurgical research

Around the time of the development of the Hunt-Douglas hydrometallurgical process, a great deal of significant pyrometallurgical research was also being conducted. One of the more important contributors to the advancement of pyrometallurgy was Alfred Stansfield, McGill University’s first professor of metallurgy. A graduate of England’s Royal School of Mines, Stansfield assisted William Roberts-Austen at the Royal Mint where he improved the design of the recording pyrometer. He joined the staff of the Royal School of Mines in 1898 and came to Canada in 1901. Among his notable contributions to the field were his publications, The Electric Furnace: its evolution, theory and practice (1907), The Commercial Feasibility of the Electric Smelting of Iron Ores in B.C. (1919), and The Electric Furnace for Iron and Steel (1923).

Around that time, William L. Goodwin and William Nicol, who had both studied at Heidelberg in Germany, also carried out important metallurgical research at Queen`s University in Kingston.

Not just researchers, but mentors too, played a critical role in the advancement of metallurgy. One such mentor was George Guess, a distinguished extractive metallurgist who headed the Department of Metallurgy at the University of Toronto. One of his students, Telfer E. Norman, had submitted a thesis that contained some impressive thermochemical calculations that described a new concept in the smelting of copper and nickel concentrates. Guess encouraged Norman to send a copy of the thesis to the editor of the Engineering and Mining Journal. Fearing that the editor would reject his student’s submission only because he was an undergraduate student, Guess sent the paper out from his home address, without naming himself as a co-author. The paper was published in 1936 in the journal’s October-November issue under the title, “Autogenous Smelting of Copper Concentrates with Oxygen-Enriched Air.” Norman’s work thus preceded Finnish company Outokumpu’s 1947 development of flash smelting technology by more than a decade.

At the National Research Council, Lloyd M. Pidgeon, a 1929 graduate of McGill University, developed a process for producing magnesium metal using the reaction between calcined dolomite and ferrosilicon. An interested group of prominent Toronto mining men raised capital, enabling Pidgeon to establish a pilot plant. After a year and a half of encouraging results, commercial applications of the process seemed viable. This led to the formation of Dominion Magnesium, which Pidgeon joined in 1941 as a director of research. Because of the demand for magnesium during World War II, six magnesium plants were built throughout North America. Pidgeon, who also developed metallothermic technologies for the production of calcium and strontium, was appointed professor and head of the Department of Metallurgical Engineering at the University of Toronto, a post he held until his retirement in 1969.

In 1938, Gérard Letendre, another alumnus of the Royal School of Mines, established the first Department of Mining and Metallurgy at Laval University’s School of Mines in Quebec City. Some years later, André Hone founded and chaired the Department of Metallurgy at Montreal’s École Polytechnique.

Roger Potvin, who joined Laval University in 1940 to teach electrometallurgy and corrosion, had been involved in research into the recovery of elemental sulphur from pyrite by chlorination. During World War II, he served as a consultant for the military research laboratory at Val Cartier in Quebec. In 1945, Potvin was sent by the Canadian Department of Reconstruction to help the Allied occupation forces’ investigations into the state and development of metallurgical technology in Germany. He examined the production of beryllium by the electrolysis of beryllium chloride, and the production of zirconium and titanium. His reports were published in the CIM Transactions in 1946. In addition, Potvin inspected light alloy casting works in southern Germany — the Metallgesellschaft Research Laboratory, the Vereinigte Deutsche Metallwerke company and the production of thorium and uranium. His findings were published as British Intelligence Objective Sub-Committee (BIOS) reports.

Between 1946 and 1950, Potvin and his colleague, Albert Cholette, a professor of chemical engineering at Laval, proposed an electric furnace process for the treatment of the iron ores of Quebec. The proposal did not receive the blessings of Premier Maurice Duplessis, who believed it would be more profitable for Quebec to ship the ore to the United States. Duplessis was supported by Gerard Letendre, who chaired Laval University’s Department of Mining and Metallurgy at that time. This difference fuelled an intra-faculty conflict that Cholette described in his book Le fer du Nouveau-Québec et la Sage de la Siderurgie (2000).

Another noteworthy researcher was Clarence S. Samis. Born in Arcola, Saskatchewan, Samis was educated in Winnipeg and earned his doctorate from the University of London in 1937. He worked in the industry for few years before joining the University of British Columbia in 1945, where he conducted extensive pyro- and hydro-metallurgical research.

During this era, William-Henry Gauvin left his home in Paris to pursue his doctoral studies at McGill University. After earning his PhD in 1944, he worked for two years in the industry before returning to his alma mater as an associate professor of chemical engineering. He retained his industry connections, acting as consultant to the Pulp and Paper Research Institute of Canada. Eventually in 1957, he became the head of its Chemical Engineering Division.

Historical metallurgy
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