Guysborough’s Alumina

In the 1950s, the Canadian Alumina Corporation had big plans to open a mine and processing facility in Guysborough County. However, despite years of trying, it struggled with a common challenge in mining: metallurgy, or how to separate a mineral from its ore.

While the company was ultimately unsuccessful, its exploration work illustrates that Nova Scotia has the potential to produce alumina, which is used to make aluminum, a critical mineral used in things like renewable energy and electric vehicles.

The Canadian Alumina Corporation (CAC) was incorporated in 1954 in Halifax. It bought the Canso Mining Corporation, which gave it a large number of exploration projects and mineral claims throughout Nova Scotia, including the historical gold districts of Forest Hill ( and Goldboro. The Smithfield lead property in Guysborough County ( was another Canso Mining Corporation project taken over by the CAC.

The president of the Canso Mining Corporation, Archibald J. Mason, became president of the CAC. Mason was born in Birmingham, England, in 1889 and immigrated to Hamilton, Ontario, with his family in 1903, according to the Springhill Heritage Group.

He became a singer and projectionist in the early days of movies. He was sent to Halifax at the age of 18 to install projection machinery and went on to operate theatres in Saint John, New Brunswick, St. John’s, Newfoundland, and in Wolfville, Parrsboro and Springhill, Nova Scotia. For 30 years he was president of the Maritime Motion Picture Exhibitors Protection Association.

Mason had a brief career in musical theatre, appearing on Broadway for one month in a play called “Buddies” and touring part of the United States, after which he returned to Nova Scotia. He later served as a municipal councillor and mayor in Springhill and as a member of Nova Scotia’s legislature from 1949-53.

While the Canadian Alumina Corporation had exploration plans for a number of its claims, its main focus was its proposed alumina mine in Dort’s Cove, Guysborough County.

The CAC drilled a total of nine diamond drillholes between Delaney and Hyde brooks. Tests suggested the area contained a 32,000,000-ton block of alumina-bearing shale with an average content of 25% alumina.

The CAC’s 1958 annual report said, “The ore would be extracted from the open pit mine, which will have a possible length of four thousand feet by seven hundred feet wide. Working this area to a depth of 105 feet should give an ore supply of at least twenty-five years, at the initial three thousand tons a day output level.”

However, the annual report also said the company’s “pons asinorum” (main obstacle) was coming up with an economically-viable process to separate the alumina from the shale. (As an aside, pons asinorum is Latin for "Bridge of Asses." It literally refers to the apparent reluctance of donkeys to cross bridges but means a problem that severely tests the ability of an inexperienced person.)

According to the report, “Men of science in Europe and North America have spent many years seeking a way to produce pure alumina from minerals other than bauxite and your company engineers have, at various times, investigated and closely studied all the information available on the subject and all the processes evolved to date. The end result of this research has been the creation of a new process - one described and illustrated in this report- and one which in the opinion of all who have studied it may provide the long sought answer to the problem of extracting alumina from shaley clay on an economic basis.”

The company was referring to the fact that almost all alumina is extracted from bauxite, a type of rock. Aluminum does not occur in its pure form in nature because it reacts with air and water to form other chemical compounds. Alumina, which is aluminum oxide or rusted aluminum, is extracted from bauxite and processed to make the aluminum that is in countless products we all use every day, including the electronic device you are reading this on.

It takes approximately 4 to 5 tonnes of bauxite ore to produce 2 tonnes of alumina. In turn, it takes approximately 2 tonnes of alumina to produce 1 tonne of aluminum.

While alumina is in other types of rock and clay, including at a number of sites in Nova Scotia, extracting from bauxite is still the most cost-effective way to produce alumina. The CAC’s challenge was to come up with a metallurgical process that would keep its costs competitive with alumina produced from bauxite.

The annual report claimed the company had accomplished this but the celebration was premature. A series of memos in Nova Scotia Department of Mines files show that the company struggled for several years to prove its theoretical solution would work in practice. Various consultant and engineering reports expressed skepticism.

The CAC eventually built a pilot-scale plant at the laboratories of the Department of Mines and Technical Surveys in Ottawa “to test the process and to perfect the equipment necessary for its operation.”

The CAC’s annual report identified the key challenge: “…as sulphuric acid used for the digestion of the ore is required in large quantities - 1 ton of acid per 1 ton of ore - it is essential that fullest possible acid recovery be made. In this regard the new extraction process should be eminently successful, and it is this feature of a high sulphuric acid recovery percentage that makes the Canadian Alumina process economically feasible.”

Unfortunately, CAC’s system did not recapture enough of the expensive sulphuric acid to make the project viable. While CAC was able to separate the alumina from the shale ore, the process could not compete with lower-cost bauxite production. A 1961 consulting engineer’s report put it this way: “The immediate prospects for the development of a process to recover alumina or other materials from the Nova Scotia shale owned by Canadian Alumina Corporation are poor. Technically, the recovery of alumina and cement from the shale is quite feasible, however the processes known at present do not appear to be economic.”

Metallurgical challenges are common in mining. Each mineral deposit is unique, and some minerals are more challenging to separate from ore than others, so it is necessary devise a milling process at each mine that is environmentally-responsible, effective at separation and keeps production costs low. Sites that were not economically-viable in the past due to metallurgical challenges often become viable with scientific advancements, so Nova Scotia may one day produce alumina.

Today, aluminum plays a crucial role in clean energy and is used in things like solar cells, wind turbines and electric vehicles. Along with copper, it is also used in electricity grids and other wires and cables. The International Energy Agency estimates that 150 million tonnes of copper and 210 million tonnes of aluminum are used in the electricity grids operating today. The IEA projects that electricity grid upgrades, necessary to accommodate renewable energy and electric vehicles, will cause copper demand to grow from 5 million tonnes in 2020 to as much as 10 million tonnes in 2040, and aluminum demand to grow from 9 million tonnes in 2020 to as much as 16 million tonnes in 2040.

See the story of the historical Cheticamp lead mine for another example of a mine that had metallurgical challenges: