Sydney Cement Company
Nova Scotia’s first cement plant was founded in Sydney in 1905. It was also Canada’s first manufacturer of slag cement, meaning it used slag from the Sydney steel mill as an ingredient.
The Sydney Cement Company produced its own brand of cement, called Rampart, that it sold in eastern Canada and as far away as Mexico and the West Indies.
The company was located at the junction of the Intercolonial and Sydney & Louisburg Railways, giving it excellent infrastructure both for bringing materials and equipment to its plant, and for shipping finished product out.
The company used marble, a type of limestone, from the Marble Mountain quarry as its source of lime, an important ingredient in cement (https://notyourgrandfathersmining.ca/marble-mountain).
The company had an agreement to buy slag from the Dominion Iron and Steel Company for 90 years at a rate of 50 cents per ton dry weight, delivered at the cement works. Slag is impurities that are removed during the steelmaking process. It occurs as a molten liquid melt and is a complex solution of silicates and oxides that solidifies as it cools.
The 1906 Nova Scotia Department of Mines annual report described the process by which the slag was used by the Sydney Cement Company: “The slag as it flows from the furnace ladles, has a stream of water directed upon it, which granulates it as it drops into a rail-car beneath. It is then taken to the cement works, where it passes through two cylindrical revolving dryers, each about 30 feet long. From there it is conveyed to a hopper, and as it issues therefrom is mixed with about 3 to 5 per cent of freshly slacked [slaked] lime… The united supply of slag and lime passes into a cylindrical, revolving mixing (and grinding) mill, about 20 x 5 feet, lined with flint blocks and filled with loose flint pebbles. At the end of this mill a certain amount of refuse is separated and discarded. The material is now elevated and parted into two lots, each of which goes through a feed regulator into a final grinding mill, of the same size and construction as the mixing mill, where the material is ground to a great degree of fineness by the flints. From these two grinding mills the finished cement is elevated and goes by automatic conveyors to large storage bins, and, as required, it passes by a conveyor and elevator to small hoppers from which it is packed in barrels or stout paper bags ready for the market, where it is sold under the name of ‘Rampart Brand Cement.’"
The Sydney Cement Company’s plant could produce about 500 barrels of cement in 24 hours, at a cost of about 90 cents per barrel.
The 1906 annual report estimated that the cement market in the Maritimes and Newfoundland was about 375,000 barrels per year. The use of cement in construction was increasing in that period and there was no other cement factory east of Ottawa.
The company’s cement was used in 1906 in laying foundations for streets in Halifax, sidewalks in Bridgetown and North Sydney, and samples of it were used in a new sewer on Park Street in Halifax. It was also used to build Halifax’s Maritime Business College building and in the foundations of various buildings.
The company demonstrated the product at the 1906 Nova Scotia Exhibition by erecting “an attractive building (walls and cornice, with doorway and window,) constructed of hollow concrete building blocks, of various dressed-stone patterns, made from the company’s Rampart brand cement…”
In 1908, the company employed 60 men and manufactured 58,762 barrels of slag cement.
Negotiating the deal for slag with the Dominion Iron and Steel Company was likely made easier by the fact that the Sydney Cement Company’s president was Alexander Charles Ross (1847-1921), one of the men credited with consolidating many of Cape Breton coal mines under the Dominion Coal Company. This later led to the establishment of the Dominion Iron and Steel Company and the Sydney steel mill (https://notyourgrandfathersmining.ca/henry-whitney).
Ross had a number of business interests but made much of his fortune in real estate and was, at one time, the largest property owner in Sydney. He was also a director of several mining companies and served as a Member of Parliament, representing North Cape Breton and Victoria in the House of Commons from 1906 to 1908.
The terms cement and concrete are often used interchangeably, but cement is actually an ingredient of concrete. Concrete, which is the most widely used manufactured material on the planet, is a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and portland cement. (Gravel and crushed stone are both small rocks. The difference is that gravel is broken down naturally, while crushed stone is broken down by a machine, i.e. a rock crusher.)
Cement comprises 10-15% of the concrete mix and is the key ingredient – the glue that holds concrete together. The cement and water harden and bind the aggregates into a rock-like mass. This hardening process continues for years meaning that concrete actually gets stronger as it gets older.
Cement is usually manufactured by heating a precise mixture of finely ground limestone, clay and sand in a rotating kiln to temperatures reaching 1450ºC. This results in the production of cement clinker, an intermediate product in the manufacture of cement. The cement clinker emerges from the kiln, is cooled, and then finely ground to produce the powder we know as cement.
Cement has been manufactured in Brookfield, Colchester County, since 1965. A quarry onsite provides the necessary limestone.
