The principal use for gypsum is wallboard. Crude gypsum is pulverized and heated to form stucco, which is mixed with water and aggregate (sand, vermiculite or expanded perlite) and applied over wood, metal or gypsum lath to form interior wall finishes. Gypsum board, lath and sheathing are formed by introducing a slurry of stucco, water, foam, pulp and starch between 2 unwinding rolls of absorbent paper, resulting in a continuous sandwich of wet board. Gypsum is also used as a filler in paint and paper manufacture, as a substitute for salt cake in glass manufacture and as a soil conditioner.
Approximately 75% of Canadian production comes from Nova Scotia; Ontario, Manitoba and BC also produce gypsum. Wallboard manufacturers are located in these provinces as well as in Québec, Newfoundland, New Brunswick and Alberta. Crude gypsum is a low-cost, high-bulk mineral commodity. The US is the world's leading producer of gypsum, and other important producers are China, Iran, Thailand and Spain.
The present structure of the gypsum industry in Canada is expected to remain about the same, although future availability of synthetic gypsum resulting from more strenuous environmental controls will substitute for natural gypsum in some regions. The RECYCLING of scrap and waste gypsum from construction sites and wallboard manufacturing lines will continue to become more important in both Canada and the US.
Author G.O. VAGT
Links to Other Sites
Life of a Rock Star
This site tells the story of an extraordinary group of scientists who tramped, paddled and rolled across Canada in the nineteenth century to study the geology of Canada's varied terrain.
A History of Mining and Mineral Exploration in Canada
Click on the cover image to view an online copy of a comprehensive report that traces the emergence of Canada's mineral industry. From Natural Resources Canada.