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Dalhousie Pozzolan



Dalhousie pozzolan is a rock made of volcanic ash ejected about 400 million years ago by the active volcano of Mount Sugarloaf. This rock can partly replace cement, with no processing other than grinding, and reduce the amount of clinker (calcined limestone) used in the production of Portland cement.

Purpose of the project

The objective of the project is to provide the cement industry with a very low carbon footprint cementitious material that will reduce the clinker-cement ratio and thus reduce the need for clinker, the production of which is the source of significant greenhouse gas (GHG) emissions.

When limestone is calcined in a cement plant kiln, its decomposition under the effect of heat leads to the production of carbon dioxide (CO2). Since the ground pozzolan does not need to be calcined, all emissions related to the decomposition of the limestone as well as those related to the use of fossil fuels for heat production will be avoided.


Reduction of GHG emissions from the cement industry

Dalhousie Pozzolan project has the potential to reduce the cement industry's GHG emissions up to 4 megatonnes per year, starting in 2026, without imposing without significant increases in production costs on cement plants so they remain competitive.

Gains for cement plants

On average, the production of one ton of clinker results in about 0.8 t of GHG emissions. Pozzolan could replace up to 30% of clinker, reducing the GHG emissions associated with its production by almost as much. Moreover, this substitution would have no major impact on the cost of cement production. 


Availability of pozzolan

Before 2026, it will be possible to supply this material in the form of crushed stone, which must however be crushed by the buyer.


The pozzolan deposit has been identified in Dalhousie, at the northern tip of New Brunswick, on the shores of Chaleur Bay and at the mouth of the Restigouche River (Canada).

​Dalhousie Pozzolan project benefits from the presence of existing major infrastructure, including a port opening onto the Atlantic Ocean that can accommodate 30,000-ton ships year-round, a railway, a former industrial site, and finally the quarry itself which has been in operation for several decades to meet certain needs for regional aggregate.


Progress of the project

Analyses of the chemical composition of several stone samples taken from the site have been carried out to date, as well as tests on concrete incorporating this pozzolan. These tests have shown that the presence of the oxides that qualify the rock as natural pozzolan was consistently higher than the required standard, and that the 7 and 28 day strength of the concrete incorporating this pozzolan also exceeded the acceptance standards.
Further testing is currently underway by both the Dalhousie Pozzolan Project proponents and cement producers interested in this clinker substitute. 

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