Our operations

Once it arrives at CEZinc, either by land or sea, zinc ore goes through four main stages before it is transformed into a finished product.

1. Roasting: is the first stage in the zinc extraction process. Concentrated ore is roasted in furnaces at 1,000°C to extract the sulphur, which is converted into sulphuric acid and marketed as such. The sulphur is then removed from the roasted ore, which is crushed and sent for leaching.

2. Hydrometallurgy: The roasted ore is leached in a hot sulphuric acid solution which dissolves the zinc, cadmium, copper, cobalt and iron. The latter is then precipitated as jarosite and converted into an inert product. Copper, cadmium and other metals are removed from the solution and recovered either as pure metals or as by-products for sale. The purified solution is pumped to the electrometallurgical plant where the zinc is recovered.

3. Electrometallurgy: At the electrolysis stage, the zinc in solution becomes solid. Under the effect of a direct electric current, it is deposited on aluminium cathodes. These are then peeled off. The result is zinc sheet with a purity of 99.99%.

4. Moulding: Zinc sheets from the electro-metallurgical industry are melted, then the molten metal is poured into moulds or converted into shot and/or granules.

The refinery depends on a steady supply of concentrate. For 50 years, almost 100% of the zinc concentrate supply came from Eastern Canada. Since 2015, more than 50% of the raw material has been imported for processing in Quebec.

As in the case of aluminium, access to abundant, low-cost hydroelectric power explains the decision to build and maintain a world-class facility in Quebec, which has been in operation since the 1960s.

Zinc refining is a high value-added process that requires large amounts of energy. Energy costs account for one third of CEZinc's expenses.

CEZinc's annual electricity consumption is 1.2 TWh, equivalent to the annual consumption of 100,000 households.