4.1.3 Converting

At Noranda, the molten matte that still contains iron and sulphur is conveyed to a converter with silica flux to remove the iron, while the remainder of the sulphur evaporates after processing via two tall chimneys.

Diagram of the Bessemer converter. Source

Copper converter in operation, 1930. Source

Copper converter at Noranda, 1934. Source

When Noranda first went into operation, the blister copper produced was 98.5% pure. It was shipped to Nichols Copper in Laurel Hill, New Jersey, in the United States, for refining and separation of the associated precious metals (gold, silver, selenium and tellurium).

In 1929, Noranda had an electrolytic copper refinery built in East Montreal, Canadian Copper Refiners, mandated to increase the purity of the copper to over 99.9% chiefly to meet the needs of the electric power transmission industry. This rapidly expanding market led Noranda to build the nearby Canada Wire and Cable.

Completed in 1931, the East Montreal refinery allowed Noranda’s copper purification operations to be fully vertically integrated and prompted the company to add an anode furnace to the Noranda refinery which increased the copper concentration to over 99.4%.

		Anodes produced at Noranda, 1934.
	Source

The Canadian Copper Refiners’ anode refinery recovers gold, silver, selenium and tellurium, highly valuable by-products, especially gold which was even worth more than copper during the great depression of the 1930s.