The two Equinox-class ships will join the company's Great Lakes - St Lawrence Waterway dry-bulk fleet upon its scheduled delivery in the first half of 2018.
The Seaway Max size ships will have the capacity to carry 29,300t at maximum Seaway draft. The ships will feature all of the Equinox-class specificities, including the exhaust gas scrubber technology.
Five Equinox-class vessels are already under construction as part of Algoma's plans to invest around $450m for its fleet renewal programme.
The fleet renewal programme is aimed at the retirement of certain older vessels.
Algoma president and CEO Ken Bloch Soerensen said: "Our search for a shipyard in China to replace the now-bankrupt Nantong Mingde Heavy Industries ("Mingde") led us to Yangzijiang. We have been pleased with the professionalism and enthusiasm the yard has shown for our project and the quality that they have shown on work done for other ship owners."
The ships are equipped with a modern tier-two compliant engine for optimised fuel efficiency.
The company has added three Equinox-class bulk carriers and two coastal class self-unloaders to the domestic dry-bulk fleet during the last six years.
When the seven new vessels enter the service, the average life of the company's dry-bulk fleet will be reduced by 13 years, from the current 31 of the current fleet, stated the company.