In a merger of two large Canadian inorganic chemical firms, Chemtrade Logistics has agreed to purchase Canexus for $680 million. Chemtrade had sales of more than $1 billion in 2015. It is one of North America’s largest producers of sulfuric acid and also makes sodium nitrate, sodium chlorate, and potassium chloride. Canexus, which had sales last year of about $425 million, is a major producer of sodium chlorate and also makes chlorine and caustic soda. In 2015, Canexus agreed to be purchased by another Canadian firm, Superior Plus, but U.S. antitrust authorities blocked the deal.