The Catalyst Paper Mill in Rumford in 2017. Staff photo by Shawn Patrick Ouellette RUMFORD — Catalyst Paper announced Friday that it plans to sell the Rumford paper mill and one other mill in Wisconsin to a subsidiary of Nine Dragons Paper for $175 million. Nine Dragons, which is traded on the Hong Kong Stock Exchange and has production facilities in China, described itself in a press release as “the largest containerboard producer in China and Asia and a leading paper product manufacturer globally.” Catalyst has owned the Rumford mill for three years and employs approximately 620 people there.