Cabot has signed a contract to obtain lignite-based activated carbon from ADA Carbon Solutions. As part of the agreement, Cabot is selling its lignite mine in Marshall, Texas, to ADA , which will shut it down. Cabot will also idle activated-carbon kilns at the site. Lignite-based activated carbon is used to remove mercury from coal-fired power plant emissions. Cabot built up the business anticipating high demand for these products, but the full market didn’t materialize.