An undated file photo of workers at a Cristal plant in Ashtabula, Ohio, which federal regulators have pressed Cristal to divest as a condition to its proposed sale to Stamford, Conn.-based Tronox. An undated file photo of workers at a Cristal plant in Ashtabula, Ohio, which federal regulators have pressed Cristal to divest as a condition to its proposed sale to Stamford, Conn.-based Tronox. An undated file photo of workers at a Cristal plant in Ashtabula, Ohio, which federal regulators have pressed Cristal to divest as a condition to its proposed sale to Stamford, Conn.-based Tronox. An undated file photo of workers at a Cristal plant in Ashtabula, Ohio, which federal regulators have pressed Cristal to divest as a condition to its proposed sale to Stamford, Conn.-based Tronox. STAMFORD — Chemicals and minerals maker Tronox has completed its $1.7 billion acquisition of the titanium dioxide business of Saudi Arabian firm Cristal, after settling a 16-month legal dispute with the U.S. Federal Trade Commission. The FTC had litigated since December 2017 to block the deal between the previously rival firms, arguing that it would reduce competition in the market for titanium dioxide, a...