(MB) Zinc prices on the London Metal Exchange ended 2.4% higher at the close of trading on Tuesday June 5, reaching the highest level since April 24, while three-month nickel and copper also finished strongly. The US aluminium billet upcharge was unchanged at an all-time high this week, with market participants confirming ongoing difficulty in obtaining spot material. Umicore will build its first cathode production plant in Poland and anticipates supplying automotive-sector customers in Europe by 2020. The reasons behind the company’s decision were said to be proximity to European customers, access to a technically skilled work force and a low-carbon electricity supply from renewable energy.  In ferrous news, market sources have told Metal Bulletin that the European Commission might impose preliminary measures in its safeguard case into imported steel products as early as July this year.  The Mexican government will launch a dispute settlement process against the United States at the World Trade Organization in response to the US tariffs imposed on shipments of steel and aluminium from Mexico.  The European Union has closed its anti-dumping investigation into ferro-silicon imports from Egypt and the Ukraine, according to a statement on the European Commission’s website on June 5.  Japan’s Nippon Steel & Sumitomo Metal Corp has finished the purchase of Swedish special steel producer Ovako.