GENERAL REFRACTORIES <GRX> TO SELL OPERATIONS General Refractories Co said it agreed to sell its European refractories and building products operations for about 62 mln dlrs to an Austrian investor group. The European operations had sales of 186 mln dlrs in 1985, the last year for which results have been released, the company said. The sale, to a group headed by Girozentrale Bank of Austria, is subject to shareholder approval by April 24, 1987, it said. Its board has approved the deal, it said. General Refractories' mineral operations are not affected.