The federal Bureau of Mines conducted static tests at 2,500 deg. F on 39 refractory compositions, and dynamic tests at 2,825 deg +- 35 deg f on 31 commercial refractory brick specimens to determine their resistance to corrosion and erosion by a slag similar in composition to that used in producing insulating mineral wool. The static tests showed fireclay, low-alumina compositions (<70 percent al2o3), zircon, zirconia, sic, and clay-bonded graphite refractories to be unsuitable. Dynamic test results indicated that magnesia and chromia compositions were superior to high-alumina compositions (<- 70 percent al2o3) as a furnace lining for melting mineral wool. Data from these tests indicated that magnesia and chromia compositions with low ro/r2o3 mole ratios were more resistant to attack by mineral wool slags than ones with high ro/r2o3 mole ratios. Work done in cooperation with the University of Alabama.