EE WAS PART OF CREW REPAIRING SPIDER AREA OF COOLER ON AGGLOMERATOR LINE 4. EE WAS USING 4 1/2"" HAND GRINDER TO REMOVE RUST ON STEEL STRUCTURAL MEMBER PRIOR TO WELDING. LARGE AMNOUNT OF DEBRIS WAS AIRBORNE AND LANDED IN HIS FACE. HE TREATED 6 HOURS LATER AFTER CONTINUED IRRITATION FOLLOWING FLUSHING WITH EYEWASH.