Method of manufacturing durable lance pipes for oxygen smelting

Claim 1

A DURABLE LANCE FOR OXYGEN SMELTING OF STEEL CONSISTING OF A CALORIZED MILD STEEL PIPE HAVING AN AIR DRIED OUTER COATING HAVING A THICKNESS OF FROM 0.3 TO 2MM. AND AN AIR DRIED INNER COATING HAVING A THICKNESS OF ABOUT 0.4 MM., SAID OUTER COATING CONSISTING OF A MIXTURE OF FROM 30 TO 70 PARTS BY WEIGHT OF A MATERIAL OF THE GROUP CONSISTING OF SILICATES, MULLITE, SPINEL, FORSTERITE, KAOLIN AND AGALMTOLITE HAVING A GRAIN SIZE OF ABOUT 200 MESH, 70 TO 30 PARTS BY WEIGHT OF WQUARTZ HAVING A GRAIN SIZE OF ABOUT 100 MESH AND A SUITABLE AMOUNT OF A BONDING MATERIAL OF THE GROUP CONSISTING OF SODIUM SILICATE AND POTASSIUM SILICATE AND SAID INNER COATING CONSISTING OF A MIXTURE OF 30 TO 70 PARTS BY WEIGHT OF A POWDER OF ABOUT 100 MESH AND 70 TO 30 PARTS BY WEIGHT OF A POWDER OF ABOUT 200 MESH OIF A MATERIAL OF THE GROUP CONSISTING OF METAL OXIDES, CARBIDES, SILILCIDES, BORIDES AND NITRIDES HAVING A PURITY OF AT LEAST 95%, 1 TO 10 PARTS BY WEIGHT OF A SILICATE SERVING AS A MILL ADDILTION, 10 TO 30 PARTS BY WEIGHT OF A BONDING MATERIAL OF THE GROUP CONSISTING OF SODIUM SILICATE AND POTASSIUM SILICATE AND FROM 1 TO 10 PARTS BY WEIGHT OF A MATERAIL OF THE GROUP CONSISTING OF GRAPHITE, SILILCON CARBIDE AND METAL POWDERS.