Novel Method of Productivity Improvement and Waste Reduction Through Recycling of Submerged Arc Welding Slag

The traditional welding flux is costly and the flux used in Submerged Arc Welding (SAW) generates wastages known as Slag. It is generally thrown away as a waste after use. This poses the problem of storage, disposal, and environmental pollution and needs landfill space apart from exhaust of non-renewable resources. If by recycling the used flux can be reused in product yielding same quality parameter as the new flux, then the cost of the input will go down significantly. However, this requires extensive trial and error experimentation because it is often difficult to know how the slag ingredients interact after recycling to determine the operational characteristics of the recycled flux and the final performance of the welded structure. Keeping this in mind an experiment has been conducted in a manufacturing unit with small investment. As far as possible weld qualification tests were performed using recycled flux to get it to be qualified in a National Accreditation Board of Laboratories in the final products made from recycled slag. While comparing, it was indeed revealed that the product has better chemical analysis, dye penetration test, radiography, mechanical tests and metallurgical investigations than the product from new flux. Cost analysis of recycled slag per 100 kg was calculated and compared with the equivalent fresh flux available in the market according to the principle of market value method or reversal cost method. It is similar to the technique of by product revenue deducted from production cost. The cost analysis has revealed in terms of % of saving that it could be to the extent of 70.73%.