Waste reduction and recycling
A part of the metal scrap (steel) generated during production activities is reused directly in-house as a raw material in electric furnaces. As for other waste, we are engaged in reducing ultimate disposal amount of waste through re-resourcing (e.g. collection of scrap iron, collection of zinc out of melting dust). Oxidized slag generated from steelmaking is recycled at a rate as high as 90% or more and is reused for civil construction material and concrete material.
The amount of discharged industrial waste remained almost flat since FY2010 but decrease 5.5% year-on-year in FY2014. Meanwhile, the ultimate amount of disposed industrial waste marked 422 tons, an increase of 14.7% from the previous term in spite of our efforts on 3Rs (Reduce, Reuse, Recycle). This attributes to the decrease in the reuse of refractory materials at the old steelmaking plant in connection with transformation to the new steelmaking plant.
We will continue to promote recycling and reduce the ultimate disposal amount through the expansion and improvement of 3R activities.
Recycling of cutting oil by clarification treatment
Various cutting oils are being used in the production processes of our operations, and these also constitute one of our major environmental issues. At Ayase Factory, we apply clarification treatment to the used cutting oil and bring it back for reuse. We will eventually implement this at all other factories.
Obtained revised JIS Certification for Oxidized Slag
Toyohashi Factory has established a system in which oxidized slag generated within the electric furnace during the refining process and reduced slag discharged from the ladle after continuous casting subsequent to the refinery process are completely separated, treated, processed and recycled by installation of a slag cooling facility and crushing facility. In April 2013, the factory obtained JIS A 5011-4: A slag aggregate for concrete category No.4 : electric furnace slag aggregate. In addition, the factory acquired in December 2013, another certificate for Revised JIS A 5011-4 and started to produce and sell electric furnace oxidized slag aggregate for concrete.
Oxidized slag aggregate is heavier in specific gravity than natural materials such as sand and gravel that have been used as concrete aggregate materials and so we expect slag to be used for heavy concrete aggregate such as wave dissipation blocks. The sales expansion of oxidized slag aggregate for concrete has a favorable effect as it reduces the extraction of natural aggregate materials and thus its impact to natural environments and also curbs energy consumption. We will exert our continued efforts to reduce environmental load through review of our business activities.