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 increased about 26% year-on-year in FY2016 as the slag volume grew due to increased crude steel production. Meanwhile, ultimate amount of disposed industrial waste remained almost flat at 468 tons since the previous year.
We continue to promote recycling and reduce the amount of ultimate disposed industrial waste through the expansion and improvement of 3R activities.
Recycling of machining oil by purification treatment
At Topy Industries, various types of machining oil are used at its manufacturing processes and reuse of the machining oil has become one of the major concerns in terms of environmental impact. At Ayase Factory, the used machining oil undergoes purification treatment and is reused. We plan to introduce this system to 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.
Electric Furnace Slag for Recycled Road-bed Material ECO Stone™ obtains “AIKURU ” certificate
The electric furnace slag for recycled roadbed materials (Product Name: ECO StoneTM) is a recycled roadbed material made by crushing, sheaving and mixing oxidized slag and reduced slag. The ECO Stone™ obtained a license on August 31, 2014 under the Aichi Prefecture Recycle Materials Evaluation System (Pet name: AIKURU), which started in 2002. The license certifies that the materials meet quality, performance and environmental safety requirements, and that it can be used for public works. Certificate Number 2)-201. ECO Stone™ meets the environmental criteria by a great margin in terms of elusion and inclusion of hazardous materials.