廃棄物は有害� �無害か？ [PDF].pdf

In the past, casting engineering released many environmentally unfriendly substances, so environmentally friendly processes have been implemented, known as the 3Rs: Reduce, Reuse, and Recycle. Examples of recycling include using casting dust as cement raw materials and aluminum slag as flux for steel production. However, recent environmental regulations for cement raw materials have become stricter, requiring lower levels of impurities such as Cr, Cl, and alkali metals. The casting process generates various wastes, including dust, sand, and slag, which can be recycled as cement raw materials, road materials, or refractory materials. Challenges in recent years include the need for high-quality raw materials, reduction of low-grade materials, and recycling of iron and aluminum. Iron casting uses many scrap materials and is considered a model for recycling, while aluminum recycling has also made significant progress, with most materials being recycled and only a small amount being landfilled.