ー ENVIRONMENT －
For Reduction of Environmental Impact
Contributing to environmental conservation is a basis of our business management. Through initiatives to promote efficient use of resources and material recycling, we are committed to the reduction of environmental impact and the recycling of resources.
The Kyoei Steel Group strives to be a company that coexists with society and contributes to the global environment through its resource-recycling business, together with the steel business that uses steel scrap as raw materials and the material recycling business that melts waste safely.
As a member of a resource recycling-based industry, we promote saving of energy and resources and expansion of recycling, work to reduce environmental impact, and contribute to the formation of environmentally sound society for local communities.
While observing environmental laws and regulations, we pay attention to the local environment, and endeavor to improve the environment and prevent pollution through continuous environmental management activities.
As a member of local communities, through interactions with local governments and residents, we promote environmental activities in harmony with the local environment.
Environmental Data (domestic consolidated subsidiaries total)
■CO2 emissions intensity（t-CO2/t）
■Energy consumption (oil equivalent) (kl/1,000 tons)
■Production volume (1,000 tons)
Initiatives for reduction of environmental impact
Introducing regenerative burners to achieve both energy saving and low-NOx combustion
When a reheating furnace for steel is used, the internal temperature of the furnace reaches as high as 1,200°C.
To maintain this temperature, it is necessary to continuously feed fresh air and fuel into the furnace and keep the furnace burning.
Therefore, improving the efficiency of energy use has become a major challenge in reducing environmental impact.
To address this challenge, we have gradually introduced regenerative burners, which are energy-saving burners.
A regenerative burner system is composed of two burners, each of which is integrated with a heat accumulator. When one burner is firing, exhaust gas passes through the accumulator of the other burner to heat the accumulator, thus recovering energy from the exhaust gas.
When the other burner burns, combustion air is preheated by allowing it to pass through the heat accumulator that was previously heated. In this way, the energy of exhaust gas, which is conventionally discarded, can be recovered, achieving high combustion efficiency.
This heat storage effect improves heat exchange efficiency, resulting in energy saving.
Also, to perform low NOx (nitrogen oxide) combustion, fuel and air are directly sprayed into the high temperature furnace from separate nozzles, which significantly slows down the combustion speed and substantially reduces NOx generation.
■ Structure of regenerative burners
Introducing “direct rolling” to improve the efficiency and energy saving of production lines
We continually pursue energy and resource saving in production processes while ensuring a high level of product quality.
As an initiative to this end, we introduced an innovative production process called “direct rolling,” which directly connects the casting process and the rolling process.
Conventionally, steel scrap is melted in an electric arc furnace and then cooled and solidified by being passed through a continuous casting machine to form semi-finished products called “billets.”
After that, the cooled billets are reheated to a predetermined temperature in a reheating furnace, to be processed into the intended form and size. This is the conventional process.
In recent years, the hot charge rolling process, whereby the billets are charged into a reheating furnace at a higher temperature and rolled, has been widely employed.
At Kyoei Steel, in order to work on further energy saving in the rolling process, we have introduced direct rolling technology, which enables direct rolling after casting.
As a result, reheating has become unnecessary and the amount of fuel use has been substantially reduced.
Also with lower CO2 emissions, we have achieved a production process that is environmentally friendly and has little environmental impact.
■ Schematic diagram of processes (conventional → direct rolling)
Initiatives for resource recycling
Effective use of heat from electric arc furnaces
When an electric arc furnace is working, arc heat of a temperature of 3,000 to 7,000°C is generated.
While the average temperature of a general waste incinerator is 800ºC, using this "ultra-high temperature" makes it possible to safely and reliably melt and completely detoxify waste.
Based on the desire to make better use of the characteristics of electric arc furnaces in promoting initiatives for recycling, energy saving and environmental conservation, we have been a pioneer in the material recycling business for over 30 years.
We utilize electric arc furnace operation technology to detoxify waste and at the same time recycle steel resources as part of steel products.
We believe that promoting resource recycling, which is a system to properly process ever-increasing waste and produce products, is an important mission that we must fulfill as a corporate citizen.
Offering comprehensive waste disposal services
Our material recycling business started from the treatment of medical waste, such as injection needles and surgical scalpels, and gradually increased the number of items to treat, reflecting the expanding needs of the times. Material recycling has now become a pillar of our Group’s business.
In recent years, in addition to the introduction of a new crusher (Yamaguchi Division) in order to carry out stable treatment of carbon fiber (CFRP), we introduced destructive treatment of CFC gas, waste treatment and fuel gas production by a gasification furnace, and waste drinking water treatment using neutralizing equipment. Through these initiatives, our material recycling has evolved into a business that is capable of comprehensively provide a wide variety of waste treatment services.
We will continue to contribute to resource recycling and environmental conservation in Japan through our comprehensive recycling system centered on electric arc furnaces.
Comprehensive recycling system centered on electric arc furnaces
The MESSCUD system: medical waste treatment system, the starting point of our material recycling business
From solving social problems to providing highly sustainable services
At that time in 1980, many used injection needles were illegally dumped, causing infection, and became a serious social problem.
While the number of medical appliances made of materials that were not suitable for heat sterilization, such as plastics and electronic devices, was increasing, many appliances were thrown away after use in order to isolate the portions that had come into contact with patients.
Seeing a media report on this trend, one of our employees thought, “We can melt dangerous items in an electric arc furnace.” This was the beginning of MESSCUD.
To carry out and receive income for the disposal of items that had been incinerated by local governments, we, as a private business, faced many obstacles to overcome, including gaining the understanding of medical circles.
While honestly explaining the seriousness of the social problem, we developed safe and secure treatment processes.
Our MESSCUD business started in 1988.
Following the establishment of the “Infectious Waste Management Manual based on the Waste Management Law” in accordance with the revision of the Waste Management Law in 1992, MESSCUD surged in popularity overnight.
Today, it is recognized as a safe and sustainable treatment method, supported by many customers.