Supporting the Development of the Mitsubishi Materials Group
100 years of the Central Research Institute and Naoshima Smelter & Refinery

2017 marks the 100th anniversary of both the Central Research Institute, which plays a crucial role in the group’s research and development activities, and the Naoshima Smelter & Refinery, which handles everything from high efficiency copper smelting and refining via groundbreaking processes, through to processing and recycling all manner of waste products. We take a look back at their history, to see how these facilities have supported the development of the Mitsubishi Materials Group.

Central Research Institute - 100 Years of History

As of 2017, Mitsubishi Materials Central Research Institute has been supporting the group's development for 100 years, ever since the establishment of the Mining Research Institute, which was the starting point for all Mitsubishi technologies. Having started life as one of the most pioneering private research facilities in Japan, the institute has created countless new technologies and products across the group's wide-ranging field of business.
We are determined to become a leading business group contributing to society by creating unique technologies for the next 100 years too. In this feature, we take a look back at a century of history at the Central Research Institute, which is at the heart of our research and development activities.

A pioneering private research facility in Japan [1917 onwards]

Mitsubishi Goshi Kaisha, the predecessor to the Mitsubishi Group, set up the Mining Research Institute as a private research institute in the Shinagawa area of Tokyo in 1917, partway through World War I, at a time when such facilities were rare in Japan. This went on to become the present day Central Research Institute. It was started thanks to the foresight of Koyata Iwasaki (fourth president of the Mitsubishi Zaibatsu ), President of Mitsubishi Goshi Kaisha.
The Mining Research Institute continued to expand its field of research and development, in line with emerging needs over time, and in 1939 relocated to the city of Omiya (now Saitama) in Saitama prefecture, once the institute had outgrown the Shinagawa site.
After World War II, the institute was presided over by Taihei Mining Co., Ltd., which took over metal mining operations from Mitsubishi Mining Company Ltd. The coal research division meanwhile became the Coal Research Department (Production Division) at Mitsubishi Mining. Work to expand and modernize facilities continued full speed ahead from that point onwards, as the institute continued to branch out into other areas of R&D.

Contributing to the diversification of business [1964 onwards]

The Mining Research Institute changed its name to the Central Research Institute in 1964. Based on the diversification strategy being implemented by Mitsubishi Metal Mining Company Ltd., whose core operations at that time included advanced materials processing as well as mining and smelting, the institute began to bring in technologies from leading overseas companies, and carry out wide-ranging research in areas such as high-purity silicon, chemical products and aluminum cans. It was during this time that the Mitsubishi Process was commercialized, having been introduced in 1959. Although Mitsubishi Metal Research Institute Co., Ltd. was spun off as a separate company in 1976, it reverted to Mitsubishi Metal Corporation in 1983.
In 1990, Mitsubishi Metal Corporation and Mitsubishi Mining & Cement Co., Ltd. merged to form Mitsubishi Materials Corporation, integrating both companies' research divisions at the same time.
Structural improvements were made with an emphasis on new sectors, developing new products and technologies, and basic technologies. This created a corporate laboratory that could handle basic research and development on a companywide basis, focusing on the "seeds" of business for the future.

Continuing development with an eye constantly on market trends (2007 onwards)

In 2007, the Central Research Institute moved to its current location in the city of Naka in Ibaraki prefecture. After that point, the institute concentrated on three key growth markets - vehicles, IT and electronics, and urban resource recycling - and achieved significant results. These days, the institute focuses on next-generation vehicles, IoT and AI, as well as energy and recycling, in an effort to contribute to a more sustainable society.
While focusing on materials and process technologies ever since it was first established, the Central Research Institute has also expanded into applied fields and generated synergy along the way.
To date, the institute has built up an array of basic technologies, in areas such as analysis, evaluation and CAE*, and core technologies, including reaction processes, metal and processing, and thin films and interfaces. These have become shared assets and strengths for the entire group.
The institute will continue to take these strengths to new heights, and nurture growth businesses in the future, as well as contributing to our business by providing support for the development of process technologies to increase business competitiveness.

* CAE: Computer Aided Engineering. Technology used to develop materials and processes based on computer-operated simulations

Major results and contributions in each business area
Sector Major results and contributions
Cement Conserving energy (incineration simulations), kiln operation support system
Metals Mitsubishi process, precious metal refining process, new copper alloy
Advanced Materials & Tools Cemented carbide tool materials, ultra-high pressure technology, coating technology
Electronic Materials Silicon-related basic technology, target manufacturing technology, high reliability insulating substrates (DBA), titanium black
Aluminum Lightweight aluminum can technology (plastic forming technology)
Others/Universal Analysis technology, CAE, home appliance recycling technology, energy-related technology, wastewater treatment technology

Embrace change and encourage innovation

Kazuki MizushimaKazuki Mizushima
Executive Officer
Deputy General Manager,
Technology Division
The title and position are as of the publication date of this article.

We have overcome numerous crises as a group to achieve changes over the course of our history, and the Central Research Institute has acted as a driving force every step of the way. While focusing on materials, our researchers take on challenges on a daily basis, and continue to send out products and technologies into the world, products and technologies that have the power to drastically transform and enrich people's lives. Recycling urban resources meanwhile offers tremendous potential in terms of promoting a more environmentally earth-friendly and sustainable society.
Against a backdrop of "megatrends" such as autonomous driving, IoT and AI, we are on the verge a groundbreaking new era. As we look ahead to the next 100 years, the Central Research Institute will continue to embrace further changes, and encourage innovation based on a renewed customer focus and increased speed, as we continue to create new products and businesses.
Fueled by the combined passion of our researchers, we are determined to develop human resources with a wide range of experience and expertise, and create a bold corporate culture that is keen to take on challenges without fear of failure. We are also committed to promoting open innovation, and to translating that into the very best results.

R&D results that got us where we are now

Continually evolving analysis and evaluation technologies<Analysis>
We have had an analysis division analyzing and evaluating products of the group ever since the establishment of the Mining Research Institute. This has helped us to maintain cutting-edge technical capabilities, supported technical development, and contributed to improvements in product quality.

photoInstrument analysis lab (1940)

  • Established as research institute for Mitsubishi Goshi Kaisha
  • Analysis division founded
  • Tungsten carbide powder manufacturing and sintering technology
  • Relocated to Omiya (then), Saitama prefecture
Supporting the semiconductor industry using highly advanced technology<Electronic Materials & Components>
We commenced research into manufacturing high-purity silicon in 1958. In the early 1980s, we began developing sputtering targets, which are now used as key components in technology such as organic electroluminescence displays.

photoSputtering targets

  • Development of nuclear power for peaceful uses
  • Research of high-purity silicon manufacturing
Taking on the challenge of the ultimate copper smelting and refining technology<Metals>
We began basic research into the Mitsubishi Continuous Smelting and Converting Process (Mitsubishi Process) in 1959. We have also contributed to the creation of a recycling-oriented society through the subsequent development of processes such as precious metal refining.

photoInitial firing ceremony at a Mitsubishi Process furnace

  • Renamed Central Research Institute
  • Visit by the Showa Emperor and Empress
  • Ultrahigh pressure generation technology
  • Environmental measures at abandoned mines
  • Basic testing of the Mitsubishi Process
  • Titanium carbide films formation
Developing advanced alloy manufacturing and plastic forming technologies<Advanced Materials & Tools, Aluminum>
As part of our metal processing operations, dating back to the establishment of the Mining Research Institute, we have branched out into manufacturing materials for cemented carbide tools, and alloys, as well as plastic forming technologies for aluminum cans. We also recycle tungsten for use in cemented carbide tools

photoDeveloping a wide range of alloy materials

  • Split off as a separate company
  • Development of heat- and corrosion-resistant alloys
  • Reverted to Mitsubishi Metal Corporation
  • Black titanium powder
  • Research and development of target materials
  • Al can plastic forming technology
  • Geothermal reservoir management
  • Recycling precious metal products
Products used in the world's first hybrid vehicle<Electronic Materials & Components>
Having been conducting research into bonding processes for a range of different materials since the 1980s, in the 1990s that led to the development of high reliability insulating circuit substrates (DBA), which were used in the world's first hybrid vehicle.

photoDBA (Direct Bonded Aluminum)

  • Renamed General Research Institute
  • High reliability insulating circuit substrates (DBA)
  • New processes for precious metals
Working to reduce environmental impact<Cement, Environment & Energy>
Based on technologies in areas such as coal and mining, we began to explore the recycling processes of home appliances from the 1990s onwards. CAE technology introduced in the 1980s is now also applied to the cement manufacturing process.

photoAutomatic screw-removing device for flat screen televisions

  • Renamed Central Research Institute
  • Relocated to Naka, Ibaraki prefecture
  • Recycling home appliances
  • Cement kiln operation support system
  • Recycling tungsten
  • New copper alloy for terminals
  • Flexible thin-film thermistors


Naoshima Smelter & Refinery - 100 Years of History

2017 also marks the 100th anniversary of the Naoshima Smelter & Refinery, established in 1917 by Mitsubishi Goshi Kaisha. Having started out with a small-scale reverberatory furnace, the facility evolved exponentially thanks to the Mitsubishi Process, and in recent years has become a world-leading smelter and refinery thanks to its E-Scrap processing operations. We take a look back at the history of the Naoshima Smelter & Refinery, as one of the group's key facilities.

Establishing smelting technology and expanding production capacity (1917 onwards)

Our metals business originated in 1873, when Mitsubishi founder Yataro Iwasaki acquired the Yoshioka Mine in Okayama prefecture. During the period from the 1900s into the 1910s, Mitsubishi Goshi Kaisha began smelting at facilities attached to mines that the company owned around the country. Due to countermeasures to tackle mining-induced pollution however, and advances in extraction and ore dressing technologies for low-grade ore in Japan, small-scale mine development became more common. This led to the idea of establishing a central smelter and refinery that would collect and handle copper concentrate from mines in the surrounding area. The result was the establishment of the Naoshima smelter & Refinery in 1917, equipped with a reverberatory furnace powered by the very latest technology. With the understanding and support of the local authorities, the village of Naoshima in Kagawa prefecture was chosen as the location because it was close to domestic mines and the Osaka Refinery, convenient for importing raw materials from overseas, and posed few concerns in terms of smoke pollution. As smelting and refining gathered pace, facilities were expanded and upgraded, and production increased, as Naoshima began to take in copper concentrate from other mines too.
Despite difficulties during the period after World War II, when operations were interrupted due to shortages of coal and manpower, the facility's copper production capacity continued to increase incrementally as Japan moved towards economic recovery.

Innovations in copper smelting and refining (1974 onwards)

The development that had the biggest impact on the Naoshima Smelter & Refinery was the advent of the Mitsubishi Continuous Smelting and Converting Process (Mitsubishi Process), the first process of its kind in the world, in 1974. By connecting three furnaces via enclosed launders, this process made it possible to operate continuously, from loading raw materials through to refining. It was a revolutionary achievement, in terms of increasing efficiency, conserving energy, and reducing environmental impact, and forms the basis of operations at the Naoshima Smelter & Refinery to this day. We also began increasingly exporting our patented technologies to other countries.
With the closure of the Osaka Refinery, the group's precious metal production became concentrated at the Naoshima Smelter & Refinery. In 1989, we built a precious metal plant that boasted the highest metal production capacity in the east.

Promoting our recycling business (2000 onwards)

The Basic Act on Establishing a Sound Material-Cycle Society came into effect in 2000, amidst growing momentum towards measures to tackle waste products and recycling throughout society. Having provided assistance with industrial waste-related issues on the neighboring island of Teshima, the Naoshima Smelter & Refinery went on to build a washing and treatment plant for fly ash and a incinerating and melting plant for recycling waste, and began branching out into the recycling business. The unique Mitsubishi Process, which involves injecting copper concentrate and air via lances, is well suited to processing large volumes of recycled raw materials. Combined with its incinerating and melting plant for recycling waste, this enabled Naoshima to push full steam ahead with recycling operations. We started to take in and process recycled raw materials such as fly ash and automotive shredder dust from external waste processing facilities, as well as home appliances and waste substrates. We began to recover copper and precious metals used in the copper smelting process too.
Our capacity for processing E-Scrap is now at a world-leading level, enabling us to achieve impressive results from a financial point of view, as well as environmental. In 2016, we established our Second E-Scrap Center at the Naoshima Smelter & Refinery, as well as a new company in the Netherlands, called MM Metal Recycling B.V. We are planning to take in even more E-Scrap from Europe in the future, as we continue to expand our recycling business further.

Naoshima Smelter & Refinery and the local community

Having grown up hand-in-hand with the town of Naoshima, the Naoshima Smelter & Refinery is fully committed to contributing to the local area, on the basis that developing the local community is synonymous with developing the smelter and refinery itself.
We also undertake activities across the entire island, in an effort to create a more environmentally friendly, recycling-oriented society.


N-NEXT Plan Establishing a global E-Scrap recycling business


Ahead of the Naoshima Smelter & Refinery's centenary in 2017, in 2011 we formulated the N-NEXT Plan*, a six-year plan revolving around key issues in three areas; profit, safety and the environment. Based on the slogan "Creating a safe and reliable smelter and refinery for our children and grandchildren," the aim is to face up to the rapidly changing world around us, and establish a facility that offers unbeatable value, with an eye to making it through the next 100 years.
This plan is designed to establish Naoshima as a world-leading smelter and refinery, aesthetically as well as financially, as the thriving cornerstone underpinning the development of our E-Scrap recycling operations into a global business.

* N-NEXT: (Naoshima. New Era with excellent Tradition) Plan aimed at creating a Naoshima Smelter & Refinery for the dawn of a new era, while maintaining the best traditions from the past

Always paving the way for the future at Naoshima Smelter & Refinery

Yasunobu SuzukiYasunobu Suzuki
Senior Managing Executive Officer
President, Metals Company
The title and position are as of the publication date of this article.

From installing Japan's first reverberatory furnace when it started operating in 1917, to introducing revolutionary Mitsubishi Process continuous smelting and converting technology in 1974, the Naoshima Smelter & Refinery has always been a cutting-edge facility that is ahead of its time. We launched our precious metal business in 1989, when our precious metal refinery was relocated from the Osaka Refinery. Having completed our copper smelting plant in 1991, we later completed facilities for recycling waste and fly ash in 2004. This enabled us to get our recycling operations off the ground in earnest, based on a profit structure underpinned by three businesses: copper smelting, precious metals and recycling.
With the completion of our Second E-Scrap Center in 2016, we increased our annual E-Scrap processing capacity to 110,000 tons, putting the Naoshima Smelter & Refinery right at the heart of the group's E-Scrap processing operations.
The Japanese manufacturing industry may have found itself in a very different position in recent years due to shifts in the world economy, but we remain committed to safety and are as determined as ever to outperform our competitors both financially and environmentally, driven by technological innovation and a pioneering spirit built up over 100 years.

  • Established as central smelter and refinery for Mitsubishi Goshi Kaisha

photoNaoshima Smelter & Refinery (circa 1932)

  • Started operation of a reverberatory furnace and commenced production with a monthly capacity of 300 tons of blister copper
  • Commissioned the No.2 reverberatory furnace and No.1 copper tankhouse with a monthly production capacity of 7,500 tons of electrolytic copper

photoMitsubishi Process furnace under construction (1973)

  • Commissioned continuous smelting furnace (Mitsubishi Process), with a monthly production capacity of 4,000 tons of refined copper (anode)
  • Commissioned No.2 copper tankhouse, taking monthly production capacity to 13,000 tons of electrolytic copper
  • Transferred precious metal efinery from Osaka Refinery
  • Commenced production of precious metals
  • Shut down the operations of No.2 reverberatory furnace and former continuous smelting furnace
  • Commenced production using a new continuous smelting furnace (Mitsubishi Process), with a monthly production capacity of 17,000 tons of refined copper
  • Increased monthly production capacity to 15,800 tons of electrolytic copper
  • Conducted joint research into processing fly ash in Teshima with Kagawa Prefectural Government

photoIncinerating and Melting Plant for Recycling Waste (2003)

  • Commissioned washing and treatment plant of fly ash
  • Commissioned incinerating and melting plant for recycling waste
  • Commenced using hydro-metallurgy process for precious metals
  • Increased monthly production capacity to 19,500 tons of electrolytic copper
  • Implemented Hyper Recycling Plan (to increase recycling capacity by upgrading existing processing facilities)
  • Received Minister of the Environment's 2014 Commendation for Global Warming Prevention Activities
  • Completed Second E-Scrap Center
  • Established MM Metal Recycling B.V.