Ceramic Tableware Recycling by Green Life 21 Project - Red Objects

mass-production in Japan. It produces approximately 60% of the entire production volume in Japan
and the area has a history of expanding production businesses in a mass-consumption economy.
Given this background, the Mino ware production area is highly aware that global environmental
issues, including waste measures, are a significant challenge when maintaining and developing the
production area.
The global environmental issue in terms of ceramic ware is to reduce the environmental burden
from the overall product life-cycle: from raw material procurement, manufacturing, logistics, usage
to disposal. We now face three problems. The first is the sustainable use of exhaustible resources,
such as clay, silica stones, and feldspar. There are concerns over shortages in raw materials due to
mine closures and the exhaustion of quality materials. Reusing used tableware is one
countermeasure. Second, there is the issue of reducing energy consumption and CO2 emission
during firing in the ceramic manufacturing process. The firing process includes many steps, such as
bisque firing, glaze firing and overglaze firing and its energy consumption, as converted into
amounts of CO2 emission, accounts for approximately 70% of the overall manufacturing process.
As the oil price becomes higher, more reduction of firing energy is needed. Third, there is the use of
metal oxides for coloring and painting tableware(Miyachi & Hasegawa 2009, p. 31). It is obvious
that we are required not only to comply with the Food Sanitation Act concerning the elution of lead
and cadmium, but also to procure raw materials in a way that has less impact on the global
environment.
In order to respond to these global environmental issues, the Gifu Prefectural Ceramics Research
Institute, to which the author belongs, took the initiative to organize the Green Life 21 Project
(hereinafter referred to as “GL21”) with the voluntary participation of approximately 30 Mino ware
companies. Together, we began to address these issues through ceramic ware recycling.
2. Ceramic Ware Recycling Technology
In order to recycle ceramic ware, it is necessary to start with establishing the recycling technology
that makes it possible. Engineers from public research organizations are the main actors involved in
this issue. The amount of used tableware that is discarded in Japan in one year is estimated to
exceed approximately 100,000 tons and if industrial waste (fired products) in the production area is
added, it amounts to about 140000 tons. Most of it is disposed in landfills. Ceramics have the
characteristics of being nonflammable, insoluble and indefectible, so material recycling is
considered to be appropriate for the recycling of used tableware. Since the materials used for
tableware are of good quality when compared with building materials or tiles, it is important to have
a concept of circulation from tableware to tableware.
The used tableware that is collected is reproduced after undergoing the processes needed to
change it into raw materials as shown in Figure 1. Mino ware has set the standard for the ratio of
combination of recycled materials at 20% because a higher combination ratio causes the lowthermal
expansion of the green body and it ruins the compatibility of the green body and the glaze
and decreases product strength. This standard also allows the use of existing manufacturing
facilities and technologies, enables all manufacturers to enter into the recycling system and
facilitates the expansion of recycling activities. The 20% of recycled materials combination may be
an initial step in the ceramic ware recycling. Studies of the plasticity of recycled green body and the
glaze that conforms to the green body (low-thermal expansion glaze) will be essential to reaching a
high combination ratio. Further collaboration with engineers is required.
RED Objects⏐⏐Collaboration in Experimental Design Research
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