January 11 2006
A model project concerning recycling of mixed plastics wastes from the construction sector that includes PVC
Vinyl Environmental Council

The Kanto construction waste association, along with Dowa Mining and Vinyl Environmental Council (VEC) agreed in July last year to start from this year a model project to recycle mixed plastic wastes including PVC that are discharged from the construction sector.

The amount of by-products that are generated from building houses and buildings are falling each year since construction companies are trying to curb such emission and these by-products are sorted at the building site. However, construction wastes to be generated from the future renovation and demolition of buildings and housings that had been built during the Japanese economic boom between the mid 50s to the early 70s are expected to increase. Our project aims to boost the recycling rates of plastics used as construction materials in various applications. So many kinds of plastic wastes generate from the construction sector and it is hard to distinguish them, and there had been no choice but to landfill them. We would like to contribute to building a recycle oriented society by promoting recycling of these mixed plastic wastes as is.

Since the year before the last, the 3 parties jointly conducted a thermal recycling demonstration by using representative samples of mixed plastic wastes from the construction sector at the Kosaka smelter belonging to the Dowa Mining group. It was demonstrated that it is technically feasible to treat such wastes.

This year, mixed plastic wastes from the construction sector supplied by the Kanto construction waste association will continuously be recycled at the Okayama plant of Dowa Mining. This is to demonstrate that various plastic wastes from the construction sector including PVC products can actually be thermally recycled, and to set up a social system. Today we have reached a full scale model project, after the launching and preparation since July last year.

Our model project's goal is commercialization, and we intend to test a wide range of plastic wastes from this sector in vast amounts for an extended period of time. We will check the below points which previously had not been clarified for commercialization, in order to come up with specific conditions for implementation.

1. Should be able to treat all kinds of mixed plastic wastes (incl. PVC wastes) from the construction sector.
Mixed wastes are uneven and differ according to the types of works, such as building and demolition, and also upon each phase of the works. Therefore the system needs to be able to accept various kinds of wastes and treat them efficiently. This model project is to be supported fully by the Kanto construction waste association and its member intermediate treatment companies. It will treat a large number of plastic wastes (approx. 1200 tons) that comes from various sites (more than 10 intermediate treatment facilities will provide the samples), for a long period of time (1 year).

2. Should have a reasonable treatment speed and stability for continuous treatment.
Based on the demonstration last year, Dowa Mining will check whether chlorine containing wastes can be treated continuously at their recycling plant in Okayama, by putting their excellent technology into full use.

3. Should be cost efficient and should be used as a social system for recycling.
The Okayama plant of Dowa Mining is a thermal recycling plant which recovers heat. It can also pre sort inorganic matters (glass, metal, gravel) from the mixed plastic wastes for effective use.
By all means necessary, we will cut costs in order to set up an economical system.

About 5 months have passed and although we are still at the midpoint of the project, the above points are gradually becoming clearer. The model project will be continued until July this year in order to gain more experience and findings. After the model project we plan to operate full scale on a commercial basis.

By commercializing this thermal recycling of mixed plastic wastes from the construction sector, the landfill issue would improve. Since plastic wastes are deemed as an important resource and should be used efficiently, we hope to contribute to realizing a sound material-cycle society through this undertaking.