RITE-CHIBA No.3 and No.4 LABORATORY in KAWASAKI STEEL CORPORATION

The development of a technology for efficient dechlorination of waste plastics by processing thermally with a solvent and production of a reducing agent which can be injected into blast furnaces from the dechlorinated plastics is now in progress. The results obtained in 2000 were as follows.

1. Design of the Pre-Treatment Equipment

The qualities and quantities of inorganic materials among several waste plastics were analyzed to make clear the optimal pre-treatment equipment for the minimum separation required for this process.

2. Research of Apparatus for Processing Technology of Waste Plastics

The following results were obtained by operating a bench scale test plant.

1) It is possible to remove approximately 90% of the chlorine from the waste collected by some local governments.The ability of dechlorination was accelerated according to the increase of the processing temperature and the agitating velocity.

2) Recovery of solvent and separation of sublimated substances were easily performed by solvent-circulation type heat exchanger without any plugging troubles.

3) For the continuous solidification and crashing of molten waste plastics, a belting cooler and crasher was successfully operated. The ability of solidification depended on the thickness of molten plastics on the belt.

4) No corrosion of the pipes and vessels made of carbon steel by the gas of hydrogen chloride was observed during the researching term by keeping particular temperature.

3. Evaluation and Research on Transportation and Injection Properties of Pulverized Reducing Agent

At actual blast furnaces, pneumatic transportation and injection of the pulverized reducing agent (dechlorinated waste plastics) were performed without any troubles. The pulverized materials did not attack the injection nozzle. Additionally, normal phenomena were observed in the raceway.

4. Rough Planning of the Pilot Plant

Based on the processing data obtained by several research and e xperiments, a basic design of the pilot plant for this process was carried out. The design includes the pre-treatment equipment, the dechlorination process, plot plan, and the building.

From the results of whole research, this dechlorination technology of waste plastics by processing thermally with a solvent can be applied commercially, and also can be recognized as a superior technology for conversion of waste plastics to a reducing agent of blast furnaces.