Development of energy-saving techonology for a melting furnace using RPF as a combustion improver.

Abstract

Aiming to reducing the direct use of fossil fuels in Kubota’s surface melting furnace, a series of test were conducted changing fuel from kerosene to RPF (waste plastic). As a result of the test, self-sustained combustion (fossil fuel-free) operation was achieved for more than 84 hours continuously. The running cost per ton of incinerated ash (assessed by fuel cost, exhaust gas treatment cost, and fly ash treatment cost) was reduced by 33%. Exhaust gas analysis and slag heavy metal content and elution tests were all below the standard values, thus it is confirmed that the operation using RPF were no problems. Regarding the distribution analysis of elements by melting process, it was confirmed that heavy metals migrate to fly ash, and high-melting elements, including precious metals, migrate to slag. In the future, we are planning to develop technology to utilize not only highly granulated RPF but also wastes (waste plastic, recycling residue, etc.) as fuel.