Recycle Mine Park - Kozan Recycling Business - June 1995

Mining Industry Recycling Business

Overview
In response to the depletion of metal resources and waste problems, the mining industry has expanded its recycling business to recover precious metals from metal waste in addition to the traditional method of extracting metals from mined ores. This initiative aims to make effective use of resources and protect the environment.

Chugai Mining's Initiatives
Chugai Mining's recycling business is particularly noteworthy in Japan's mining industry. Chugai Mining has been engaged in ore refining since 1932 (Showa 7). Still, in 1973, following the oil shock, the company began recovering defective products from the electronics industry and extracting gold from them. This business made it possible to recover metal resources from existing waste without the need to mine new ore.

The company further expanded its recycling business by developing technology to recover silver from waste film and photographic waste solutions generated by hospitals. In 1978, following the collapse of the tailings dam at the Mochikoshi mine due to an earthquake off the coast of Izu Oshima, the company shifted its focus to recycling precious metal waste instead of mining ores.

Refining Process and Wastewater Treatment
The Mochikoshi mine, currently functioning as a refinery, has pre-treatment processes, including roasting, alkali recovery, and acid recovery. In the refining process, 99.999% pure gold and 99.99% electric silver are extracted through smelting and electrolysis. The alkali, acid, cyanide, and other wastewater generated in this process are appropriately treated and detoxified. In addition, low-grade precious metal-containing materials that could not be recovered are sold as valuable materials to other mining companies with specialized technologies.

Introduction of Multi-Purpose Roasting Furnace
Chugai Mining has expanded its waste treatment business by introducing a multi-purpose roasting furnace capable of handling various industrial wastes, including the incineration of confidential documents. This initiative has significantly increased the recycling rate of industrial waste.

Significance of Mining Company Recycling Business
The Japanese mining industry has also seen the transformation of closed mines into comprehensive recycling centers. Even after mining operations have ceased, maintenance of the mine for disaster prevention is required, making it possible to utilize the extensive facilities and refining equipment for waste treatment and recycling projects, contributing to regional revitalization.

The Ministry of International Trade and Industry (MITI) has recognized these advantageous conditions of the mining industry and has formulated the "Recycle Mine Park Plan" to support these initiatives. In FY1995, the ministry allocated approximately 40 million yen to promote model projects that use the infrastructure of abandoned mines for recycling household appliances and other waste, thereby contributing to regional development.

Challenges and Outlook
The recycling business in the mining industry contributes to the effective use of resources and the reduction of environmental impact.