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|Name of recycling technology||Recycling of Sludge/Dust containing Valuable Metals (Nickel/Zinc)|
|Name of recycler||Daido EcoMet Co., Ltd.|
|Name of eco industrial park||-|
|Receiving waste materials for recycling||- Dust and reduced slag generated from electric arc furnaces (EAFs) for steel making (Zn: 18%)
- Sludge generated from acid pickling of stainless steel products (Ni(OH)2: 2-3%)
- Sludge generated from nickel plating (Ni:≥5%)
|Recycled products/recovered materials||- Zinc raw materials (Zn: 40-50%)
- Nickel alloy (Ni: 7-14%)
- Aggregate (gravel for construction materials, etc.)
Zinc raw material
|Capacity of recycling plant||43,000 t/year|
|Area of recycling plant||2,310 m2|
|Number of employees in recycling plant||Employees at Chita Plant, Daido EcoMet Co., Ltd.: 55
Among them, recycling equipment staff: 19
(As of April 2011)
|Start of recycling operation||March 1996|
(1) Drying process
Using heat generated in the melting process, dries wet sludge to powder.
(2) Melting and reducing process
Dry, powder-like sludge is directly melted at high temperature generated by a specially designed fuel-oxygen burner. Carbon (reducing agent) injected into the molten sludge reduces metals (nickel and iron). A high-specific gravity nickel-iron alloy forms in the lower layer, while molten slag remains as the upper layer. These layers are collected separately. Nickel alloy is used as a material for stainless steel. The molten slag after cooling is used as aggregate for road construction.
(1) Melting process: A specially designed fuel-oxygen burner is used to directly melt dust and slag from electric arc furnaces at high temperature. Zinc is vaporized, leaving molten slag. After collection and cooling, the molten slag is used as aggregate for road construction.
(2) Cooling and recovery process: Rapidly cools exhaust gas from melting furnaces. Collects powder containing a high concentration of zinc with a dust collector. The collected powder is used as a zinc raw material.
|Background of starting recycling business and participating in eco-town program||
|Fund procurement||- Their parent company (Daido Steel Co., Ltd.) constructed the zinc material recovery equipment, while Daido EcoMet operates it.
- The company provided the capital investment for the nickel alloy recovery equipment through a loan from the parent company. Since the subsidiary (Daido EcoMet Co., Ltd.) is financially independent from the parent company, the loan must be repaid.
- The national government and the Aichi Prefectural Government valued the high performance of the nickel alloy recovery technology and awarded the company subsidies.
|Major success factors||
|Issues and Challenges||
|Future prospects||- The company's business is basically to recycle byproducts from the steel industry.
- Human resources (intellectual resources) are essential to overcoming challenges in developing new technologies. The company plans to continue to use its experience in metallurgical technology to develop new technologies.