Some Problems of Recycling Industrial Materials

The industrial system should learn from the natural ecosystem. The resource utilization efficiency should be increased and the environmental load should be decreased, depending on the materials recycled in the system. The classification of industrial materials from the viewpoint of large-scale recycling was stated. Recycling of materials, on three different levels, was introduced in the industrial system. The metal flow diagram in the life cycle of products, in the case of no materials recycled, materials partially recycled, and materials completely recycled, was given. The natural resource conservation and the waste emission reduction were analyzed under the condition of materials completely recycled. The expressions for the relation between resource efficiency and material recycling rate, and the relation between eco-efficiency and material recycling rate were derived, and the curves describing the relationship between them were protracted. The diagram of iron flow in the life cycle of iron and steel products in China, in 2001, was given, and the iron resource efficiency, material recycling rate, and iron eco-efficiency were analyzed. The variation of iron resource efficiency with the material recycling rate was analyzed for two different production ratios.