| Heavy metal pollution accumulated from the long-term of the mineral mining, processing and rapid industrialization has become prominent gradually in our country., Especially lead pollution events broke out frequently in recent years. In consideration of the serious harm to the national ecological environment and the health of the residents from the lead pollution, and lead smelting industry is one of the main pollution sources at the same time, the best available technology in lead smelting industry should be put forward to cut or eliminate lead and other pollutants emissions. Therefore, it is a particular important study to establish a scientific, systemic, integrated lead smelting pollution prevention and control technology evaluation system, in order to evaluate the relevant technologies and pick out the best available technologies.Based on the basic process of lead smelting、combined with the characteristics of the lead smelting, Life Cycle Assessment was chosen to identify the product evaluation scope which is from raw materials to products, and the heavy metal pollution prevention and control technology were evaluated in this scope. Material Flow Analysis was studied in lead smelting. This paper analyzes the reasons of pollutants generation and emission in different perspective, such as the environmental management, raw material, smelting process and equipment,"three wastes" treatment technology and so on, to determine the node of pollutants generation and emission, and put forward two main pollution prevention and control key processes-smelting process and "three wastes" treatment process.In the principle of six contexts, which are pertinence, objectivity and scientificity, the overall process analysis and evaluation, the idea of comprehensive pollution prevention and control, relative independence, easy manipulation and simplicity, expansibility, referenced to relevant state laws and regulations for lead smelting industry, industrial policies, technology, environmental protection, safety and health standards and other provisions, comprehensive evaluation indicator system was established in this study. The target layer, the points target layer, the indicator layer are in this system. Target layer is lead smelting pollution prevention and control level. The points target layer contains six main factors including environmental management, smelting process and equipment, flue gas for manufacturing sulfuric acid,"three wastes" treatment, waste heat utilization, the surrounding environment renovation. The indicator layer contains24particular indexes including ISO14000, SO2conversion rate, the qualified rate of waste water, the rate of waste residue comprehensive utilization efficiency and so on. This study also provides the specific definition and calculation method for each indicator.Combining with the expert opinions, indicator weights in various levels are identified by applying Attribute Hierarchical Model with10/10-18/2scale. Based on the the analysis of various kinds of environmental technology evaluation methods, attribute comprehensive evaluation method was selected as evaluation method. According to this theory, the five levels, which are best, better, medium, worse, worst, were divided. Through the actual value of the indicator, the attribute measure of single index and comprehensive attribute measure was calculates in this study, and made comprehensive assessment with a double standard of confidence and scored.In order to validate the established comprehensive evaluation index system and evaluation methods of practical, the research chooses two lead smelting enterprises for profession qualification model in our country, A (the Kivcet lead smelting process) and B (the ISP lead smelting process), as case objects. The two smelting enterprises were evaluated by the established the indicator system and evaluation method. The results show that, enterprise A belongs to level Ⅱ, which score is85.97, and enterprise B of the score77.19belongs to level Ⅲ under the condition of confidence0.7. The results demonstrate the established evaluation framework is feasible, and the indicator system can reflect pollution prevention and control level of the lead smelting enterprise. |
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