长江经济带典型锌 冶 炼 园 区 不 同 固 废 处 置 模 式 生 态 效率研究

In China, there are many kinds of solid wastes of copper, lead and zinc non-ferrous smelting, which are rich in a variety of environmental toxic elements, such as cadmium, chromium, mercury and arsenic. At present, the disposal mode of solid wastes is still single and a large number of valuable metal components such as copper, lead zinc, silver and nickel have not been effectively separated. The problems of solid waste pollution control and efficient resource utilization are prominent, which have become the key factors restricting the green and sustainable development of the industry. This paper studied a typical case of copper, lead and zinc comprehensive smelting base an example in the Yangtze River Economic Belt, and set up three scenarios of zinc smelting solid waste disposal, namely, direct treatment (scenario 1), internal circulation (scenario 2) and collaborative utilization (scenario 3). In order to further carry out a comprehensive evaluation and an analysis of ecological efficiency for the three scenarios, we combined material input-output method with analytic hierarchy process (AHP) and entropy method. The multi-dimensional ecological efficiency index accounting method system was established, including resource and energy consumption, environmental risk, material cycle and economic benefit. The ecological efficiency of the three scenarios was comprehensively evaluated and analyzed as well. The results showed that scenario 3 strengthened the collaborative transformation of zinc smelting solid wastes between copper and lead smelting systems, and its ecological efficiency comprehensive evaluation index was the highest, which was 0.2246, 313.6% and 25. 5% higher than scenario 1 and scenario 2 respectively; From the perspective of resource energy consumption, scenario 2 had the highest energy consumption per unit product, reaching 0.3086; The comprehensive utilization rate of solid waste in scenario 3 was the highest in respect of material circulation and economic benefits, reaching 97.6%. The recovery rate of copper, lead and zinc was 97.2%, and the total profit was 481.313 million yuan, however, in terms of environmental risk, while the emission of heavy metals in the solid waste in scenario 3 decreased by 1470.4 tons per year, the emission of heavy metals such as lead, arsenic, cadmium and mercury in the exhaust gas increased by more than three times compared with scenario 1, reaching 1.59 tons per year. To sum up, scenario 3 had significant advantages in the comprehensive utilization of solid waste secondary resources and economic benefits. Therefore, strengthening the collaborative utilization of solid waste among the copper-lead-zinc industry chain can not only greatly reduce the solid waste redundancy, improve the recovery efficiency of valuable metal resources, increase economic benefits, but also effectively reduce the risk of water and soil environmental pollution. Nevertheless, the emission of heavy metal pollution in the atmosphere still needs to be paid more attentions.