煤矿固废资源化利用的生态效率与碳减排——以淮北市为例

工业固废的大量堆积产生多种环境危害,工业固废的资源化利用能够节约资源和缓解环境压力。建筑行业是能源消耗和碳排放的主要部门之一,其中建筑材料生产阶段的能耗和碳排放占有重要的地位。粉煤灰、煤矸石是常见的工业固体废物,尤其是在以煤炭为主要能源的地区。粉煤灰、煤矸石资源化利用的途径之一是用于制造新型墙体砖。本文以煤炭资源型城市淮北市的新型墙体砖(粉煤灰砌块、煤矸石砖)和传统墙体砖(粘土砖、粘土多孔砖)为案例,对墙体砖生产过程的生态效率和碳排放进行分析和比较。在淮北市墙体材料行业碳排放不增加的前提下,以最优生态效率为目标,建立线性规划模型,对淮北市4种主要墙体材料的产量进行规划。分析结果表明:新型墙体材料的生态效率高于传统墙体材料;煤矸石砖生产过程的碳排放系数高于传统墙体砖;粉煤灰砌块生产过程的碳排放系数介于粘土砖和粘土多孔砖之间。在淮北市墙体材料行业碳排放不增加的前提下,与现有的产量相比,淮北市应禁止粘土砖的生产,适当减少粘土多孔砖的产量,适当增加粉煤灰砌块和煤矸石砖的产量,以达到最优生态效率。在最优生态效率的情况下,淮北市新型墙体材料煤矸石砖对煤矸石工业固废的利用率将由目前的15.8%增加到25.2%。

The research on eco-efficiency and canbon reduction of recycling coal mining solid wastes: a case study of Huaibei City, China

Resources conservation and mitigation of the pressure on the environment could be achieved by recycling of industrial solid waste. As a very important economic sector, construction industry is one of the main sources of energy consumption and carbon emissions in China. The production of building materials play an important part in energy consumption and carbon emissions in construction industry. In addition, building materials production is an alterative way of reusing the solid wastes from coal-driving electric-generating plants which can significantly reduce the energy consumption or carbon emssions of building material industry. Coal fly ash and coal gangue are common industrial solid wastes from coal mining or coal combustion processes. The quantity of coal fly ash and coal gangue is very large especially in coal-resources-based region, for example Huaibei City in China. Novel wall materials can be produced from recycling coal fly ash and coal gangue which is an effective way of energy saving, resources conservation and mitigation of environmental hazards. In this study, we take the novel wall materials (fly ash block, coal gangue brick) made from industrial solid wastes and conventional wall materials (clay brick, perforated clay bricks) made from clay in Huaibei City as examples to analyze the eco-efficiency and carbon emissions of them. Then we established a linear programming model to regulate the production of four kinds of wall materials in order to achieve the highest eco-efficiency and reduce canbon emissions for wall material industry in Huaibei. The results show that the eco-efficiency of novel wall materials are higher than that of conventional ones. The carbon emissions of coal gangue brick is higher than that of conventional wall materials while the carbon emissions of fly ash block is between the clay brick and the perforated clay brick. In order to achieve the highest eco-efficiency and carbon reduction of wall material industry in Huaibei, the use of clay brick for building materials production should be forbidden and the production of perforated clay brick should be decreased while the production of coal gangue brick and the fly ash block should be increased. As a result, the ratio of recycling coal gangue solid wastes increased from 15.8% to 25.2%. These results can be useful in the identification of available techniques for building materials made from recycling industrial solid wastes.