基于物质代谢分析的高铝煤炭循环利用全产业链评估研究

Evaluation of Whole Industrial Chain of High-Alumina Coal Recycling Based on Material Flow Analysis

高铝煤炭广泛分布于我国内蒙古自治区中西部煤田,富含丰富的铝、硅、锂、镓等有价元素,对其进行资源协同开发,有望大幅提升我国铝资源供给体系韧性并提高固废利用率,以及改善燃煤电厂的飞灰堆存等环境污染问题.本研究以大唐国际托电园区的高铝粉煤灰示范生产线为案例,解析了高铝煤炭中各类无机资源的分布规律,并在全面梳理“原料—工艺—技术—产品/副产品”匹配机制的基础上,构建了集成“高铝煤炭清洁燃烧工艺-多级预脱硅工艺-氧化铝低能耗提取工艺”于一体的高铝煤炭循环利用全产业链;采用物质代谢分析方法,研究高铝煤炭循环利用全过程中有价元素的迁移转化规律,建立了高铝煤炭伴生有价元素的走向与分配模型,识别了该产业链中物质代谢优化调控的关键环节;此外,以传统铝土矿炼铝产业和木浆造纸产业为参考基准,核算了该产业链推广应用的经济、环境效益.结果表明,高铝煤炭循环利用全产业链中有价元素总体循环回收利用率超过80.0%,在内蒙古自治区推广应用该产业链,每年可生产1303.0×10^(4)t氧化铝,联产964.0×10^(4)t活性硅酸钙和3192.0×10^(4)t硅钙渣,创造年收入401.2×10^(8)元,节约3505.0×10^(4)t铝土矿,保护11.5 km^(2)植被.研究显示,高铝煤炭循环利用全产业链的有价元素回收率高,具有良好的环境和经济效益.

High-alumina coal is widely distributed in the central and western coalfields of Inner Mongolia,and is rich in valuable elements such as aluminum,silicon,lithium and gallium.The comprehensive and efficient utilization of high-alumina coal is expected to greatly improve the resilience of China′s aluminum supply system and the utilization rate of solid waste,and alleviate environmental pollution problems such as fly ash storage in coal-fired power plants with considerable economic benefits.This study analyzes the distribution of various inorganic resources in high-alumina coal by taking the high-alumina fly ash demonstration production line at the Datang Group’s Tuodian Park as an example.On the basis of comprehensively combing the matching mechanism of’raw material-production processtechnology-product/by-product’,an integrated industrial chain of high-aluminum coal recycling system is established,which consists of’clean combustion process of high-alumina coal-multi-stage pre-desilication process-low-energy-consumption extraction process of alumina’.By employing material metabolism analysis,the migration and transformation laws of valuable elements in the industrial chain are studied,and the distribution model of the associated valuable elements is developed to identify the key links in the optimization of the industrial chain material metabolism.In addition,the economic and environmental benefits of the industrial chain compared with the traditional bauxite and aluminum smelting industries and the wood pulping industry are calculated.The results show that:(1)The overall recycling rate of valuable elements in the entire industrial chain of the high-alumina coal recycling system exceeds 80%.(2)The promotion and application of this industrial chain in Inner Mongolia Autonomous Region can produce 1303×10^(4)t of alumina and coproduce 964.0×10^(4)t of active calcium silicate and 3192.0×10^(4)t of calcium silicate slag,creating an annual income of 401.2×10^(8)RMB.About 3505.0×10^(4)t of bauxite resources can be saved and 11.5 km^(2)of vegetation can be protected.The research shows that the recovery rate of valuable elements is high and the economic and environmental benefits are enormous in the integrated industrial chain of highaluminum coal recycling system.