摘要
针对中国铝土矿资源不足的状况,利用高铝粉煤灰生产氧化铝不仅有望缓解铝资源的不足,而且可减少粉煤灰对大气、水体的污染和大量土地资源的占用。高铝粉煤灰提取氧化铝技术主要包括酸法、碱法和酸碱联合法。采用碱法提取氧化铝技术,具有对设备腐蚀性小,与现有氧化铝生产设备相容性好,对水体和空气不产生二次污染等优势。与石灰石烧结法和预脱硅-碱石灰烧结法等代表性碱法技术相比,采用预脱硅-低钙烧结法制备氧化铝技术,处理物料总量、一次性资源消耗量和CO2排放量,分别减少22.1%～52.4%、24.6%～52.0%、20.0%～66.2%;综合耗能降低16.4%～36.3%;剩余硅钙固体排放量减少27.5%～71.5%。因此,预脱硅-低钙烧结法技术在物耗、能耗、环境相容性和产品方案等方面均有明显优势,符合高效节能和清洁生产的要求,有望实现高铝粉煤灰生产氧化铝的完全资源化利用。
The studies of extracting aluminum oxide from high-alumina coal fly ash as potential alumina resources are significant for making up the inadequacy of bauxite resources and lowering degree of dependence on alumina resources import. Compared to acid method and acid alkaline technology, alkaline technology is promising without eroding equipment seriously and consistent to the industrial technology of the alumina production as well. Alkali methods mainly consist of limestone calcination method, predesilication-soda- limestone calcination method and predesilication-soda-limestone with low Ca/Si calcination method. Importantly, the total raw materials volume would decrease 52. 4% and 22. 1% respectively for the same alumina output using the last method than the other two methods. The energy consumption was lessened 36.8% and 16.4% while the volume of CO2 produced reduces 66.2% and 20. 0% as well. The byproduct of the limestone calcination method and predesilication-soda-limestone calcination method are 2CaO·SiO2 mainly used for producing cements. However, the byproduct of the last method is calcium silicate which decreases 71.5% and 27.5% separately than the two other methods. Moreover, calcium silicate could be processed into new-type construction materials with high performance and value. Therefore, predesilication-soda-limestone with low Ca/Si ratio calcination method is promising for production of alumina by high-alumina coal fly ash considering the total processed raw materials volume, energy consumption, byproducts and environmental compatibility.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2014年第5期313-324,共12页
Earth Science Frontiers
基金
中央高校基本科研业务费项目(2652014017)
矿物材料国家专业实验室开放基金项目(09A001)
国电宁夏太阳能有限公司委托项目
西安理想华夏科技创新有限公司委托项目
关键词
中国铝土矿
高铝粉煤灰
氧化铝
预脱硅
低钙碱石灰烧结
Chinese bauxite resources
high-alumina coal fly ash
alumina
desilication
low-Ca/Si soda-lime-stone calcination
