节点文献
磷石膏制备建筑材料现状及技术路线分析
Analysis of Current Situation and Technical Route of Building Materials Prepared by Phosphogypsum
【摘要】 我国提出了2030年“碳达峰”与2060年“碳中和”目标,生态环保产业相应面临着机遇与挑战。工业固体废弃物资源化利用可以有效助推“碳达峰”“碳中和”。本文分析了大宗工业固废磷石膏在建筑材料领域的应用技术及产品。指出现有磷石膏利用方式存在的问题及解决方案。提出磷石膏综合利用产品需要多元化,提高热量利用效率,降低生产成本。Ⅱ型无水石膏产品能有效降低磷石膏中磷,氟化合物和有机质的不利影响;α-半水石膏产品有较高的强度,低标准稠度用水量;这两个产品是磷石膏在建筑材料领域无害化利用的方向。流态化煅烧直接换热制备Ⅱ型无水石膏,β-半水石膏已经实现了工业化,这个技术将为磷石膏综合利用产品多元化提供技术支撑。
【Abstract】 China has put forward the goals of “carbon peak” in 2030 and “carbon neutrality” in 2060, and the ecological environmental protection industry is facing opportunities and challenges accordingly. The utilization of solid waste as resource can effectively promote carbon peaking and carbon neutrality. This paper analyzes the utilization technology and products of phosphogypsum in building materials. The main industrial technology method for the comprehensive utilization of phosphogypsum are calcination, autoclaving, hydrothermal method, etc. The main product is the removal of part or all of the crystallized water in dihydrate gypsum to prepare building gypsum(β-hemihydrate gypsum), high-strength gypsum(α-hemihydrate gypsum), and anhydrous gypsum(II). Due to uneven heating in the calcination process, the product quality is unstable. Phosphogypsum contains phosphorus, fluorine compounds and some organic matter, which makes the strength of building gypsum low, and the market application is limited. The industrialized methods for preparing α-hemihydrate gypsum include autoclave method and pressurized liquid phase method. Both of these preparation methods are intermittent production methods. The processing capacity of a single production unit is low, which is not conducive to the large-scale production process of α-hemihydrate gypsum. In addition, impurities such as organics and metal salts in phosphogypsum can affect the color of the product during the preparation of α-hemihydrate gypsum, thus limiting the application of the product in areas where whiteness is required. The existing industrialized technology can only produce a single product and lacks flexibility. Based on the existing problems in the utilization of phosphogypsum, it is proposed that the comprehensive utilization products of phosphogypsum need to be diversified, improve heat utilization efficiency, reduce production costs, develop large-scale core reaction equipment, and develop a simple and cost-effective method for treating impurities in phosphogypsum. Anhydrite Ⅱ products can effectively reduce the adverse effects of phosphorus, fluorine compounds and organic matters in phosphogypsum; α-hemihydrate gypsum products have high strength and low standard consistency water consumption;Producing the above products are the direction of harmless utilization of phosphogypsum in the field of building materials. The first phosphogypsum fluidized calcination demonstration device in China was introduced. The unit adopts fluidized calcination technology, and the device has completed trial production and commissioning, and the phosphogypsum treatment capacity and product quality have reached the design index. The advantages of this technology are as follows:(1) Direct heat exchange between phosphogypsum and hot gas in the calcination furnace, high heat and mass transfer efficiency, and low comprehensive energy consumption.(2) One unit can produce two products, anhydrite Ⅱ and β-hemihydrate gypsum.(3) The distributed control system(DCS) is used with a high degree of automation, the calcination temperature and time can be flexibly controlled.(4) The calcination process has a short process flow, high efficiency, and can operate continuously.(5) The fluidized calciner occupies a small area and has a large processing capacity for a single set, which is convenient for large-scale.(6) The calcination temperature is uniform and the product quality is stable. The technology will provide technical support for diversification of comprehensive utilization products of phosphogypsum.
【Key words】 phosphogypsum; comprehensive utilization; anhydrite Ⅱ; α-hemihydrate gypsum; β-hemihydrate gypsum; fluidized calcination;
- 【文献出处】 工程研究——跨学科视野中的工程 ,Journal of Engineering Studies , 编辑部邮箱 ,2023年04期
- 【分类号】TQ177.375;TU50
- 【网络出版时间】2023-08-31 14:28:00
- 【下载频次】185