Yunnan Yuntianhua Environmental Protection and Technology Co., Ltd.
State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences
College of Chemical Engineering, Nanjing Tech University

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。

China has put forward the goals of “carbon peak” in 2030 and “carbon neutrality” in 2060, and the ecologicalenvironmental protection industry is facing opportunities and challenges accordingly. The utilization of solid waste as resource caneffectively promote carbon peaking and carbon neutrality. This paper analyzes the utilization technology and products ofphosphogypsum in building materials. The main industrial technology method for the comprehensive utilization of phosphogypsumare calcination, autoclaving, hydrothermal method, etc. The main product is the removal of part or all of the crystallized water indihydrate gypsum to prepare building gypsum (β-hemihydrate gypsum), high-strength gypsum (α-hemihydrate gypsum), andanhydrous gypsum (II). Due to uneven heating in the calcination process, the product quality is unstable. Phosphogypsum containsphosphorus, fluorine compounds and some organic matter, which makes the strength of building gypsum low, and the marketapplication is limited. The industrialized methods for preparing α-hemihydrate gypsum include autoclave method and pressurizedliquid phase method. Both of these preparation methods are intermittent production methods. The processing capacity of a singleproduction unit is low, which is not conducive to the large-scale production process of α-hemihydrate gypsum. In addition, impuritiessuch as organics and metal salts in phosphogypsum can affect the color of the product during the preparation of α-hemihydrategypsum, thus limiting the application of the product in areas where whiteness is required. The existing industrialized technology canonly produce a single product and lacks flexibility. Based on the existing problems in the utilization of phosphogypsum, it is proposedthat the comprehensive utilization products of phosphogypsum need to be diversified, improve heat utilization efficiency, reduceproduction costs, develop large-scale core reaction equipment, and develop a simple and cost-effective method for treating impuritiesin phosphogypsum. Anhydrite Ⅱ products can effectively reduce the adverse effects of phosphorus, fluorine compounds and organicmatters 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 firstphosphogypsum fluidized calcination demonstration device in China was introduced. The unit adopts fluidized calcinationtechnology, and the device has completed trial production and commissioning, and the phosphogypsum treatment capacity andproduct quality have reached the design index. The advantages of this technology are as follows: ① Direct heat exchange betweenphosphogypsum and hot gas in the calcination furnace, high heat and mass transfer efficiency, and low comprehensive energyconsumption. 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 calcinationprocess has a short process flow, high efficiency, and can operate continuously. ⑤ The fluidized calciner occupies a small area andhas a large processing capacity for a single set, which is convenient for large-scale. ⑥ The calcination temperature is uniform and theproduct quality is stable. The technology will provide technical support for diversification of comprehensive utilization products ofphosphogypsum.

云南省工业领域科技计划项目重点研发计划项目(202103AA080012)

郭旭东, 张晖, 钟晋, 等. 磷石膏制备建筑材料现状及技术路线分析[J]. 工程研究——跨学科视野中的工程, 2023, 15(4): 313-325.

Guo X D, Zhang H, Zhong J. et al. Analysis of current situation and technical route of building materials prepared byphosphogypsum[J]. Journal of Engineering Studies, 2023, 15(4): 313-325.