Department Física de la Materia Condensada, Universidad de Sevilla, Avda. Reina Mercedes s/n, 41012 Sevilla, Spain.
Pro2TecS-Chemical Process and Product Technology Centre, Department of Chemical Engineering, ETSI, Campus de El Carmen s/n, University of Huelva, 21071 Huelva, Spain.
Int J Environ Res Public Health. 2021 Jun 21;18(12):6664. doi: 10.3390/ijerph18126664.
This work addresses the reuse of waste products as a raw material for lime putties, which are one of the components of mortar. 1:3 Lime/sand mortars very similar to conventional construction mortars were prepared using a lime putty obtained from the treatment of phosphogypsum with sodium hydroxide. The physical, rheological and mechanical properties of this phosphogypsum-derived mortar have been studied, as well as the mineralogical composition, microstructure by scanning electron microscope (SEM) and curing process by monitoring carbonation and ultrasonic propagation velocity. Considering the negative influence of sulphates on the hardened material, the behaviour of the material after sulphates precipitation by adding barium sulphate was additionally tested. Carbonation progressed from the outside to the inside of the specimen through the porous system by Liesegang rings patterns for mortars with soluble sulphates, while the carbonation with precipitated sulphates was controlled by diffusion-precipitation. Overall, the negative influence of low-sulphate contents on the mechanical properties of mortars was verified. It must be highlighted the importance of their precipitation to obtain adequate performance.
本工作涉及将废物再利用为石灰腻子的原材料，而石灰腻子是灰浆的组成部分之一。通过用氢氧化钠处理磷石膏获得的石灰腻子，制备了与传统建筑灰浆非常相似的 1:3 石灰/砂灰浆。研究了这种磷石膏衍生灰浆的物理、流变和力学性能，以及矿物组成、扫描电子显微镜（SEM）微观结构和通过监测碳化和超声传播速度的固化过程。考虑到硫酸盐对硬化材料的负面影响，还通过添加硫酸钡来测试硫酸盐沉淀后材料的行为。对于可溶性硫酸盐的砂浆，碳化是通过多孔系统从外部到内部通过莱泽根环图案进行的，而沉淀硫酸盐的碳化则受扩散-沉淀控制。总的来说，验证了低硫酸盐含量对灰浆力学性能的负面影响。必须强调其沉淀的重要性，以获得足够的性能。
