A Sustainable Composite Cementitious Material Manufactured by Phosphogypsum Waste

Abstract

The phosphogypsum is a by-product of the phosphate fertilizer industry. It has accumulated over several decades, and not only takes up a large amount of land, but also poses a significant risk to the environment and resource waste. In order to promote the use of phosphogypsum, its hydration hardening characteristics are studied using a scanning electron microscope, X-ray diffractometer and mercury intrusion porosimeter. When the amount of phosphogypsum is increased, a decreasing trend in the reaction degree, non-evaporable water and portlandite is observed. Among them, the reaction degree and non-evaporable water, flexural strength and compressive strength reached their maximum when the content of phosphogypsum was 10%, which were as follows: 22.34 %, 21.13 %, 9.02 MPa and 49.8 MPa, respectively. Meanwhile, phosphogypsum can participate in the secondary hydration reaction in the system and act as a microaggregate. The addition of no more than 30% phosphogypsum can enhance mechanical characteristics, reduce porosity, refine pore size distributions and densify the microstructure. The findings of this study may aid in the production of phosphogypsum-based composite cementitious materials with superior performance, thereby promoting phosphogypsum recycling and protecting the environment.

Application of the Industrial Byproduct Gypsum in Building Materials: A Review

“…A significant quantity of Fe 2 O 3 is found in TG, while the content of CaSO 4 is relatively low [29]. PG comprises minor quantities of H 3 PO 4 , Ca(H 2 PO 4 ) 2 •H 2 O, CaHPO 4 •2H 2 O, and various trace metals [30]. FG contains CaF 2 and H 2 SO 4 in the range of 1% to 3% [31].…”

“…PG has been used in several studies on gelling materials. Only PG and cement hav been used to prepare cementitious materials to study the effect of PG doping on the prop erties of cementitious materials [30]. PG content affected the rate of hydration reactions At the same time, the greater the PG doping was, the greater the porosity, but the por size distribution of the mortar improved to a small extent when 10% PG was doped com pared with when no PG was doped.…”

“…Using PG to replace part of the cement realizes the resourceful use of th PG has been used in several studies on gelling materials. Only PG and cement have been used to prepare cementitious materials to study the effect of PG doping on the properties of cementitious materials [30]. PG content affected the rate of hydration reactions.…”

Effects of Pretreated Phosphogypsum and Granulated Blast-Furnace Slag on the Rheological Properties of the Paste Excited by NaOH

“…Therefore, an increasing number of experts and scholars are calling for the implementation of carbon tax policies to promote the transformation of the cement industry and reduce carbon emissions. It is noteworthy that after proper pretreatment, many industrial solid wastes in Guizhou, China, demonstrate a certain pozzolanic activity and even hydraulicity, and can be used as supplementary cementitious materials for cement and concrete [ 6 , 7 ]. In particular, since the German scholar Kuhl proposed alkali-excited cementitious materials, which have the advantages of a low cost, corrosion resistance, high-temperature resistance, and low energy consumption, they have extensively attracted the attention of scholars [ 8 , 9 ].…”

Effects of Sodium Gluconate on the Fluidity and Setting Time of Phosphorus Gypsum-Based Self-Leveling

“…Due to the incomplete understanding of phosphogypsum in the early days, a lot of phosphogypsum was piled up near rivers and oceans, and the accumulation of a large amount of phosphogypsum caused significant damage to the surrounding environment, such as polluting the nearby soil and making the water source eutrophic, etc. [3][4][5]. Therefore, during the period of rapid national development, it is of great significance to seek new ways of complete utilization of phosphogypsum to improve the comprehensive utilization rate of phosphogypsum and to promote the construction of socialist modernization and civilization.…”