Influence of different additives on the mechanical performance of a-hemihydrate gypsum from phosphogypsum

Application and Development Prospects of Phosphogypsum in Different Phases: A Review

“…Mild reaction conditions 2) Not requiring special equipment 3) Easily control of conversion process and product quality [42] 1) Low yield 2) Corrosion of sodium, magnesium, and calcium plasma to the equipment [18] To further elucidate the intricate relationship among process preparation, experimental conditions, crystal morphology, and material strength, Table 3 presents a comprehensive comparison of crystal morphologies across different process routes. The [G was initially pretreated using the ball milling method by Hongbin Tan et al [43] Subsequently, a mixture of gypsum and tap water in a mass ratio of 1:5 was introduced into an autoclave, followed by the addition of maleic acid to adjust the solution's pH value to 5. After stirring for 30 minutes and aging at 140℃ for 2 hours, the product flexural strength /compressive strengths of 8.2 MPa/25.4 MPa.…”

“…SEM characterization revealed that the hydration products of the washed samples exhibited predominantly rod-shaped crystals with enhanced bonding strength, thereby improving the mechanical properties of the gypsum products, and the 2 hours compressive/flexural strength of the products was 5.7/3.0 MPa. Longjian Zhang et al [52] discovered that, under the experimental conditions of calcination at 180℃ for 4 hours, PG underwent complete transformation into β-hemihydrate gypsum. At this stage, the product exhibited a compressive strength of 9.2 MPa after 28 days.…”