Study On Phosphogypsum To Building Lightweight Thermal Insulation Material

Phosphogypsum is the industrial waste residue when manufacturing the phosphoric in phosphate fertilizer and so on. Nowadays, the way of dumping in the ocean and stockpiling in the land are been widely processing to the phosphogypsum, which had caused serious environmental impact. The impurities in phosphogypsum, such as phosphoric acid, fluoride, phosphates, organic ingredients and so on, had effected the use of phosphogypsum at a large extent. The Utilization of phosphogypsum is very low, and can not be widely applied to the market. With the significant improvement of people`s living life, the series of policies about restricting the use of clay brick and encouraging the development of new materials have promoting the exploration and research on phosphogypsum preparation lightweight, which promoting the efficient use of resources and the protection of environment.This paper studied the preparation of lightweight insulation blocks. Phosphogypsum as the basic raw material andα- hemihydrate gypsum as the cementitious, materials, fiberglass, foam as the ingredients had been used to prepare the reusable and high utilization of lightweight insulation blocks by using steam curing on twice, and the phosphogypsum has not been the processing of calcining. First, the lime had been mixed with phosphogypsum to neutralize acidic substances to improving the final strength of insulation block. Then α- hemihydrate gypsum had been prepared on using a steam curing. The best stirring time and stirring speed, steam curing temperature and time are 3min, 300 r / min, 140 ℃、3h by using a single design factor. After the lightweight insulation block has been By using the single factor and orthogonal test to determine the best ratio and composition of the system, discuss the main process parameters of lightweight insulation blocks. The hydration product, hydration mechanism, microstructure and so on had been observed by SEM、XRD、DSC/TG analysis and other testing methods.This paper shows the the feasibility of lightweight insulation block molding. After the mixing of phosphogypsum and α- hemihydrate gypsum, fiberglass, foam according to certain proportions could moulding lightweight insulation block with compressive strength 1.69 MPa, flexural strength 1.74 MPa, thermal conductivity 0.18 w / m ? k and softening coefficient of 0.83 according to certain proportions...