Study On Preparation Of Light Wall Materials By Phosphogypsum α Hemihydrate Gypsum

Phosphogypsum is an industrial by-product from the processing of phosphoric acid by the phosphate rock, its main component is calcium sulfate dihydrate, and contains phosphoric acid, phosphate, fluoride, a small amount of radioactive material and fatty acids, organic amines and ketone impurities. In China, phosphogypsum production is variously estimated to be more than 40 million tons per year. The use of phosphogypsum is probably well below 10% of output. The main reason is the presence of minor components having a negative impact on the performance of product. And the by-product is usually occupied considerable land areas exposed to weathering processes, causing serious environmental damage of soil, air, water. Currently, a great deal of researchers at home and abroad devoted themselves to the utilization of phosphogypsum. At present, the use of phosphorus gypsum manufacture building materials are the main effective way of phosphogypsum resource utilization.The building energy consumption accounts for about 50% of the total energy consumption of society in our country, so the foaming plaster wall materials as a kind of green environmental protection material, having light, noise, thermal insulation, sound insulation and other characteristics are more and more attention and widely used. So the using of phosphorus gypsum alpha half water gypsum manufacture the lightweight wall material, it can not only reduce the consumption of natural gypsum, and can use such a large tonnage of emissions, has great economic benefits and environmental benefits.In this paper the phosphogypsum alpha half water gypsum is manufactured by the laboratory pilot test base. It manufacture the light wall materials by adding foaming materials preparation, then studying the light wall materials of process conditions and the regularity of foaming material affectting the performance. By testing means of the electronic universal testing machine, scanning electron microscopy (SEM) to research its structure and crystal morphology of the half water gypsum. The research content mainly includes the following aspects: (1) Studying the based performance of phosphogypsum alpha half water gypsum of be manufactured by the laboratory pilot test base. It main test its three main properties:one is the liquidity, main purpose is to obtain water consumption standard, next it is to test its retarding time, getting the initial setting time and final setting time. Last it is to test the dry basis of gypsum block flexural and compressive strength by the standard of water. The results show that the experiment material finally choose water consumption is 0.45 according to the GB9776-2008 standard for building gypsum of the standard slurry cake diameter is 180 mm ±5 mm. The water usage for standard consistency water consumption is a standard table fluidity. So the initial setting time of block is 5 min, final setting time of the block is 27 min. The bending strength dry base block is 7.2 MPa; the compressive strength of dry base block is 22.6 MPa, density of the dry block is 1.40 g/cm3.(2) The research of hydrogen peroxide foam process research. First, it select the hydrogen peroxide solution foaming process through the contrast test; Secondly, it research the hydrogen peroxide, excitation agent, retarder and the ratio of surfactant content on the influence law of light wall materials by single factor experiment, multi-factor experiment; Thirdly,it is to determine the technological process of phosphorus gypsum alpha half water gypsum manufacturing light wall materials process.(3) The characterization analysis result of phosphogypsum half water gypsum light wall materials using hydrogen peroxide solution foaming material show that the bubble of light wall materials is uniform, pore diameter between 0.8-1.2 mm.The wall of hole is whole, the block surface is smooth. Through test, the intensity of block relative to the above is higher. At the same time, due to the increase in the Numbers of stomata and better stomatal pore wall integrity, block the heat preservation, sound insulation, water resistance of block will be improved.By experiments show that the water cement ratio of 0.45,3.00 mL/kg pulp hydrogen peroxide dosage,0.20 g, dosage of MnO2 and retarder admixture is 0.50‰,0.10‰ dosage of surface active agent and, under the process of phosphorus gypsum block dry base compressive strength is 7.90 MPa, flexural strength is 2.31 MPa, the volume density of 0.80 g/cm3.