| Phosphate is an inorganic acid, it is extremely important chemical raw material for widely used in feed, flame retardants, food industry, and water treatment industry, electronics industry, and detergent industry and so on. The major production methods of the phosphoric acid are wet process phosphoric acid and hot phosphoric acid, with the thermal phosphoric acid there is kiln phosphoric acid. Wet-process phosphoric acid is low energy consumption than the thermal phosphoric acid, but the purity of the products is low. There is a high purity of the thermal phosphoric acid, it can be used for the LCD, chip, high-purity electronic grade phosphoric acid, food grade, pharmaceutical grade, toothpaste grade phosphate and so on, but low utilization rate and high energy consumption are the big problems during phosphoric acid productions.Yunnan research institute of chemical industy has developed the patented technology of yellow phosphorus combustion heat recovey and utilization of devices and their thermal phosphoric acid production system.The patented technology is greatly promoted in the industry, and it promotes the progress of thermal phosphoric acid production and energy-saving technology. However, due to lack of material structure and its formation conditions the formation of yellow phosphorus combustion process burning phosphorus tower P4O10wi-th H2O system, limit the use of high-grade heatand the further development of engineering technology.This thesis has designed and produced a small device. It directly uses phosphorus pentoxide and water which is bring by nitrogen going reaction then through condensation to collection products. This reaction simulates the yellow phosphorus burning to generate P4O10then reacts with the small amou-nt of moisture into the air. Form a layer of cladding (conjunctiva material) experiment in the inner wall of the burning phosphorus tower equipment. By adjusting the proportion of phosphorus pentoxide and water as well as reaction temperature, in order to get the conjunctiva matter similar to industrial production on the device.Firstly we use the different form of phosphorus pentoxide to do heating experiment find out the evaporation rate of hexagonal h-of P2O5is relatively stable, so choosing h-P2O5as a raw material react with the water. Through the calculation of phosphorus contented and residence time of industrial production, designing a set of laboratory experiments small reactor. By the preliminary exploration of the burning phosphorus to generate conjunctiva ma-terial to select reaction temperature and H2O/P4O10quality as the two experi-mtal impact factors experiment,the selected range are450～870℃and1:32～1:2. Through analysis the phosphorus pentoxide content,thermo gravimetric and X-ray diffraction of certain conditions reaction products, The following conclusions:when the temperature is lower conjunctive material’ can be divided into the white layer and the transparent layer, and the tempera-ture is relatively higher conjunctive material can be divided into the white layer, semi-transparent layer and transparent layer. White layer is phosphorus ento-xde, translucent layer is phosphorus pentoxide and with little phosphor-ic acid, transparent layer is most of new material and containing traces of metaphosphoric acid or pyrophosphate. Whole the conjunctiva matter is a mix-ture. Experimental of controlling time found that the conjunctiva matter first generation white layer and then transfer into a semi-transparent layer finally becomes the transparent layer. Through the crit-ical point experiments always have equipment on the roof of the scope of the study conjunctive material ge-nerated so do not worry about corrosion of the top cover.The above information combined with thermodynamics and reaction structured preliminary analysis of the product of the formation mechanism of the reaction of phosphorus pentoxide and water laboratory to simulate the yellow phosphorus combustion generated conjunctiva matter further comments and s-uggestions. |
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