固废磷化渣资源化的研究-化学工程专业论文.docxVIP

PAGE PAGE VI III III Abstract Widely used as a metal surface treatment technology, phosphating process has a wide range of applications in the chemical industry, metallurgy, automobile, aerospace,shipbuilding and other fields. Bound to produce the solid waste phosphate residue, with iron phosphate.and zinc phosphate as the main component , phosphating process emits solid waste to the environment, causing secondary pollution. Therefore, the research on the process of transforming phosphate residue in the solid waste into resources has a great significance. In this paper, the new process.of treating solid waste phosphate residue with caustic soda to extract the valuable phosphorus, iron resources has been studied. Through chemical analysis, there are four elments in phosphate residue, with PO43-51.8%,Fe3+27.5%,Zn2+2.35% and they main exist in the form of iron phosphate.and zinc phosphate. In this work ,the methods to prepare twelve H2O phosphate sodium , nano-hydroxyapatite (HAP) and phosphoric acid have been studied to utilize the phosphate residue solid waste. Preparation of twelve H2O phosphate sodium:At 110 ° C and stirring condition, as the mass ratio of 1.25:1, the NaOH solution was slowly added to the phosphate residue. After reaction about 2 hours, adding a amount of water strictly controled the pH between 10 and 11, then continued to react for 0.5 hours, At this point ,the extraction rate of PO43- in the phosphate residue turned out to be 91.45%.Finally ,Na3PO4 solution was filtered, evaporated, crystallizated, with the mass fraction of sodium phosphate crystals up to 98.55%; Preparation of nano-hydroxyapatite:In the stirring and ultrasonic condition, by chemical precipitation ,Na3PO4 solution was slowly dropped into the saturated Ca(OH)2 solution to prepare nano-HAP, and the HAP was characterized by infrared absorption spectroscopy (FT-IR), X Ray diffraction (XRD) and scanning electron microscopy (SEM) . The results showed that nano-HAP prepar