Synthesis And Application Of Hydroxamic Acid Polyacrylamide Flocculant

Based on the summary and analysis of existed studies of polymer flocculant, series of researches were conducted to synthesis hydroxamic acid polyacrylamide flocculant and the application in the red mud settling.By measuring the molecular weight and time required for dissolution of the product, the technological parameters were systematically studied, such as monomer concentration and pretreatment, modes of feeding the initiator V50and its concentration, dosage of sodium formate, initiating temperature and reaction time. Under the optimum technological parameters, the synthesized polyacrylamide hydrosol had high molecular weight and could be dissolved rapidly.With hydroxylamine hydrochloride and sodium hydroxide as modified reagent for hydrolyzing and oximation.polyacrylamide hydrosol was directly modified in the method of two-stage temperature control technology. By analysing ferric chloride adsorption coloration, infrared spectroscopy and red mud flucculation performance of the product, optimum conditions were obtained:PAM concentration was8%, the pH of hydroxylamine alkali solution was13.5, no alkali supplement, hydroxylamine amide molar ratio was1:1, hydroxamation at60℃for3hours and hydrolyzing at85℃for2hours.For self-made hydroxamic acid flocculant and several flocculant products used commonly in the alumina industry, the solid content, the infrared spectra and their flocculation properties in different types of red mud were analyzed. Compared with other flocculants, the red mud flucculation performance of synthesized hydroxamic acid anionic polyacrylamide was significantly improved, which gived faster settlement as well as higher clarity of supernatant.