Preparation And Producing Improvement Of Magnesium Acetate Solution During The Producing Process Of Cellulose Acetate Fiber

In this thesis, the preparation process of the magnesium acetate solution was studied and improved during the production of cellulose acetates. In this process, the magnesium acetate solution was obtained by mixing the magnesium oxide (MgO) particles and20%acetic acid solution, and then being filtered to remove solid impurities. This paper studied the influence factors on the reaction activity of MgO, on the influence factors and filtering improvement of magnesium acetate solution.Several factors on the reaction activity of MgO were studied. The results showed the change of temperature rise rate related with the reactivity of MgO. The highter the temperature rise, the better the reactivity of MgO. The more amount of particles in100to200mesh of MgO showed better reactivity. When the temperature rise was greater than or equal to6℃, the reactivity of MgO could meet the production requirements. In the actual producing process, it was appropriate to increase the proportion of100to200mesh particles.In the part of research on the influence on the reaction and improvement of the magnesium acetate solution, the results showed that the higher temperature was not conducive for the iron ions to form Fe(OH)3precipitate, which led to lower iron ion retention rate. By cooling, the iron ion retention rate increased. With the decrease of the residual acetic acid, pH value increased and the magnesium iron retention rate gradually increased, peaked at98%. Hence, pH=5.7-6.3was suitable for the preparation of magnesium acetate solution. The iron retention rate increased when the reaction time increased, and the resulted clarifying degree of filtrate increased. As a result,6hours of reaction time fitted. The iron retention rate of orthophosphate was better than that of other iron types. Finally, the production results showed that, the iron ion content of magnesium acetate was reduced to below1Oppm, and the iron retention rate was more than94.6%.Studing filtering improvement of the magnesium acetate solution, diatomaceous earth and polymeric flocculating agent were used to deal with blocked filters by small particles and the viscous. The results showed that diatomaceous earth did well in improving the filtering efficiency of magnesium acetate solution, but because the contained iron, potassium and sodium could dissolve in90℃, diatomaceous earth should not be used in industry. Under low acidity, eight polyacrylamide flocculants exhibited effective filtration property, and the clarity and turbidity of filtrates significantly improved. Among them AP1120showed the optimum fitration, where the power could be added directly, and the optimum dosage was 8ppm. The temperature had little effect on the flocculation but done well in the solubility of flocculants. High temperature was benefit for the mass production of magnesium acetate.All aboved results had been proved effectively by industrial equipments.