규산알루민산마그네슘의 합성조건과 유동학적 특성

Synthesis Conditions and Rheological Characteristics of Aluminum Magnesium Silicate

Aluminum magnesium silicate was synthesized by reacting the mixed solutions of sodium aluminate and magnesium chloride with sodium silicate solution in this study. The optimal synthesis conditions based on the yield of the product has been attained according to Box-Wilson experimental design. It was found that the optimal synthetic conditions of aluminum magnesium silicate were as follows: Reaction temperature=69~81oC; concentration of two reactants, sodium aluminate and magnesium chloride= 13.95~14.44w/w%; molar concentration ratio of the two reactants, [NaAlO2]/[MgCl2]=3.63~4.00;reaction time=12~15 min;drying temp. of the product=70~76oC. Aluminum magnesium silicate synthesized under the optimal synthesis condition was dispersed in 0.75, 1.0 and 1.5w/w% aqueous solution or suspension of six dispersing agents, and the rheological properties of the dispersed systems prepared have been investigated at 15oC and 25oC using Brookfield LVT Type Viscometer. The acid-consuming capacity of the most excellent product was 272~278ml of 0.1N-HCl per gram of the antacid. The flow types of 5.0w/w% aluminum magnesium silicate suspension were dependent upon the kind and concentration of dispersing agents added. The apparent viscosity of the suspension was generally increased with concentration of dispersing agents and was not significantly changed or decreased as the temperature was raised. A dispersing agent, hydroxypropyl cellulose suspension, exhibited an unique flow behavior of antithixotropy. The flow behavior of the suspension dispersed in a given dispersing agent not always coincided with that of the dispersing agent solution or suspension itself.