Application of overhead stirrer in active silicic acid polymerization

Active silicic acid is an important raw material for preparing a silicic acid coagulant and a novel metal ion-containing polysilicate-based inorganic polymer flocculating agent, and the polymerization rate of the active silicic acid is significantly affected by the stirring speed. Experiments have shown that the morphological changes of active silicic acid during polymerization are monitored and characterized by laser light scattering, turbidity, viscosity and other characterization methods. The results show that the faster the stirring speed, the faster the polymerization rate of silicic acid. However, the effective particle size formed is smaller; the preparation of active silicic acid under static conditions is beneficial to the formation of high molecular weight, high viscosity, high turbidity polysilicic acid, which is more conducive to the adsorption of polysilicic acid. This provides an experimental basis for the preparation of high-efficiency coagulants.

It is well known that in a chemical experiment, stirring is often used to accelerate a certain chemical reaction rate, because agitation can cause more effective collisions between reactant particles to accelerate the progress of the entire reaction. However, in the complex process of silicic acid polymerization, the effect of agitation will be different from that played in the general chemical reaction process. It will play two roles: 1) Destroy the silicon produced during the polymerization of monomolecular silicic acid. The result of the oxyalkylene bond will result in a significant decrease in the rate of polymerization of the silicic acid, thereby prolonging the freezing time of the polysilicic acid; 2) stirring will accelerate the effective collision between the monomolecular silicic acid particles, which will accelerate the polymerization and shorten the polysilicic acid. The freezing time.

In the active silicic acid polymerization experiment, it is very important to choose a stable stirrer. The agitator widely used in the industry is an overhead stirrer produced by VELP, Italy. The VELP overhead stirrer is made of corrosion-resistant material and epoxy-coated metal construction. The VELP overhead stirrer can be stirred for a maximum viscosity of 50,000 mPa*s. The VELP Overhead Mixer has two clear, easy-to-read displays that show the current speed and set speed. The VELP overhead stirrer has constant speed control. When the viscosity of the sample changes, the stirring speed of the VELP overhead stirrer is always constant. When the mixer malfunctions, the system prevents the operation from continuing and ensures the safety of the instrument.