Study On The Preparation Of Amorphous Silica By High Gravity Technology

As an important inorganic polymer chemical product and a rubber reinforcing agent, amorphous silica has been widely used and has been making the improving role in the modern chemical industry. Compared with the traditional method with the drawbacks of more reaction time and consumption of energy, the new preparation method technology developed by the High Gravity State Key Laboratory, Beijing University of Chemical Technology has a lot advantages such as less production time and energy consumption, easier control of the product’s quality.Preparation method of high gravity in laboratory stage has been developed successfully and all the performance parameters of the sample can reach standards of industry and nation. In view of this, a manufacturer decided to cooperate with the laboratory group to enlarge the original reactor of small scale by forty times on the basis of the laboratory stage. A new reactor and the matching process of continuous preparation process have been redesigned. The study on the modification of the silica prepared by the high gravity method has been made. Issues involved in the experiment are as follows:(1)According to the requirements of the manufacturer, the preparation process had been enlarged by forty times based on the laboratory stage and the sodium silicate flow-rate was controlled on10m3/h approximately. A new Rotating Packed Bed had been designed and made, correspondent improvement and process optimization had also been made according to the existing problems in the experiment.(2)A single factor experiment was designed to study the influence of the preparation method in silica. Gradual optimization of the experimental operating parameters were made during the experiment which included changing the different reaction temperatures, the rotational speed of the rotating bed, the aging time, aging temperature, filter cake washing time, the way samples dried, then BET specific surface area, DBP oil absorption value, and soluble salt of the samples were measured and all the parameters involved above reached the national and industrial standards. All the effort made above could provide effective experimental data and experimental process for the next level of industrialization..(3)Different modification agents such as TMCS and HMDOS were used to modify the silica prepared by high gravity method. The modified silica was of great hydrophobicity. In order to further determine the effects of the modified agents, modified silica was used to mix with styrene-butadiene rubber, mixing effects and mechanical properties of the resulting rubber improved dramatically. In the same condition the modification effect of HMDOS was better than the TMCS.