Preparation method of silica gel for polyolefin catalyst carrier

Abstract

The invention provides a preparation method of a silica gel carrier for a polyolefin catalyst. The silica gel is prepared through a gel reaction by using alkaline silica gel, silicate and an inorganic acid as raw materials. The preparation process comprises the steps of: taking the alkaline silica sol as a reaction base solution; adding the silicate and the inorganic acid through a concurrent flow mode; and finishing the preparation process of the silica gel carrier by controlling a pH value of a reaction system and combining a high temperature hydrothermal reaction. The preparation method of the silica gel carrier for the polyolefin catalyst has the advantages that in the reaction, new colloidal particles generated in the gel reaction and the sol reaction directly react with hydroxyl on the silicon sol surface, and the cross-linking between sol particles is finished by constant aggregation; and the high temperature hydrothermal reaction at the later period quickens the reaction between gel particles, thereby greatly improving the pore volume and the aperture of the silica gel. Because the performance of the added silica sol is similar to that of the silica gel, the process control is easy. The silica gel pore volume and the aperture are improved, and the technology repeatability is good. The preparation method of the silica gel carrier for the polyolefin catalyst brings benefits for the industrial production.

Description

technical field [0001] The invention relates to a method for preparing silica gel, in particular to a method for preparing a silica gel carrier for polyolefin catalysts. Background technique [0002] Silica gel has special pore structure, large specific surface area and excellent thermal stability, and has been widely used as adsorbent, desiccant, chromatographic column support and catalyst support. At present, there are many ways to prepare silica gel. The most common method is to use silicate and inorganic acid as raw materials, react at a certain pH value to form a gel, and then undergo aging, washing, pickling, drying and other processes to obtain silica gel. [0003] The silica gel carrier for polyolefin catalyst requires suitable specific surface area, pore volume and pore diameter. In order to obtain better or specific silica gel physical properties, many improved process schemes have been reported for the preparation of silica gel carrier. Including using inorganic ...

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Problems solved by technology

The inventors have shown through experiments that the repeatability of the process is difficult to control due to the complexity of the process (formation of primary particles in the early stage, repeated sol and gel in the later stage), or the addition of pore-enlarging agents (fatty alcohols), and the quality stability of silica gel products is poor.

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