Method for purifying non-metallic impurities in titanium-containing filtrate

Abstract

The invention relates to the field of polyolefin catalysts, and discloses a method for purifying non-metallic impurities in titanium-containing filtrate. The method comprises the following steps: 1) evaporating the titanium-containing filtrate through a film evaporator to obtain titanium-containing distillate; 2) mixing the titanium-containing distillate with an alcohol organic solvent and an inert organic solvent to obtain a mixture of the titanium-containing distillate; 3) standing and layering the mixture, and carrying out liquid-liquid separation on the oily mixture at the lower layer and the supernate; and (4) carrying out distillation separation on the supernate to obtain titanium tetrachloride and an organic solvent, wherein the titanium-containing filtrate is one or a mixture of two or more of mother liquor and titanium treating fluid generated in the ethylene polymerization catalyst preparation process. According to the method, the utilization rate of the raw materials is obviously increased, waste acid residues generated in the treatment process are greatly reduced, non-metal impurities in the filtrate are effectively removed, and the recovery rate of titanium tetrachloride in the titanium-containing distillate is greatly increased.

Description

Technical field [0001] The present invention relates to polyolefin catalysts, and in particular relates to a method for purifying titanium-containing non-metallic impurities in the filtrate. Background technique [0002] In the industrial production of polyolefins, the titanium catalyst due to the high catalytic efficiency and inexpensive to obtain a more widely used. At present a common method for preparing such a catalyst is firstly prepared which is dissolved magnesium, such as magnesium or a magnesium compound by uniformly dispersed in one or more solvents, the further addition of magnesium was prepared under the action of organic builders lysate and phosphorus-containing solution by dissolving magnesium and a halogen-containing compound such as titanium tetrachloride is prepared by reacting magnesium or a magnesium compound as the main structure of the catalyst, during which accelerator may be added for a variety of improved performance, these accelerators , silicon element....

AI Technical Summary

Problems solved by technology

One problem with this process is that a large amount of waste acid slag containing various organic substances is produced during the hydrolysis process, which requires further treatment, so it faces increasingly serious environmental and economic pressures

[0007] Although the above-mentioned first method reduces the generation of acid water to a certain extent, the resulting solid waste contains a large amount of organic matter, which obviously requires further subsequent treatment, and the treatment process is complicated.

The second method, although the recovery rate of titanium tetrachloride is improved, but at high temperature, oily lumps are formed in the waste liquid, which affects the subsequent evaporation process

In the third method, although the conditions such as the temperature of the thin-film evaporator are optimized, the problem of high-temperature coking of the material is solved, but the impurities are not effectively removed, and the recovery rate of tetrahalides is still not ideal.