Method for preparing pearlescent pigment from ilmenite hydrochloric acid acidolysis solution by co-extraction

A preparation method of pearlescent pigment coating materials is provided. The method of the present invention lies in that titanium-iron ions in ilmenites are dissolved by using a hydrochloric acid at a certain temperature and pressure, and then ferrous chloride in the acidolysis solution is precipitated by adding hydrogen chloride gas, the remaining titanium-iron ions are separated from other colored ions by means of co-extraction using an extractant upon oxidation, and an enriched titanium oxydichloride solution and ferrous hydrous oxide are obtained by employing a fractional back extraction and enrichment method, the titanium oxydichloride solution can be used for mica-titanium based pearlescent pigment coating materials, and can also be used for preparing titanium dioxide; and the acidified ferrous hydrous oxide and the oxidized ferrous chloride can be used as iron based pearlescent pigment coating materials or used for preparing iron oxide pigments.