Titaniumrich hydrochloric acid leaching residue, use thereof and preparation method of titanium dioxide

摘要

Enriched titanium hydrochloric acid extract residue is provided, for use as the feed stock in the preparation of titanium pigment by sulfuric acid process. The present invention belongs to the field of the preparation of titanium pigment and particularly, relates to the enriched titanium hydrochloric acid extract residue prepared from ilmenite by hydrochloric acid leaching, its use and the method of preparing titanium pigment. The method for preparing titanium pigment using the enriched titanium hydrochloric acid extract residue can effectively utilize the fine ilmenite in Panxi area (the utilization rate is almost 100%), obtain the titanium sulfate solution with an ultralow ratio of iron to titanium dioxide (Fe/TiO2) and double the throughput of digesting equipment. Said method can simultaneously spare two steps of iron removal by freezing and titanium sulfate solution concentration with much energy consumption, reduce the times of washing with metatitanic acid, thereby, both of the discharge of acid waste water and the production of FeSO4 are reduced. Said method provides a feed stock selection for preparing titanium pigment by sulfuric acid process.

主权项

1. Enriched titanium hydrochloric acid extract residue suitable for use in the preparation of titanium pigment by sulfuric acid process, wherein the extract residue is composed of metatitanic acid aggregates and loose and porous residue obtained after removing iron from crystal lattice of ilmenite (FeTiO3) by hydrochloric acid leaching, wherein the loose and porous residue comprises rutile, titanaugite and amorphous TiO2, and wherein the extract residue is prepared by:
a. preparing enriched titanium hydrochloric acid extract residue solid from ilmenite by hydrochloric acid leaching and; b. drying the solid prepared in step a to obtain enriched titanium hydrochloric acid extract residue having a water content of no more than 20%, and wherein the extract residue can be dissolved by sulfuric acid wherein the extract residue is white, light yellow or light grey particle or powder and comprises 65-97 wt % amorphous TiO2, the total iron content is no more than 8 wt % and the specific gravity of the extract residue is 2.9-3.6.