The production of high-grade synthetic rutile from low-grade titanium-bearing ores

摘要

The present invention relates, first, to a two-stage leaching process using concentrated hydrochloric acid wherein ground ore is leached with two separate quantities of hydrochloric acid at different temperatures. Second, the invention relates to a one-step leaching process using concentrated HCl and a fixed acid to ore ratio to prevent hydrolysis of titanium. Afterwards the dissolved titanium is precipitated from the filter liquor by hydrolysis and the still soluble iron chlorides are then optionally subjected to oxyhydrolysis to recover iron oxide and HCl. The process was developed for low-grade ores (under 12% Ti02), and can naturally be applied advantageously to higher grade titanium-bearing ores, that upgrades a variety of inferior quality titanium-iron ores into premium titanium concentrate and iron oxide products.