Extraction of products from titanium-bearing minerals
AssigneeAvertana Limited
InventorsDavid Jonathan Hassell, James Kevin Obern, Sean Daniel James Molloy, Sherif Owen Zaki Emad Marshall Ibrahim, Mohammed Shereez Ali
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Abstract
The invention relates to a process for extracting metals and salts from titanium-bearing minerals such as perovskite. More particularly, although not exclusively, the invention relates to extracting titanium dioxide and optionally other compounds from melter slag derived from an iron-making process.
Claims24
A method of recovering titanium dioxide, aluminium sulphate and magnesium sulphate from a particulate material, said method comprising:
- a. contacting the particulate material with sulphuric acid and heating to form a sulphated mixture;
- b. filtering the sulphated mixture to produce a filter cake and a first permeate comprising sulphuric acid;
- c. contacting the filter cake with water to form a sulphated suspension comprising titanyl sulphate;
- d. filtering the sulphated suspension to produce a permeate comprising at least titanyl sulphate, and a retentate comprising insoluble residue;
- e. contacting the permeate comprising at least titanyl sulphate with water to produce a hydrolysis liquor;
- and
- f. hydrolysing the titanyl sulphate;
- g. separating titanium dioxide hydrate from the hydrolysis liquor to produce a permeate comprising aluminium sulphate and magnesium sulphate, and a retentate comprising titanium dioxide hydrate;
- and
- h. precipitating aluminium sulphate from the permeate;
- i. precipitating magnesium sulphate from the permeate;
- wherein step h. may be carried out after step d or after step g.
The method of any one of the preceding claims wherein the precipitation of magnesium sulphate comprises the steps of:
- a. increasing the acid concentration of the permeate comprising magnesium sulphate to form an acidified liquor;
- and
- b. filtering the acidified liquor to produce a retentate comprising precipitated magnesium sulphate.
The method of any one of the preceding claims wherein the particulate material comprises greater than 8 m % titanium dioxide, greater than 10 m % aluminium oxide and greater than 10 m % magnesium oxide.
The method of any one of the preceding claims wherein the particulate material comprises greater than 15 m % titanium dioxide, greater than 10 m % aluminium oxide and greater than 13 m % magnesium oxide.
The method of any one of the preceding claims wherein the particulate material comprises a ratio of titanium dioxide to aluminium oxide (TiO2:Al2O3) of approximately 0.2 to 2.6.
The method of any one of the preceding claims wherein the particulate material comprises a ratio of titanium dioxide to magnesium oxide (TiO2:MgO) of approximately 0.5 to 3.0.
The method of any one of the preceding claims wherein the particulate material is selected from the group consisting of iron slag, melter slag, obtained from iron slag, obtained from melter slag, obtained from an iron manufacturing process, and obtained from a steel manufacturing process.
The method of any one of the preceding claims wherein the method further comprises the step of grinding raw material to form the particulate material of step a.
The method of any one of the preceding claims wherein the particulate material is contacted with 4-10 times its stoichiometric quantity of sulphuric acid.
The method of any one of the preceding claims wherein the step of filtering the sulphated mixture further comprises contacting the mixture with compressed air.
The method of any one of the preceding claims wherein the permeate comprising at least titanyl sulphate is heated to remove water and increase the free acidity.
The method of any one of the preceding claims wherein the hydrolysis liquor is contacted with water containing titanium dioxide particles.
A product produced by the method of any one of the preceding claims, the product being selected from:
- a. titanium dioxide;
- b. silica;
- c. calcium sulphate;
- d. aluminium sulphate;
- or
- e. magnesium sulphate.
A system for the recovery of products from a particulate material, the system comprising:
- a. a reactor adapted to receive and heat sulphuric acid and particulate material comprising at least titanium dioxide and produce a sulphated mixture;
- b. a first filtration unit adapted to receive the sulphated mixture and produce a first permeate comprising at least sulphuric acid, and a filter cake comprising at least titanyl sulphate;
- c. a reactor adapted to receive a solution comprising titanyl sulphate and heat said solution to produce a hydrolysis liquor;
- d. a separation unit adapted to receive the hydrolysis liquor and separate titanium dioxide hydrate.
- e. at least one precipitation tank to facilitate precipitation of aluminium sulphate;
- and
- f. at least one further filtration unit to facilitate separation of precipitated aluminium sulphate.
- g. at least one precipitation tank to facilitate precipitation of magnesium sulphate;
- and
- h. at least one further filtration unit to facilitate separation of precipitated magnesium sulphate.
Dependencies are inferred from the claim text.