Sulfate digestion process for high purity TiO₂ from titania slag

Abstract

A titania slag product of Rosetta ilmenite assaying 72% TiO₂ is treated by the sulfate process option of the pigmentary TiO₂ manufacture. The relevant factors of acid concentration, particle size, slag/acid ratio besides the reaction temperature, and time have been studied. After dissolving the cured mass in dilute acid and clarification, the obtained solution was subjected to hydrolysis of its titanium content. The final product was bleached under reducing conditions to redissolve the residual coloring impurities before being dewatered and calcinated. The obtained results indicated that a leaching efficiency of about 92% was realized due to the presence of some refractory components in the working slag material, namely, rutile and magnesium iron titanate. The obtained white pigment assay attained up to 99.85% TiO₂, while the analyzed impurities involve 77 ppm Mn and only 14 and 7 ppm of total iron and V, respectively.

Keywords

titania / slag / sulfate process / pigment

References

[1] Harben P W. The Industrial Minerals HandyBook, 3rd Edition, London, UK. 1999, 216-223

[2] Becher R G, Canning R G, Goodheart B A, Uusna S. A new process for upgrading ilmenite minerals sands. Proc. Australas. Inst. Min. Metall. 1965, 21: 1261-1283

[3] Chen James H, Tex C C. US Patent, <patent>3825419</patent>, 1974

[4] Schoukens A F S, Morris D J, Stephen MC. US Patent, <patent>6733561 B2</patent>, 2004

[5] Sahu K K, Alex T C, Mishra D, Agrawal A. An overview on the production of pigment grade titania from titania-rich slag. Waste Manage Res, 2006, 24: 74-79

[6] Mackey T S. Upgrading ilmenite into a high-grade synthetic rutile. Journal of Metals, 1994, April: 59-64

[7] Gueguin M. US Patent, <patent>4078039</patent>, 1978

[8] Gueguin M. US Patent, <patent>4933153</patent>, 1990

[9] Gueguin M. US Patent, <patent>5063032</patent>, 1991

[10] Gueguin M. US Patent, <patent>5389355</patent>, 1995

[11] Elger G W, Kirby D E. US Patent, <patent>3996332</patent>, 1976

[12] Jarish B. US Patent,<patent> 4038363</patent>, 1977

[13] Van Dyk J P, Vegter N M, Visser C P, De lange T, Winter J D, Walpole E A, Nell J. US Patent, <patent>6803024 B1</patent>, 2004

[14] Borowiec K, Grau A E, Gueguin M, Turgeon J F. US Patent, <patent>5830420</patent>, 1998

[15] Elger G W, Holmes R A. US Patent, <patent>4362557</patent>, 1982

[16] Borowiec K. Sulphidization of solid titania slag. Scandinavian journal of metallurgy, 1991, 20: 198-204

[17] Liang B, Li C, Zhang C, Zhang Y. Leaching kinetics of Panzhihua ilmenite in sulfuric acid. Hydrometallurgy, 2005, 76: 173-179

[18] Han K N, Rubcumintara T, Fuerstenau M C. Leaching behavior of ilmenite with sulfuric acid. Metall Trans, B, Process Metall, 1986, 18B: 325-330

[19] Sinha H N. Solubility of titanium minerals. In: Preprints-International Conference on “Advances in Chemical Metallurgy” Bhabha Atomic Research Center. Bombay, India, 1979, 2: paper 35

[20] Johnsson M, Pettersson P, Nygren M. Thermal decomposition of fibrous TiOSO₄·2H₂O to TiO₂. Thermochimica Acta. 1997, 298: 47-54

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