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Structural control of Na 2 TiO 3 in pre‐treating natural rutile ore by alkali roasting for TiO 2 production
Author(s) -
Meng Fancheng,
Liu Yahui,
Chu Jinlong,
Wang Weijing,
Qi Tao
Publication year - 2014
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.21994
Subject(s) - roasting , rutile , particle size , alkali metal , materials science , mass fraction , metallurgy , titanium , mineralogy , chemical engineering , chemistry , composite material , organic chemistry , engineering
To improve the use of natural rutile ore with fine particle size and high contents of MgO and CaO in China, a novel pre‐treatment method of natural rutile ore by NaOH roasting to prepare α ‐Na 2 TiO 3 for TiO 2 production was proposed. γ ‐Na 2 TiO 3 is a stable by‐product that can lead to serious caking in the reactor and low titanium yield. Thus, structural control in alkali roasting is necessary. The influence of particle size of natural rutile ore, NaOH‐to‐ore mass ratio, roasting temperature and roasting time on the crystal forms of Na 2 TiO 3 was systematically investigated. The optimized reaction parameters were as follows: average particle size of natural rutile ore, −9.2 µm; NaOH‐to‐rutile mass ratio, 1.2; roasting temperature, 550 °C; and roasting time, 70 min. In these conditions, the titanium conversion and the fraction of α ‐Na 2 TiO 3 exceeded 99.5 % and 98 %, respectively. Moreover, the addition of H 2 O or as‐prepared partial α ‐Na 2 TiO 3 as crystal seeds into the reaction system could prepare the roasting product with α ‐Na 2 TiO 3 as its main phase using −45 µm (−325 mesh) natural rutile ore.