About Chloride Process

Figure 1. The preliminary process flow diagram of the unit operations.





Chemistry Overview


Conventionally for Chloride processes, the first step is for the ore inlet to be reduced with the carbon ion.


TiO2 + C → Ti+ CO2                 


2 FeTiO3 + 7 Cl2 + 6 C → 2 TiCl4 + 2 FeCl3 + 6 CO


The Titanium ion is then oxidized and reacted to synthesize TiCl4.


Next, distillation was performed to convert the aqueous TiCl4 to TiO2 Rutile in pure oxygen flame or plasma at 1200C-1700C.  Consequently, the chlorine ions are recovered after energy have been inputted to the reaction.


TiCl4+ O2→TiO2+ 2Cl2                           


The higher the percentage TiO2 content of the feedstock is, the lower the volume of the waste will be produced.


Process Units


The standard Chloride process with Titanium Dioxide feedstock consists of four major process units: Oxidation, Chlorination, Condensation, and Purification.


This is a continuous process which the chlorine released from the oxidation unit is recycled to the beginning of the process. Figure 1 describes the preliminary process flow diagram of the unit operations.


Chlorination is operating at ~1000C in a fluidized bed reactor with the addition of coke. Consequently, the process unit yields a gas stream contains titanium tetrachloride, oxides of carbon, and impurity metals of the feedstock in metal chloride form.


The gas stream is then reacted with the recycled liquid TiCl4 and cools it to a level for the metal chlorides to be separated out as solids. The metal chloride impurities are commonly neutralized with lime or limestone, and the metal gets deposed to the landfill. Then, TiCl4 gets further condensed as a liquid. The liquid subsequently serves as an inlet for the purification unit. 


After the purification of the TiCl4, the liquid gets fed into the high temperature oxidation reactor. The high temperature oxidation reactor contains oxygen in plasma reactor or toluene burner. Oxygen reacts with TiCl4 to reform Titanium Dioxide. The chlorine gas released from the reactor is afterward recycled back to the process.


Finally, the Titanium Dioxide base material is cooled and sent to the treatment units. Consequently, the semi-finished product was transferred to the milling and drying units to produce the final products.