The production process of TiO2 pigment comprehends two steps. The first step is the production of the base material. In the second step, the post treatment (see section Post Treatment (PT) ), the base material is coated to add additional properties like dispersibility or weatherability.
Two technologies are available for the production of the base material: The sulphate process (see section Sulphate Process (SP)) and the chloride process (see section Chloride Process (CP)).
In the sulphate process (SP) sulphuric acid is used. This process was developed in the 20’s of the last century.
In the chloride process (CP) chlorine is used. The process was developed in the 50’s of the last century.
Ti-Cons offers the technology for SP, CP and PT.
The following tables shows the advantages and the disadvantages of SP and CP:
| Chloride Process (CP) | Sulfate Process (SP) |
|---|---|
| Less flexible due to raw material quality | Wider range of raw material – especially Ilmenite – available |
| Better product quality regarding the optical and chemical properties | Product quality regarding the optical properties of Rutile base material is lower |
| Production of anatase pigment is not possible | Production of anatase pigment is possible |
| Smaller buildings | Larger buildings |
| Fewer vessels | More vessels |
| Less man power necessary | More man power necessary |
| Higher requirements to the qualification of the staff | Lower requirements to the qualification of the staff |
| Continuous Process | Mainly batch process |
| Less environmental impact due to less waste | More environmental impact due to more waste |
| Possibility to rework some of the waste to sellable co-products | Process needs co-product management and attractive markets for co-products |
| Requires stable production environment and infrastructure | Process is easier to handle because of batch process |
| Less amount of co-products | High amount of co-products |
| Because of the closed loop the process is more sensitive | Production does not stop totally if one step fails |
| Higher safety requirements due to the use of Cl2 and TiCl4 | Lower safety requirements. In case of use of disulfuric acid, higher safety requirements are necessary |
| Higher degree of automation necessary | Lower degree to automation can be sufficient |
| Generally the production costs are lower. | Generally the production costs are higher. |