Concentration method and special device for sulfuric acid process titanium dioxide solution

Abstract

The invention discloses a concentrating method of titaniferous solution for sulfate process titanium dioxide and a special device. The secondary steam produced in the evaporation concentration process of a clear titaniferous solution returns to an evaporation concentration system after being pressurized and heated through a mechanical steam compressor, and an evaporation system runs under -0.08MPa. The local overheating cannot be caused in the titaniferous solution concentration process, and the stability of the concentrated titaniferous solution is superior to that of the conventional single-effect concentration. The concentrating method has the characteristics that the steam consumption is greatly reduced, the energy-saving effect is obvious, and the stability of the titaniferous solution is good.

Description

technical field [0001] The invention relates to a method for concentrating titanium dioxide liquid by sulfuric acid process and a special device. Background technique [0002] In the production process of sulfuric acid titanium dioxide, the titanium liquid obtained after reacting ilmenite with sulfuric acid, clarifying and filtering, and separating ferrous sulfate cannot be directly used for hydrolysis to prepare hydrated titanium dioxide (also known as metatitanic acid) due to its low concentration. . Such dilute titanium solution (also known as clear titanium solution) must be concentrated to a certain concentration before entering the next step of hydrolysis. [0003] The dilute titanium solution mainly contains solutes such as titanyl sulfate, titanium sulfate, and ferrous sulfate. Generally, the dilute titanium solution can be concentrated by heating and evaporating. Since the boiling point of titanium liquid is about 104-114°C under normal pressure, and the titanium ...

AI Technical Summary

Problems solved by technology

[0006] 1. Large steam consumption

Due to the use of single-effect evaporation, it takes 1.25-1.5 tons of steam to evaporate one ton of water;

[0007] 2. The concentrated titanium solution has poor stability

Because the single-effect concentration uses raw steam at 125-138°C, it is easy to cause local overheating of the titanium liquid, so that the early hydrolysis of the titanium liquid produces solid-phase titanyl sulfate crystals that block the evaporator tubes, and the titanyl sulfate dispersed in the titanium liquid Crystals will grow and deposit like seeds, causing unnecessary losses to production

At the same time, due to the existence of these bad crystallization centers, the performance of the hydrolyzed product will be seriously affected, and the quality of the finished titanium dioxide will be affected;

[0008] 3. The thin-film evaporator used for the concentration of titanium liquid uses titanium metal materials, and the price is relatively high;

[0009] 4. Due to the single-effect concentration, the scale of the device is small, which cannot meet the development needs of large-scale titanium dioxide devices

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