Method for preparing TiO2 raw material for chlorination process from titanium-rich fine powder

Abstract

The invention provides a method for preparing a TiO2 raw material for a chlorination process from titanium-rich fine powder. The method comprises the following steps: S1, weighing the titanium-rich fine powder, and uniformly mixing the titanium-rich fine powder with a solid organic binder and petroleum coke at room temperature; S2, uniformly covering the surface of a mixed material obtained in thestep S1 with petroleum coke, and then performing low-temperature coking at 380-420 DEG C for 2.5-4 hours; and S3, crushing the material having undergone low-temperature coking in the step S2 into particles for the first time, then carrying out high-temperature coking at 900-1200 DEG C for 20-60 minutes, and crushing a coked material into particles again so as to obtain the TiO2 raw material for the chlorination process. The method can prepare the TiO2 raw material with high yield (higher than 92%) and qualified granularity for the chlorination process and realizes the cyclic utilization of the titanium-rich fine powder; and the batching procedure of a later chlorination reaction is reduced by adding the petroleum coke in advance.

Description

technical field [0001] The invention belongs to the technical field of preparation of titanium dioxide raw materials by chlorination method, and in particular relates to a method of preparing TiO by chlorination method by using titanium-rich fine powder. 2 raw material method. Background technique [0002] Currently, TiO 2 There are mainly two kinds of production processes: sulfuric acid method and chlorination method. Both methods have their own advantages and disadvantages: the sulfuric acid method has mature technology, simple equipment, and low requirements on raw materials, so it is widely used, but its process flow is long, the operation is complicated and There are many three wastes produced; the chlorination method has received more and more attention due to its advantages such as advanced production technology, large production capacity, simple process, low energy consumption, and superior product performance, but it has high requirements for raw materials, and req...

AI Technical Summary

Problems solved by technology

[0002] Currently, TiO 2 There are mainly two kinds of production processes: sulfuric acid method and chlorination method. Both methods have their own advantages and disadvantages: the sulfuric acid method has mature technology, simple equipment, and low requirements on raw materials, so it is widely used, but its process flow is long, the operation is complicated and There are many three wastes produced; the chlorination method has received more and more attention due to its advantages such as advanced production technology, large production capacity, simple process, low energy consumption, and superior product performance, but it has high requirements for raw materials, and requires titanium grades greater than 85 %, low impurity content (CaO2 The content is about 95%, and it is used for the chlorination method of titanium dioxide. The price of this kind of slag is called UGS) is high, which greatly increases the production cost

This method will produce a certain amount of fine powder in the crushing process, the fine powder particle size is below 200 mesh, TiO 2 The grade is greater than 95%, (CaO+MgO)%<0.5%, the tap density is small, and it is easy to be blown away by the chlorine gas in the boiling chlorination furnace, so it cannot be directly put into the chlorination furnace as a raw material, but its composition and qualified particle size material The same, so the yield is reduced to a large extent, if it cannot be recycled well, it will cause a waste of titanium resources, and also produce a certain amount of solid pollutants

[0004] Regarding the recycling of fine powders, many researchers have studied titanium-containing fine powders such as titanium slag fine powder, artificial rutile fine powder, and fluidized chlorination bed reaction ash. Some companies will return to the electric furnace for re-melting. But it will increase the cost of electric energy, and because the fine powder of titanium-rich material involved in the present invention is also different from the above-mentioned materials in nature, high-temperature calcination has little effect on particle growth, so the conventional recovery method is not applicable

[0005] On the other hand, in the production process of the chlorination method, not only titanium materials need to be put into the boiling chlorination furnace, but also a certain proportion of petroleum coke and titanium materials need to be put into the reaction to provide a reducing atmosphere. Therefore, before the production of the boiling chlorination furnace Not only does it take a certain amount of man-hours to mix petroleum coke and titanium materials, but also calcined coke is required for petroleum coke. If green coke is used, its gasification activity is poor, and it is easy to burn incompletely when boiling. In addition, during boiling reaction, petroleum coke and The titanium material is not tightly connected, it is easy to be blown away by chlorine gas, and stratification occurs, resulting in insufficient reaction

[0006] Patent CN104058450A discloses "a granulation method for titanium coke particles", which specifically discloses the steps of heating, mixing, fractionating, coking, crushing and grading, and calcining the mixture of fine-grained titanium-containing materials and polymer hydrocarbons, and preparing A granulation method that meets the raw material requirements of the chlorination method, but this patent requires the raw materials to be heated separately and then mixed at 350-450°C. Industrial implementation requires high equipment and high cost

[0007] Patent CN109761271A discloses "a method for recycling titanium-containing fine materials", which specifically discloses that titanium-containing fine materials, water, and binder are mixed in a certain proportion, and then subjected to extrusion molding, calcination, crushing, screening and other processes Preparation of chlorinated raw materials with qualified particle size, although this method is relatively simple, but the product yield obtained by this method is low, and both this patent and the previous patent need to proportion petroleum coke in the later stage, and the proportioned petroleum coke and Titanium material is prone to stratification under the action of chlorine gas, resulting in insufficient reaction

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