RU2653519C2 - Method for production of titanium tetrachloride - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to process for production of titanium tetrachloride by chlorination of a mineral titanium-containing feedstock in a fluidized bed reactor and can be used in the technology of producing a titanium sponge and pigmentary titanium dioxide. Titanium tetrachloride is obtained by chlorinating titanium-containing materials in a fluidized bed of ground titanium-containing material and carbon with the supply of chlorinating gas at a temperature of 700–1,000 °C. Titanium-containing material is treated with sodium hydroxide solution at a liquid/solid ratio of 3 ml/g before chlorination. Sodium hydroxide solution is treated at a temperature of 120–160 °C for 90–180 minutes.

EFFECT: technical result of the invention is an increase in conversion of titanium dioxide contained in the mineral feed.

3 cl, 1 tbl, 5 ex

Description

The invention relates to a method for producing titanium tetrachloride by chlorination of mineral titanium-containing raw materials in a fluidized bed reactor, and can be used in the technology of producing titanium sponge and pigment titanium dioxide.

A known method of producing titanium tetrachloride by chlorination of titanium mineral raw materials in shaft reactors (Zelikman A.N., Korshunov B.G. Rare metals metallurgy. M .: Metallurgy, 1991, p. 170-173). In mine reactors, briquettes are subjected to chlorination, which are obtained by mixing titanium mineral raw materials and petroleum coke (20-25 wt.%). A binder, for example sulphide-cellulose liquor, coal tar or oil pitch, is added to the mixture. The resulting mixture is pressed on roller presses into pillow-shaped briquettes measuring 50 × 40 × 35 mm. In order to increase depravity and remove volatile substances, briquettes are calcined without air at 850-950 ° C in special furnaces.

The disadvantages of this method are:

- a complex technology for the preparation of feedstock, requiring the use of auxiliary substances and high-temperature calcining of the resulting briquettes, and, as a result, high costs that increase the cost of the resulting titanium tetrachloride;

- high explosive risk of exhaust gases due to the predominance of carbon monoxide in them.

- low rate of chlorination of titanium compounds, as the process proceeds in the intradiffusion region.

Closest to the claimed method is a method for producing titanium tetrachloride by chlorination with gaseous chlorine of crushed particles of mineral raw materials containing titanium dioxide with a particle size of more than 325 mesh (0,044 mm), as well as carbon particles, while chlorination is carried out in a fluidized (fluidized) layer ( U.S. Patent No. 2,555,374 of November 2, 1949).

The disadvantage of this method is the low conversion of titanium dioxide contained in mineral raw materials.

An object of the invention is to increase the conversion of titanium dioxide contained in mineral raw materials.

This problem is solved by activating mineral raw materials by treatment with an alkali solution.

Examples illustrating the method:

Example 1 (prototype)

The chlorination process was carried out in a laboratory setup, including a fluidized bed reactor, a quartz condenser and a glass quenching column. The fluidized bed reactor - a quartz apparatus with a diameter of 30 mm and a height of 200 mm - is equipped with a conical gas distributor, electric heating, a sleeve for a thermocouple and a fitting for unloading solid reaction products.

A titanium-quartz concentrate with a grain size of -0.25 + 0.16 mm (60 mesh) was chlorinated. The grain size of petroleum coke is 0.4 + 0.16 mm (~ 40 mesh). Titanium-quartz concentrate had the following composition (in terms of oxides of elements): TiO ₂ - 49.53 wt.%; SiO ₂ - 45.20 wt.%; Al ₂ O ₃ - 2.9 wt.%; Fe ₂ O ₃ - 1.36 wt.%; others - 1.01 wt.%. The molar ratio of carbon: titanium dioxide = 1: 5. Chlorination temperature 900 ° C. The linear velocity of chlorine is 0.067 m / s. The experiment time is 50 minutes. The conversion of titanium dioxide was 82.8%.

Example 2 (prototype)

At the installation and under the conditions described in example 1, titanium-quartz concentrate with a grain size of -0.63 + 0.16 mm was chlorinated.

The conversion of titanium dioxide was 32.4%.

Examples 3

A titanium-quartz concentrate of the composition shown in Example 1 and having a grain size of -0.25 + 0.16 mm was treated with a 3 wt.% Aqueous solution of sodium hydroxide at a liquid / solid ratio of 3 ml / g. The selected ratio of liquid / solid = 3 is the minimum technologically acceptable ratio, which provides the possibility of uniform wetting of the concentrate and its mixing using mechanical devices.

The concentration of sodium hydroxide solution of 3 wt.% Is the minimum concentration, which, with the used liquid / solid ratio = 3, provides a reagent content in the liquid that activates the concentrate and allows to achieve the claimed technical result - an increase in the conversion of titanium dioxide.

Processing was carried out at a temperature of 160 ° C for 90 minutes. The composition of the concentrate after processing is shown in the table.

Then, the titanium-quartz concentrate treated in the described manner was subjected to chlorination at the facility and under the conditions described in Example 1.

The results of the experiment are shown in the table.

Example 4

A titanium-quartz concentrate of the composition shown in Example 1 and having a grain size of -0.25 + 0.16 mm was treated with a 15 wt.% Aqueous solution of sodium hydroxide at a liquid / solid ratio = 3 ml / g. Processing was carried out at a temperature of 130 ° C for 90 minutes. The composition of the concentrate after processing is shown in the table.

Then, the titanium-quartz concentrate treated in the described manner was subjected to chlorination at the facility and under the conditions described in Example 1.

The results of the experiment are shown in the table.

Example 5

A titanium-quartz concentrate of the composition shown in Example 1 and having a grain size of -0.63 + 0.16 mm was treated with a 30 wt.% Aqueous sodium hydroxide solution at a liquid / solid ratio = 4 ml / g. Processing was carried out at a temperature of 120 ° C for 180 minutes. The composition of the concentrate after processing is shown in the table.

Then, the titanium-quartz concentrate treated in the described manner was subjected to chlorination at the facility and under the conditions described in Example 1.

The results of the experiment are shown in the table.

Analysis of the data presented in examples 1-5 shows that pre-treatment of the initial titanium-quartz concentrate with sodium hydroxide solution at a temperature of 120-160 ° C for 90-180 minutes and a liquid / solid ratio = 3 ml / g leads to an increase in conversion titanium dioxide by chlorination of the treated concentrate in a fluidized bed reactor.

Claims (3)

1. A method of producing titanium tetrachloride, including chlorination of titanium-containing materials in an apparatus with a fluidized bed of crushed titanium-containing material and carbon with the supply of chlorinating gas at a temperature of 700-1000 ° C, characterized in that the titanium-containing material is treated with sodium hydroxide solution before chlorination. 2. The method according to p. 1, characterized in that the treatment of the titanium-containing material with a sodium hydroxide solution is carried out at a liquid / solid ratio of 3 ml / g. 3. The method according to claim 2, characterized in that the titanium-containing material is treated with a sodium hydroxide solution at a temperature of 120-160 ° C for 90-180 minutes.