FR2460893A1 - Titanium tetra:chloride prodn. by chlorination - of titaniferous material entering reactor in countercurrent to carboniferous material - Google Patents

Abstract

TiCl4 prodn. involves the simultaneous introduction of a countercurrent stream of raw material (I) contg. titaniferous and carbinferous material in Cl2 and an additional Cl2 stream into a bed of carboniferous material (II) at 600-700 deg.C, where reaction takes place, (II) being added continuously in an amt. of over 1/3 the vol. of the reaction zone. Pref. a titaniferous (oxy)chloride pulp is introduced into the reaction zone every 3-10 s in countercurrent to added (II) at a rate of max. 0.8 m/s. TiCl4 is used in the mfr. of Ti, which is widely used for equipment for the chemical, shipbuilding, machine, aircraft, paint and lacquer industries. Uniform distribution of Cl2 throughout the reaction zone is ensured, which increases the productivity and simplifies the technology of the process and gives an increased yield of TiCl4 more cheaply than usual.

Description

 The present invention relates to the metallurgical industry, more precisely chlorine metallurgy, and in particular relates to a process for producing titanium tetrachloride and a device for implementing this process.

Titanium tetrachloride is used in particular in the production of metallic titanium, which is widely used in many industrial branches: in the chemical industry, for the manufacture of acid-resistant apparatus, conduits and tanks; in shipbuilding, for the manufacture of anti-corrosive plating on ships; in mechanical construction and in aeronautical construction, for the manufacture of various parts; in the paint and varnish industry, for the manufacture of durable coatings.

A process for the production of titanium tetrachloride is known by chlorination of a raw material containing titanium, denominated in what follows "titanium material". This process consists in introducing a ground raw material comprising a titanium material and a material consisting of carbon or containing it, hereinafter called "carbonic material", into an immobile layer of pitch coke or petroleum coke in a stream of chlorine gas,
Another process for the production of titanium tetrachloride is known, consisting in chlorinating a starting product previously put in briquettes and comprising a titanium material and a carbonic material, by bringing against the current of chlorine gas and this starting product in the reaction zone.

These methods have disadvantages, which are that they are of low productivity and that the implementation of the method is complicated. In addition, in the known processes for producing titanium tetrachloride, a significant entrainment of the starting products is observed outside the reaction zone, so that the titanium tetrachloride obtained is contaminated by these products. The production of titanium tetrachloride from a briquetted product makes the process much more expensive.

 Are known devices for producing titanium tetrachloride, comprising a vertical cylindrical body provided with a conical bottom and pipes for the supply of the starting product and a carbonic material, arranged in the upper part of the body, pipes supply of chlorine gas arranged in the conical bottom, and exhaust pipes for finished products.

The entire body of the device is coated with an expensive refractory and acid-resistant material.

The disadvantage of the known device is that its productivity is limited due to insufficient heat dissipation in the upper part of the body, because during the reaction between the starting materials, in the upper part of the body there appears a temperature of the order of 700 to 9000C which destroys the refractory lining and the body of the device. To avoid such high temperatures, it is necessary to conduct the process batchwise. In addition, the construction of the known device does not prevent losses of starting materials due to the high speeds of the gas streams. In addition, the construction of the known device does not allow uniform distribution of chlorine gas throughout the volume of the body.

The object of the invention is to avoid the aforementioned drawbacks
In the context of the invention, it is therefore proposed to create a process for the production of titanium tetrachloride and a device for its implementation, which would make it possible to ensure a uniform distribution of the chlorine gas throughout the volume of the reaction zone. of the device, which would make it possible to increase the productivity of the process, to simplify its technology, to make the titanium tetrachloride obtained cheaper, to increase the yield of targeted product and to reduce its content of impurities.

 This object is achieved by the fact that during the production of titanium tetrachloride by simultaneous introduction and direct flow, within a stream of chlorine gas, of starting materials comprising a material containing titanium, or "titanium" material, and a material consisting of or containing carbon, or "carbonic" material, in a layer of carbonic material having a temperature of 600 2 700cC, into which is also introduced an additional stream of chlorine gas, said layer of carbonic material being the zone of reaction between said starting materials and chlorine gas and of obtaining titanium tetracloride, according to the invention the supply of carbon dioxide in said reaction zone takes place continuously and countercurrently with respect to chlorine gas and to the starting materials, and this in sufficient quantities to fill more than a third of the volume of said reaction zone.

Thanks to the invention, the specific productivity of the titanium tetrachloride production process reached 1.5 to 2.0 tonnes / hour per
2 m, and the yield of titanium tetrachloride, 94 to 96%, the cost of the finished product was reduced by 50-60%, and the content of titanium tetrachloride obtained in solid residue was reduced by three to five times comparison of known methods.

To further increase the yield of titanium tetrachloride and avoid losses of titanium material during its chlorination, a pulp of oxychlorides and / or chlorides is introduced into the reaction zone, in the same direction as the carbonic material supplied. titanic, every 3 to 10 s and at a speed not exceeding 0.8 m / s.

 It is advantageous to use for the production of titanium tetrachloride a device comprising a vertical cylindrical body provided with a vault rigidly fixed to said body and a frustoconical bottom, and comprising pipes for supplying chlorine gas and materials outlet and evacuation pipes for the reaction products, this body being produced, according to the invention, in two cylindrical parts connected to each other by a part of frustoconical shape whose angle d of opening towards the upper cylindrical part of the body is 30 to 900, while the supply pipes for the starting materials within the chlorine gas flow are provided substantially at the level of the function of said lower cylindrical part at said bottom, the supply pipes of chlorine gas are produced in the bottom of the body at a height preferably between 1/3 and 2/3 of the height of the frustoconical bottom, and the evacuation pipes for the secondary reaction products are arranged ées in the body has a height of, substantially, 1/20 to 1/4 of the inside diameter of the upper part of the body, counting from the place where the lower part of the body is assembled to its frustoconical part.

 To extend the operating life of the device and make it cheaper, it is advantageous, according to the invention, for the upper cylindrical part of the body and its vault to be provided with a jacket forming with the walls of the body and its vault a cavity for a coolant.

 Thanks to this arrangement of the tubes for supplying the starting materials to the device and thanks to the peculiarities of the configuration of the body, it has become possible to ensure a uniform distribution of chlorine throughout the volume of the body and thus to increase the productivity. specific to the process and the yield of the targeted product (in titanium tetrachloride).

Other characteristics and advantages of the invention will appear on reading the detailed description which follows of the process for producing titanium tetrachloride, the device for implementing this process and concrete examples of implementation. of said Drocede, with reference to the single appended drawing schematically representing the device for producing titanium tetrachloride (view in longitudinal section).

The invention applies to the treatment and production of titanium tetrachloride from starting materials containing 75 to 80% by weight of a material containing titanium, or "titanium" material, of a particle size not exceeding pitch 0.1 mm, containing titanium oxides, iron protoxide, silicon oxide, chromium oxide, and 25 to 20% by weight of a material consisting of or containing carbon, or "carbonic" material, of a particle size not exceeding 0.15 mm, for example pitch, petroleum or blast furnace coke.

 The starting materials used are obtained by mixing the titanium material and the carbonic material introduced in appropriate proportions, for example in a conical drum granulator.

 The process according to the invention therefore consists in that the aforementioned starting materials are introduced, within a stream of chlorine gas, into a layer of carbon dioxide material such as, for example, pitch coke, petroleum or blast furnace in pieces.

 The authors of the invention have found that it is advantageous that the amount of carbon dioxide in which the reaction for the formation of titanium tetrachloride takes place is greater than one third of the total volume of the reaction zone. Indeed, if this condition is not fulfilled (the chlorine gas being brought under a relative pressure of 0.7 atmosphere), the intensity of the process decreases. According to the invention, said carbon dioxide is brought into the reaction zone continuously and against the current with respect to the chlorine gas and the starting materials. The carbon dioxide feed rate is approximately G0015 m / s. These conditions for supplying the starting reactants ensure an intense heat exchange between the particles of starting material and carbonic material, and make it possible to extend the duration of contact between the reaction agents and bringing to 100% the assimilation of chlorine by the titanium material; in addition, they make it possible to reduce the entrainment of the titanium material (in the form of dust) with the reaction products and thus to avoid contamination of the titanium tetrachloride obtained.

It should be noted that the share of the chlorine gas stream supplied with the starting materials is preferably from 10 to 15X of the total amount of chlorine gas brought into the reaction zone.

 To increase the yield of titanium tetrachloride, to be able to use the waste produced from titanium tetrachloride and to further prevent entrainment of titanium material in the form of dust with the reaction products, it is advantageous to bring into the zone reaction, approximately every 3 to 10 s, a pulp of titanium oxychlorides and / or chlorides, preferably at a speed not exceeding 0.8 m / s. Titanium oxychloride or chloride pulps are waste products of titanium tetrachloride, formed during the clarification of condensed titanium tetrachloride. Said pulp is a mixture of iron, aluminum, silicon, vanadium chlorides and / or aluminum, silicon, titanium oxychlorides, containing finely dispersed particles of titanium material and carbon dioxide reducing material. The solid content of this mixture (pulp) is preferably about 475 g / l.

According to the invention, it is advantageous to carry out the manufacture of titanium tetrachloride, from the aforementioned starting materials, in a device essentially comprising a vertical cylindrical body 1 made of steel. The upper part of the body 1 comprises a vault 2 rigidly assembled to the latter. The bottom of the cylindrical body 1 is in the form of a truncated cone 3. According to the invention, it is advantageous to produce the body 1 in two cylindrical parts of different diameters.

The upper part 4 of the body 1 has an internal diameter of 1.5 times larger than the internal diameter of the lower part 5 of the body 1. It has been found that, respecting this condition, the optimum speed of movement of the currents is obtained. reaction agents (when using the device according to the invention) and the maximum yield of titanium tetrachloride.

 The upper part 4 is connected to the lower part 5 of the body 1 by a part 6 in the form of a truncated cone. To respect the aforementioned relationship between the diameters of the upper part 4 and the lower part 5 of the body 1, the frustoconical part 6 preferably has an angle 9 of 30 to 900 of opening towards the upper part 4 of the corpus 1. If the opening angle <is greater than 900, the movement of the starting materials in the device according to the invention risks being disturbed and delayed, that is to say that the walls of the part 6 of frustoconical shape form sort of a threshold on the path of the reaction agents.

On the other hand, if the opening angle is less than 300, the speed of movement of the reaction agents changes, so that a large quantity of unreacted reagents may be entrained out of the device.

 In the vault 2 of the body 1 is provided a tube 7 for the supply of carbon dioxide in the device. A tube 8 serving to bring the pulps of oxychlorides and / or chlorides to the device is disposed in the wall of the upper part 4 of the body 1. At the place where the frustoconical bottom 3 is connected to the lower part 5 of the body 1, there is provided a tube 9 serving to supply the device with the starting materials composed of a titanium material and a carbon dioxide reducing material, this supply taking place in a stream of chlorine gas. In the device according to the invention, there are also provided pipes 10 for supplying chlorine gas, which it is advantageous to have in the walls of the frustoconical bottom 3 at a level comprised substantially between 1/3 and 2/3 of the height of said bottom.

The chosen height of arrangement of the tubes 10 a uniform distribution of chlorine gas throughout the volume of the device, which promotes a high yield of titanium tetrachloride. I1 is advantageous that the pipes 10 for supplying chlorine gas are aamoinsaan4mbB deqmsu.ib body 1, at a height whose value is substantially between 1/20 and 1/4 of that of the inner diameter of the upper part 4 of the body 1, counting from the junction point of the lower part 5 of the body 1 and of the frustoconical part 6, there is provided a tube 11 intended to evacuate from the device the gas-vapor mixture of secondary products of the reaction, by example of carbon, silicon oxides and, partially, titanium oxides. If the tubing ll is placed at a height greater than 1/4 of the value of the internal diameter of the upper part 4 of the body 1, there is a risk of being forced to increase the thickness of the layer of carbonic material in which will form titanium tetrachloride, which in turn requires an increase in the pressure in the chlorine gas supply lines. If the tubing 11 is at a height less than 1/20 of the value of the internal diameter of the upper part 4 of the body 1, the efficiency of the device may decrease considerably.

 A tube 12 intended for the evacuation of the gaseous products resulting from the reaction, including the titanium tetrachloride, is placed at the very top of the part 4 of the body 1.

 At the lowest point of the bottom 3 is provided a pipe 13 for removing from the device the reaction products consisting of carbon, small amounts of titanium dioxide and other metal oxides.

According to the invention, it is advantageous to rigidly fix on the cylindrical upper part 4 of the body 1 and on its vault 2 a jacket or the like 14 forming with the vault 2 and the walls of the body 1 an enclosure for the circulation of an agent cooling. The jacket 14 is preferably fixed at a distance of at least 50 min from the body 1. The jacket 14 can be made from thin steel sheets or from glass-metal fibers. The coolant used is water.

 The jacket 14 eliminates the need to use an interior coating or lining in this zone, and therefore reduces the cost of the entire device and prolongs the life of the device for producing titanium tetrachloride.

The walls of the body 1 not protected by the jacket 14 are coated with a material resistant to heat and to chlorine, for example a refractory with a high alumina content, having a porosity not exceeding 12%.

The production of titanium tetrachloride in the device described above is carried out as follows.

Before loading the abovementioned reaction agents into the device, a temperature of 600 to 800 ° C. is created inside the body 1, using ejection burners operating with natural gas1 via the pipes 10. When this temperature is reached, the burners are removed.

Via the pipe 7, the carbon dioxide, for example pitch, petroleum or blast furnace coke, brought to a temperature of at least 6009C, is brought continuously, for example at a speed of about 0.00015 m / s . Preferably, an amount of carbon dioxide is brought in which is sufficient to fill more than a third of the volume of the reaction zone. It has been found that it is preferable that the thickness of the layer of carbon dioxide material be from 1.0 to 2.5 m. The starting materials and chlorine gas are then started to supply. For this purpose, chlorine gas is supplied via the pipes 10, consisting for example of an anodic chlorine gas with a chlorine concentration of approximately 68 to 70%, the the rest being oxygen. The speed of chlorine gas at the outlet of the ejection nozzle (not shown in the drawing) is for example 432 m / s for a diameter of 15 mm from the nozzle. The starting materials containing a titanium material and a reducing material (carbonic material) are brought into a stream of chlorine gas by the pipe 9. The share of the chlorine stream brought with the starting materials is 10 to 15% the amount of chlorine gas supplied.

Titanium tetrachloride is obtained in the device according to the invention thanks to the heat of the following chemical reactions
Thiol + 2C = Cl2 = TiCi4 + 2CO + Q
Ti02 + C + C12 = TiC14 + C02 + Q
The process is carried out by continuously removing the reaction products from the device. The gas-vapor mixture consisting of TiC14, SiC14,
A1C13, FeC13, VOC13, Fez12, CO, C02, 2 COC12 is evacuated through tubing 11.

The unreacted residue and containing TiO2, C, MgC12, CaCl2, MgO; CaO is evacuated through tubing 13.

 The titanium tetrachloride resulting from the reaction of the starting materials and of the chlorine gas is evacuated from the device by the tube 12. The titanium tetrachloride obtained in accordance with the invention contains practically no impurities.

The titanium pulp of chlorides and / or oxychlorides is brought to the device by the tubing 8 for example at a temperature of 400 to 10000C.

 It is advantageous, according to the invention, to bring the pulp approximately every 3 to 10 s and preferably at a speed not exceeding 0.8 m / s. The fractions in the form of dust of the titanium material and of the carbon dioxide reducer entarnated with the gas-vapor mixture are wetted by the pulp supplied and descend to the reaction zone; there then takes place an evaporation of the titanium tetrachloride from the pulp and in the same time the titanium and aluminum oxychlorides transform into chlorides with simultaneous complementary chlorination of the small particles of titanium dioxide to titanium tetrachloride.

Such a process for producing titanium tetrachloride makes it possible to reduce the entrainment of dust by wetting and returning the fine fractions of titanium material and carbon dioxide, to extract titanium tetrachloride from the pulps and thus to increase the yield. of the device from 15 to 20%.

 At the aforementioned feed rates of the starting materials, chlorine gas and carbon dioxide, there occurs in the reaction zone an intense heat exchange between the particles of titanium material and carbon dioxide and their heating until the temperature of 9800 C.

 Carbon dioxide partially burns, reacting with the oxygen in the chlorine gas, forming carbon monoxide. At the high temperatures used and under the aforementioned conditions for supplying the reaction agents, intense chlorination of the titanium material takes place, with titanium tetrachloride obtained.

 Such a way of conducting the process makes it possible to prolong the time of contact of the titanium material with the chlorine gas in the mobile multichannel layer of carbonic material and to bring to 100% the assimilation of chlorine by the titanium material, to decrease the training of the material to be chlorinated in the form of dust, thus avoiding contamination of the titanium tetrachloride obtained and increasing the extraction of the targeted product up to 93.7%.

 Example 1.

 75% by weight of titanium material with a particle size of 0.1 min, containing titanium oxides, iron protoxide, silicon oxide, aluminum oxide, chromium oxide, and 25% by weight pitch coke with a particle size of 0.15 mm is mixed in a drum granulator. The starting material obtained, containing 24.3% of carbon, is brought through the pipes 9, within a stream of chlorine gas, in a layer of pitch coke (temperature 6500C) arriving continuously through the pipe 7 to counter-current to the starting material. Through the pipes 10, chlorine gas is brought into the pitch coke layer. The speed of the chlorine updraft is 0.148 m / s and that of the gas stream in the coke layer is 0.27 m / s. The temperature of the operation is from 780 to 8500C, the consumption of chlorine, from 9 1 / mon. The transformation of 1660 g of starting materials gives 1690 g of titanium tetrachloride. No traces of chlorine were detected in the product obtained, even by increasing the chlorine flow rate to 15 1 / mon and by continuously loading and unloading.

 The titanium oxide content of the secondary products resulting from the reaction is 16.3%.

 Example 2.

 80% by weight of titanium material with a particle size of 0.09 mm, containing titanium oxides, iron protoxide, silicon oxide, aluminum oxide, l, are mixed in a drum granulator. chromium oxide, and 20% by weight of petroleum coke with particle size of 0.15 mm. Through the pipes 9, the starting product thus obtained is brought continuously, in a stream of chlorine gas and for 7 hours, into the reaction zone where there is a layer of petroleum coke (the temperature of which is 7000C) arriving continuously through the tubing 7 against the current relative to the starting material. The thickness of the petroleum coke layer is 1.8 to 2.0 m. Through the pipes 10, chlorine gas is admitted into the petroleum coke layer. the speed of the chlorine updraft is 0.148 m / s, and the consumption of chlorine gas is 1200 to 1400 kg / h.

The operation is carried out at a temperature of 9800C.

 The transformation of 7.0te starting material gives 10.5 t of titanium tetrachloride. The yield of titanium tetrachloride is 93.7%.

Example 3.

77% by weight of titanium material with particle size of 0.1 mm, containing titanium oxides, iron protoxide, silicon oxide, aluminum oxide, aluminum oxide, are mixed in a drum granulator. chromium oxide, and 23% by weight pitch coke with particle size of 0.15 mm. Through the pipes 9, the starting material thus obtained is brought, within a stream of chlorine gas, into the reaction zone where there is a layer of petroleum coke (temperature 6500C) arriving continuously through the pipe 7 to against the flow of the starting material. The chlorine gas is introduced into the layer of petroleum coke through the pipes 10.

An oxychloride pulp containing (by weight) 17.5% titanium, 3.15% iron, 2.48% aluminum, 0.22% silicon, 0.08% magnesium, 0.07% calcium, 0.23% manganese, 0.11% vanadium, 0.14% chromium, 65.1% chlorine, 10.9X oxygen, is introduced into the device through the tubing 8 every 3 seconds at a speed of 0.7 m / s. The temperature of the operation is from 780 to 8500 C. The pulp wets the fine particles of titanium material and carbon dioxide reducer (pitch coke) entrained by the gas-vapor mixture formed during the operation, and brings them down in the reaction zone of the dispoisitif. I1 then occurs a vaporization of titanium tetrachloride and additional chlorination of the fine particles of titanium dioxide to titanium tetrachloride. The gas-vapor mixture entrained outside the device is condensed and titanium tetrachloride of a high degree of purity (96 to 98%) is obtained, the titanium oxide content of the waste not exceeding 1%. , and that in carbon, at 10%.

 Example 4.

80% by weight of titanium material with a particle size of 0.09 mm, containing titanium oxides, iron protoxide, silicon oxide, aluminum oxide, are mixed in a drum granulator. chromium oxide, and 20% by weight of blast furnace coke with particle size of 0.15 mm. Via the pipes 9, the starting material thus obtained is fed continuously, within chlorine gas, into the reaction zone where there is a layer of pitch coke (whose temperature is 6800C) fed continuously through the pipe. 7 against the flow of the starting material. The thickness of the pitch coke layer is 1.8 to 2.0 m. The chlorine gas is introduced into the pitch coke layer through the tubes 10.A pulp of oxychlorides composed (by weight) of: 18.8% titanium, 2.16% iron, 3.0% aluminum , 0.11% silicon, 0.08% magnesium, 0.16% vanadium, 11.5% oxygen, 68.7% chlorine, is brought into the device through the tubing 8 every 10 s at a speed of 0.7 m / s. your operating temperature is from 780 to 8500C. The pulp wets the fine particles entrained by the gas-vapor mixture formed during the operation and brings them back down into the reaction zone of the device.

I1 then occurs a vaporization of titanium tetrachloride and a transformation of titanium and aluminum oxychlorides into chlorides of these metals.

 The gas-vapor mixture entrained outside the device is condensed and titanium tetrachloride of a high degree of purity is obtained. The yield of titanium tetrachloride is 97 to 98%. The reaction side products contain a maximum of 1% of titanium oxide and a maximum of 10% of carbon.

 Of course, the invention is in no way limited to the embodiments described and shown which have been given only by way of example.

In particular, it includes all the means constituting the technical equivalents of the means described, as well as their combinations, if these are carried out according to the spirit and implemented within the framework of the claims which follow.

2. Method for producing titanium tetrachloride according to claim 1, characterized in that introduced into the reaction zone approximately every 3 to 10 s, a titanium pulp of oxychlorides and / or chlorides, brought to a speed not exceeding 0.8 m / s and in the same direction as the manner made up of carbon in which the reaction must take place.

 3. Device for producing titanium tetrachloride by the method according to one of claims 1 and 2, consisting of a vertical cylindrical body to which is rigidly fixed a vault, a bottom of frustoconical shape, supply pipes of chlorine gas and starting materials, from a discharge pipe for the reaction products, characterized in that the said body is produced in two cylindrical parts connected to one another by a part in the form of a truncated cone, the l angle C opening towards the upper cylindrical part of said body is preferably from 30 to 900, that the pipes for supplying the starting materials within a stream of chlorine gas are arranged at the junction point of said lower cylindrical part at said bottom, that the chlorine gas supply pipes are provided in the bottom of said body, at a level between thirds and two thirds of the height of the frustoconical bottom, and that the discharge pipe for secondary products of reaction is at a height of value between 1/20 and 1/4 of that of the inside diameter of the upper cylindrical part of the body, counting from the junction of the lower cylindrical part of the body to its part in shape

Claims (2)

of truncated cone.  4. Device for producing titanium tetrachloride according to claim 3, characterized in that on the upper cylindrical part of said body and on its vault is mounted a jacket forming with the walls of the body and its vault an enclosure for the circulation of a coolant.  5. Titanium tetrachloride, characterized in that it is obtained in accordance with the process forming the subject of one of claims 1 and 2.