WO2014000592A1 - Fluidized bed without sieve plate and method for preparing boron trichloride - Google Patents

Description

 Fluidized bed without sieve plate and preparation method of boron trichloride

Technical field

 The present invention relates to the field of material synthesis, and more particularly to a fluidized bed without a sieve plate and a method for preparing boron trichloride. Background technique

 Boron trichloride can be used in processes such as diffusion, ion implantation, dry etching, and fabrication of solar cell components in silicon semiconductor devices; it can also be used as a base material for the production of optical fibers and as a catalyst in the polymerization of styrene, and also for aluminum. , zinc, magnesium and copper alloys are purified to remove nitrides, carbides and oxides from molten metals; as soldering fluxes for alloys such as aluminum, iron, zinc, tungsten and monel; boron trichloride is also used It is used to extinguish the magnesium fire and rocket propellant in the heat treatment furnace; it can be used as an intermediate for preparing ethyl borohydride, high temperature resistant metal boride, and pyrolytic boron nitride.

At present, the preparation of boron trichloride mainly has two kinds of process systems, one is a system using a molten salt bath, such as US Patent Nos. 2, 097, 482, US 3, 019, 089, US 3, 152, 869, US 4, 125, 590. Etc., that is, the boron-containing salt is first converted into boron carbide. The process is usually carried out by forming a boron salt into boron oxide, reacting with carbon to form a sintered boron carbide block, and finally reacting with chlorine gas to form boron trichloride, boron oxidation. The process of reacting carbon with carbon to form boron carbide requires a higher temperature, generally above 800 °C; the other uses a fluidized bed system with a sieve plate, such as Canadian patent CA 632713 with boron, carbon and chlorine through the flow The catalytic bed is prepared at 600 ° C to prepare boron trichloride. The control process is complicated and the yield is low. Although the reaction temperature is lowered, the phosgene by-product C0C12 is produced, and the boiling point of C0C1 ₂ is 8.2. °C, very close to 12.5 °C of BC1 ₃ , which makes it difficult to separate and purify the next step, and the molten raw material is easy to block the sieve plate holes, which needs to be cleaned regularly, resulting in continuous production. . Summary of the invention

 In view of the problems of the prior art, it is an object of the present invention to provide a fluidized bed without sieve plates and a method for preparing boron trichloride which overcomes the clogging of the sieve plates in the prior art.

Another object of the present invention is a method for preparing boron trichloride, which solves the reaction The process produces phosgene which is difficult to separate impurity gases.

 In order to achieve the above object, in a first aspect, the present invention provides a fluidized bed without a sieve plate, comprising: a bed body; a carrier gas source for supplying a carrier gas from the lower portion of the bed body toward the upper portion of the bed body; a reaction gas supply device for supplying a reaction gas to the bed; a raw material supply device for supplying a powder raw material to the bed; a heating device for heating the bed; and a slag discharge port for discharging the reaction slag generated by the reaction in the bed; , connected to the bed, separating the substance reacted in the bed to obtain the final product.

 In order to achieve the above object, in a second aspect, the present invention provides a preparation method of boron trichloride, which adopts the fluidized bed without sieve plate according to the above first aspect, and the preparation method of the boron trichloride The method comprises: filling the alkaline earth metal boride of the powder raw material into the bed of the fluidized bed without the sieve plate through the raw material supply device; opening the carrier gas source, and introducing the carrier gas into the bed of the fluidized bed without the sieve plate, The bed material of the alkaline earth metal boride of the powder raw material in the fluidized bed without the sieve plate is in a fluidized state; the heating device is turned on to heat the bed body, and after the temperature reaches the predetermined temperature, the reaction gas is supplied with anhydrous hydrogen chloride; After a specified period of time, the separation unit is opened and activated to obtain the desired boron trichloride.

 The beneficial effects of the present invention are as follows.

 The fluidized bed without sieve plate can react at lower temperature and reduce energy consumption. The improvement of the structure of the device solves the problem that the reaction process is easy to block the hole of the sieve plate, so that the device is simple, easy to operate, and the reaction can be Continuously, increasing production efficiency. The alkaline earth metal boride and hydrogen chloride are used as raw materials to solve the problem that the reaction process produces phosgene which is difficult to separate impurity gases. DRAWINGS

 Figure 1 is a schematic view showing the structure of a fluidized bed without a sieve plate according to the present invention;

 Figure 2 is a horizontal cross-sectional view showing the relationship between a carrier gas guide and a carrier gas inlet structure of a fluidized bed without a sieve plate according to the present invention;

Figure 3 is a vertical cross-sectional view showing the relationship between a carrier gas guide and a carrier gas inlet structure of a fluidized bed without a sieve plate according to the present invention; Wherein, the reference numerals are as follows

 1 bed body 2 carrier gas source 3 reaction gas supply device

 4 raw material supply device 5 heating device 6 slag discharge port

 7 Separation device 71 Gas-solid separation device 72 Pneumatic separation device

 73 Condensing unit 9 Reactive gas treatment unit

 10 carrier gas guide 101 bevel 103 inner wall

 21 carrier gas inlet A vertical axis

Concrete implementation

 A fluidized bed of a sieveless plate and a method for preparing boron trichloride according to the present invention will be described below with reference to the accompanying drawings. First, a fluidized bed of a sieveless plate according to the first aspect of the present invention will be described.

 As shown in Fig. 1, a fluidized bed without a sieve plate according to the present invention comprises: a bed body 1; a carrier gas source 2, which supplies a carrier gas from the lower portion of the bed body 1 toward the upper portion of the bed body 1 to the bed body 1; The gas supply device 3 supplies the reaction gas to the bed 1; the raw material supply device 4 supplies the powder material to the bed 4; the heating device 5 heats the bed 1; the slag discharge port 6 and the reaction in the bed 1 The generated reaction slag is discharged; the separation device 7 is connected to the bed 1, and the substance reacted by the bed 1 is separated to obtain a final product.

 In the fluidized bed without a sieve plate according to the present invention, preferably, the shape of the bed 1 is a cylindrical shape. Preferably, the bed 1 is made of carbon or silicon carbide made of high purity quartz, silicon dioxide, silicon nitride or coated with said material.

 As shown in Fig. 1, in the fluidized bed without a sieve plate according to the present invention, preferably, the fluidized bed without the sieve plate further comprises: a reaction gas treatment device 9 for the reaction gas supply device 3 The reaction gas supplied to the bed 1 is subjected to dehydration drying and heating to increase the temperature.

 As shown in Fig. 1, in the fluidized bed without a sieve plate according to the present invention, preferably, the fluidized bed without the sieve plate further comprises: a carrier gas guide 10 for supplying the carrier gas source 2 The carrier gas to the bed 1 is guided.

As shown in Figures 1 and 2, in the fluidized bed without a sieve plate according to the present invention, preferably, The carrier gas guide 10 has a slope 101 that tapers toward the bed 1.

 As shown in Fig. 2, in the fluidized bed without a sieve plate according to the present invention, preferably, the carrier gas of the carrier gas source 2 enters the direction of the carrier gas inlet 21 of the carrier gas guide 10 with respect to the carrier gas guide The inner wall 103 at the position where the carrier gas inlet 21 is connected is inclined.

 As shown in Fig. 3, in the fluidized bed without a sieve plate according to the present invention, preferably, the carrier gas of the carrier gas source 2 enters the direction of the carrier gas inlet 21 of the carrier gas guide 10 with respect to the carrier gas guide The inner wall 103 at the position of the connection carrier gas inlet 21 of 10 is inclined and inclined upward with respect to the vertical axis A in the direction of the carrier gas inlet 21 in the plane with respect to the vertical axis A of the bed 1.

 As shown in Fig. 2, in the fluidized bed without a sieve plate according to the present invention, preferably, the carrier gas inlet 21 is at least two, wherein at least one pair of carrier gas inlets 21 are along the inner wall 103 of the carrier gas guide 10. Relative settings.

 In the fluidized bed without a sieve plate according to the present invention, preferably, the separation device 7 comprises:

 a gas-solid separation device 71 for separating a gaseous substance and a solid substance in the substance after the reaction of the bed 1;

 a gas separation device 72 for separating a plurality of gaseous substances in the substance after the reaction of the bed 1;

 The condensing device 73 obtains the final product by condensation. Preferably, the gas-solid separation device

71 adopted

For the filtration method, a filter column composed of glass fibers is preferably used. Preferably, the gas separation device 72 can be carried out according to various gas properties contained in the substance after the reaction of the bed 1 by, for example, but not limited to, chemical reaction or chemical adsorption. The condensing device 73 can be obtained according to the final needs Material properties, using condensation separation to obtain the final product, more preferably, the condensing device

73 A tubular condenser can be used.

 Next, a method of preparing boron trichloride according to the second aspect of the present invention will be described.

 The method for preparing boron trichloride according to the second aspect of the present invention comprises the fluidized bed without the sieve plate according to the above aspect, wherein the preparation method of the boron trichloride comprises: passing the alkaline earth metal boride of the powder raw material The raw material supply device 4 is filled in the bed 1 of the fluidized bed device without the sieve plate; the carrier gas source 2 is turned on, and the carrier gas is introduced into the bed 1 of the fluidized bed device without the sieve plate, so that the powder raw material is The bed 1 of the fluidized bed device without sieve plate is in a fluidized state; the heating device 5 is turned on to heat the bed body 1, and after the temperature reaches a predetermined temperature, the reaction gas is supplied with anhydrous hydrogen chloride; after the reaction reaches a prescribed period of time , open and start the separation device 7 to obtain the desired boron trichloride.

 In the method for producing boron trichloride according to the present invention, the method may further include the steps of: opening the slag discharge port while opening and starting the separation device 7, and discharging the reaction slag formed by the reaction in the bed body 1.

 In the method for producing boron trichloride according to the present invention, preferably, the alkaline earth metal boride is calcium boride or magnesium boride, and has a diameter of 20 to 200 mesh.

 In the method for producing boron trichloride according to the present invention, preferably, the reaction gas, water-free hydrogen chloride, is subjected to dehydration drying and heating and heating by the reaction gas treatment device 9 before being introduced into the bed 1.

 In the method for producing boron trichloride according to the present invention, preferably, the reaction process temperature is 550 ° C to 700 ° C, and the reaction time is 1 to 2 h.

 In the method for producing boron trichloride according to the present invention, preferably, the flow rate of the alkaline earth metal boride is 80 to 85 g/h, and the flow rate of anhydrous hydrogen chloride is 500 to 600 g/h.

In the method for producing boron trichloride according to the present invention, preferably, the opening is Starting the separation device 7 to obtain the desired boron trichloride includes condensing the reacted material to obtain boron trichloride. Preferably, the condensation temperature is from -10 °C to - 30 °C.

 In the method for producing boron trichloride according to the present invention, the calcium boride is preferably calcium hexaboride.

 When the alkaline earth metal boride is calcium hexaboride, the reaction equation is:

CaB ₆ +20HCl=6BCl ₃ +CaCl ₂ +10H ₂

The main substances in the reaction include: BC1 ₃ , carrier gas, hydrogen, BC1 ₃ , oxygen, nitrogen, Cl ₂ , HC1 and the like, and calcium chloride slag and calcium boride. In the gas-solid separation device 71, calcium chloride slag and calcium boride are preferably separated from other gases by a filter column composed of glass fibers to achieve gas-solid separation; in the gas separation device 72, preferably hot copper is used. Oxygen and hydrogen can be separated by powder or carbon powder, Cl ₂ and HCl can be removed by alkaline solid adsorbent, and sodium or potassium hydroxide is preferably used for alkaline solid; after gas-solid separation and gas-gas separation, condensation In the device 73, the BC1 ₃ gas is condensed by controlling the condensation temperature of the condensing device to separate the BC1 ₃ from the carrier gas, and the carrier gas is discharged from the condensing device 73 and recovered. Preferably, the carrier gas discharged from the condensing device 73 is treated by an alkaline solution soaking and drying activated carbon packed column to recover the purity of the recovered carrier gas. Preferably, the alkaline solution is a sodium hydroxide solution or a potassium hydroxide solution.

 When the alkaline earth metal boride is magnesium boride, the reaction equation:

MgB ₂ + 8HC1 = 2BC1 ₃ + MgCl ₂ + 4H ₂

The main substances in the reaction are: BC1 ₃ , carrier gas, hydrogen, BC1 ₃ , oxygen, nitrogen, Cl ₂ ,

Gas such as HC1, magnesium chloride residue, magnesium boride, and the like. The operation of the separation device 7 (the gas-solid separation device 71, the gas separation device 72, and the condensing device 73) may be the same as that of the above-described calcium hexaboride, and the repeated description thereof will be omitted.

In the method for producing boron trichloride according to the present invention, preferably, the carrier gas The body is an inert gas. The inert gas may be nitrogen, argon, helium or a mixed gas of two of them. Preferably, nitrogen is selected. 5米7h〜10米7h。 Preferably, the flow rate is 0. 5m7h~10 m7h.

 In the method for preparing boron trichloride according to the present invention, preferably, the flow rate of the carrier gas into the bed 1 of the fluidized bed without the sieve plate after the reaction gas is supplied with anhydrous hydrogen chloride is lowered to The amount of fluidized state of the alkaline earth metal boride is maintained.

 Third, an embodiment of a method for producing boron trichloride according to the present invention will be described.

 Example 1

The powdered calcium hexaboride having a particle diameter of 20 to 30 mesh is filled in the bed 1 of the fluidized bed without the sieve plate by the raw material supply device 4 at a flow rate of 80 g/h; the carrier gas source 2 is turned on, and the nitrogen gas is introduced into the absence of In the bed 1 of the fluidized bed of the sieve plate, the powdered calcium hexaboride is in a fluidized state in the bed 1 of the fluidized bed without the sieve plate; the heating device 5 is turned on to heat the bed 1 at a temperature After 550 ° C, 500 m / h flow rate into the bed 1 into the reaction gas treatment device 9 dehydration drying reaction of anhydrous hydrogen chloride, while continuously reducing the nitrogen flow to maintain the fluidized state of calcium boride, reaction lh; Thereafter, the separation device 7 is opened and started, and calcium chloride slag and calcium boride are separated by a filter column composed of glass fibers in the gas-solid separation device 71, and then oxygen and hydrogen are removed by the hot copper powder in the gas separation device 72. 15 then, after removing the Cl ₂ and HCl by a solid sodium hydroxide adsorbent, and finally condensing at -10 ° C in a condenser 73 using a tubular condenser to obtain colorless boron trichloride, from the condenser 73 exhausted nitrogen is passed through sodium hydroxide Soaking liquid, the drying process is filled with activated carbon column treatment. .

 Example 2

100~120 mesh powder calcium hexaboride is filled into the bed 1 of the fluidized bed without sieve through the raw material supply device 4 at a flow rate of 85 g/h; the carrier gas source 2 is turned on, and the argon gas is introduced into the sieveless plate. In the bed 1 of the fluidized bed, the powdered calcium hexaboride is in a fluidized state in the bed 1 of the fluidized bed without the sieve plate; the heating device 5 is turned on to heat the bed 1 at a temperature After 700 °C, the reaction gas of the dehydration and drying by the reaction gas treatment device 9 is introduced into the bed 1 at a flow rate of 600 g/h, and the flow rate of the argon gas is continuously lowered to maintain the fluidized state of the calcium boride. 5h; then opening and starting the separation device 7, separating the calcium chloride residue and the calcium boride by the filter column composed of the glass fiber in the gas-solid separation device 71, and then passing the oxygen through the hot carbon powder in the gas separation device 72. And hydrogen removal, followed by removal of Cl ₂ and HCl by solid potassium hydroxide adsorbent; finally condensing at -30 ° C in a condenser 73 using a tubular condenser to obtain colorless boron trichloride, condenser The argon gas discharged from the stream 73 is recovered, and the nitrogen gas discharged from the condenser 73 is treated with an activated carbon packed column which is immersed in a potassium hydroxide solution and dried.

 Example 3

The powdered magnesium boride of 180~200 mesh is filled into the bed 1 of the fluidized bed without the sieve plate through the raw material supply device 4 at a flow rate of 82 g/h; the carrier gas source 2 is opened, and the helium gas is introduced into the sieveless plate. In the bed 1 of the fluidized bed, the powdered magnesium boride is in a fluidized state in the bed 1 of the fluidized bed without the sieve plate; the heating device 5 is turned on to heat the bed 1 after the temperature reaches 650 ° C. The reaction gas anhydrous dehydrogenated by the reaction gas treatment device 9 was introduced into the bed 1 at a flow rate of 550 g/h, and the flow rate of the helium gas was continuously lowered to maintain the fluidized state of the calcium boride, and the reaction was carried out for 2 hours _; The separating device 7 separates magnesium chloride slag and magnesium boride by a filter column composed of glass fibers in the gas-solid separation device 71, and then removes oxygen and hydrogen through the hot carbon powder in the gas separation device 72, and then passes through solid state hydration. The potassium adsorbent removes Cl ₂ and HCl; finally, condensation is carried out at -10 ° C in a condenser 73 using a tubular condenser to obtain colorless boron trichloride, and the helium gas discharged from the condenser 73 is subjected to hydrogen. Soaking in sodium oxide solution, A column filled with activated carbon dry treatment process.

 Finally, the detection results of the examples will be described.

Table 1 shows the test results of Examples 1-3. When testing, for condenser 8 (using column Tubular condenser) The incoming gas is tested. The detection method uses a Fourier transform infrared spectrometer (FTIR) and a UV analyzer.

 Table 1 Test results of Examples 1-3

 As seen from Table 1, the method for producing boron trichloride according to the present invention can obtain boron trichloride having a high purity.

Claims

Claim  1. A fluidized bed without a sieve plate, comprising:  Bed body (1);  a carrier gas source (2) for supplying a carrier gas from the lower portion of the bed (1) toward the bed (1) toward the upper portion of the bed (1);  a reaction gas supply device (3) for supplying a reaction gas to the bed (1);  a raw material supply device (4) for supplying a powder raw material to the bed body (4);  a heating device (5) for heating the bed (1);  a slag discharge port (6) for discharging the reaction slag generated by the reaction in the bed body (1);  The separation device (7) is connected to the bed (1) to separate the reacted matter of the bed (1) to obtain the final product.  2. The fluidized bed without a sieve plate according to claim 1, wherein the fluidized bed without the sieve plate further comprises: a carrier gas guide (10) for the carrier gas source (2) The carrier gas supplied to the bed (1) is guided.  3. A sieveless fluidized bed according to claim 2, characterized in that the carrier gas guide (10) has a bevel (101) which tapers towards the bed (1).  4. A sieveless fluidized bed according to claim 2, characterized in that the carrier gas of the carrier gas source (2) enters the carrier gas inlet (21) of the carrier gas guide (10) in the direction of the carrier The inner wall (103) of the gas guide (10) at the position where the carrier gas inlet (21) is connected is inclined.  5. The sieveless fluidized bed according to claim 2, characterized in that the carrier gas of the carrier gas source (2) enters the carrier gas inlet (21) of the carrier gas guide (10) in the direction of the carrier The inner wall (103) of the gas guide (10) at the position where the carrier gas inlet (21) is connected is inclined and in the direction of the carrier gas inlet (21) in the plane with respect to the vertical axis (A) of the bed (1) It is inclined upward with respect to the vertical axis (A). 6. The sieveless fluidized bed according to claim 4, wherein the carrier gas The inlets (21) are at least two, wherein at least one pair of carrier gas inlets (21) are disposed opposite each other along the inner wall (103) of the carrier gas guide (10).  A method for producing boron trichloride, which comprises the fluidized bed without a sieve plate according to any one of claims 1 to 6, wherein the preparation method of the boron trichloride comprises:  The powder raw material alkaline earth metal boride is filled in the bed (1) of the fluidized bed without the sieve plate through the raw material supply device (4);  The carrier gas source (2) is turned on, and the carrier gas is introduced into the bed (1) of the fluidized bed without the sieve plate, so that the powder raw material alkaline earth metal boride is in the bed of the fluidized bed without the sieve plate (1) In a fluidized state;  Turn on the heating device (5) to heat the bed (1), and after the temperature reaches the specified temperature, pass the reaction gas anhydrous hydrogen chloride;  After the reaction has reached a specified period of time, open and start the separation unit (7) to obtain the required boron trichloride.  The method for preparing boron trichloride according to claim 7, further comprising the steps of: opening the slag discharge port (6) while opening and starting the separation device (7), and the bed body (1) The reaction slag generated by the reaction inside is discharged.  The method for producing boron trichloride according to claim 7, wherein the reaction gas anhydrous hydrogen chloride is subjected to dehydration drying and heating to be heated before being introduced into the bed (1).  The method for preparing boron trichloride according to claim 7, wherein the carrier gas is introduced into the bed (1) of the fluidized bed without the sieve plate after the reaction gas is passed through anhydrous hydrogen chloride. The flow rate is reduced to the amount that maintains the fluidized state of the alkaline earth metal boride.