A rotary kiln gas path system for producing battery-grade vanadium oxide

Abstract

The present invention relates to a rotary kiln gas path system for producing battery-grade vanadium oxide, comprising: a cylinder body; a first end head and a second end head respectively communicated with two ends of the cylinder body; a feeding screw communicated with the first end head and the cylinder body; a first storage bin communicated with the feeding screw; a dust collector communicated with the upper end of the first end head; a first hopper communicated with the bottom of the dust collector; a pickling tower connected to the top of the dust collector; a first induced draft fan with two ends respectively connected to the pickling tower and the dust collector; a second hopper communicated with the lower end of the first end head; a third hopper connected to the second hopper; a fourth hopper communicated with the lower end of the second end head; a second storage bin connected to the fourth hopper; an observation cylinder installed on the side part of the second end head; a purifier communicated with external air; and a second induced draft fan communicated with the purifier and the observation cylinder. Through the system of the present invention, the proportion of Si≤0.01% in the vanadium oxide product obtained after calcination by the present invention is 100%.

Description

Technical Field

[0001] The present invention belongs to the field of non-ferrous metallurgy technology, and more specifically, relates to a rotary kiln gas path system for producing battery-grade vanadium oxide. Background Art

[0002] In the products obtained by the battery-grade vanadium oxide process, Si is the main element that causes the product quality to fail to meet the standards. Through long-term tracking of the production process, it is found that the Si content in the AMV input into the rotary kiln is ≤0.007%, meeting the raw material quality requirements; while the proportion of Si ≤0.01% in the obtained product vanadium oxide (V 2 O 5 ) is only 60%. This indicates that impurities Si are introduced during the production process of the rotary kiln system, resulting in product quality fluctuations.

[0003] "Equipment and Method for Producing Powdered Vanadium Pentoxide" written by Wei Linsen proposed a production method for calcining quantitatively added APV after drying in a rotary kiln to prepare powdered vanadium pentoxide. In this method, the material input into the rotary kiln is ammonium polyvanadate (APV), and the obtained product powdered vanadium pentoxide is non-battery-grade vanadium oxide; the volume concentration of oxygen gas in the rotary kiln is 19.5 - 20.8%, and the quality control of the gas participating in the reaction is not clearly defined, nor is the control of the dust removal system clearly defined.

[0004] "Process for Calcining Ammonium Metavanadate to Produce Powdered Vanadium Pentoxide" written by Zhang Chunyu proposed that ammonium metavanadate with a water content of 30 - 40% has a water content ≤0.3% after vacuum drying, and it is put into a calcining device to pass rich oxygen air for deammoniation oxidation. After the deammoniation oxidation is completed, then continue to blow rich oxygen air into the calcining device for cooling, and discharge the material to obtain a mixture of powdered vanadium pentoxide or vanadium oxide. The obtained product powdered vanadium pentoxide is also non-battery-grade vanadium oxide.

[0005] Currently, the heavy dissolution and crystallization process is used to produce battery-grade vanadium oxide, and its process route is as follows: Vanadium slag is subjected to sodium roasting and then water-leached to obtain a vanadium-containing leaching solution. After the vanadium-containing leaching solution is purified and decontaminated by adding calcium chloride, multiple vanadium precipitation and re-dissolution operations are carried out to obtain ammonium metavanadate (AMV). After drying AMV, it enters the rotary kiln for calcination to obtain battery-grade vanadium oxide.

[0006] However, for this process of producing battery-grade vanadium oxide, sampling and analysis are carried out, and the results are shown in Table 1 below.

[0007]

[0008] From the analysis of Table 1, the main reasons for the impurity Si brought into the production process of the rotary kiln system are as follows: (1) The air entering the rotary kiln contains fine particulate dust (including Si dust), and after the reaction of air and materials in the rotary kiln, part of Si enters the product; (2) The gas after the reaction in the rotary kiln carries a small amount of vanadium-containing dust into the dust collector, which is intercepted by the dust removal bag in the dust collector and enters the powder collection bin at the bottom of the dust collector. The material in the bin returns to the feed bin of the rotary kiln through the screw under the bin and enters the rotary kiln again together with AMV for calcination into the product; (3) The dust removal bag of the dust collector is blown back for regeneration. Due to the small volume of the powder collection bin, the material in the powder collection bin is blown up and returns to the rotary kiln through the dust removal pipeline and enters the product; (4) During the production process, a small amount of impurity-containing air enters the system when the material leaves the system.

[0009] Therefore, at present, the proportion of Si≤0.01% in the product vanadium oxide obtained after calcination is not high, and improvement is needed. Summary of the Invention

[0010] In view of the deficiencies of the prior art, the present invention proposes a rotary kiln gas path system for producing battery-grade vanadium oxide. By improving the system, under the same conditions of the AMV calcination reaction, the proportion of Si≤0.01% in the product vanadium oxide reaches 100%.

[0011] To solve the above technical problems, the present invention adopts the following technical solutions:

[0012] According to an aspect of the present invention, there is provided a rotary kiln gas path system for producing battery-grade vanadium oxide, including:

[0013] A cylinder;

[0014] A first end and a second end, the first end is communicated with one end of the cylinder and the second end is communicated with the other end of the cylinder;

[0015] A feed screw, the feed screw passes through the side of the first end and extends into the interior of the cylinder;

[0016] A first bin, the first bin contains reaction raw materials and is communicated to the feed screw through a pipeline with a first valve;

[0017] A dust collector, a powder collection bin is arranged at the bottom of the dust collector, an air blowing back pipe communicated with the outside and provided with a second valve is installed at the top of the dust collector, and the side of the dust collector is communicated to the upper end of the first end through a pipeline with a third valve;

[0018] A first hopper, the upper end of the first hopper is communicated with the powder collection bin of the dust collector through a pipeline with a fourth valve, and the lower end of the first hopper is communicated with the outside through a pipeline with a fifth valve;

[0019] An acid washing tower;

[0020] The first induced draft fan, one end of the first induced draft fan is connected to the pickling tower and the other end is connected to the top of the dust collector;

[0021] The second hopper, the second hopper is arranged at the lower end of the first end and is connected to the cylinder body;

[0022] The third hopper, the upper end of the third hopper is connected to the second hopper through a pipeline with a sixth valve and the lower end of the third hopper is connected to the outside through a pipeline with a seventh valve;

[0023] The fourth hopper, the fourth hopper is arranged at the lower end of the second end and is connected to the cylinder body;

[0024] The second silo, the upper end of the second silo is connected to the fourth hopper through a pipeline with an eighth valve and the lower end of the second silo is connected to the outside through a pipeline with a ninth valve;

[0025] The observation cylinder, the observation cylinder is installed on the side of the second end;

[0026] The purifier; one end of the purifier is connected to the outside air; and

[0027] The second induced draft fan, one end of the second induced draft fan is connected to the other end of the purifier and the other end of the second induced draft fan is connected to the observation cylinder.

[0028] In an embodiment of the present invention, the gas path system further includes:

[0029] The first pressure gauge and the second pressure gauge, the first pressure gauge and the second pressure gauge are respectively installed at the upper ends of the first end and the second end;

[0030] The first flow meter and the second flow meter, the first flow meter is installed on the pipeline where the third valve is connected to the first end, and the second flow meter is installed on the pipeline where the second induced draft fan is connected to the observation cylinder;

[0031] The oxygen analyzer, the oxygen analyzer is installed on the pipeline where the third valve is connected to the first end.

[0032] In an embodiment of the present invention, the reaction raw material contained in the first silo is ammonium metavanadate AMV.

[0033] In an embodiment of the present invention, a cloth bag for gas-solid separation is arranged in the dust collector, and the cloth bag intercepts solid particulate matters so that the solid particulate matters stay on the surface of the cloth bag.

[0034] In an embodiment of the present invention, the gas path system further includes:

[0035] The sight glass, the sight glass is installed at the end of the observation cylinder.

[0036] In one embodiment of the present invention, the sight glass is a circular plexiglass.

[0037] In one embodiment of the present invention, the observation cylinder is installed on the side of the second end head facing the center of the cylinder body.

[0038] In one embodiment of the present invention, the cylinder body and the first end head and the second end head respectively adopt dynamic seals.

[0039] In one embodiment of the present invention, the second valve and the third valve are configured for interlocking control.

[0040] In one embodiment of the present invention, the lower cone angles of the first hopper, the second hopper, the third hopper and the fourth hopper range from 30° to 45°; the lower cone angles of the first silo and the second silo range from 30° to 45°.

[0041] By adopting the above technical solutions, the present invention has the following advantages compared with the prior art:

[0042] Under the same conditions of the AMV calcination reaction, the proportion of Si≤0.01% in the product vanadium oxide of the system of the present invention is significantly increased and reaches 100%. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The figure shows a schematic diagram of the rotary kiln gas path system for producing battery-grade vanadium oxide provided by the present invention.

[0044] LIST OF REFERENCE NUMERALS

[0045] 1 Pickling tower, 2 First induced draft fan, 3 Dust collector, 4 First valve, 5 Second valve, 6 Third valve, 7 Fourth valve, 8 Fifth valve, 9 First flowmeter, 10 Oxygen analyzer, 11 First pressure gauge, 12 First silo, 13 First hopper, 14 Feed screw, 15 First end head, 16 Second hopper, 17 Sixth valve, 18 Third hopper, 19 Seventh valve, 20 Cylinder body, 21 Fourth hopper, 22 Eighth valve, 23 Second silo, 24 Ninth valve, 25 Second end head, 26 Sight glass, 27 Observation cylinder, 28 Second flowmeter, 29 Second pressure gauge, 30 Second induced draft fan, 31 Purifier, 32 Powder collection bin. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments of the present invention are described in detail, those skilled in the art can easily appreciate that various modifications are feasible without substantially departing from the teachings of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, parameters, etc. of the following exemplary embodiments.

[0047] As Figure 1 shown, a rotary kiln gas path system for producing battery-grade vanadium oxide includes:

[0048] Cylinder body 20;

[0049] A first end 15 and a second end 25, the first end 15 is communicated with one end of the cylinder body 20 and the second end 25 is communicated with the other end of the cylinder body 20;

[0050] Feeding screw 14, the feeding screw 14 passes through the side of the first end 15 and extends into the interior of the cylinder body 20;

[0051] A first bin 12, the first bin 12 contains reaction raw materials and is communicated to the feeding screw 14 through a pipeline with a first valve 4;

[0052] Dust collector 3, a powder collecting bin 32 is arranged at the bottom of the dust collector 3, an air blowing pipe communicating with the outside and having a second valve 5 is installed at the top of the dust collector 3, and the side of the dust collector 3 is communicated to the upper end of the first end 15 through a pipeline with a third valve 6;

[0053] A first hopper 13, the upper end of the first hopper 13 is communicated with the powder collecting bin 32 of the dust collector 3 through a pipeline with a fourth valve 7 and the lower end of the first hopper 13 is communicated with the outside through a pipeline with a fifth valve 8;

[0054] Pickling tower 1;

[0055] A first induced draft fan 2, one end of the first induced draft fan 2 is communicated with the pickling tower 1 and the other end is communicated to the top of the dust collector 3;

[0056] A second hopper 16, the second hopper 16 is arranged at the lower end of the first end 15 and is communicated with the cylinder body 20;

[0057] A third hopper 18, the upper end of the third hopper 18 is communicated with the second hopper 16 through a pipeline with a sixth valve 17 and the lower end of the third hopper 18 is communicated with the outside through a pipeline with a seventh valve 19;

[0058] A fourth hopper 21, the fourth hopper 21 is arranged at the lower end of the second end 25 and is communicated with the cylinder body 20;

[0059] A second silo 23, the upper end of the second silo 23 is connected to the fourth hopper 21 through a pipeline with an eighth valve 22, and the lower end of the second silo 23 is connected to the outside through a pipeline with a ninth valve 24;

[0060] An observation cylinder 27, the observation cylinder 27 is installed on the side of the second end 25;

[0061] A purifier 31; one end of the purifier 31 is connected to the outside air; and

[0062] A second induced draft fan 30, one end of the second induced draft fan 30 is connected to the other end of the purifier 31, and the other end of the second induced draft fan 30 is connected to the observation cylinder 27.

[0063] Through the above system of the present invention, under the same conditions of the AMV calcination reaction, the proportion of Si≤0.01% in the product vanadium oxide reaches 100%.

[0064] In the above technical solution, the gas path system further includes:

[0065] A first pressure gauge 11 and a second pressure gauge 29, the first pressure gauge 11 and the second pressure gauge 29 are respectively installed at the upper ends of the first end 15 and the second end 25;

[0066] A first flowmeter 9 and a second flowmeter 28, the first flowmeter 9 is installed on the pipeline connecting the third valve 6 and the first end 15, and the second flowmeter 28 is installed on the pipeline connecting the second induced draft fan 30 and the observation cylinder 27;

[0067] An oxygen analyzer 10, the oxygen analyzer 10 is installed on the pipeline connecting the third valve 6 and the first end 15.

[0068] In the above technical solution, the reaction raw material contained in the first silo 12 is ammonium metavanadate AMV.

[0069] In the above technical solution, a cloth bag for gas-solid separation is provided in the dust collector 3, and the cloth bag intercepts solid particles and makes the solid particles stay on the surface of the cloth bag.

[0070] In the above technical solution, the gas path system further includes:

[0071] A sight glass 26, the sight glass 26 is installed at the end of the observation cylinder 27.

[0072] In the above technical solution, the sight glass 26 is a circular plexiglass.

[0073] In the above technical solution, the observation cylinder 27 is installed on the side of the second end 25 facing the center of the cylinder body 20.

[0074] In the above technical solution, dynamic seals are respectively adopted between the cylinder body 20 and the first end 15 and the second end 25, that is, the cylinder body 20 rotates while the first end 15 and the second end 25 remain stationary.

[0075] In the above technical solution, the second valve 5 and the third valve 6 are configured for interlocking control, that is, when the second valve 5 is opened for reverse air blowing operation, the third valve 6 is closed; when the second valve 5 is closed, the third valve 6 is opened.

[0076] In the above technical solution, the lower cone angles of the first hopper 13, the second hopper 16, the third hopper 18, and the fourth hopper 21 range from 30° to 45°, preferably 30°; the lower cone angles of the first silo 12 and the second silo 23 range from 30° to 45°, preferably 30°.

[0077] The above technical solution of the present invention will be described in detail below through specific embodiments.

[0078] Such as Figure 1As shown in the figure, the raw material AMV in the first bin 12 is transported into the cylinder body 20 through the first valve 4 by the feeding screw 14. The purifier 31 purifies the external air and introduces the purified air into the cylinder body 20. After the raw material AMV and the purified air fully react, the product vanadium oxide enters the fourth hopper 21, and then enters the second bin 23 through the eighth valve 22, and then enters the packaging system through the ninth valve 24. The first induced draft fan 2 is turned on and the second induced draft fan 30 is kept on. The air is purified by the purifier 31 and then enters the observation cylinder 27, and then enters the cylinder body 20 to fully react with the raw material AMV. The gas flow of the gas-borne substances then enters the dust collector 3 through the third valve 6 for gas-solid separation. The gas enters the pickling tower 1 through the first induced draft fan 2 to remove ammonia gas and fine vanadium-containing particles in the gas and then is discharged up to standard. The gas-solid separation is carried out by the cloth bag of the dust collector 3. The solid particulate matter is intercepted by the cloth bag and stays on the surface of the cloth bag. The second valve 5 is opened, and the reverse blowing air of the reverse blowing air pipe blows the vanadium-containing particulate matter on the surface of the cloth bag into the powder collecting bin 32 of the dust collector 3, and then enters the first hopper 13 through the fourth valve 7. Due to the sudden increase in the chamber space formed between the first end 15 and the cylinder body 20 or the closing of the third valve 6, some vanadium-containing particulate materials fall into the second hopper 16 and enter the third hopper 18 through the sixth valve 17. The materials in the third hopper 18 are regularly sent away through the seventh valve 19 and returned to the first bin 12. The first flowmeter 9 and the oxygen analyzer 10 are installed on the pipeline between the third valve 6 and the first end 15 to detect the gas flow and oxygen content after the reaction respectively. The first pressure gauge 11 and the second pressure gauge 29 are installed on the upper ends of the first end 15 and the second end 25 respectively to detect the pressures at the feeding end and the discharging end of the rotary kiln respectively. The second flowmeter 28 is installed on the air inlet pipeline between the second induced draft fan 30 and the observation cylinder 27 to detect the air inlet flow. The observation cylinder 27 is installed on the side of the second end 25 at the discharging end of the rotary kiln, facing the center of the cylinder body 20; a sight glass 26 is installed at the end of the observation cylinder 27 for observing the material reaction, operation condition and the inner wall condition of the cylinder body 20.

[0079] In the above system, the diameter of the cylinder body 20 is 1 m and the length is 20 m. The rotary kiln cylinder body 20 is dynamically sealed with the first end 15 at the feed end and the second end 25 at the discharge end, that is, the cylinder body 20 rotates while the first end 15 and the second end 25 remain stationary. The volume of the second hopper 16 is 1.0 m³, and the inclination angle of the lower cone is 30°; the volume of the third hopper 18 is 3 m³, and the inclination angle of the lower cone is 30°; the sixth valve 17 and the seventh valve 19 cannot be opened simultaneously to prevent external air from carrying impurities into the interior of the rotary kiln; the materials in the third hopper 18 are regularly sent away and returned to the first bin 12. The volume of the first bin 12 is 12 m³; the diameter of the feed screw 14 is 200 mm and the length is 1.5 m, and the end extends into the reduced diameter of the cylinder body 20 to prevent the second hopper 16 from being frequently full due to backfeeding. The feed screw can be frequency-converted, and the maximum material-carrying capacity is 0.5 t / h. The volume of the fourth hopper 21 is 1.5 m³, and the inclination angle of the lower cone is 30°; the volume of the second bin 23 is 3 m³, and the inclination angle of the lower cone is 30°; the eighth valve 22 and the ninth valve 24 cannot be opened simultaneously to prevent external air from carrying impurities into the interior of the rotary kiln. The volume of the first hopper 13 is 1.0 m³, and the materials in the first hopper 13 are also regularly sent away and stored as raw materials for producing non-battery-grade vanadium oxide; the fourth valve 7 and the fifth valve 8 cannot be opened simultaneously to prevent external air from entering and disturbing the air flow inside the rotary kiln or causing vanadium-containing dust to escape during the reverse air blowing operation. The diameter of the observation cylinder 27 is 200 mm and the length is 200 mm. The sight glass 26 is made of circular organic glass and is installed at the end of the observation cylinder 27; the intake pipe is installed on the cylinder body of the observation cylinder 27 to play a role in cooling and protecting the sight glass 26. The production capacity of this system for producing battery-grade vanadium oxide is 4 t / d (i.e., the feed rate is 0.22 t / h). The flow rate of the second flowmeter 28 is about 250 m³ / h, and the flow rate of the first flowmeter 9 is about 300 m³ / h; the oxygen volume concentration measured by the oxygen analyzer 10 is about 17.3%; the first induced draft fan 2, the second induced draft fan 30 and the third valve 6 are well matched to ensure a slightly negative pressure inside the cylinder body 20. The pressures of the first pressure gauge 11 and the second pressure gauge 29 are preferably about -5 Pa. The second valve 5 and the third valve 6 are interlocked: when the second valve 5 is opened for reverse air blowing operation, the third valve 6 is closed to prevent the dust removal ash from flowing back into the cylinder body 20 and causing product quality fluctuations; when the second valve 5 is closed, the third valve 6 is opened for normal dust removal gas filtration operation. The intake pipe of the purifier 31 is DN 500 mm, the pipe from the purifier 31 to the observation cylinder 27 is DN150 mm, the pipe from the first end 15 at the feed end of the rotary kiln to the dust collector 3 is DN200 mm, and the pipe from the dust collector 3 to the pickling tower 1 is DN 300 mm.

[0080] After the implementation of the above system, samples of each material were taken for analysis, and the results are shown in Table 2 below.

[0081]

[0082] As can be seen from the results in Table 2 above, compared with the results in Table 1 implemented without using the above system of the present invention, after implementing through the above system of the present invention, the qualified rate of the Si content of the battery-grade vanadium oxide produced by the present invention is 100%, that is, the proportion of Si≤0.01% in the vanadium oxide product obtained after calcination is 100%.

[0083] The above are only the preferred embodiments of the present invention and are not used to limit the scope of implementation of the present invention; if the present invention is modified or equivalently replaced without departing from the spirit and scope of the present invention, it should be covered within the protection scope of the claims of the present invention.

Claims

1. A rotary kiln gas path system for producing battery-grade vanadium oxide, characterized in that, it includes: a cylinder body; a first end and a second end, the first end is communicated with one end of the cylinder body and the second end is communicated with the other end of the cylinder body; a feeding screw, the feeding screw passes through the side of the first end and extends into the interior of the cylinder body; a first bin, the first bin contains reaction raw materials and is communicated with the feeding screw through a pipeline with a first valve; a dust collector, a powder collecting bin is arranged at the bottom of the dust collector, an air blowing pipe communicated with the outside and provided with a second valve is installed at the top of the dust collector, and the side of the dust collector is communicated with the upper end of the first end through a pipeline with a third valve; a first hopper, the upper end of the first hopper is communicated with the powder collecting bin of the dust collector through a pipeline with a fourth valve and the lower end of the first hopper is communicated with the outside through a pipeline with a fifth valve; an acid pickling tower; a first induced draft fan, one end of the first induced draft fan is communicated with the acid pickling tower and the other end is communicated with the top of the dust collector; a second hopper, the second hopper is arranged at the lower end of the first end and is communicated with the cylinder body; a third hopper, the upper end of the third hopper is communicated with the second hopper through a pipeline with a sixth valve and the lower end of the third hopper is communicated with the outside through a pipeline with a seventh valve; a fourth hopper, the fourth hopper is arranged at the lower end of the second end and is communicated with the cylinder body; a second bin, the upper end of the second bin is communicated with the fourth hopper through a pipeline with an eighth valve and the lower end of the second bin is communicated with the outside through a pipeline with a ninth valve; an observation cylinder, the observation cylinder is installed on the side of the second end; a purifier; one end of the purifier is communicated with external air; and a second induced draft fan, one end of the second induced draft fan is communicated with the other end of the purifier and the other end of the second induced draft fan is communicated with the observation cylinder.

2. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, the gas path system further includes: a first pressure gauge and a second pressure gauge, the first pressure gauge and the second pressure gauge are respectively installed at the upper end of the first end and the upper end of the second end; a first flow meter and a second flow meter, the first flow meter is installed on the pipeline where the third valve is communicated with the first end, and the second flow meter is installed on the pipeline where the second induced draft fan is communicated with the observation cylinder; an oxygen analyzer, the oxygen analyzer is installed on the pipeline where the third valve is communicated with the first end.

3. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, the reaction raw materials contained in the first bin are ammonium metavanadate AMV.

4. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, a cloth bag for gas-solid separation is arranged in the dust collector, and the cloth bag intercepts solid particulate matters so that the solid particulate matters stay on the surface of the cloth bag.

5. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 2, characterized in that, the gas path system further includes: a sight glass, and the sight glass is installed at the end of the observation cylinder.

6. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 5, characterized in that, the sight glass is a circular plexiglass.

7. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, the observation cylinder is installed on the side of the second end head facing the center of the cylinder body.

8. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, the cylinder body and the first end head and the second end head respectively adopt dynamic seals.

9. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, the second valve and the third valve are configured for interlocking control.

10. The rotary kiln gas path system for producing battery-grade vanadium oxide according to claim 1, characterized in that, the lower cone angles of the first hopper, the second hopper, the third hopper and the fourth hopper range from 30° to 45°; the lower cone angles of the first silo and the second silo range from 30° to 45°.

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