A device, system and method for removing saltpeter

Abstract

The present invention discloses a saltpeter removal device, which includes a saltpeter removal kettle and an inner barrel disposed inside the saltpeter removal kettle, the lower barrel wall and bottom of the inner barrel being evenly distributed with through holes, a first liquid inlet being provided on the top of the saltpeter removal kettle, a first liquid outlet being provided on the bottom of the saltpeter removal kettle, the first liquid inlet and the first liquid outlet being connected by a pipe, a pump assembly being provided between the pipes connecting the first liquid inlet and the first liquid outlet, a first liquid outlet pipe being provided inside the saltpeter removal kettle, one end of the first liquid outlet pipe being connected to the first liquid inlet, and the other end of the first liquid outlet pipe being close to the upper part of the inner barrel. The present invention circulates the solution by providing a pump assembly, so that the solution is in full contact with the metal powder particles, thereby increasing the saltpeter removal rate, and the solution circulation plays a stirring role, thereby avoiding the violent movement of the metal caused by direct stirring by a stirring device, and solving the technical problems in the prior art of directly stirring the metal by a stirring device, which leads to the friction between the metal and the equipment, the introduction of new impurities, and the slow saltpeter removal rate.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment for preparing metals and their compounds, and in particular to a device, system and method for removing nitrate. Background Art

[0002] The purpose of driving out the nitric acid is to remove excess nitric acid in the silver nitrate solution and increase the pH of the solution, thereby producing high-purity silver nitrate. In the process of preparing silver nitrate crystals using silver powder or silver ingots, the driving out of the nitric acid to remove free nitro groups is a very important production process, especially for silver nitrate used as a photosensitive material in the electronics industry. This material has very high requirements on the purity of silver nitrate. The impurity content in silver nitrate directly affects the material performance. Therefore, the driving out of the nitric acid operation is an important process that cannot be ignored.

[0003] The existing technology for removing nitrate generally adopts the method of continuously heating and evaporating, continuously adding pure water, and continuously boiling the silver nitrate solution to remove excess nitric acid. Although the pH of the solution can be increased, thereby improving the purity of the silver nitrate solution, the method of removing excess nitric acid in the solution by heating and evaporating is inefficient, which not only causes waste of steam or other heat sources, but also produces a large amount of acidic condensate containing nitrate, which increases the wastewater treatment cost of the enterprise to a certain extent and greatly increases the production cost.

[0004] In the prior art, the nitration-driving operation also involves contacting metal powder particles with an acidic solution. The nitration-driving operation is completed after the metal powder particles and the acidic solution have fully reacted. In order to allow the metal powder particles to fully contact the acidic solution and accelerate the nitration-driving process, a stirring device is often used to stir the metal powder particles. Although this nitration-driving operation can allow the metal powder particles to fully contact the acidic solution and accelerate the nitration-driving process, directly stirring the metal powder particles with a stirring device will produce violent movement, and the metal powder particles can easily rub against the equipment, thereby causing equipment wear. More seriously, the friction equipment process will cause new impurities to be introduced into the solution, making subsequent impurity removal more troublesome and bringing new impurity problems.

[0005] In view of the shortcomings of the existing technology, a device, system and method for removing nitrate that can improve the efficiency of removing nitrate and save production costs are urgently needed in this industry. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a system, device and method for removing saltpeter.

[0007] To achieve the aforementioned objectives, the present invention adopts the following technical solutions.

[0008] The present invention provides a saltpeter driving device, which includes a saltpeter driving kettle and an inner barrel arranged in the saltpeter driving kettle, wherein the lower barrel wall and the bottom of the inner barrel are evenly distributed with through holes, the top of the saltpeter driving kettle is provided with a first liquid inlet, and the bottom of the saltpeter driving kettle is provided with a first liquid outlet, the first liquid inlet and the first liquid outlet are connected through a pipeline, a pump assembly is also provided between the pipeline connecting the first liquid inlet and the first liquid outlet, and a first liquid outlet pipe is also provided in the saltpeter driving kettle, one end of the first liquid outlet pipe is connected to the first liquid inlet, and the other end of the first liquid outlet pipe is close to the upper part of the inner barrel.

[0009] As a further improvement of the present invention, the saltpeter driving device also includes a condenser, a spray tower, a fan and an exhaust pipe. The top of the saltpeter driving kettle is also provided with an air outlet. The tube-side inlet of the condenser is connected to the air outlet through a pipeline, the tube-side inlet of the spray tower is connected to the tube-side outlet of the condenser through a pipeline, the tube-side inlet of the fan is connected to the tube-side outlet of the spray tower through a pipeline, the tube-side inlet of the exhaust pipe is connected to the tube-side outlet of the fan through a pipeline, and the fan is used to introduce the waste gas that has been treated by the spray tower to meet the standards into the exhaust pipe for high-altitude discharge.

[0010] As a further improvement of the present invention, the saltpeter driving device also includes a first liquid storage barrel, and the bottom of the saltpeter driving kettle is also provided with a second liquid outlet. The first liquid storage barrel is used to store the solution after the saltpeter driving operation is completed, and its pipe side inlet is connected to the second liquid outlet through a pipeline.

[0011] As a further improvement of the present invention, the saltpeter-driving device also includes a second liquid storage tank, which is used to store and provide the solution required for the saltpeter-driving operation, and its pipe-side outlet is connected to the pipe-side inlet of the pump assembly.

[0012] As a further improvement of the present invention, the side wall of the nitrate-driving kettle is provided with a coil, and the coil is used for heat exchange to control the reaction temperature in the nitrate-driving kettle.

[0013] As a further improvement of the present invention, a feed port is further provided on the top of the nitre-driving kettle, and the feed port is used to add reaction raw materials into the inner barrel.

[0014] As a further improvement of the present invention, an observation window is further provided on the top of the nitre-driving kettle, and the observation window is used to observe the reaction conditions in the nitre-driving kettle.

[0015] The present invention also provides a nitrate-eliminating system for use in a process for preparing silver nitrate, comprising any one of the above-mentioned nitrate-eliminating devices.

[0016] The present invention also provides a method for driving out the nitrate, comprising the following steps: feeding metallic silver powder into an inner barrel through a feed port; checking and closing a first liquid outlet and a second liquid outlet, and opening a first liquid inlet and an air outlet, controlling a pump assembly to pump a solution from a second liquid storage barrel, so that the solution passes through the pump assembly, the first liquid inlet, and the first liquid outlet pipe from the second liquid storage barrel in sequence, and then enters the inner barrel, and finally enters the bottom of the nitrate driving kettle through a through hole in the inner barrel, and stops pumping the solution from the second liquid storage barrel when the solution submerges the through hole in the barrel wall of the inner barrel. ; Check and open the first liquid outlet, control the pump assembly to pump the solution from the bottom of the nitre-driving kettle, and the solution passes through the first liquid outlet, the pump assembly, the first liquid inlet, the first liquid outlet pipe in sequence from the bottom of the nitre-driving kettle into the inner barrel, and finally flows back to the bottom of the nitre-driving kettle from the through hole of the inner barrel, and the circulating solution reacts with the metallic silver powder in the inner barrel; after the reaction is completed, check and close the first liquid outlet and the pump assembly, and open the second liquid outlet, so that the solution after the reaction is completed enters the first liquid storage barrel through the second liquid outlet.

[0017] As a further improvement of the present invention, during the reaction, the reaction pressure is -0.07 to -0.09 MPa, and the reaction temperature is 60 to 80°C.

[0018] The present invention arranges a pump assembly to circulate the solution, so that the solution is in full contact with the metal powder particles, thereby improving the rate of removing the nitrate. The solution circulation plays a stirring role, avoiding the violent movement of the metal caused by direct stirring through a stirring device, and solving the technical problems in the prior art of directly stirring the metal through a stirring device, which leads to the friction between the metal and the equipment and the introduction of new impurities, as well as the slow rate of removing the nitrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a structural schematic diagram of a saltpeter removal system.

[0020] Among them: 1-nitre-dripping kettle; 2-inner barrel; 3-first liquid inlet; 4-air outlet; 5-first liquid outlet; 6-second liquid outlet; 7-pump assembly; 8-first liquid outlet pipe; 9-second liquid outlet pipe; 10-third liquid outlet pipe; 11-fourth liquid outlet pipe; 12-condenser; 13-spray tower; 14-fan; 15-exhaust pipe; 16-first liquid storage barrel; 17-second liquid storage barrel; 18-coil; 19-feed port; 20-observation window. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solution in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] Reference Figure 1 According to a first aspect of the present invention, a saltpeter driving device is provided, which includes a saltpeter driving kettle 1 and an inner barrel 2 arranged in the saltpeter driving kettle 1, and through holes are evenly distributed on the lower barrel wall and the bottom of the inner barrel 2. Preferably, through holes are evenly distributed on the lower 1 / 2 barrel wall and the bottom of the inner barrel 2. There are metal powder particles in the inner barrel 2. The evenly distributed through holes on the lower barrel wall and the bottom of the inner barrel 2 can allow the solution to fully contact with the metal powder particles, so that the solution after the reaction is completed can flow out through the through holes, and can prevent the solution from overflowing from the upper part of the inner barrel 2. The diameter of the through hole depends on the particle size of the metal powder. The present invention uses silver powder to produce high-grade pure silver nitrate, and its through hole diameter is set to 0.5mm.

[0023] A first liquid inlet 3 is provided on the top of the nitrate-driving kettle 1, and a first liquid outlet 5 is provided at the bottom of the nitrate-driving kettle 1. The first liquid inlet 3 and the first liquid outlet 5 are connected by a pipe. A pump assembly 7 is also provided between the pipes communicating with the first liquid inlet 3 and the first liquid outlet 5. A first liquid outlet pipe 8 is also provided in the nitrate-driving kettle 1. One end of the first liquid outlet pipe 8 is connected to the first liquid inlet 3, and the other end of the first liquid outlet pipe 8 is close to the upper part of the inner barrel 2. Under the action of the pump assembly 7, the solution first flows out of the nitrate-driving kettle 1 through the first liquid outlet 5, and then flows into the nitrate-driving kettle 1 from the first liquid inlet 3. The solution is passed through the first liquid outlet pipe 8 into the inner barrel 2 to react with the metal powder particles. The solution after reacting with the metal powder particles flows out through the through hole to the bottom of the nitrate driving kettle 1, and then flows out of the nitrate driving kettle 1 through the first liquid outlet 5. This process is repeated in this way to complete the flow cycle of the solution. The solution is circulated through the pump assembly 7 to accelerate the contact between the solution and the metal powder particles, thereby increasing the nitrate driving rate and avoiding the violent movement of the metal powder particles caused by direct stirring by the stirring device. The nitrate driving rate is increased while ensuring that no new impurities are introduced by friction with the equipment.

[0024] As a further preferred embodiment of a saltpeter-driving device of the present invention, the number of inner barrels 2 is 3, and a second liquid outlet pipe 9, a third liquid outlet pipe 10, and a fourth liquid outlet pipe 11 are further provided in the saltpeter-driving kettle 1. One end of the second liquid outlet pipe 9, the third liquid outlet pipe 10, and the fourth liquid outlet pipe 11 forms a four-way structure with the first liquid outlet pipe 8, and the other ends of the second liquid outlet pipe 9, the third liquid outlet pipe 10, and the fourth liquid outlet pipe 11 are respectively close to the upper part of the three inner barrels 2. After the solution enters the first liquid outlet pipe 8 through the first liquid inlet 3, the four-way structure diverts the solution to the second liquid outlet pipe 9, the third liquid outlet pipe 10, and the fourth liquid outlet pipe 11, and finally flows into the three inner barrels 2 respectively through the second liquid outlet pipe 9, the third liquid outlet pipe 10, and the fourth liquid outlet pipe 11. The number of inner barrels 2 and liquid outlet pipes can be adjusted according to actual needs, which will not be elaborated in this application.

[0025] The present invention provides a saltpeter removal device, which also includes a condenser 12, a spray tower 13, a fan 14 and an exhaust pipe 15. The top of the saltpeter removal kettle 1 is further provided with an air outlet 4. The tube-side inlet of the condenser 12 is connected to the air outlet 4 through a pipeline, the tube-side inlet of the spray tower 13 is connected to the tube-side outlet of the condenser 12 through a pipeline, the tube-side inlet of the fan 14 is connected to the tube-side outlet of the spray tower 13 through a pipeline, the tube-side inlet of the fan 14 is connected to the tube-side outlet of the spray tower 13 through a pipeline, and the tube-side inlet of the exhaust pipe 15 is connected to the tube-side outlet of the fan 14 through a pipeline. The fan 14 is used to introduce the waste gas treated by the spray tower 13 into the exhaust pipe 15 and then discharge it into the air. The waste gas and water vapor generated by the reaction are discharged through the air outlet 4. The water vapor enters the condenser 12 and is condensed. The condensed water vapor can be used for subsequent further recovery. A small amount of metal byproducts mixed in the water vapor is extracted, thereby improving the product recovery rate. The waste gas enters the spray tower 13 and is treated to meet the standards and then introduced into the exhaust pipe 15 for high-altitude discharge.

[0026] The present invention provides a saltpeter removal device, which also includes a first liquid storage barrel 16 and a second liquid storage barrel 17. A second liquid outlet 6 is also provided at the bottom of the saltpeter removal kettle 1. The first liquid storage barrel 16 is used to store the solution after the saltpeter removal operation is completed, and its pipe side inlet is connected to the second liquid outlet 6 through a pipeline. The second liquid storage barrel 17 is used to store and provide the solution required for the saltpeter removal operation, and its pipe side outlet is connected to the pipe side inlet of the pump assembly 7. Before the saltpeter removal starts, the original solution is injected into the device through the second liquid storage barrel 17. During the saltpeter removal, the second liquid storage barrel 17 and the first liquid storage barrel 16 are not connected to the device. After the saltpeter removal is completed, the second liquid outlet 6 is opened to transport the solution after the saltpeter removal operation to the first liquid storage barrel 16.

[0027] The present invention provides a saltpeter removing device, which also includes a coil 18, a feed port 19 and an observation window 20. The coil 18 can be heated by steam or cooled by cooling water. The reaction temperature in the saltpeter removing kettle 1 is controlled by heat exchange in the coil 18. The present invention uses silver powder to produce high-grade pure silver nitrate, and its reaction temperature is 70±5°C. The feed port 19 is used to add reaction raw materials to the inner barrel 2, and the observation window 20 is used to observe the reaction situation in the saltpeter removing kettle 1. The consumption of metal powder particles in the inner barrel 2 can be observed through the observation window 20. When the metal powder particles in the inner barrel 2 need to be replenished, the feed port 19 can be used to add metal powder particles to the inner barrel 2. At least one feed port 19 is correspondingly provided for one inner barrel 2. The number of inner barrels 2 in the present invention is 3, and the number of corresponding feed ports 19 is also 3.

[0028] According to a second aspect of the present invention, there is provided a system for removing nitrate from the silver nitrate, which is used in a process for preparing silver nitrate and comprises the aforementioned device for removing nitrate from the silver nitrate.

[0029] According to a third aspect of the present invention, there is provided a method for removing nitrate, comprising the following steps:

[0030] The metallic silver powder is fed into the inner barrel 2 through the feed port 19 . The number of inner barrels 2 in the technical solution of the present invention is 3, and the corresponding number of feed ports 19 should also be 3. The metallic silver powder is fed into each inner barrel 2 through each feed port 19 .

[0031] Check and close the first liquid outlet 5 and the second liquid outlet 6, open the first liquid inlet 3 and the air outlet 4, control the pump assembly 7 to pump the solution from the second liquid storage barrel 17, so that the solution passes through the pump assembly 7, the first liquid inlet 3, and the first liquid outlet pipe 8 from the second liquid storage barrel 17 in sequence and enters the inner barrel 2, and finally enters the bottom of the nitre-driving kettle 1 through the through hole of the inner barrel 2. When the solution submerges the through hole in the barrel wall of the inner barrel 2, stop pumping the solution from the second liquid storage barrel.

[0032] In this embodiment, the gas pressure of the reaction in the nitrate-driving kettle 1 is controlled to be -0.07 to -0.09 MPa, and the reaction temperature is 60 to 80°C. When the gas pressure or temperature is too low, the reaction rate is too slow, which will lead to a prolonged reaction time. Too high a temperature will cause the solution to boil over, and may even cause safety risks. In addition, too high a temperature will damage the pump assembly and affect its service life. The number of inner barrels 2 in the technical solution of the present invention is 3. When the solution passes through the pump assembly 7 and the first liquid inlet 3 from the second liquid storage barrel 17 and enters the first liquid outlet pipe 8 in sequence, the solution at the four-way structure will be diverted to each inner barrel 2 through the second liquid outlet pipe 9, the third liquid outlet pipe 10, and the fourth liquid outlet pipe 11, and finally enter the bottom of the nitrate-driving kettle 1 from the through-holes of each inner barrel 2 until the solution stops pumping the solution after it has submerged the through-holes in the barrel wall of all inner barrels 2.

[0033] Check and open the first liquid outlet 5, control the pump assembly 7 to pump the solution from the bottom of the nitre-driving kettle 1, and the solution passes through the first liquid outlet 5, the pump assembly 7, the first liquid inlet 3, the first liquid outlet pipe 8 from the bottom of the nitre-driving kettle 1 in sequence, and then enters the inner barrel 2, and finally flows back to the bottom of the nitre-driving kettle 1 from the through hole of the inner barrel 2. The circulating solution reacts with the metallic silver powder in the inner barrel 2.

[0034] In this embodiment, the gas pressure of the reaction in the nitrate-driving kettle 1 is continuously controlled to be -0.07 to -0.09 MPa, and the reaction temperature is 60 to 80°C. The number of inner barrels 2 in the technical solution of the present invention is 3. When the solution passes through the first liquid outlet 5, the pump assembly 7, and the first liquid inlet 3 from the bottom of the nitrate-driving kettle 1 and enters the first liquid outlet pipe 8, the solution at the four-way structure will be diverted to each inner barrel 2 through the second liquid outlet pipe 9, the third liquid outlet pipe 10, and the fourth liquid outlet pipe 11, and finally enter the bottom of the nitrate-driving kettle 1 from the through hole of each inner barrel 2, and the circulating solution reacts with the metallic silver powder in each inner barrel 2.

[0035] When the reaction time reaches 3 to 5 hours, the pH value of the solution is detected every 10 minutes. When the pH value of the reaction solution in the nitrate removal kettle 1 is detected to be greater than 3, the reaction can be judged to be over. After the reaction is over, check and close the first liquid outlet 5 and the pump assembly 7, and open the second liquid outlet 6 to allow the solution after the reaction to enter the first liquid storage barrel 16 through the second liquid outlet 6.

[0036] The present invention provides a method for removing nitric acid from a silver nitrate solution, the purpose of which is to remove excess nitric acid from the silver nitrate solution, thereby producing high-grade pure silver nitrate. The chemical equation for the reaction between metallic silver powder and nitric acid is: 4HNO3+3Ag=3AgNO3+NO+2H2O. The waste gas generated by the reaction is discharged through an outlet 4, and then treated by a spray tower 13 to meet the standards. The waste gas is then introduced into an exhaust pipe 15 by a fan 14 and discharged into the air at high altitude. The water vapor generated by the reaction will be mixed with precious metals, and direct discharge will cause waste of resources and pollute the environment. The water vapor generated by the present invention is condensed and collected by a condenser 12. The condensed and collected water vapor can be recycled, thereby improving the recovery rate of the product.

[0037] The present invention arranges a pump assembly to circulate the solution, so that the solution is in full contact with the metal powder particles, thereby improving the rate of removing the nitrate. The solution circulation plays a stirring role, avoiding the violent movement of the metal caused by direct stirring through a stirring device, and solving the technical problems in the prior art of directly stirring the metal through a stirring device, which leads to the friction between the metal and the equipment and the introduction of new impurities, as well as the slow rate of removing the nitrate.

[0038] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A method for removing nitrate, characterized in that: The method for driving away the nitrate is based on a nitrate driving system, and the nitrate driving system includes a nitrate driving device; The nitrate-eliminating device includes a nitrate-eliminating kettle and an inner barrel disposed within the nitrate-eliminating kettle, wherein the lower barrel wall and the bottom of the inner barrel are evenly distributed with through holes, the top of the nitrate-eliminating kettle is provided with a first liquid inlet, the bottom of the nitrate-eliminating kettle is provided with a first liquid outlet, the first liquid inlet and the first liquid outlet are connected by a pipe, a pump assembly is further provided between the pipes communicating with the first liquid inlet and the first liquid outlet, and a first liquid outlet pipe is further provided within the nitrate-eliminating kettle, one end of the first liquid outlet pipe is connected to the first liquid inlet, and the other end of the first liquid outlet pipe is close to the upper portion of the inner barrel; The saltpeter driving device further comprises a first liquid storage barrel, a second liquid outlet is further provided at the bottom of the saltpeter driving kettle, and the pipe side inlet of the first liquid storage barrel is connected to the second liquid outlet through a pipe; The saltpeter-removing device further comprises a second liquid storage barrel, wherein the pipe-side outlet of the second liquid storage barrel is connected to the pipe-side inlet of the pump assembly; The top of the nitre-driving kettle is also provided with a feed port; The method for catching up with the nitre-removing agent comprises the following steps: (1) Feed the metallic silver powder into the inner barrel through the feed port; (2) Check and close the first liquid outlet and the second liquid outlet, and open the first liquid inlet and the air outlet, control the pump assembly to pump the solution from the second liquid storage barrel, so that the solution passes through the pump assembly, the first liquid inlet, the first liquid outlet pipe, and then enters the inner barrel, and finally enters the bottom of the nitrate-driving kettle through the through hole of the inner barrel. When the solution submerges the through hole of the barrel wall of the inner barrel, stop pumping the solution from the second liquid storage barrel; (3) Check and open the first liquid outlet, control the pump assembly to pump the solution from the bottom of the nitrate-driving kettle, and the solution passes through the first liquid outlet, the pump assembly, the first liquid inlet, the first liquid outlet pipe, and then enters the inner barrel. Finally, it flows back to the bottom of the nitrate-driving kettle from the through hole of the inner barrel. The circulating solution reacts with the metallic silver powder in the inner barrel. (4) When the reaction time reaches 3 to 5 hours, the pH value of the solution is detected every 10 minutes. When the pH value of the reaction solution in the nitrate removal kettle is greater than 3, the reaction can be judged to be over. After the reaction is over, check and close the first liquid outlet and pump assembly, and open the second liquid outlet so that the solution after the reaction is completed enters the first liquid storage tank through the second liquid outlet.

2. The method for catching up with saltpeter according to claim 1, wherein During the reaction, the reaction pressure is -0.07 to -0.09 MPa, and the reaction temperature is 60 to 80°C.

3. The method for catching up with saltpeter according to claim 1, wherein The saltpeter removing device also includes a condenser, a spray tower, a fan and an exhaust pipe. The top of the saltpeter removing kettle is also provided with an air outlet. The tube-side inlet of the condenser is connected to the air outlet through a pipeline, the tube-side inlet of the spray tower is connected to the tube-side outlet of the condenser through a pipeline, the tube-side inlet of the fan is connected to the tube-side outlet of the spray tower through a pipeline, the tube-side inlet of the exhaust pipe is connected to the tube-side outlet of the fan through a pipeline, and the fan is used to introduce the waste gas that has been treated by the spray tower to meet the standards into the exhaust pipe and then discharge it into the air.

4. The method for catching up with saltpeter according to claim 1, wherein The side wall of the nitre-driving kettle is provided with a coil, and the coil is used for heat exchange to control the reaction temperature in the nitre-driving kettle.

5. The method for catching up with saltpeter according to claim 1, wherein An observation window is also provided on the top of the nitre-driving kettle, and the observation window is used to observe the reaction conditions in the nitre-driving kettle.

Images