CN218573645U

CN218573645U - Device of high-efficient oxidation metal

Info

Publication number: CN218573645U
Application number: CN202121930789.2U
Authority: CN
Inventors: 陈海贤; 曹佳培
Original assignee: Zhejiang Haihong Holding Group Co ltd
Current assignee: Zhejiang Haihong Holding Group Co ltd
Priority date: 2021-08-17
Filing date: 2021-08-17
Publication date: 2023-03-07
Anticipated expiration: 2031-08-17

Abstract

The utility model discloses a device for high-efficiency oxidation of metal, which comprises a reaction kettle barrel and a hollow stirring shaft, wherein the hollow stirring shaft is sequentially provided with a stirring shaft air suction port, a self-suction type hollow turbine and an auxiliary stirring paddle from top to bottom, and the self-suction type stirrer consists of the self-suction type hollow turbine and the auxiliary stirring paddle; a liquid inlet is arranged above the position of the hollow stirring shaft close to the self-suction type hollow turbine, and the stirring shaft air suction port, the liquid inlet, the self-suction type hollow turbine and the hollow stirring shaft are communicated; the liquid inlet is used for enabling the reaction solution to enter a self-suction hollow turbine, and the gas at the upper part of the liquid level is entrained to reenter the reaction solution under the action of the centrifugal force of stirring; the upper part of the reaction kettle barrel is provided with an interface for introducing oxygen into the upper space of the reaction kettle. The utility model discloses use the integral type to solve nitrogen oxide's absorption and utilization from inhaling formula stirring reation kettle, reduce the consumption of nitric acid raw materials, no nitrogen oxide discharges, no external circulating equipment, and the oxidation reaction is high-efficient succinct.

Description

Device of high-efficient oxidation metal

Technical Field

The utility model belongs to the technical field of metal oxidation, mainly a device of high-efficient oxidation metal.

Background

Nitric acid has strong oxidizability and can directly oxidize and dissolve metals such as silver, indium, copper and the like to obtain nitrate. Metals such as tin, antimony, tungsten and the like can also be oxidized by nitric acid, but the reaction product is a hydrate of the corresponding oxide, such as an insoluble substance such as metastannic acid. After the concentrated nitric acid and the concentrated hydrochloric acid are mixed, inert metals such as gold, platinum, palladium and the like can be oxidized and dissolved. In the above oxidation processes, nitrogen oxide off-gas of nitrous oxide, nitric oxide or nitrogen dioxide is by-produced. These nitrogen oxides are serious air pollutants, and the exhaust gas needs to be removed by a post-treatment device, such as absorption of alkali liquor. Industrially, nitric acid solution or aqua regia is a common practice, and the generated nitrogen oxides are subjected to waste gas treatment, as described in patent CN211169853U, and the removal of nitrogen oxides by lye absorption brings waste liquid and cannot reduce the consumption of nitric acid.

Patent publication No. CN111068476A provides a device for treating NOX tail gas in a process of dissolving metals by nitric acid, and a gas-liquid mixing module mixes gas and liquid in a kettle body. An oxygenation control sensor collects an oxygen surplus detection signal in the kettle body and sends the oxygen surplus detection signal to an automatic control system; the pressure sensor and the temperature sensor respectively collect a pressure signal and a temperature signal of the kettle body and send the pressure signal and the temperature signal to the automatic control system; the automatic control system respectively controls the nitric acid control metering module, the oxygenation control module, the safe pressure relief module and the temperature control module to adjust the adding speed, the oxygenation speed and the temperature of the nitric acid in the kettle body according to the oxygen surplus detection signal, the pressure signal and the temperature signal. The utility model discloses a through external circulating pump and PLC controller come NOX tail gas and solution to carry out gas-liquid mixture conversion NOX tail gas through special gas-liquid mixing module in addition, it is more complicated.

Similarly, patent publication No. CN204039465U discloses an airflow circulation speed control reaction device for dissolving metal by aqua regia oxygen method, which solves the problem of environmental pollution caused by a large amount of NO gas drifting with wind in the prior art, and is characterized in that: the reaction kettle is additionally provided with an airflow circulating device consisting of an air valve, an air bag, a gas circulating fan, a frequency converter, a fan flow regulating valve, a pipeline and an airflow distributor and a reaction speed control device consisting of a liquid storage kettle, a liquid seal tank, an alarm and a pipeline. The method also needs a complex external circulating fan and a pipeline for recycling the nitrogen oxides.

In summary, the existing recycling of the nitrogen oxide waste gas after the metal nitric acid oxidation reaction needs additional complicated equipment such as an external circulating fan, a PLC controller, a sensor and the like, and the control method and the device are complicated.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects in the prior art and provide a device for efficiently oxidizing metal.

The purpose of the utility model is accomplished through following technical scheme. A device for efficiently oxidizing metal comprises a reaction kettle barrel and a hollow stirring shaft, wherein the hollow stirring shaft is sequentially provided with a stirring shaft air suction port, a self-suction type hollow turbine and an auxiliary stirring paddle from top to bottom, and the self-suction type stirrer consists of the self-suction type hollow turbine and the auxiliary stirring paddle; a liquid inlet is arranged above the position of the hollow stirring shaft close to the self-suction type hollow turbine, and the stirring shaft air suction port, the liquid inlet, the self-suction type hollow turbine and the hollow stirring shaft are communicated; the liquid inlet is used for enabling the reaction solution to enter the self-suction hollow turbine, and the gas at the upper part of the liquid level is entrained to reenter the reaction solution under the action of the centrifugal force of stirring; the upper part of the reaction kettle barrel is provided with an interface for introducing oxygen into the upper space of the reaction kettle.

Preferably, the reaction solution is a nitric acid solution or a mixed solution of nitric acid and hydrochloric acid.

As a preferable technical scheme, the auxiliary stirrers are in a multilayer radial flow type or axial flow type, and the number of the auxiliary stirrers is more than or equal to one layer.

As a preferable technical scheme, the device can be additionally provided with a jacket, a heat exchange coil or a baffle plate according to the requirement.

The beneficial effects of the utility model are that:

1. the device has no external circulating equipment, and uses a simple integrated self-suction reaction kettle to solve the absorption and utilization of nitrogen oxides, thereby achieving the purpose of no nitrogen oxide emission;

2. greatly reduces the consumption of the nitric acid raw material.

3. The reaction speed is high. The high-speed rotating stirrer not only brings high-efficiency gas-liquid dispersion mass transfer, but also promotes the metal surface to be updated and accelerates the reaction of metal oxidation.

Drawings

Fig. 1 is a schematic structural diagram of an apparatus for efficiently oxidizing metal according to the present invention.

Description of reference numerals: 1. a hollow stirring shaft; 2. the upper space of the reaction kettle; 3. the air suction port of the stirring shaft; 4. a reaction kettle barrel; 5. a liquid inlet; 6. a self-priming hollow turbine; 7. a jacket; 8. an auxiliary stirring paddle; 9. a metal; 10. and (3) reaction solution.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and embodiments:

as shown in fig. 1, a device for efficiently oxidizing metal comprises a reaction kettle barrel 4 and a hollow stirring shaft 1, wherein a stirring shaft air suction port 3, a self-suction hollow turbine 6 and an auxiliary stirring paddle 8 are sequentially fixed on the hollow stirring shaft 1 from top to bottom, and a self-suction stirrer is composed of the self-suction hollow turbine 6 and the auxiliary stirring paddle 8; a liquid inlet 5 is arranged above the position of the hollow stirring shaft 1 close to the self-suction type hollow turbine 6, and the stirring shaft air suction port 3, the liquid inlet 5, the self-suction type hollow turbine 6 and the hollow stirring shaft 1 are communicated; the reaction solution 10 enters a self-suction hollow turbine 6 through a liquid inlet 5, the gas at the upper part of the liquid surface is entrained to reenter the reaction solution 10 under the action of the centrifugal force of stirring, the reaction solution and the sucked gas are sheared and dispersed, and NO is accelerated ₂ And (3) dissolving the gas, and introducing oxygen into the upper space 2 of the reaction kettle through an upper connector of the reaction kettle barrel 4.

The reaction solution 10 is a nitric acid solution or a mixed solution of nitric acid and hydrochloric acid.

The auxiliary stirrers 8 are of a multilayer radial flow type or an axial flow type, and the number of the auxiliary stirrers 8 is more than or equal to one layer.

The device can be additionally provided with a jacket 7, a heat exchange coil or a baffle plate according to the requirement.

The utility model discloses a method for efficiently oxidizing metal, which comprises the steps of oxidizing and dissolving metal 9, nitric acid solution or mixed solution of nitric acid and hydrochloric acid and oxygen in a reaction kettle provided with a self-suction stirrer; the reaction process comprises the following steps: (1) The metal is oxidized by nitric acid in the solution to generate N2O, NO and NO2 gas; (2) The generated gas enters the upper space of the reaction kettle, and the introduced oxygen oxidizes N2O and NO in the generated gas into NO2; (3) NO2 gas in the upper space of the reaction kettle is sucked into the hollow stirring shaft from a stirring shaft air suction port under the centrifugal action of the self-suction stirrer and then enters the solution at the lower part again; (4) Under the strong stirring of the self-suction stirrer, NO2 gas and the solution are mixed and dispersed, the contact area of the NO2 gas and the solution is increased, and the NO and the nitric acid are generated by reaction with water; (5) And the generated nitric acid continuously dissolves metal, NO enters the upper space of the reaction kettle again to react with oxygen, and the nitrogen oxide is completely absorbed by the solution repeatedly.

The metal is one of gold, silver, platinum, palladium, indium, tin, antimony, tungsten, vanadium, gallium, germanium and copper or an alloy thereof.

The metal is in the shape of block, particle or powder.

The oxygen is pure oxygen, oxygen-enriched gas or air, and the pressure is 0.1-20 MPa.

The molar ratio of the nitric acid to the hydrochloric acid in the mixed solution of the nitric acid and the hydrochloric acid is 0.1-10.

The molar amount of the metal is excessive according to the reaction molar ratio.

Example 1

Using the apparatus shown in FIG. 1, 1.5m was measured ³ 30% nitric acid and 1000kg of metallic silver particles 2m in size ³ In the reaction kettle, in order to improve the utilization rate of the nitric acid, the metal silver particles are excessive by about 10 percent, 0.5MPa of oxygen is introduced above the reaction kettle and then the reaction kettle is closed, and the rotating speed of the hollow stirring shaft 1 is set to 700rpm. And heating the steam in the jacket to 90 ℃, reacting for 6 hours, and separating to obtain 1.42 tons of silver nitrate, wherein the utilization rate of the nitric acid is 99 percent.

Comparative example 1

Referring to the example 1, the self-suction stirrer is changed into a common solid stirrer, other conditions are not changed, 1.05 tons of silver nitrate is obtained after 4 hours of reaction, and the utilization rate of nitric acid is 70.4%. The comparison between the example 1 and the comparative example 1 shows that the yield and the nitric acid utilization rate are greatly improved after the method and the device are used.

Example 2

Referring to example 1, 355kg of metallic indium particles were used in place of metallic silver, and other conditions were not changed, so that 0.839 ton of indium nitrate was obtained and the nitric acid yield was 99.3% after the completion of the reaction.

Example 3

Referring to example 1, 295kg of metallic copper particles were used in place of metallic silver, and after the reaction was completed, 781kg of copper nitrate was obtained, with a nitric acid utilization of 98.8%.

Example 4

Using the apparatus shown in FIG. 1, 1.5m was measured ³ 2m of a mixture of 35% concentrated hydrochloric acid and 65% concentrated nitric acid in a volume ratio of 3 ³ In the reaction kettle, 90% oxygen-enriched gas of 2MPa is introduced above the reaction kettle and then is closed, and the rotating speed of the hollow stirring shaft 1 is set to be 500rpm. Heating the steam in the jacket to 80 ℃ for 1 hour, starting the exothermic reaction, stopping the reaction, and reacting for 2 hours to obtain the chloropalladate solution. Because the nitrogen oxide generated in the nitric acid reaction process is re-oxidized into nitric acid under the action of oxygen, the content of the nitric acid in the reaction liquid is maintained at 99.6 percent after the reaction is finished, and the nitric acid can be repeatedly used as aqua regia after the concentrated hydrochloric acid is supplemented.

Example 5

Referring to example 4, 300kg of gold powder was used instead of palladium metal, and the reaction was carried out under otherwise unchanged conditions, with only hydrochloric acid being consumed, and the nitric acid content in the reaction solution was maintained at 99.2% after the reaction.

Example 6

Referring to example 4, 300kg of platinum metal was used instead of palladium metal, hydrochloric acid was consumed only for the reaction, and the nitric acid content in the reaction solution was maintained at 99.8% after the reaction was completed.

Example 7

Using the apparatus shown in FIG. 1, 0.6m was measured ³ Of 65% nitric acid and 300kg of metallic tin particles 1m in size ³ In the reaction kettle, the upper part of the reaction kettle is closed after 10MPa of compressed air is introduced, and the rotating speed of the hollow stirring shaft 1 is set to be 500rpm. Oxygen of tin in nitric acidThe metastannic acid precipitate is produced under chemical treatment, and nitric oxide and nitrogen dioxide are produced. Under the action of the self-priming stirrer, the nitrogen oxides are oxidized again by oxygen in the air and react with water to be converted back into nitric acid, so that the nitric acid is not consumed. The jacket was heated in an oil bath to 120 ℃ and after 7 hours of reaction, 426kg of metastannic acid was isolated. After the reaction is finished, the content of nitric acid in the reaction solution is maintained at 99.8 percent and the nitric acid can be repeatedly used.

Comparative example 2

Referring to example 7, the self-priming stirrer was changed to a common solid stirrer, the other conditions were not changed, the nitric acid content in the reaction solution after the reaction was completed was only 23%, a large amount of nitrogen oxide yellow smoke was removed, and the reaction solution was difficult to reuse. Example 7 was compared with comparative example 1 and found that the nitric acid utilization was greatly improved together with the use of the method and apparatus of the present aspect.

Examples 8 to 12

Referring to example 7, the following results were obtained by substituting metallic tin particles with metallic antimony, tungsten, vanadium, gallium, and germanium particles, obtaining corresponding hydrated oxides after oxidation reaction, and detecting the nitric acid content in the reaction solution after the reaction was completed:

serial number	The content of nitric acid is maintained%
		Example 8	98.7
Example 9	99.4
		Example 10	99
Example 11	99.2
		Example 12	99.8

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An apparatus for efficiently oxidizing a metal, comprising: the self-suction type stirring device comprises a reaction kettle barrel (4) and a hollow stirring shaft (1), wherein a stirring shaft air suction port (3), a self-suction type hollow turbine (6) and an auxiliary stirring paddle (8) are sequentially arranged on the hollow stirring shaft (1) from top to bottom, and the self-suction type stirring device is composed of the self-suction type hollow turbine (6) and the auxiliary stirring paddle (8); a liquid inlet (5) is arranged above the position, close to the self-suction type hollow turbine (6), of the hollow stirring shaft (1), and the stirring shaft air suction port (3), the liquid inlet (5), the self-suction type hollow turbine (6) and the hollow stirring shaft (1) are communicated with each other; wherein the liquid inlet (5) is used for leading the reaction solution (10) to enter the self-suction hollow turbine (6), and the gas at the upper part of the liquid surface is entrained to reenter the reaction solution (10) under the action of the centrifugal force of stirring; and the upper part of the reaction kettle barrel (4) is provided with an interface for introducing oxygen into the upper space (2) of the reaction kettle.

2. The apparatus for efficient oxidation of a metal according to claim 1, wherein: the reaction solution (10) is a nitric acid solution or a mixed solution of nitric acid and hydrochloric acid.

3. The apparatus for efficient oxidation of a metal according to claim 1, wherein: the auxiliary stirring paddles (8) are of a multilayer radial flow type or an axial flow type, and the number of the auxiliary stirring paddles (8) is more than or equal to one layer.

4. The apparatus for efficient oxidation of a metal according to claim 1, wherein: also comprises a jacket (7) and a heat exchange coil or a baffle.