Reaction device for normal-pressure leaching of nitric acid
By designing a reaction apparatus that includes a reactor, an absorption tower, and a temperature control device, the problems of nitrogen oxide pollution and temperature control during nitric acid leaching were solved, achieving nitrogen oxide recovery and temperature regulation, and improving the recovery rate of valuable metals and environmental friendliness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-14
- Publication Date
- 2026-03-24
AI Technical Summary
Nitric acid produces large amounts of nitric oxide and nitrogen dioxide gases during the leaching reaction, which pollute the environment and fails to meet environmental protection requirements. At the same time, the leaching reaction is vigorous and easily leads to solution overflow, so temperature control is necessary to prevent the kettle from overflowing. Existing technologies are difficult to solve this problem effectively.
Design a reaction apparatus including a reaction vessel, an absorption tower, an absorption tower circulation device, and an oxygen supply device. Nitrogen oxides are absorbed by the absorbent in the absorption tower to generate nitric acid, and the reaction temperature is controlled by a temperature control device to achieve nitrogen oxide recovery and temperature regulation.
It achieves environmentally friendly recycling and temperature control of nitrogen oxides, improves the recovery rate of valuable metals, reduces production costs, and meets environmental protection requirements.
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Figure CN224031064U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to non-ferrous metal wet leaching technical field, especially relate to a reaction unit for nitric acid normal pressure leaching. BACKGROUND
[0002] Sulfide nickel ore processing technology has been very mature, the usual process is that sulfide nickel ore is obtained after flotation, pyrometallurgy, wet pressure leaching solution containing nickel, cobalt and other metals, and then subsequent processing is carried out. The material using this process must have the characteristics of high nickel content and low magnesium content, if the raw material is low in nickel and high in magnesium, the production temperature of the pyrometallurgical process will be greatly increased, resulting in increased production cost and rising safety hazard coefficient.
[0003] Sulfide nickel ore will produce a material containing less than 5% nickel and nearly 20% MgO in the flotation process, which cannot be directly fed into the pyrometallurgical system. In order to treat this part of the material and achieve the purpose of high recovery rate of valuable metals, nitric acid with oxidizing property is selected as leaching agent for leaching under normal pressure. A large amount of nitric oxide and nitrogen dioxide gas will be produced during the leaching reaction, which is very harmful to the environment, and must be recovered by absorption device, otherwise it cannot meet the environmental protection requirements.
[0004] Because the leaching reaction is an exothermic reaction, the reaction is violent at the beginning of leaching, and it is easy to cause solution overflow and excessive amount of nitrogen oxides, so the temperature needs to be reduced to prevent the reactor from being blown, and heating is needed in the later stage of reaction to make the material precipitate and improve the recovery rate of valuable metals. In order to solve the above problems in the process of nitric acid entering and leaving, the device is designed for reactions with violent leaching reaction and producing harmful gases. CONTENT OF THE UTILITY MODEL
[0005] (1) The technical problem to be solved: because a large amount of nitric oxide and nitrogen dioxide gas will be produced during the leaching reaction of nitric acid, which is very harmful to the environment and cannot meet the environmental protection requirements, the utility model provides a reaction device for nitric acid normal pressure leaching to make up for the above defects.
[0006] (2) The technical scheme adopted by the utility model is as follows:
[0007] The utility model provides a reaction device for nitric acid normal pressure leaching, including reaction kettle, absorption tower, absorption tower circulating device and oxygen supply device, be provided with acid adding mouth, water adding mouth, material adding mouth, nitrogen oxide exhaust outlet, temperature detection device access port and discharge port on the reaction kettle, the reaction kettle is connected temperature control device, the reaction kettle is equipped with stirring device, be provided with nitrogen oxide gas import, oxygen import, absorbent circulation import one and absorbent circulation export one on the absorption tower, nitrogen oxide exhaust outlet is connected nitrogen oxide gas import through first pipeline, oxygen import is connected oxygen supply device through oxygen supply pipeline, absorption tower circulating device is provided with absorbent in the inside, the lower part of absorption tower circulating device is provided with absorbent circulation export two and tail gas export one, absorbent circulation export one extends to the inside of absorption tower circulating device, absorbent circulation export two is connected the import of absorption liquid circulating pump one through second pipeline, and the export of absorption liquid circulating pump one is connected absorbent circulation import one through third pipeline.
[0008] Further technical solutions are that the secondary absorption device is further provided, the secondary absorption device is provided with a tail gas inlet, a tail gas outlet two, an absorbent circulation inlet two and an absorbent circulation outlet three, the secondary absorption device is provided with absorbent in the inside, the absorbent circulation outlet three is connected with the import of the second absorption liquid circulating pump through the fourth pipeline, the export of the second absorption liquid circulating pump is connected with the absorbent circulation inlet two through the fifth pipeline, and the tail gas inlet and the tail gas outlet one are connected through the gas pipeline.
[0009] Further technical solutions are that the stirring device includes a stirrer located in the inside of the reaction kettle, a driving shaft is fixed in the middle of the stirrer, the driving shaft penetrates the top of the reaction kettle and is rotationally connected therewith, and the upper end of the driving shaft is connected with a stirring motor.
[0010] Further technical solutions are that the kettle body of the reaction kettle is provided with a jacket, the jacket is provided with a heating medium outlet and a heating medium inlet, the heating medium supply port of the temperature control device is connected with the heating medium inlet, and the heating medium return port of the temperature control device is connected with the heating medium outlet.
[0011] Further technical solutions are that the oxygen supply pipeline is provided with an oxygen control valve and an oxygen flowmeter.
[0012] Further technical solutions are that the first pipeline is provided with a nitrogen oxide pressure gauge.
[0013] Further technical solutions are that the lower part of the secondary absorption device is connected with a discharge pipe one, the discharge pipe one is provided with a valve one, the lower part of the absorption tower circulating device is connected with a discharge pipe two, the discharge pipe two is provided with a valve two, the discharge pipe one and the discharge pipe two are connected with a main pipeline, the main pipeline is connected with an acid storage tank, the main pipeline is connected with a conveying pump one, the acid storage tank is connected with the acid adding mouth through an acid supply pipeline, and the acid supply pipeline is connected with a conveying pump two.
[0014] (3) By adopting the above technical scheme, the present application has the beneficial effects that
[0015] 1. In the reaction process, the nitrogen oxides in the reaction kettle are discharged through the nitrogen oxide exhaust outlet, the first pipeline and the nitrogen oxide gas inlet into the absorption tower, the oxygen supply device supplies oxygen to the absorption tower, the absorption liquid circulating pump one transports the absorbent in the absorption tower circulating device to the absorbent circulating inlet and into the absorption tower, the absorbent (recycled dilute nitric acid) absorbs the nitrogen oxide gas to form nitric acid, the released nitric oxide reacts with oxygen to generate nitrogen dioxide, and the nitrogen dioxide reacts with the absorbent to generate nitric acid, the device can absorb the nitrogen oxide gas generated in the reaction process, the obtained absorption acid (nitric acid) can be recycled for leaching reaction, the tail gas can be discharged up to standard, and the environment is friendly.
[0016] 2. The sulfide nickel ore can be leached at normal pressure, the temperature control device connected with the reaction kettle can control the temperature during the leaching process, ensures that the leaching process does not overflow, and adjusts the temperature according to the requirement, meets the requirement of heating in the later reaction stage, makes the material precipitate, and improves the recovery rate of the valuable metal.
[0017] 3. The absorption acid can be reused for leaching the material after reaching a certain concentration, the utilization rate of the nitric acid is improved, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS
[0018] Fig. 1 is the overall structure schematic view of the present application;
[0019] Fig. 2 is the structure schematic view of the reaction kettle;
[0020] Fig. 3 is the connection relationship schematic view of the absorption tower circulating device, the secondary absorption device and the acid storage tank. DETAILED DESCRIPTION
[0021] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples.
[0022] As Figs. 1-3The reaction device for nitric acid normal pressure leaching includes a reaction kettle 1, an absorption tower 4, an absorption tower circulating device 9 and an oxygen supply device 22. The reaction kettle 1 is provided with an acid adding port 24, a water adding port 25, a material adding port 26, a nitrogen oxide exhaust outlet 29, a temperature detecting device connecting port 28 and a discharge port 32. The reaction kettle 1 is connected with a temperature control device 19. The reaction kettle 1 is provided with a stirring device. The absorption tower 4 is provided with a nitrogen oxide gas inlet 5, an oxygen inlet 6, an absorbent circulating inlet 7 and an absorbent circulating outlet 8. The nitrogen oxide exhaust outlet 29 is connected with the nitrogen oxide gas inlet 5 through a first pipeline. The oxygen inlet 6 is connected with the oxygen supply device 22 through an oxygen supply pipeline. The absorption tower circulating device 9 is internally provided with an absorbent. The lower part of the absorption tower circulating device 9 is provided with an absorbent circulating outlet 10 and a tail gas outlet 12. The absorbent circulating outlet 8 extends to the inside of the absorption tower circulating device 9. The absorbent circulating outlet 10 is connected with the inlet of an absorbent circulating pump 11 through a second pipeline. The outlet of the absorbent circulating pump 11 is connected with the absorbent circulating inlet 7 through a third pipeline.
[0023] When in use, the reaction kettle 1 is fixed through a rack. The stirring device includes a stirrer 30 located in the inside of the reaction kettle 1. A driving shaft is fixed in the middle of the stirrer 30. The driving shaft penetrates the top of the reaction kettle 1 and is rotationally connected with the reaction kettle 1. The upper end of the driving shaft is connected with a stirring motor 27. The kettle body of the reaction kettle 1 is provided with a jacket 31. The jacket 31 is provided with a heating medium outlet 2 and a heating medium inlet 3. The heating medium supply port 20 of the temperature control device 19 is connected with the heating medium inlet 3. The heating medium return port 21 of the temperature control device 19 is connected with the reaction kettle heating layer outlet 2. The temperature control device 19 is a cold and hot all-in-one machine for the existing reaction kettle 1. The machine is controlled by a PLC automatic control system. A temperature detecting sensor is arranged at the temperature detecting device connecting port 28. The temperature detecting sensor is connected with the automatic control system of the cold and hot all-in-one machine and can detect the temperature in the inside of the reaction kettle 1.
[0024] When leaching, quantitative water is added into the reaction kettle 1 through the water adding port 25, and then the nickel sulfide mineral material is added into the reaction kettle 1 through the material adding port 26, the stirring motor 27 is started to drive the stirrer 30 to stir to carry out slurry. Then the temperature control device 19 is started, and the temperature control device 19 is set to the cooling state through the PLC control system, the nitrogen oxide absorption device including the absorption tower 4, the absorption tower circulating device 9 and the secondary absorption device 13 is opened, and then the acid feeding device including the acid storage tank 40 and the conveying pump two 44 is opened, the conveying pump two 44 conveys the nitric acid in the acid storage tank 40 to the acid adding port 24, the nitric acid is slowly added into the reaction kettle 1 from the acid adding port 24, and then the oxygen supply device 24 is opened to supply oxygen to the absorption tower 4. About 1h after the acid is fed, the temperature control device 19 is set to the heating state through the PLC control system, and the temperature control device 19 is set to a certain temperature to start heating. The amount of acid added is controlled according to the amount of material added, and the amount of oxygen introduced is adjusted according to the nitrogen oxide pressure gauge 34. After the reaction is completed, the temperature control device 19 is closed first, and then the stirring device is closed. When the nitrogen oxide pressure gauge 34 returns to zero, the absorption liquid circulating pump one 11 and the absorption liquid circulating pump two 16 are closed. The whole reaction system is in a closed state, and the above-mentioned material has excellent corrosion resistance.
[0025] The solution, gas and added medium in the utility model go to the process as follows:
[0026] The nickel sulfide mineral material is reacted with water and acid in the reaction kettle 1 to produce nitrogen oxide mixed gas, the nitrogen oxide gas is discharged from the nitrogen oxide exhaust port 29 into the absorption tower 4, the nitrogen monoxide reacts with oxygen in the absorption tower 4 to generate nitrogen dioxide (nitrogen dioxide is extremely soluble in water to generate nitric acid), the nitrogen dioxide in the absorption tower 4 reacts with the absorption liquid to produce nitric acid, and the nitrogen oxide gas that is not completely absorbed is discharged through the tail gas outlet one 12 of the absorption tower circulating device 9, enters the secondary absorption device 13 inside from the tail gas inlet 14 through the gas pipeline, the secondary absorption device 13 is equivalent to a secondary absorption tower, the absorption liquid in the secondary absorption device 13 is added with an oxidizing agent, the absorption liquid is circulated and conveyed to the absorption agent circulating inlet two 17 through the absorption liquid circulating pump two 16, the absorption agent circulating inlet two 17 is equivalent to a spray head, the sprayed absorption liquid absorbs the nitrogen oxide gas to generate nitric acid, the tail gas outlet two 18 is a nitrogen oxide tail gas detection port, if the detection is not up to standard, a tertiary absorption device can be added, and the working principle of the tertiary absorption device is the same as that of the secondary absorption device. After the material reaction is completed, the material is discharged from the bottom discharge port 32 of the reaction kettle and immersed and filtered.
[0027] The absorption liquid in the absorption tower circulating device 9 enters the absorption tower through the absorption liquid circulating pump 11 and the absorption circulating inlet 7, and after reacting with nitrogen oxide, enters the absorption tower circulating device 9 through the absorption circulating outlet 8. When the concentration of nitric acid in the absorption tower circulating device 9 or the secondary absorption device 13 is greater than or equal to 35% (mass percentage), the nitric acid in the absorption tower circulating device 9 or the secondary absorption device 13 is transported to the acid storage tank 40 through the delivery pump 41, and is used as a leaching agent. When the valve 36 is opened, the nitric acid in the secondary absorption device 13 is transported to the acid storage tank 40 through the delivery pump 41. When the valve 38 is opened, the nitric acid in the absorption tower circulating device 9 is transported to the acid storage tank 40 through the delivery pump 41. The working principle of the secondary absorption device 13 is similar to that of the absorption tower,
[0028] The high and low temperature heat conducting oil in the temperature control device 19 is in a low temperature state at the beginning of the reaction, enters the heating medium inlet 3 of the jacket 31 of the reaction kettle 1 from the heating medium outlet 20 of the temperature control device 19, and then from the heating medium outlet 2, and then from the heating medium return port 21, returns to the temperature control device 19.
[0029] The oxygen supply pipeline is provided with an oxygen control valve 23 and an oxygen flow meter 33.
[0030] The first pipeline is provided with a nitrogen oxide pressure gauge 34.
[0031] The above is only a preferred embodiment of the present application.
Claims
1. A reaction apparatus for leaching nitric acid at atmospheric pressure, characterized in that, The apparatus includes a reactor (1), an absorption tower (4), an absorption tower circulation device (9), and an oxygen supply device (22). The reactor (1) is equipped with an acid inlet (24), a water inlet (25), a material inlet (26), a temperature detection device inlet (28), a nitrogen oxide exhaust outlet (29), and a discharge outlet (32). The reactor (1) is connected to a temperature control device (19). The reactor (1) is equipped with a stirring device. The absorption tower (4) is equipped with a nitrogen oxide gas inlet (5), an oxygen inlet (6), an absorbent circulation inlet (7), and an absorbent circulation outlet (8). The gas outlet (29) is connected to the nitrogen oxide gas inlet (5) through the first pipe, and the oxygen inlet (6) is connected to the oxygen supply device (22) through the oxygen supply pipeline. The absorbent is installed inside the absorption tower circulation device (9). The lower part of the absorption tower circulation device (9) is provided with absorbent circulation outlet two (10) and tail gas outlet one (12). The absorbent circulation outlet one (8) extends into the absorption tower circulation device (9). The absorbent circulation outlet two (10) is connected to the inlet of the absorbent liquid circulation pump one (11) through the second pipe. The outlet of the absorbent liquid circulation pump one (11) is connected to the absorbent circulation inlet one (7) through the third pipe.
2. The reaction apparatus for atmospheric pressure leaching of nitric acid according to claim 1, characterized in that, It also includes a secondary absorption device (13), which is provided with a tail gas inlet (14), a tail gas outlet two (18), an absorbent circulation inlet two (17) and an absorbent circulation outlet three (15). The secondary absorption device (13) is provided with an absorbent. The absorbent circulation outlet three (15) is connected to the inlet of the absorbent circulation pump two (16) through a fourth pipe. The outlet of the absorbent circulation pump two (16) is connected to the absorbent circulation inlet two (17) through a fifth pipe. The tail gas inlet (14) and the tail gas outlet one (12) are connected through a gas transmission pipe.
3. The reaction apparatus for atmospheric pressure leaching of nitric acid according to claim 1, characterized in that, The stirring device includes a stirrer (30) located inside the reactor (1). A drive shaft is fixed in the middle of the stirrer (30). The drive shaft passes through the top of the reactor (1) and is rotatably connected to it. The upper end of the drive shaft is connected to a stirring motor (27).
4. The reaction apparatus for atmospheric pressure leaching of nitric acid according to claim 1, characterized in that, The reactor (1) is provided with a jacket (31) on its body. The jacket (31) is provided with a heating medium outlet (2) and a heating medium inlet (3). The heating medium supply port (20) of the temperature control device (19) is connected to the heating medium inlet (3), and the heating medium return port (21) of the temperature control device (19) is connected to the heating medium outlet (2).
5. The reaction apparatus for atmospheric pressure leaching of nitric acid according to claim 1, characterized in that, The oxygen supply pipeline is equipped with an oxygen control valve (23) and an oxygen flow meter (33).
6. The reaction apparatus for atmospheric pressure leaching of nitric acid according to claim 1, characterized in that, A nitrogen oxide pressure gauge (34) is installed on the first pipeline.
7. The reaction apparatus for atmospheric pressure leaching of nitric acid according to claim 2, characterized in that, The lower part of the secondary absorption device ((13)) is connected to the discharge pipe 1 (35), and valve 1 (36) is installed on the discharge pipe 1 (35). The lower part of the absorption tower circulation device ((9)) is connected to the discharge pipe 2 (37), and valve 2 (38) is installed on the discharge pipe 2 (37). The discharge pipe 1 (35) and the discharge pipe 2 (37) are connected to the main pipeline (39). The main pipeline (39) is connected to the acid storage tank (40). The main pipeline (39) is connected to the transfer pump 1 (41). The acid storage tank (40) is connected to the acid inlet ((24)) through the acid supply pipeline (43). The acid supply pipeline (43) is connected to the transfer pump 2 (44).