Multi-stage cyanidation reaction system and method

Abstract

The invention relates to the technical field of cyanide reaction processing, and discloses a multistage cyanidation reaction system, which comprises a feeding unit, a reaction unit and an output unit, the reaction unit comprises an initial reaction kettle, a plurality of middle reaction kettles and a tail end reaction kettle which are distributed side by side, the initial reaction kettle, the plurality of middle reaction kettles and the tail end reaction kettle are mutually connected in series and are distributed, and the initial reaction kettle, the plurality of middle reaction kettles and the tail end reaction kettle are used for sequentially carrying out reaction processing on materials; the feeding unit comprises a gas inlet pipe and a feeding pipe, the gas inlet pipe is used for feeding the hydrogen cyanide gas to the initial reaction kettle, and the feeding pipe is used for conveying hydroxyvaleraldehyde and an alkaline raw material to the initial reaction kettle; and the output unit is used for outputting materials and tail gas after the reaction of the tail end reaction kettle. The invention also aims to provide a multi-stage cyanidation reaction which is suitable for the multi-stage cyanidation reaction. The method has the beneficial effects of sufficient raw material reaction, low cyanogen content in waste gas and high production and processing efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of cyanide reaction processing, and in particular to a multi-stage cyanidation reaction system and method. Background Art

[0002] Cyanide is a common compound in industry and is used in a variety of industrial production processes. Among them, cyanide compounds such as hydrogen cyanide and cyanohydrin are widely used in fields such as chemical synthesis, pharmaceuticals and pesticides, and metal processing. As a common organic compound, dihydroxyhexanenitrile is usually prepared by the gas-liquid reaction of hydrogen cyanide and hydroxypentanal under alkaline conditions.

[0003] In the process of preparing dihydroxyhexanenitrile, hydroxypentanal and alkali are usually continuously added to the reaction kettle from the upper part of the kettle, and hydrogen cyanide gas is continuously introduced into the reaction kettle from the bottom of the kettle. When the raw materials in the reaction kettle are fed to the specified liquid level height, the input of raw materials such as hydrogen cyanide and hydroxypentanal is stopped. After the hydrogen cyanide and hydroxypentanal react under normal temperature and pressure in the alkaline environment in the reaction kettle for 4-6 hours, dihydroxyhexanenitrile is obtained, and then the prepared dihydroxyhexanenitrile material is output.

[0004] However, in the process of preparing dihydroxyhexanenitrile by the above-mentioned scheme, in the prior art, the reaction of hydrogen cyanide and hydroxypentanal is usually carried out in a single reaction kettle, which easily leads to insufficient reaction of hydrogen cyanide with hydroxypentanal in the reaction kettle, resulting in a large amount of hydrogen cyanide and hydroxypentanal residues in the tail gas discharged after production, causing waste of raw materials and increasing the production cost of dihydroxyhexanenitrile. And since hydrogen cyanide is a highly toxic compound, when a large amount of hydrogen cyanide is contained in the discharged tail gas, the discharged tail gas needs to be deeply treated to prevent the tail gas containing hydrogen cyanide from being discharged into the air, causing environmental pollution. When deeply treating the tail gas generated after production, additional treatment equipment and costs are required to treat the hydrogen cyanide in the tail gas, further increasing the complexity and production cost of the dihydroxyhexanenitrile production process. Summary of the Invention

[0005] The present invention aims to provide a multi-stage cyanidation reaction system and method to solve the technical problem of incomplete reaction of hydrogen cyanide in the prior art, resulting in increased costs.

[0006] To achieve the above object, the present invention adopts the following technical solution: A multi-stage cyanidation reaction system, comprising a feeding unit, a reaction unit and an output unit. The reaction unit includes an initial reaction kettle, several intermediate reaction kettles and a terminal reaction kettle arranged side by side. The initial reaction kettle, several intermediate reaction kettles and the terminal reaction kettle are connected in series. The initial reaction kettle, several intermediate reaction kettles and the terminal reaction kettle successively carry out reaction processing on the material. The feeding unit includes an inlet pipe and a feeding pipe. The inlet pipe is used to supply hydrogen cyanide gas to the initial reaction kettle, and the feeding pipe is used to transport hydroxypentanal and an alkaline raw material to the initial reaction kettle. The output unit is used to output the material and tail gas after the reaction of the terminal reaction kettle.

[0007] Principle and advantages of this solution: When producing dihydroxyhexanenitrile by reacting hydrogen cyanide with hydroxypentanal, hydrogen cyanide, hydroxypentanal and an alkaline raw material are transported into the initial reaction kettle in proportion for preliminary reaction. The liquid and gas obtained after the preliminary reaction in the initial reaction kettle are respectively subjected to further reactions through several intermediate reaction kettles in sequence. The remaining raw materials after the reaction in several intermediate reaction kettles are finally reacted in the terminal reaction kettle and then output.

[0008] When this solution reacts hydrogen cyanide with hydroxypentanal in an alkaline environment, by connecting multiple reaction kettles in series, hydrogen cyanide and hydroxypentanal can react multiple times in the alkaline environment of multiple reaction kettles, so that the hydrogen cyanide gas participating in the reaction after the initial reaction can be transported to the next-stage reaction kettle for further reaction, ensuring that the hydrogen cyanide and hydroxypentanal transported to the reaction kettle for reaction can be fully reacted and utilized, avoiding a large amount of residual hydrogen cyanide in the tail gas discharged after the reaction, and reducing the treatment difficulty of the tail gas after the reaction processing.

[0009] Moreover, by reacting hydrogen cyanide with hydroxypentanal multiple times, the concentration of the dihydroxyhexanenitrile material generated by the reaction can be further increased to 95%-98%, improving the quality of the produced dihydroxyhexanenitrile material. At the same time, by connecting multiple reaction kettles in series, during the production process, multiple reaction kettles can react hydrogen cyanide and hydroxypentanal at different reaction stages simultaneously, enabling the reaction unit to continuously react on the material and improving the production and preparation efficiency of the material.

[0010] Preferably, as an improvement, each of the initial reaction kettle, several intermediate reaction kettles and the terminal reaction kettle is provided with a feed inlet and a gas inlet. The feed inlet is located at the top of one side of the reaction kettle and is used to convey reaction raw materials into the reaction kettle; the gas inlet is located at one end near the bottom of one side of the reaction kettle and is used to convey gas raw materials into the reaction kettle; an air outlet is opened on one side of the reaction kettle away from the feed inlet at the top, and the air outlet is used to output the gas after reaction in the reaction kettle; an outlet is opened at the bottom of the reaction kettle, and the outlet is used to output the liquid material after reaction in the reaction kettle.

[0011] Preferably, as an improvement, the feed inlets of the intermediate reaction kettle and the terminal reaction kettle are connected to the outlets of the previous reaction kettle of their own, and the gas inlets of the intermediate reaction kettle and the terminal reaction kettle are connected to the air outlets of the previous reaction kettle of their own. This enables the gas and liquid generated after the reaction in the previous-stage reaction kettle to be conveyed into the next-stage reaction kettle again in the form of gas raw materials and liquid raw materials, so that the remaining gas and liquid after the reaction in the previous-stage reaction kettle can be mixed and reacted again, improving the reaction effect of the raw materials in the multi-stage reaction kettle.

[0012] Preferably, as an improvement, each reaction kettle in the reaction unit has a plurality of gas inlets, and the plurality of gas inlets are evenly distributed at one end near the bottom of the side wall of each reaction kettle; an intake branch pipe is provided in the gas inlet, and the intake branch pipe extends into the reaction kettle. By providing a plurality of gas inlets on the side wall of the reaction kettle, when hydrogen cyanide gas is conveyed into the reaction kettle, it can be evenly distributed circumferentially from the bottom of the reaction kettle into the reaction kettle, improving the uniformity of the distribution of hydrogen cyanide gas in each area of the reaction kettle, ensuring that the hydroxypentanal raw material in the reaction kettle can fully react with hydrogen cyanide, and improving the reaction effect of hydrogen cyanide and hydroxypentanal.

[0013] Preferably, as an improvement, one end of the intake branch pipe located in the reaction chamber is connected with a plurality of aeration parts. By providing aeration parts on each intake branch pipe, when hydrogen cyanide gas is conveyed in the reaction kettle, it can strongly contact with hydroxypentanal under the action of the aeration parts, so that hydrogen cyanide impacts in hydroxypentanal to achieve the effect of stirring and mixing. While simplifying the stirring structure in the reaction kettle, it improves the mixing efficiency between hydrogen cyanide gas and hydroxypentanal liquid and increases the reaction speed.

[0014] Preferably, as an improvement, the gas inlet is at 10%-30% of the height of the side wall of the reaction kettle from the bottom to the top. This enables hydrogen cyanide to be input from the bottom of the reaction kettle as much as possible, ensuring that hydrogen cyanide gas can more fully contact and react with hydroxypentanal in the reaction kettle.

[0015] Preferably, as an improvement, the intake manifold extends into the reactor from the intake port along the radial direction of the reactor, and the extension length of the intake manifold into the reactor is not less than 1 / 3 of the radius of the reactor. This enables the intake manifold to cover more space inside the reactor, avoiding dead zones where hydrogen cyanide coverage is lacking in the reactor, which could cause some hydroxypentanal inside the reactor to fail to come into contact with hydrogen cyanide, thereby affecting the reaction effect between hydrogen cyanide and hydroxypentanal.

[0016] The present invention also aims to provide a multi-stage cyanidation reaction method applicable to the above multi-stage cyanidation reaction system, which is characterized by including the following steps:

[0017] Step 1: Transport hydrogen cyanide, hydroxypentanal, and an alkali raw material to the starting reactor, and let the respective raw materials undergo a preliminary reaction in the starting reactor to obtain primary tail gas and primary reaction materials.

[0018] Step 2: Input the primary tail gas and primary reaction materials obtained in Step 1 into each intermediate reactor in sequence, and let them undergo reactions in each intermediate reactor in sequence to obtain intermediate tail gas and intermediate reaction materials.

[0019] Step 3: Transport the intermediate tail gas and intermediate reaction materials in Step 2 to the terminal reactor, and let them undergo reactions in the terminal reactor to obtain terminal tail gas and terminal reaction materials.

[0020] Step 4: Transport the terminal reaction tail gas and terminal reaction materials obtained in Step 3 to the next processing step for processing.

[0021] Preferably, as an improvement, in Step 1, the molar ratio of hydroxypentanal, hydrogen cyanide, and alkali is 1:(1.05 - 1.15):1.5. Through multiple reactions of hydrogen cyanide and hydroxypentanal in a multi-stage reactor, while enabling hydrogen cyanide and hydroxypentanal to react fully in an alkaline environment to obtain high-quality dihydroxyacetonitrile materials, it can reduce the usage of raw materials and lower the production cost of dihydroxyacetonitrile.

[0022] Preferably, as an improvement, in Steps 1 to 3, the reaction time of the initial reactor, each intermediate reactor, and the terminal reactor is not less than 1 hour. Through multiple reactions of hydrogen cyanide and hydroxypentanal in multiple reactors, while ensuring that hydrogen cyanide and hydroxypentanal can react fully, it reduces the residence time of hydrogen cyanide and hydroxypentanal in each reactor. While ensuring the reaction effect of hydrogen cyanide and hydroxypentanal in each stage of the reactor, it reduces the reaction time of hydrogen cyanide and hydroxypentanal in each reactor, thereby improving the production and processing efficiency of each reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic structural diagram of the multi-stage cyanidation reaction system in an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the reactor structure in the embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the intake branch pipe structure in the embodiment of the present invention.

[0026] Figure 4 This is a flowchart of the multi-stage cyanidation reaction method in the embodiment of the present invention. Detailed implementation manners

[0027] The following is a further detailed description through specific implementation manners:

[0028] The reference numerals in the accompanying drawings of the specification include: feeding unit 1, intake pipe 101, feeding pipe 102, reaction unit 2, initial reactor 201, initial reactor 202, terminal reactor 203, reaction chamber 204, feeding port 205, intake port 206, material conveying pipe 207, gas conveying pipe 208, conveying pump 209, intake branch pipe 210, aeration member 211, output unit 3, discharge pipe 301, exhaust pipe 302.

[0029] As shown in the Figure 1 accompanying drawings, a multi-stage cyanidation reaction system includes a feeding unit 1, a reaction unit 2 and an output unit 3. The feeding unit 1 is used to convey raw materials to the reaction unit 2. The reaction unit 2 is used to react and process the raw materials. The output unit 3 is used to output the materials and tailings obtained after the reaction in the reaction unit 2.

[0030] The reaction unit 2 includes a plurality of reactors, and the plurality of reactors are arranged side by side with each other. As shown in the Figure 2 accompanying drawings, a reaction chamber 204 is provided in the reactor. The reaction chamber 204 is used to react on the materials. A feeding port 205 and an intake port 206 are provided on the reactor. The feeding port 205 is located at the top on one side of the reactor, and the feeding port 205 penetrates through the side wall of the reactor. The feeding port 205 is used to convey reaction raw materials into the reactor. The intake port 206 is located at one end near the bottom on one side of the reactor, and the intake port 206 penetrates through the side wall of the reactor. The intake port 206 is used to convey hydrogen cyanide gas into the reactor. An air outlet is provided on the top of the reactor on the side far from the feeding port 205, and the air outlet penetrates through the side wall of the reactor. The air outlet is used to output the gas after the reaction in the reactor. An output port is provided at the bottom of the reactor, and the output port is used to output the liquid material after the reaction in the reactor. The specific structure of the reactor is prior art and will not be elaborated here.

[0031] Multiple reactors are connected in series. The multiple reactors successively carry out reaction processing on the material. Among them, the first reactor in the arrangement order of the multiple reactors is the starting reactor 201, and the last reactor in the arrangement order of the multiple reactors is the terminal reactor 203. A number of intermediate reactors are successively arranged side by side between the starting reactor 201 and the terminal reactor 203. The feed inlet 205 of the intermediate reactor and the terminal reactor 203 is connected to the outlet of the previous reactor in front of itself through a feed pipe 207, and the gas inlet 206 of the intermediate reactor and the terminal reactor 203 is connected to the gas outlet of the previous reactor in front of itself through a gas pipe 208.

[0032] A delivery pump 209 is provided on the feed pipe 207. The delivery pump 209 is used to transport the liquid material output from the previous-stage reactor to the feed inlet 205 of the next-stage reactor. The delivery pump 209 can be a liquid delivery pump 209. The specific structure of the delivery pump 209 is prior art and will not be elaborated here. When the reacted liquid material is transported to the next-stage reactor, it can be transported from the outlet at the bottom of the previous-stage reactor to the feed inlet 205 at the top of the next-stage reactor under the push of the delivery pump 209, ensuring the efficiency of transporting the liquid material between the multi-stage reactors.

[0033] The feeding unit 1 includes an air inlet pipe 101 and a feed pipe 102. One end of the air inlet pipe 101 is communicated with the gas inlet 206 of the starting reactor 201, and the other end of the air inlet pipe 101 is communicated with a hydrogen cyanide gas conveying device. The air inlet pipe 101 is used to transport hydrogen cyanide gas into the starting reactor 201. One end of the feed pipe 102 is communicated with the feed inlet 205 of the starting reactor 201, and the other end of the feed pipe 102 is communicated with a raw material conveying device. The feed pipe 102 is used to transport hydroxypentanal and basic raw materials into the starting reactor 201. The specific content of transporting raw materials into the reactor is prior art and will not be elaborated here.

[0034] The output unit 3 includes a discharge pipe 301 and an exhaust pipe 302. One end of the discharge pipe 301 is communicated with the outlet of the terminal reactor 203, and the other end of the discharge pipe 301 is communicated with the equipment for the next processing step of the material. The discharge pipe 301 is used to output the dihydroxyacetonitrile material after the reaction of the reaction unit 2. One end of the exhaust pipe 302 is communicated with the gas outlet of the terminal reactor 203, and the other end of the exhaust pipe 302 is communicated with the tail gas treatment equipment. The exhaust pipe 302 is used to output the tail gas after the reaction of the reaction unit 2.

[0035] The intake ports 206 of each reactor in the reaction unit 2 include a plurality of them, and the plurality of intake ports 206 are evenly distributed at one end of the side wall of each reactor close to the bottom. An intake branch pipe 210 is provided in each intake port 206, and the intake branch pipe 210 penetrates through the side wall of the reactor through the intake port 206. One end of the intake branch pipe 210 is communicated with the intake pipe 101 or the gas transmission pipe 208, and the other end of the intake branch pipe 210 extends into the reaction chamber 204 in the reactor. By providing a plurality of intake ports 206 on the side wall of the reactor, when transporting hydrogen cyanide gas into the reactor, it can be evenly transported into the reactor circumferentially from the bottom of the reactor, improving the uniformity of the distribution of hydrogen cyanide gas in each area of the reactor, ensuring that the hydroxypentanal raw material in the reactor can fully react with hydrogen cyanide, and improving the reaction effect of hydrogen cyanide and hydroxypentanal.

[0036] As shown in the appendix Figure 3 As shown, each intake branch pipe 210 extends from the side wall of the reactor to the center of the reactor and then to the bottom of the reactor inside the reactor. Specifically, in this embodiment, the intake branch pipe 210 can extend in a "Z" shape as a whole to the bottom of the reactor inside the reactor. This enables the intake branch pipe 210 to get as close as possible to the bottom of the reactor, ensuring that when the intake branch pipe 210 transports hydrogen cyanide gas into the reactor, it can increase the coverage range of hydrogen cyanide gas in the height direction inside the reactor, and ensuring that hydrogen cyanide can fully contact and react with the hydroxypentanal in the reactor.

[0037] A plurality of aeration members 211 are connected to one end of the intake branch pipe 210 located in the reaction chamber 204. Preferably, in this embodiment, two aeration members 211 are connected to each intake branch pipe 210, and the two aeration members 211 are distributed on both sides of the intake branch pipe 210. The aeration member 211 can be an aerator. Preferably, in this embodiment, the aeration member 211 is a disk aerator with a model number of BBO-260. By providing the aeration members 211 on each intake branch pipe 210, when transporting hydrogen cyanide gas in the reactor, it can strongly contact with hydroxypentanal under the action of the aeration members 211, causing hydrogen cyanide to impact in the hydroxypentanal to achieve the effect of stirring and mixing. While simplifying the stirring structure in the reactor, it improves the mixing efficiency between hydrogen cyanide gas and hydroxypentanal liquid and increases the reaction speed.

[0038] The plurality of intake ports 206 are evenly distributed circumferentially at 10%-30% of the height of the side wall of the reactor from the bottom to the top direction. Preferably, in this embodiment, the plurality of intake ports 206 are evenly distributed circumferentially at 20% of the height of the bottom of the side wall of the reactor. This enables hydrogen cyanide to be input from the bottom of the reactor as much as possible, ensuring that hydrogen cyanide gas can more fully contact and react with the hydroxypentanal in the reactor.

[0039] Each intake manifold 210 extends radially from the intake port 206 into the reaction chamber 204 in the reactor. The extension length of each intake manifold 210 into the reactor is not less than 1 / 3 of the reactor radius. Preferably, in this embodiment, the extension length of each intake manifold 210 into the reactor is 1 / 2 of the reactor radius. This enables the intake manifolds 210 to cover more of the space inside the reactor, avoiding dead zones where hydrogen cyanide coverage is lacking in the reactor, which could cause some of the hydroxypentanal in the reactor to be unable to contact hydrogen cyanide, thus affecting the reaction effect between hydrogen cyanide and hydroxypentanal.

[0040] The present invention also aims to provide a multi-stage cyanidation reaction system applicable to the above multi-stage cyanidation reaction system; as shown in the attached Figure 4 figures, it includes the following steps:

[0041] Step 1: Transport hydrogen cyanide, hydroxypentanal, and alkali raw materials to the starting reactor 201, and the respective raw materials undergo a preliminary reaction in the starting reactor 201 to obtain primary tail gas and primary reaction materials. Specifically, when adding the raw materials, the hydrogen cyanide gas is transported into the initial reactor through the inlet pipe 101, and the hydrogen cyanide gas is transported into the reaction chamber 204 in the initial reactor through the aeration member 211 on the intake manifold 210; hydroxypentanal and alkali are transported into the reaction chamber 204 from the feed port 205 on the initial reactor through the feed pipe 102. Among them, hydroxypentanal and alkali can be input in the form of a solution. The specific input content of hydrogen cyanide, hydroxypentanal, and alkali, as well as the specific type of alkali, are prior arts and will not be elaborated here.

[0042] Step 2: Sequentially input the primary tail gas and primary reaction materials obtained in Step 1 into each stage of intermediate reactors, and sequentially carry out reactions in each stage of intermediate reactors to obtain intermediate tail gas and intermediate reaction materials. Specifically, when the intermediate tail gas and intermediate materials are reacted again through the intermediate reactors, the remaining gas after the reaction in Step 1 is transported into the next-stage intermediate reactor through the gas transmission pipe 208, and the liquid material obtained after the reaction in Step 1 is transported into the next-stage intermediate reactor through the material transmission pipe 207, enabling the materials and gas after the preliminary reaction in the primary reactor to undergo a secondary reaction in the intermediate reactor. And multiple intermediate reactors sequentially react the materials after the reaction in the previous-stage initial reactor or intermediate reactor again.

[0043] Step 3: Transport the intermediate tail gas and intermediate reaction materials in Step 2 to the terminal reactor 203, and carry out a reaction in the terminal reactor 203 to obtain terminal tail gas and terminal reaction materials;

[0044] Step 4: Convey the tail gas from the terminal reaction and the terminal reaction materials obtained in Step 3 to the next processing step for processing. Specifically, after the terminal reaction kettle 203 in Step 3 performs the final reaction on the materials, the obtained dihydroxyacetonitrile materials are conveyed to the next processing step for further processing, and the tail gas remaining after the reaction in the terminal reaction kettle 203 is conveyed to the tail gas treatment equipment for treatment and then discharged.

[0045] In Step 1, the molar ratio of hydroxypentanal, hydrogen cyanide, and the base is 1:(1.05 - 1.15):1.5. Through multiple reaction kettles, hydrogen cyanide and hydroxypentanal are reacted multiple times, enabling hydrogen cyanide and hydroxypentanal to react fully in an alkaline environment to obtain high-quality dihydroxyacetonitrile materials while reducing the consumption of raw materials and lowering the production cost of dihydroxyacetonitrile.

[0046] Among Steps 1 to 3, the reaction time of the initial reaction kettle, each intermediate reaction kettle, and the terminal reaction kettle 203 during the reaction is not less than 1 hour. Preferably, in this embodiment, the residence time of the raw materials conveyed to each reaction kettle in the reaction kettle for reaction is 1 hour. Through multiple reactions of hydrogen cyanide and hydroxypentanal in multiple reaction kettles, while ensuring that hydrogen cyanide and hydroxypentanal can react fully, the residence time of hydrogen cyanide and hydroxypentanal in each reaction kettle is reduced. While ensuring the reaction effect of hydrogen cyanide and hydroxypentanal in each stage of the reaction kettle, the reaction time of hydrogen cyanide and hydroxypentanal in each reaction kettle is reduced, and the production and processing efficiency of each reaction kettle is improved.

[0047] Compared with the prior art, when reacting hydrogen cyanide and hydroxypentanal in an alkaline environment in this solution, by connecting multiple reaction kettles in series, hydrogen cyanide and hydroxypentanal can react multiple times in the alkaline environment of multiple reaction kettles, enabling the unreacted hydrogen cyanide gas after the initial reaction to be conveyed to the next-stage reaction kettle for re-reaction, ensuring that the hydrogen cyanide and hydroxypentanal conveyed to the reaction kettle for reaction can be fully reacted and utilized, avoiding a large amount of residual hydrogen cyanide in the tail gas discharged after the reaction, and reducing the treatment difficulty of the tail gas after the reaction process.

[0048] Moreover, through multiple reactions of hydrogen cyanide and hydroxypentanal, the concentration of the generated dihydroxyacetonitrile materials can be further increased to 95% - 98%, improving the quality of the produced dihydroxyacetonitrile materials. At the same time, by connecting multiple reaction kettles in series, during the production process, multiple reaction kettles can react hydrogen cyanide and hydroxypentanal at different reaction stages simultaneously, enabling the reaction unit 2 to continuously react the materials and improving the production and preparation efficiency of the materials.

[0049] It should be noted that, for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can still be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope claimed in this application shall be subject to the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. A multi-stage cyanidation reaction system, characterized in that: It includes a feeding unit, a reaction unit and an output unit. The reaction unit includes an initial reactor, a plurality of intermediate reactors and a terminal reactor arranged side by side. The initial reactor, the plurality of intermediate reactors and the terminal reactor are arranged in series with each other. The initial reactor, the plurality of intermediate reactors and the terminal reactor react and process the materials in sequence. The feeding unit includes an air inlet pipe and a feeding pipe. The air inlet pipe is used to feed the hydrogen cyanide gas to the initial reactor, and the feeding pipe is used to transport hydroxyvaleraldehyde and alkaline raw materials to the initial reactor. The output unit is used to output the materials and tail gas after the reaction of the terminal reactor.

2. A multi-stage cyanidation reaction system according to claim 1, characterized in that: Each of the initial reactor, several intermediate reactors and the terminal reactor is provided with a feed port and an air inlet. The feed port is located at the top of one side of the reactor, and the feed port is used to transport reaction raw materials into the reactor; the air inlet is located at one end of one side of the reactor close to the bottom, and the air inlet is used to transport gas raw materials into the reactor; a gas outlet is provided on the side of the top of the reactor away from the feed port, and the gas outlet is used to output the gas after the reaction in the reactor; an output port is provided at the bottom of the reactor, and the output port is used to output the liquid material after the reaction in the reactor.

3. A multi-stage cyanidation reaction system according to claim 2, characterized in that: The feed inlet of the intermediate reactor and the terminal reactor is connected to the output port of the reactor before itself, and the air inlet of the intermediate reactor and the terminal reactor is connected to the air outlet of the reactor before itself.

4. A multi-stage cyanidation reaction system according to claim 2, characterized in that: Each reactor in the reaction unit includes a plurality of air inlets, which are evenly distributed at one end of the side wall of each reactor close to the bottom; an air inlet branch pipe is arranged in the air inlet, and the air inlet branch pipe extends into the reactor.

5. A multi-stage cyanidation reaction system according to claim 4, characterized in that: One end of the air inlet branch pipe located in the reaction chamber is connected with a plurality of aeration components.

6. A multi-stage cyanidation reaction system according to claim 4, characterized in that: The air inlet is located at 10%-30% of the height of the side wall of the reactor from the bottom to the top.

7. A multi-stage cyanidation reaction system according to claim 4, characterized in that: The air intake branch pipe extends from the air intake port into the reactor along the radial direction of the reactor, and the extension length of the air intake branch pipe into the reactor is not less than 1 / 3 of the radius of the reactor.

8. A multi-stage cyanidation reaction method, applicable to the multi-stage cyanidation reaction system according to any one of claims 1 to 7, characterized in that: The following steps are included: Step 1: transporting hydrogen cyanide, hydroxyvaleraldehyde and alkali raw materials to the starting reaction kettle, and the raw materials undergo a preliminary reaction in the starting reaction kettle to obtain primary tail gas and primary reaction materials; Step 2: The primary tail gas and the primary reaction material obtained in step 1 are sequentially input into the intermediate reactors of each level, and reacted in the intermediate reactors of each level to obtain the intermediate tail gas and the intermediate reaction material; Step 3: transporting the intermediate tail gas and the intermediate reaction material in step 2 to the terminal reaction kettle, and reacting in the terminal reaction kettle to obtain the terminal tail gas and the terminal reaction material; Step 4: transporting the terminal reaction tail gas and terminal reaction materials obtained in step 3 to the next processing step for processing.

9. A multi-stage cyanidation reaction method according to claim 8, characterized in that: In step 1, the molar ratio of hydroxyvaleraldehyde, hydrogen cyanide and base is 1:(1.05-1.15):1.

5.

10. A multi-stage cyanidation reaction method according to claim 8, characterized in that: In steps 1 to 3, the reaction time of the initial reactor, each intermediate reactor and the terminal reactor is not less than 1 hour.

Images