A method for using a device for producing ammonium sulfate from tail gas using a gold ore dressing agent

Abstract

The application provides a method for using an equipment for preparing ammonium sulfate by using tail gas of gold ore dressing agent, the equipment comprises a particle adsorption tower, an ammonia gas absorption tower, a tail gas treatment tower, a tail gas incineration system and a wastewater treatment tank, the particle adsorption tower, the ammonia gas absorption tower and the tail gas treatment tower are sequentially communicated through pipelines, all of the three are air inlets at the bottom and air outlets at the top, and the air outlets are communicated with air inlets of the next tower through pipelines; the tail gas firstly passes through the particle adsorption tower to remove insoluble particles, then enters the ammonia gas absorption tower to react with sulfuric acid to generate ammonium sulfate, and is evaporated and crystallized, finally is centrifugally dried to prepare ammonium sulfate products, and the remaining tail gas is further treated in the tail gas treatment tower and the tail gas incineration system. The application has high ammonia recovery rate, the prepared ammonium sulfate can be used for crop fertilization, and the treatment path of the tail gas of the gold ore dressing agent is increased.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chemical production, and particularly relates to a device for preparing ammonium sulfate by using tail gas of gold ore dressing agent production and a use method thereof. BACKGROUND

[0002] In the process of preparing gold ore dressing agent by using thiourea and sodium carbonate as main raw materials, tail gas containing ammonia gas is generated, and the ammonia gas needs to be treated before being discharged. A commonly used ammonia gas treatment method is to absorb the ammonia gas to generate low-concentration ammonia water by using water circulation, and then to remove the ammonia gas from the ammonia water by rectification. For example, the invention patent CN201210213698.6 discloses a treatment method for ammonia gas in flue gas of a fly ash sintering kiln, which comprises the following steps: treating the flue gas of the sintering kiln by using a dust collection system to remove dust in the flue gas; reducing the temperature of the flue gas; absorbing the ammonia gas in the flue gas to generate low-concentration ammonia water by using fresh water and circulating liquid; removing the ammonia gas in the low-concentration ammonia water by entering the low-concentration ammonia water into a rectification tower; and transporting the ammonia gas to a decomposition workshop by using a compressor and mixing the ammonia gas with an aluminum ammonium sulfate solution in a Venturi tube. The invention purifies the ammonia gas in the flue gas of the sintering kiln by treating the flue gas, and uses the pure ammonia gas as a raw material for decomposition of the aluminum ammonium sulfate.

[0003] However, the tail gas generated in the production process of the gold ore dressing agent also carries a large amount of insoluble particle impurities, and the water circulation treatment cannot remove the insoluble particle impurities, and at the same time, the water circulation treatment also causes blockage of the equipment, which brings certain difficulties to the treatment of the tail gas and greatly increases the cost of the entire tail gas treatment process. SUMMARY

[0004] In view of the above-mentioned difficulties in the treatment of the tail gas generated in the production of the gold ore dressing agent, the application provides a device for preparing ammonium sulfate by using tail gas of gold ore dressing agent production and a use method thereof, which uses the tail gas generated in the production of the gold ore dressing agent to prepare ammonium sulfate products, and effectively removes insoluble particles in the tail gas to improve the removal rate of the ammonia gas.

[0005] The application is implemented by the following technical solutions:

[0006] A device for preparing ammonium sulfate by using tail gas of gold ore dressing agent production, comprising a particle adsorption tower, an ammonia gas absorption tower, a tail gas treatment tower, a tail gas incineration system and a wastewater treatment tank.

[0007] The particle adsorption tower, the ammonia gas absorption tower and the tail gas treatment tower are sequentially connected by pipelines, and all of them are bottom-inlet and top-outlet, and the gas outlets are connected to the gas inlets of the next towers by pipelines.

[0008] The bottom gas inlet of the particle adsorption tower is connected to a first heat exchanger, and the tail gas from a reaction kettle enters the particle adsorption tower after heat exchange by the first heat exchanger; a flocculant feeding port is arranged at the top of the particle adsorption tower, and a material outlet is arranged at the bottom of the particle adsorption tower.

[0009] The ammonia gas absorption tower is provided with a sulfuric acid feeding port at the top and a discharge port at the bottom, which are connected with a crystallization evaporator and a centrifuge in sequence; the sulfuric acid feeding port is connected with the second heat exchanger; the water outlet pipe of the centrifuge is communicated to the first heat exchanger; the water vapor outlet of the crystallization evaporator is communicated to the gas inlet of the tail gas treatment tower through a pipeline;

[0010] The tail gas treatment tower is provided with a water inlet at the top and a discharge outlet at the bottom, which are connected with a waste water treatment pool through a pipeline.

[0011] As a further improvement of the present application, the ammonia gas absorption tower is connected with a third heat exchanger; the water inlet of the third heat exchanger is communicated to the upper layer of the ammonia gas absorption tower, and the water outlet is communicated to the lower part of the ammonia gas absorption tower.

[0012] As a further improvement of the present application, the water outlet of the first heat exchanger is communicated to the waste water treatment pool.

[0013] Meanwhile, the present application also provides a use method of the equipment for preparing ammonium sulfate by using tail gas of gold ore dressing agent, which comprises the following steps:

[0014] (1) the tail gas from the reaction kettle enters the first heat exchanger for heat exchange and cooling to 80-100℃, and then is sent to the particle adsorption tower at a gas flow rate of 3-5 m / s, and then the flocculant feeding port is opened to make the flocculant enter the particle adsorption tower to adsorb the particles, dust and other impurities of the tail gas, the adsorbed tail gas enters the ammonia gas absorption tower from the gas outlet, and the adsorbed flocculant is discharged from the bottom of the tower;

[0015] (2) the adsorbed tail gas enters the ammonia gas absorption tower at a gas flow rate of 4-8 m / s, and at the same time, the sulfuric acid with a mass concentration of 45%-50% is added from the top of the ammonia gas absorption tower at a flow rate of 120-140 m 3 / h for spraying to carry out a deamination reaction to obtain ammonium sulfate filtrate, and the overflowed ammonia gas enters the tail gas treatment tower from the gas outlet at the top of the ammonia gas absorption tower for treatment;

[0016] (3) the ammonium sulfate filtrate is discharged from the bottom of the ammonia gas absorption tower and sent to the crystallization evaporator for evaporation and crystallization, the evaporated water vapor is sent to the tail gas treatment tower for treatment; after being separated by the centrifuge, the ammonium sulfate product is dried to obtain the product, and the separated water is sent to the first heat exchanger for heat exchange;

[0017] (4) the ammonia gas is further absorbed by water spraying in the tail gas treatment tower, the adsorbed treatment liquid is sent to the waste water treatment pool for secondary treatment, and the overflowed ammonia gas is sent to the tail gas incineration system for combustion treatment.

[0018] Preferably, the adsorbed tail gas is cooled to 65-70℃ before being sent to the ammonia gas absorption tower in step (1).

[0019] Preferably, the reaction liquid at the upper part of the ammonia absorption tower is first cooled to 20-25°C by the third heat exchanger, and then returned to the bottom of the ammonia absorption tower for further reaction. The final ammonium sulfate filtrate is sent to evaporation crystallization.

[0020] Preferably, the crystallization temperature of the crystallization evaporator in step (3) is 55-60°C, and the ammonium sulfate slurry with a particle size of 2-4 mm is obtained after crystallization.

[0021] Preferably, the rotation speed of the centrifugal separation in step (3) is 1200-1500 r / min; the drying is hot air drying, and the hot air temperature is 100-110°C.

[0022] Preferably, the flocculating agent in step (1) is prepared according to the following weight ratio of materials:

[0023] (1) Disperse 0.5-2 parts of chitosan powder in 30-40 parts of N-methyl-2-pyrrolidone solution and mix uniformly, then heat the solution in a 60-65°C water bath, while adding 5-6 parts of 15% sodium hydroxide solution, 2-4 parts of sodium iodide and 5-8 parts of iodomethane solution, mixing uniformly and reacting for 1h to obtain a mixed solution A;

[0024] (2) Add 30-40 parts of N-methyl-2-pyrrolidone solution, 2-4 parts of sodium iodide, 5-6 parts of 15% sodium hydroxide solution and 3-4 parts of iodomethane solution to the mixed solution A, continue to react for 0.5h, then add 0.5-1 part of iodomethane and 0.3-1 part of sodium hydroxide solid, and react for 1h to obtain a mixed solution B;

[0025] (3) Add 10-15 parts of 10% sodium chloride solution to the mixed solution B and stir for 0.5h, then slowly stir 40-50 parts of anhydrous ethanol until a large amount of precipitate is precipitated, centrifuge to collect the precipitate, and vacuum dry to obtain chitosan quaternary ammonium salt;

[0026] (4) Dissolve 5-10 parts of chitosan quaternary ammonium salt in 6-8 parts of isopropanol solution, then add 2-4 parts of 30% sodium hydroxide solution for alkalization for 2.5-3.5h to obtain a mixed solution C;

[0027] (5) Add 0.7-1 part of monochloroacetic acid to the mixed solution C, react at 60°C constant temperature water bath for 2h, then adjust the pH to 7-8 with glacial acetic acid, and react until precipitate is precipitated to obtain the modified chitosan flocculating agent.

[0028] The flocculant of this invention is synthesized by methylation reaction of chitosan with excess iodomethane to form water-soluble chitosan trimethyl quaternary ammonium salt. Then, the chitosan trimethyl quaternary ammonium salt is reacted with monochloroacetic acid to form an amphiphilic carboxymethyl chitosan quaternary ammonium salt flocculant. This flocculant adsorbs particulate matter into the gas entering the particle adsorption tower by spraying. The optimal pH for flocculation effect is 7-10. The reaction of ammonia with the flocculant solution to form weakly alkaline ammonia water does not affect the flocculation effect.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] This invention utilizes the tail gas generated during gold ore beneficiation to prepare ammonium sulfate, thus increasing the utilization pathways of this tail gas. The treatment process sequentially employs flocculant adsorption of insoluble particulate impurities, sulfuric acid deammoniation, water circulation for further ammonia removal, and tail gas re-combustion to achieve complete ammonia removal. The ammonia adsorbed by the flocculant is then reused in ammonium sulfate production, improving the ammonia recovery rate. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the device of the present invention. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings. In the embodiments, unless otherwise specified, the technical means used are all conventional technical means in the art. Example

[0033] like Figure 1 The device shown is for preparing ammonium sulfate using the tail gas from the production of gold beneficiation agents, including a particle adsorption tower, an ammonia absorption tower, a tail gas treatment tower, a tail gas incineration system, and a wastewater treatment pond.

[0034] The particle adsorption tower, ammonia absorption tower, and tail gas treatment tower are connected in sequence through pipelines. All three have bottom inlet and top outlet, and the outlet is connected to the inlet of the next tower through a pipeline.

[0035] The bottom air inlet of the particle adsorption tower is connected to the first heat exchanger. The exhaust gas from the reactor enters the particle adsorption tower after heat exchange through the first heat exchanger. The particle adsorption tower is provided with a flocculant inlet at the top and a material outlet at the bottom.

[0036] The ammonia absorption tower is equipped with a sulfuric acid inlet at the top and a crystallizer and a centrifuge at the bottom in sequence; the sulfuric acid inlet is connected to a second heat exchanger; the centrifuge outlet water pipe is connected to the first heat exchanger; the water vapor outlet of the crystallizer is connected to the inlet of the tail gas treatment tower through a pipe.

[0037] The upper gas outlet of the tail gas treatment tower is connected with a tail gas incineration system through a pipeline; the top of the tail gas treatment tower is provided with a water inlet, and the bottom outlet is connected with a wastewater treatment tank through a pipeline.

[0038] The third heat exchanger is connected with the ammonia gas absorption tower; the water inlet of the third heat exchanger is communicated to the upper layer of the ammonia gas absorption tower, and the water outlet is communicated to the lower part of the ammonia gas absorption tower.

[0039] The water outlet of the first heat exchanger is communicated to the wastewater treatment tank.

[0040] The use method of the equipment for preparing ammonium sulfate by using tail gas of gold ore dressing agent production, comprises the following steps:

[0041] (1) the tail gas from the reaction kettle enters the first heat exchanger for heat exchange and cooling to 80℃, then is sent to the particle adsorption tower at a gas flow rate of 3m / s, the flocculant inlet is opened to make the flocculant enter the particle adsorption tower to adsorb the particles, dust and other impurities in the tail gas, the adsorbed tail gas is cooled to 65℃ and then enters the ammonia gas absorption tower from the gas outlet, and the adsorbed flocculant is discharged from the bottom of the tower.

[0042] (2) the adsorbed tail gas enters the ammonia gas absorption tower at a gas flow rate of 4m / s, and 45% sulfuric acid with a mass concentration of 45% is added from the top of the ammonia gas absorption tower at a flow rate of 120m 3 / h for spraying, the reaction liquid in the upper part of the ammonia gas absorption tower is first cooled to 20℃ by the third heat exchanger, and then returns to the bottom of the ammonia gas absorption tower for further reaction, and finally the obtained ammonium sulfate filtrate is sent to evaporation crystallization, and the overflowed ammonia gas enters the tail gas treatment tower from the gas outlet at the top of the ammonia gas absorption tower for treatment.

[0043] (3) the ammonium sulfate filtrate discharged from the bottom of the ammonia gas absorption tower is sent to the crystallization evaporator for evaporation crystallization at 55℃, and the crystallized ammonium sulfate slurry with a particle size of 2mm is obtained, and the evaporated water vapor is sent to the tail gas treatment tower for treatment; the ammonium sulfate product is obtained by drying after centrifugal separation, and the separated water is sent to the first heat exchanger for heat exchange; the rotation speed of centrifugal separation is 1200r / min; the drying is hot air drying, and the hot air temperature is 100℃.

[0044] (4) the ammonia gas in the tail gas treatment tower is further absorbed by water spraying, the treated liquid after adsorption is sent to the wastewater treatment tank for secondary treatment, and the overflowed ammonia gas is sent to the tail gas incineration system for combustion treatment.

[0045] The flocculant is prepared according to the following weight ratio of materials:

[0046] (1) 0.5 parts of chitosan powder was dispersed in 30 parts of N-methyl-2-pyrrolidone solution and mixed uniformly, then the solution was heated in a 60°C water bath, while 5 parts of 15% by mass sodium hydroxide solution, 2 parts of sodium iodide and 5 parts of iodomethane solution were added, mixed uniformly and reacted for 1 h to obtain a mixed solution A;

[0047] (2) 30 parts of N-methyl-2-pyrrolidone solution, 2 parts of sodium iodide, 5 parts of 15% by mass sodium hydroxide solution and 3 parts of iodomethane solution were added to the mixed solution A, and the reaction was continued for 0.5 h, then 0.5 parts of iodomethane and 0.3 parts of sodium hydroxide solid were added, and the reaction was continued for 1 h to obtain a mixed solution B;

[0048] (3) 10 parts of 10% by mass sodium chloride was added to the mixed solution B and stirred for 0.5 h, then 40 parts of anhydrous ethanol was slowly stirred until a large amount of precipitate was precipitated, the precipitate was centrifuged and vacuum dried to obtain a chitosan quaternary ammonium salt;

[0049] (4) 5 parts of the chitosan quaternary ammonium salt was dissolved in 6 parts of isopropanol solution, then 2 parts of 30% by mass sodium hydroxide solution was added for alkalization for 2.5 h to obtain a mixed solution C;

[0050] (5) 0.7 parts of monochloroacetic acid was added to the mixed solution C, and the reaction was continued for 2 h at 60°C constant temperature water bath, then glacial acetic acid was added to adjust the pH to 7, and the reaction was continued until precipitate was precipitated to obtain a modified chitosan flocculant.

[0051] The example can realize the production of 29685.61 tons of ammonium sulfate product per year, and the ammonia recovery rate is 94.8%, which meets the tail gas emission standard. Example

[0052] The equipment structure of the example is the same as that of example 1, and the difference lies in the use method, which is as follows:

[0053] The use method of the equipment for preparing ammonium sulfate from tail gas by using a gold ore dressing agent comprises the following steps:

[0054] (1) The tail gas from the reaction kettle enters the first heat exchanger for heat exchange and cooling to 100°C, then is sent to the particle adsorption tower at a gas flow rate of 5 m / s, the flocculant inlet is opened to make the flocculant enter the particle adsorption tower to adsorb the particles, dust and other impurities in the tail gas, the adsorbed tail gas is cooled to 70°C and then enters the ammonia gas absorption tower from the gas outlet, and the adsorbed flocculant is discharged from the bottom of the tower.

[0055] (2) The adsorbed tail gas enters the ammonia gas absorption tower at a gas flow rate of 8 m / s, and 140 m 3A flow rate of 50% sulfuric acid is added for spraying at a rate of / h. The reaction liquid at the top of the ammonia absorption tower is first cooled to 25°C by the third heat exchanger and then returned to the bottom of the ammonia absorption tower for further reaction. The final ammonium sulfate filtrate is then sent for evaporation and crystallization. The overflowing ammonia gas enters the tail gas treatment tower from the top outlet of the ammonia absorption tower for treatment.

[0056] (3) The ammonium sulfate filtrate discharged from the bottom of the ammonia absorption tower is sent to the crystallization evaporator for evaporation and crystallization at 60°C. After crystallization, an ammonium sulfate slurry containing a particle size of 4 mm is obtained. The evaporated water vapor is sent to the tail gas treatment tower for treatment. After separation by centrifuge and drying, the ammonium sulfate product is obtained. The separated water is sent to the first heat exchanger for heat exchange. The centrifugal separation rotation speed is 1500 r / min. Drying is hot air drying with a hot air temperature of 110°C.

[0057] (4) Ammonia is further absorbed by water spraying in the tail gas treatment tower. The adsorbed treatment liquid is sent to the wastewater treatment pond for secondary treatment, and the overflowing ammonia is sent to the tail gas incineration system for combustion treatment.

[0058] The flocculant is prepared from the following materials in the indicated weight ratios:

[0059] (1) Disperse 2 parts of chitosan powder in 40 parts of N-methyl-2-pyrrolidone solution and mix evenly. Then heat the solution in a water bath at 65°C and add 6 parts of sodium hydroxide solution with a mass concentration of 15%, 4 parts of sodium iodide and 8 parts of iodomethane solution. Mix evenly and react for 1 hour to obtain mixed solution A.

[0060] (2) Add 40 parts of N-methyl-2-pyrrolidone solution, 4 parts of sodium iodide, 6 parts of sodium hydroxide solution with a mass concentration of 15% and 4 parts of iodomethane solution to mixed solution A. After reacting for 0.5 h, add 1 part of iodomethane and 1 part of sodium hydroxide solid. React for 1 h to obtain mixed solution B.

[0061] (3) Add 15 parts of sodium chloride with a mass concentration of 10% to the mixture B and stir for 0.5 h. Then add 50 parts of anhydrous ethanol and stir slowly until a large amount of precipitate is formed. Centrifuge to collect the precipitate and vacuum dry to obtain chitosan quaternary ammonium salt.

[0062] (4) Take 10 parts of chitosan quaternary ammonium salt and dissolve it in 8 parts of isopropanol solution, then add 4 parts of sodium hydroxide solution with a mass concentration of 30% for alkalization for 3.5h to obtain mixed solution C;

[0063] (5) Add 1 part of monochloroacetic acid to the mixture C, react for 2 hours in a constant temperature water bath at 60°C, then adjust the pH to 8 with glacial acetic acid, and react until a precipitate is formed to obtain the modified chitosan flocculant.

[0064] The embodiment can realize annual production of 28795.43 tons of ammonium sulfate product, with an ammonia recovery rate of 95.6%, and meets the tail gas emission standard. Embodiment

[0065] The equipment structure of the embodiment is the same as that of embodiment 1, and the difference lies in the use method, which is as follows:

[0066] The use method of the equipment for preparing ammonium sulfate from tail gas by using a gold ore dressing agent comprises the following steps:

[0067] (1) The tail gas from the reaction kettle enters the first heat exchanger for heat exchange and cooling to 90℃, and then is sent to the particle adsorption tower at a gas flow rate of 4m / s, and then the flocculant feeding port is opened to make the flocculant enter the particle adsorption tower to adsorb the particles, dust and other impurities in the tail gas, and the adsorbed tail gas is cooled to 68℃ and then enters the ammonia gas absorption tower from the gas outlet, and the adsorbed flocculant is discharged from the bottom of the tower.

[0068] (2) The adsorbed tail gas enters the ammonia gas absorption tower at a gas flow rate of 6m / s, and at the same time, 48% mass concentration sulfuric acid is added from the top of the ammonia gas absorption tower at a flow rate of 130m 3 / h for spraying, and the reaction liquid in the upper part of the ammonia gas absorption tower is first cooled to 24℃ by the third heat exchanger, and then returned to the bottom of the ammonia gas absorption tower for further reaction, and finally the obtained ammonium sulfate filtrate is sent to evaporation crystallization, and the overflowed ammonia gas enters the tail gas treatment tower from the gas outlet at the top of the ammonia gas absorption tower for treatment.

[0069] (3) The ammonium sulfate filtrate discharged from the bottom of the ammonia gas absorption tower is sent to the crystallization evaporator for evaporation crystallization at 58℃, and the crystallized ammonium sulfate slurry with a particle size of 3mm is obtained, and the evaporated water vapor is sent to the tail gas treatment tower for treatment; the ammonium sulfate product is obtained by drying after centrifugal separation; the separated water is sent to the first heat exchanger for heat exchange; the rotation speed of centrifugal separation is 1300r / min; the drying is hot air drying, and the hot air temperature is 105℃.

[0070] (4) The ammonia gas is further absorbed by water spraying in the tail gas treatment tower, the treated liquid after adsorption is sent to the wastewater treatment tank for secondary treatment, and the overflowed ammonia gas is sent to the tail gas incineration system for combustion treatment.

[0071] The flocculant is prepared according to the following weight ratio of materials:

[0072] (1) Disperse 1 part of chitosan powder in 35 parts of N-methyl-2-pyrrolidone solution and mix uniformly, then heat the solution in a 62℃ water bath, and at the same time, add 6 parts of 15% mass concentration sodium hydroxide solution, 3 parts of sodium iodide and 6 parts of iodomethane solution, mix uniformly and react for 1h to obtain a mixed solution A;

[0073] (2) adding 35 parts of N-methyl-2-pyrrolidone solution, 3 parts of sodium iodide, 5 parts of 15% by mass sodium hydroxide solution and 3 parts of iodomethane solution into the mixed solution A, continuing to react for 0.5 h, then adding 0.8 parts of iodomethane and 0.5 parts of sodium hydroxide solid, and reacting for 1 h to obtain a mixed solution B;

[0074] (3) adding 12 parts of 10% by mass sodium chloride into the mixed solution B, stirring and reacting for 0.5 h, then adding 45 parts of anhydrous ethanol, slowly stirring until a large amount of precipitate is precipitated, centrifuging to obtain the precipitate, and vacuum drying to obtain the chitosan quaternary ammonium salt;

[0075] (4) dissolving 8 parts of the chitosan quaternary ammonium salt in 7 parts of isopropanol solution, then adding 3 parts of 30% by mass sodium hydroxide solution to alkalize for 3 h to obtain a mixed solution C;

[0076] (5) adding 0.8 parts of monochloroacetic acid into the mixed solution C, reacting at 60°C in a constant-temperature water bath for 2 h, then adjusting the pH to 7 with glacial acetic acid, and reacting until a precipitate is precipitated to obtain the modified chitosan flocculant.

[0077] The example can realize the annual production of 29566.78 tons of ammonium sulfate product, and the ammonia recovery rate is 95.8%, which meets the tail gas emission standard.

[0078] The above examples are only exemplary embodiments of the present application, and are not used to limit the present application, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements shall also be considered to fall within the protection scope of the present application.

[0079] It is particularly pointed out that the directions or position relationships indicated by "front", "back", "left", "right", "up", "down" and the like are the directions or position relationships shown based on the drawings, or the directions or position relationships commonly placed when the product of the present application is used, and are only for the convenience of describing the present application, and cannot be understood as indicating or implying that the devices or elements indicated must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used for differentiation and description, and cannot be understood as indicating or implying relative importance.

Claims

1. A method for using equipment to prepare ammonium sulfate from tail gas of gold beneficiation agent production, characterized in that: The equipment includes a particle adsorption tower, an ammonia absorption tower, a tail gas treatment tower, a tail gas incineration system, and a wastewater treatment pond. The particle adsorption tower, ammonia absorption tower and tail gas treatment tower are connected in sequence through pipelines. All three have bottom air inlet and top air outlet, and the air outlet is connected to the air inlet of the next tower through a pipeline. The bottom air inlet of the particle adsorption tower is connected to the first heat exchanger. The exhaust gas from the reactor enters the particle adsorption tower after heat exchange through the first heat exchanger. The top of the particle adsorption tower is provided with a flocculant inlet, and the bottom is provided with a material outlet. The ammonia absorption tower is equipped with a sulfuric acid inlet at the top and a crystallizer and a centrifuge in sequence at the bottom outlet; the sulfuric acid inlet is connected to a second heat exchanger; the centrifuge outlet water pipe is connected to a first heat exchanger; the water vapor outlet of the crystallizer is connected to the inlet of the tail gas treatment tower through a pipe; the ammonia absorption tower is connected to a third heat exchanger; the inlet of the third heat exchanger is connected to the upper part of the ammonia absorption tower, and the outlet is connected to the lower part of the ammonia absorption tower. The exhaust gas treatment tower has an upper outlet connected to an exhaust gas incineration system via a pipe; the exhaust gas treatment tower has a water inlet at the top and a bottom outlet connected to a wastewater treatment tank via a pipe. The method of using the equipment for preparing ammonium sulfate from the tail gas of gold beneficiation agent includes the following steps: (1) The tail gas from the reactor enters the first heat exchanger to exchange heat and cool down to 80-100℃. Then it is sent to the particle adsorption tower at a gas flow rate of 3-5m / s. Then the flocculant inlet is opened to allow the flocculant to enter the particle adsorption tower to adsorb the particles and dust impurities in the tail gas. The adsorbed tail gas enters the ammonia absorption tower from the outlet. The adsorbed flocculant is discharged from the bottom of the tower. The adsorbed tail gas is cooled to 65-70℃ and then sent to the ammonia absorption tower. (2) The adsorbed tail gas enters the ammonia absorption tower at a gas flow rate of 4-8 m / s, and simultaneously flows from the top of the ammonia absorption tower at a rate of 120-140 m. 3 A flow rate of 45%–50% sulfuric acid is added at a rate of / h for spraying to carry out ammonia removal reaction and obtain ammonium sulfate filtrate. The overflowing ammonia gas enters the tail gas treatment tower from the top outlet of the ammonia absorption tower for treatment. (3) The ammonium sulfate filtrate discharged from the bottom of the ammonia absorption tower is sent to the crystallization evaporator for evaporation and crystallization. The evaporated water vapor is sent to the tail gas treatment tower for treatment. After separation by centrifuge and drying, the ammonium sulfate product is obtained. The separated water is sent to the first heat exchanger for heat exchange. The crystallization temperature of the crystallization evaporator is 55-60℃. After crystallization, an ammonium sulfate slurry containing particles with a diameter of 2-4mm is obtained. (4) Ammonia is further absorbed by water spraying in the tail gas treatment tower. The adsorbed treatment liquid is sent to the wastewater treatment pond for secondary treatment. The overflowing ammonia is sent to the tail gas incineration system for combustion treatment. The reaction liquid at the top of the ammonia absorption tower is first cooled to 20-25°C by the third heat exchanger, and then returned to the bottom of the ammonia absorption tower for further reaction. The final ammonium sulfate filtrate is then sent for evaporation and crystallization.

2. The method of using the equipment for preparing ammonium sulfate from the tail gas of gold beneficiation agent according to claim 1, characterized in that: The flocculant is prepared from the following materials in the indicated weight ratios: S1: Disperse 0.5 to 2 parts of chitosan powder in 30 to 40 parts of N-methyl-2-pyrrolidone solution and mix evenly. Then heat the solution in a water bath at 60 to 65°C, while adding 5 to 6 parts of 15% sodium hydroxide solution, 2 to 4 parts of sodium iodide and 5 to 8 parts of iodomethane solution. Mix evenly and react for 1 hour to obtain mixed solution A. S2: Add 30-40 parts of N-methyl-2-pyrrolidone solution, 2-4 parts of sodium iodide, 5-6 parts of 15% sodium hydroxide solution and 3-4 parts of iodomethane solution to mixed solution A. After reacting for 0.5 h, add 0.5-1 parts of iodomethane and 0.3-1 parts of sodium hydroxide solid. React for 1 h to obtain mixed solution B. S3: Add 10-15 parts of 10% sodium chloride to mixture B and stir for 0.5 h. Then add 40-50 parts of anhydrous ethanol and stir slowly until a large amount of precipitate is formed. Centrifuge to collect the precipitate and vacuum dry to obtain chitosan quaternary ammonium salt. S4: Dissolve 5-10 parts of chitosan quaternary ammonium salt in 6-8 parts of isopropanol solution, then add 2-4 parts of 30% sodium hydroxide solution for alkalization for 2.5-3.5 hours to obtain mixture C; S5: Add 0.7 to 1 part of monochloroacetic acid to the mixture C, react in a constant temperature water bath at 60°C for 2 hours, then adjust the pH to 7 to 8 with glacial acetic acid, and react until a precipitate is formed to obtain the modified chitosan flocculant.

3. The method of using the equipment for preparing ammonium sulfate from the tail gas of gold beneficiation agent according to claim 1, characterized in that: The outlet of the first heat exchanger is connected to the wastewater treatment tank.

4. The method of using the equipment for preparing ammonium sulfate from the tail gas of gold beneficiation agent according to claim 1, characterized in that: Step (3) The centrifugal separation rotation speed is 1200-1500 r / min; the drying is hot air drying, and the hot air temperature is 100-110℃.

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