CN202289862U - Zinc oxide desulfurization system - Google Patents

Abstract

The utility model discloses a zinc oxide desulfurization system, comprising: an absorption tower, the absorption tower is provided with an air inlet, an air outlet, an absorption liquid inlet and an absorption liquid outlet; a settling tank connected with the absorption liquid outlet; a pulping tank , the slurrying tank is communicated with the settling tank to send the absorbent and the supernatant into the absorption tower after being stirred; the acidizing tank is connected to the solid-containing slurry outlet of the settling tank; the sulfur dioxide desorption tower, the The sulfur dioxide desorption tower is connected with the acidification tank. According to the zinc oxide desulfurization system of the utility model, by controlling the solid content and pH value of the absorption liquid in the absorption tower, the problems of equipment blockage and scaling are obviously reduced without affecting the absorption efficiency of SO ₂ . In addition, there is no discharge of waste gas, waste liquid and waste solid, and a fully enclosed operation is realized. In addition, the equipment is simple, easy to operate and maintain, and low in cost. Compared with traditional zinc oxide desulfurization, the process is short and easy to operate, and can achieve continuous operation.

Description

Zinc oxide desulfurization system

technical field

The utility model relates to a zinc oxide desulfurization process, in particular to a zinc oxide desulfurization system.

Background technique

The traditional zinc oxide desulfurization process is as follows: the slurry containing zinc oxide (ZnO) or pure ZnO mixed with water is in contact with flue gas containing sulfur dioxide (SO ₂ ), and reacts to form zinc sulfite (ZnSO ₃ ), After the ZnSO ₃ precipitate is filtered by a filter press, the formed filter residue is sent to the roasting workshop; there is also an oxidation reaction of ZnSO ₃ under the condition of oxidizing air blowing in, and finally produces ZnSO ₄ , which contains ZnSO ₄ , ZnSO ₃ , ZnO and After the mixed solution of impurities is filtered by a filter press, the filtrate contains a large amount of ZnSO ₄ and is sent to the leaching section of the wet system. After the filter residue is dried, it is sent to the slag treatment system or roasting section of the zinc smelter.

The overall chemical reaction equation is as follows:

ZnO+SO ₂ -ZnSO ₃

ZnO+SO ₂ +1/2O ₂ -ZnSO ₄

However, the traditional zinc oxide desulfurization process has not been widely promoted in China. The reasons are as follows:

(1) ZnSO ₃ is relatively viscous, and ZnSO ₃ in the circulating fluid is easy to deposit in equipment and pipelines, causing scaling and blockage of pipelines, and it is very difficult to clean up after scaling;

(2) The oxidation of ZnSO ₃ to ZnSO ₄ requires a large amount of oxidizing air for oxidation, and the energy consumption is relatively high. The oxidation effect is controlled by many factors, and the oxidation efficiency is difficult to control;

(3) Since a large amount of filter residue is filtered out, and the filter residue is difficult to achieve a very low moisture content, if the filter is not well filtered, the filter residue is often like mud, which makes the operating environment of the first floor of the filter press workshop very poor, and these filter residues are transported outside During the process, it is impossible to achieve fully enclosed transportation, causing secondary pollution to the factory area;

(4) To separate the _ZnSO4 solution from the slag, or to filter the _ZnSO3 in the slurry, a filter press is required, and for continuous operation, the filter press has to be used one at a time, so workers must be arranged to carry out To operate and organize the filter cloth, the filtered slag has to be transported away, and a filter press workshop has to be built. The entire system occupies a large area, and the operating cost and investment are large;

Generally speaking, since tail gas desulfurization does not produce any benefits for enterprises, the lower the investment and the simpler the equipment, the better. However, the traditional zinc oxide desulfurization process, from zinc oxide pulping to subsequent filter press filtration, all The scale of the system is not large, but to make the entire process run stably and reliably, with a good operating environment and a high degree of automation, the supporting facilities such as electricity and instruments must be complete, and the investment often exceeds the company's expectations. As a result, a lot of equipment can be saved if it can be saved, and if it can be simplified, it will be simplified. As a result, there is no very good demonstration project for the zinc oxide desulfurization process, and it cannot be widely promoted.

Utility model content

The utility model aims at at least solving one of the technical problems existing in the prior art. Therefore, an object of the present utility model is to provide a zinc oxide desulfurization system, which is not prone to clogging and fouling during desulfurization, and does not discharge any waste gas, waste liquid and waste solid.

A zinc oxide desulfurization system according to the present invention comprises: an absorption tower, a reaction chamber is defined inside the absorption tower, and the lower part of the side wall of the absorption tower is provided with an air inlet to feed sulfur-containing flue gas and The top of the absorption tower is provided with an air outlet, the upper part of the side wall of the absorption tower is provided with an absorption liquid inlet and the bottom of the absorption tower is provided with an absorption liquid outlet; a settling tank, the settling tank and the absorption liquid outlet Connected to receive the absorption liquid output from the absorption liquid outlet and stir and settle the absorption liquid. The upper part of the settling tank is formed with a supernatant liquid outlet to overflow the settled supernatant liquid. The bottom of the settling tank is formed There is a solid-containing slurry outlet for discharging the settled slurry with a solid content of 30-50%; a slurrying tank, the slurrying tank is communicated with the settling tank to receive the supernatant overflowing from the settling tank , the top of the slurrying tank is provided with an absorbent inlet to add an absorbent containing zinc oxide, and the absorbent and the supernatant are stirred and then sent into the absorption tower; the acidizing tank, the acidizing tank and the The solid-containing slurry outlet of the settling tank is connected to receive the slurry with a solid content of 30-50%. The top of the acidification tank is provided with a waste acid solution inlet and a gas outlet, and the lower part of the side wall of the acidification tank is There is an acidification slurry outlet; a sulfur dioxide desorption tower, the sulfur dioxide desorption tower is an empty tower with a first-level spray layer, and the acidification slurry inlet on the upper side of the desorption tower is connected to the acidification tank to receive the reaction in the acidification tank. Outflowing slurry, the top of the sulfur dioxide desorption tower is provided with a sulfur dioxide outlet, the bottom is provided with a slurry outlet, and the side wall is provided with an air inlet.

According to the zinc oxide desulfurization system of the utility model, by controlling the solid content of the circulating absorption liquid in the absorption tower to not be higher than 8%, the problems of equipment blockage and scaling are obviously reduced. Lower solid content can reduce scaling and clogging of equipment and pipelines, reduce wear and improve service life. After the solid content is reduced, as long as the pH value of the absorption liquid in the absorption tower is controlled to be greater than 5.2, the absorption efficiency of _SO2 will not be affected. In addition, since the absorbent is zinc smelting calcine or electric dust, it usually does not need to be purchased from outside. The sulfur dioxide gas is sent to the acidification and the zinc sulfate slurry obtained by acidification is sent to the zinc smelting leaching system, which saves the waste in each system. The cost of raw materials is low, and there is no discharge of waste gas, waste liquid and waste solid in the whole system, achieving zero discharge and meeting the needs of environmental protection. In addition, the equipment is simple, easy to operate and maintain, and low in cost. Compared with traditional zinc oxide desulfurization, the process is short and easy to operate, and can achieve continuous operation.

In addition, the zinc oxide desulfurization system according to the utility model also has the following additional technical features:

The zinc oxide desulfurization system further includes a first scraper assembly, the first scraper assembly includes: a first scraper member, the first scraper member is rotatably arranged in the settling tank to remove the deposited Scraping off the solid matter at the bottom of the settling tank enables the solid matter to be discharged through the outlet of the solid-containing slurry; and a first driving device, the first driving device drives the first scraper member to rotate.

Wherein the settling tank comprises: a columnar section; and a conical section, the conical section is connected below the columnar section and formed in an inverted conical shape, wherein the solid-containing slurry outlet is formed in the conical section The bottom of the slurry makes it easier for the solid matter in the slurry to settle.

The zinc oxide desulfurization system further includes: a first valve, which is arranged between the solid-containing slurry outlet of the settling tank and the acidification tank to control the slurry with a solid content of 30% to 50%. traffic.

The zinc oxide desulfurization system further includes a first stirring assembly, the first stirring assembly includes: a first stirring member, the first stirring member is rotatably arranged in the slurrying tank to control the slurrying tank The absorber and the supernatant inside are stirred; and a second driving device, the second driving device drives the first stirring member to rotate.

The zinc oxide desulfurization system further includes a second stirring assembly, the second stirring assembly includes: a second stirring member, the second stirring member is rotatably arranged in the acidizing tank to adjust the temperature of the acidizing tank The solid impurities are stirred and reacted with the waste acid solution; and a third driving device drives the second stirring member to rotate. The zinc oxide desulfurization system further includes:

The first pump, the first pump is connected downstream of the absorption tower to send a part of the absorption liquid in the absorption tower into the settling tank and another part of the absorption liquid is sent to the absorption tower through the absorption liquid inlet circulation Inside; a second pump connected between the slurry tank and the absorption tower for sending fresh absorbent slurry into the absorption tower; and a third pump connected at Between the acidification tank and the sulfur dioxide desorption tower, the slurry in the acidification tank is sent to the sulfur dioxide desorption tower.

The zinc oxide desulfurization system further includes: a second valve, the second valve is arranged between the first pump and the settling tank to control the absorption liquid pumped from the absorption tower into the settling tank flow.

The zinc oxide desulfurization system further includes: a fourth pump connected to the slurry outlet after removing free sulfur dioxide in the sulfur dioxide desorption tower to send out the slurry flowing out of the sulfur dioxide desorption tower.

The absorption tower is an empty tower.

According to the zinc oxide desulfurization system of the present invention, calcined sand or zinc roasting smoke is used as an absorbent, and the final product can be returned to the wet leaching system of zinc smelting, so that no waste is discharged, and the solids contained in the absorption liquid The amount is low, which can solve the problem of pipeline and equipment blockage and scaling. In addition, compared with the traditional zinc oxide desulfurization system, the zinc oxide desulfurization system according to the embodiment of the utility model saves equipment such as oxidation fan, absorption tower side-entry agitator, filter press, etc., and no additional waste residue is generated in the desulfurization device , there is no need to arrange personnel to operate and transport slag, the power consumption, maintenance costs, and operating costs are lower, the equipment is simple, the process is short, the operation is convenient, and continuous operation can be realized. During the acidification process, the waste sulfuric acid of the whole plant can be treated Carry out comprehensive recycling, so that the overall process power consumption, operating costs, and overall investment are lower.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present utility model will become apparent and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is the schematic diagram of the zinc oxide desulfurization system according to the utility model embodiment; With

Fig. 2 is a process flow diagram of a zinc oxide desulfurization method using the zinc oxide desulfurization system shown in Fig. 1 .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, but should not be construed as limiting the present utility model.

In describing the present invention, it should be understood that the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer" etc. indicate directions or The positional relationship is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation , so it cannot be interpreted as a limitation of the present utility model. In addition, the terms "first", "second", etc. are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a flexible connection. Disassembled connection, or integral connection; it can be directly connected, or indirectly connected through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model in specific situations.

A zinc oxide desulfurization system according to an embodiment of the present invention will be described below with reference to FIG. 1 .

The zinc oxide desulfurization system according to the embodiment of the utility model includes: an absorption tower 1 , a settling tank 2 , a pulping tank 3 , an acidizing tank 4 and a sulfur dioxide desorption tower 5 . As shown in Figure 1, the absorption tower 1 is an empty tower with a reaction chamber defined inside, and the lower part of the side wall of the absorption tower 1 is provided with an air inlet 11 for feeding sulfur-containing flue gas, and the top of the absorption tower 1 is provided with an outlet. The gas port 12, the upper part of the side wall of the absorption tower 1 is provided with an absorption liquid inlet 13 and the bottom is provided with an absorption liquid outlet 14. Optionally, there are at least two absorbing liquid inlets 13 spaced apart from each other, and a plurality of absorbing liquid nozzles 15 are connected in each absorbing liquid inlet 13 so as to inject zinc oxide (ZnO) into the reaction chamber of the absorption tower 1. of the absorbent. Thus, the sulfur-containing flue gas enters the absorption tower 1 from the air inlet 11, and the absorption liquid containing zinc oxide (ZnO) enters the absorption tower 1 from the absorption liquid inlet 13 and moves downward and is combined with the sulfur-containing flue gas flowing upward. Reverse contact in the absorption tower 1 to remove sulfur from the sulfur-containing flue gas, and control the solid content of the circulating absorption liquid in the absorption tower 1 to be within 8%, and control the internal pH value of the circulating absorption liquid in the absorption tower to be greater than 5.2.

The settling tank 2 is communicated with the absorption liquid outlet 14 to receive the absorption liquid output from the absorption liquid outlet 14 and stir the sedimentation absorption liquid to obtain the supernatant and solid impurities, wherein the solid impurities contain ZnSO ₃ , unreacted ZnO and a large amount of unreacted Impurities in the absorbing liquid that participate in the reaction. Wherein the top of the settling tank 2 is formed with a supernatant outlet 21 to overflow the settled supernatant, and the bottom of the settling tank 2 is formed with a solid-containing slurry outlet for discharging the settled slurry with a solid content of 30% to 50%. twenty two.

Slurry tank 3 is communicated with settling tank 2 to receive the supernatant liquid overflowing from settling tank 2, specifically, supernatant liquid inlet 32 is provided with supernatant liquid inlet 32 to receive supernatant liquid above slurry tank 3, the slurry tank 3 The top is provided with an absorbent inlet 31 for adding an absorbent containing zinc oxide (ZnO), and the absorbent and the supernatant are stirred and slurried before being sent into the absorption tower 1 . Specifically, an absorbent outlet 33 is provided at the bottom of the pulping tank 3, and the absorbent and the supernatant are stirred and slurryed and then discharged through the absorbent outlet 33 and circulated into the absorption tower 1, so that the absorbent according to the embodiment of the present invention The zinc oxide desulfurization system does not discharge any waste solid impurities. Optionally, the zinc oxide-containing absorbent is calcine and/or soot obtained from roasting zinc concentrate, and the zinc oxide content is higher than 50%. Those of ordinary skill in the art know that zinc calcine is a product obtained after zinc concentrate is roasted, and mainly contains zinc oxide (ZnO), zinc sulfate (ZnSO ₄ ), zinc sulfide (ZnS) and the like.

The acidizing tank 4 is connected to the solid-containing slurry outlet 22 of the settling tank 2. Specifically, an impurity inlet 44 is provided on the top of the acidizing tank 4 to receive the slurry with a solid content of 30% to 50%, which contains a large amount of ZnSO ₃ , Unreacted ZnO and a large amount of solid impurities in the absorption liquid that do not participate in the reaction. The top of the acidizing tank 4 is provided with a waste acid solution inlet 41 for feeding waste sulfuric acid, which is waste acid produced in the sulfuric acid production system and mixed with soot, arsenic, mercury, fluorine, chlorine and other substances. The top of the acidification tank 4 is also provided with a gas outlet 42 for discharging sulfur dioxide gas, and the lower part of the side wall of the acidification tank 4 is provided with an acidification slurry outlet 43, whereby waste sulfuric acid and solid impurities react in the acidification tank 4 to generate SO _gas and acidified slurry containing ZnSO ₄ solution. In the acidification tank 4, the pH value and the liquid-solid ratio of the acidified slurry are adjusted so that the slurry can meet the requirements of the leaching system in the wet process, that is, the liquid-solid ratio is 8-10:1 and the pH value is 5.0-5.2.

The sulfur dioxide desorption tower 5 is connected to the acidification tank 4 and is an empty tower with a primary spray layer. Specifically, an acidification slurry inlet 54 is provided on the top of the sulfur dioxide desorption tower 5 to receive the acidification that flows out after the reaction in the acidification tank 4. Slurry, the top of the sulfur dioxide desorption tower 5 is provided with a sulfur dioxide outlet 51, the bottom is provided with a slurry outlet 52 and the side wall is provided with an air inlet 53, and the acidified slurry and air are reversely contacted in the sulfur dioxide desorption tower 5 to desorb the acidified slurry SO ₂ in the SO 2 and obtain a slurry after desorbing SO ₂ , which is sent to the leaching system. At the same time, the sulfur dioxide gas discharged from the acidizing tank 4 and the sulfur dioxide desorption tower 5 is sent into the sulfuric acid system for acid production.

According to the zinc oxide desulfurization system of the embodiment of the utility model, by controlling the solid content of the circulating absorption liquid in the absorption tower 1 to not be higher than 8%, the problems of equipment blockage and scaling are significantly reduced. Lower solid content can reduce scaling and clogging of equipment and pipelines, reduce wear and improve service life. After the solid content is reduced, as long as the pH value of the absorption liquid in the absorption tower 1 is controlled to be greater than 5.2, the _SO absorption efficiency will not be affected. In addition, since the absorbent is zinc smelting calcine or electric dust, it is usually not necessary to purchase from outside. The sulfur dioxide gas is sent to the acidification and the zinc sulfate slurry obtained by acidification is sent to the zinc smelting leaching system, which saves the waste in each system. The cost of raw materials is low, and there is no discharge of waste gas, waste liquid and waste solid in the whole system, achieving zero discharge and meeting the needs of environmental protection. In addition, the equipment is simple, easy to operate and maintain, and low in cost. Compared with traditional zinc oxide desulfurization, the process is short and easy to operate, and can achieve continuous operation.

As shown in Figure 1, according to an embodiment of the present utility model, the zinc oxide desulfurization system further includes a first scraper assembly 61, and the first scraper assembly 61 includes a first scraper member 611 and a first driving device 612, wherein the first A scraper member 611 is rotatably arranged in the settling tank 2 to scrape off the solid matter deposited on the bottom of the settling tank 2 so that the solid matter can be discharged through the solid slurry outlet 22, and the first driving device 612 drives the first scraper. The plate 611 is rotatable.

Optionally, as shown in Figure 1, the settling tank 2 includes a columnar section 20a and a conical section 20b, the conical section 20b is connected below the columnar section 20a and formed into an inverted conical shape, so that the solid content is 30%～ The solid impurities in the 50% slurry are easier to settle and discharge, wherein the solid-containing slurry outlet 22 is formed at the bottom of the conical section 20b.

In a further embodiment of the present utility model, the zinc oxide desulfurization system also includes a first valve 71, and the first valve 71 is arranged between the solid-containing slurry outlet 22 of the settling tank 2 and the acidizing tank 4 to control the solid content of 30%. ~50% of the slurry discharge flow rate from the settling tank 2, as shown in FIG. 1 .

According to an embodiment of the present utility model, the zinc oxide desulfurization system further includes a first stirring component 62 and a third stirring component 63 . The first stirring assembly 62 includes a first stirring member 621 and a second driving device 622, wherein the first stirring member 621 is rotatably arranged in the slurry tank 3 to stir the absorbent and the supernatant in the slurry tank 3 , the second driving device 622 drives the first stirring member 621 to be rotatable.

The second stirring assembly 63 includes a second stirring member 631 and a third driving device 632, wherein the second stirring member 631 is rotatably arranged in the acidizing tank 4 to treat the slurry with a solid content of 30% to 50% in the acidizing tank 4 Stir and react with the waste acid solution, the third driving device 632 drives the second stirring member 631 to rotate.

The zinc oxide desulfurization system further includes: a first pump 81, a second pump 82 and a third pump 83, the first pump 81 is connected to the downstream of the absorption tower 1 to transport a part of the absorption liquid in the absorption tower 1 into the settling tank 2 and Another part of the absorption liquid is circulated into the absorption tower 1 through the absorption liquid inlet 13, and the second pump 82 is connected between the slurry tank 3 and the absorption tower 1 for sending fresh absorbent slurry into the absorption tower 1. The pump 83 is connected between the acidification tank 4 and the sulfur dioxide desorption tower 5 for sending the slurry in the acidification tank 4 into the sulfur dioxide desorption tower 5 .

Optionally, as shown in FIG. 1 , a second valve 72 is provided between the first pump 81 and the settling tank 2 to control the flow of the absorption liquid pumped from the absorption tower 1 into the settling tank 2 .

As shown in Figure 1, the zinc oxide desulfurization system can also include a fourth pump 84, and the fourth pump 84 is connected with the slurry outlet 52 after removing free sulfur dioxide in the sulfur dioxide desorption tower 5 to flow out of the sulfur dioxide desorption tower 5 The slurry is sent to the next step, the wet leaching system.

The following describes the zinc oxide desulfurization process using the zinc oxide desulfurization system of the embodiment of the present invention with reference to FIG. 1 and FIG. 2 .

The zinc oxide desulfurization process comprises the following steps:

S1. Reversely contact the sulfur-containing flue gas with the absorption liquid containing zinc oxide in the absorption tower 1 to remove sulfur in the sulfur-containing flue gas.

S2. Transport the desulfurized absorption liquid to the settling tank 2 for settling to obtain a slurry and supernatant with a solid content of 30% to 50%, wherein the slurry with a solid content of 30% to 50% contains ZnSO ₃ , unreacted Complete ZnO and a large amount of solid impurities in the absorption liquid that do not participate in the reaction.

S3. Stirring and slurrying the supernatant and the absorbent containing zinc oxide in the slurry tank 3 and then transporting them back to the absorption tower 1. Optionally, the absorbent containing zinc oxide is roasted zinc concentrate obtained by roasting Sand and/or soot.

S4, reacting solid impurities and waste acid solution in the acidification tank 4 to generate SO ₂ and acidification slurry, the acidification slurry contains zinc sulfate ZnSO ₄ solution.

S5. Reversely contact the acidified slurry with air in the sulfur dioxide desorption tower 5 to desorb the SO ₂ in the acidified slurry and obtain the desorbed SO ₂ slurry.

S6, making acid from the _SO2 generated in step S4 and the _SO2 generated in step S5.

Wherein, the liquid-solid ratio of the slurry after desorbing _SO2 is controlled to be 8-10:1, and the pH value is controlled to be 5.0-5.2 for wet leaching, for example, by controlling the acidified slurry in the acidified tank in step S4 The liquid-solid ratio and pH value of the slurry are controlled to achieve a liquid-solid ratio of 8-10:1 and a pH value of 5.0-5.2 after desorbing SO ₂ .

In step S1, the solid content of the absorption liquid is controlled not to be higher than 8%, so that the content of ZnSO ₃ can be reduced, thereby significantly reducing equipment blockage and fouling problems. Lower solid content can reduce scaling and clogging of equipment and pipelines, reduce wear and improve service life. Further, after the solid content is reduced in step S1, the pH value of the absorption liquid is controlled to be greater than 5.2, which will not affect the absorption efficiency of SO ₂ .

Optionally, the sulfur-containing flue gas is transported into the absorption tower from the lower part of the absorption tower and the absorption liquid containing zinc oxide is transported into the absorption tower from the upper part of the absorption tower. Wherein, the absorption solution containing zinc oxide is obtained by mixing calcined sand and/or dust obtained by roasting zinc concentrate and water.

In some examples of the present invention, both the absorption tower 1 and the sulfur dioxide desorption tower 5 are empty towers, with simple equipment, easy operation and maintenance, and low cost.

The following describes the desulfurization process of the zinc oxide desulfurization system according to the embodiment of the present invention with reference to FIG. 1 and FIG. 2 .

The sulfur-containing flue gas enters the absorption tower 1 from the air inlet 11, and the absorption liquid containing zinc oxide (ZnO) enters the absorption tower 1 from the absorption liquid inlet 13 and moves downward and flows with the upward-flowing sulfur-containing flue gas in the absorption tower. Reverse contact in 1, the absorption liquid absorbs the sulfur dioxide in the sulfur-containing flue gas and reacts with zinc oxide (ZnO) to generate ZnSO ₃ or zinc bisulfite Zn(HSO ₃ ) ₂ , in order to prevent the scaling problem of ZnSO ₃ , control the absorption The solid content of the circulating absorption liquid in the tower 1 is such that the solid content is not higher than 8%, and the internal pH value of the circulating absorption liquid in the control absorption tower is greater than 5.2. After the reaction is complete, the absorption liquid is discharged from the absorption tower 1 from the absorption liquid outlet 14, and part of the absorption liquid is sent into the settling tank 2 through the first pump 81 for stirring and sedimentation, and the other part is recirculated and absorbed into the absorption tower 1 through the absorption liquid inlet 13 Inside.

A part of the absorption liquid sent to the settling tank 2, through the stirring and settling action of the first stirring assembly 61, ZnSO ₃ , unreacted ZnO and a large amount of calcined impurities that do not participate in the reaction are settled together, and the bottom flow of the settling tank 2 The solid content is controlled at 30-50%, so that the slurry with a solid content of 30%-50% can flow into the acidification tank 4 through the outlet 22 of the solid-containing slurry, and the supernatant through the supernatant outlet 22 of the settling tank 2 Flow out and flow into the slurry tank 3 through the supernatant inlet of the slurry tank 3 .

The absorbent containing zinc oxide (ZnO) is input to the absorbent inlet 31 of the slurry tank 3 through a feeding system (not shown) and then added to the slurry tank 3, and the absorbent and the supernatant in the slurry tank 3 After stirring and slurrying, it is sent to the absorption tower 1 by the second pump 82 to form a circulating absorption liquid.

The slurry with a solid content of 30% to 50% containing a large amount of solid impurities such as ZnSO ₃ and ZnO flowing out from the solid-containing slurry outlet 22 of the settling tank 2 enters the acidification tank 4 and is mixed with smoke, arsenic, mercury, fluorine, and chlorine. The waste sulfuric acid of other substances enters the acidizing tank 4 through the waste acid solution inlet 41, and the solid impurities react with the waste sulfuric acid to generate SO ₂ and a slurry containing ZnSO ₄ solution, wherein the third stirring component 63 stirs to accelerate the reaction. Adjust the pH value and liquid-solid ratio of the acidified slurry in the acidification tank 4, so that the final slurry can meet the requirements of the leaching system in the wet process, that is, the liquid-solid ratio is 8-10:1, and the pH value is 5.0-5.2.

The acidification slurry discharged from the acidification slurry outlet 43 of the acidification tank 4 enters in the sulfur dioxide desorption tower 5 through the acidification slurry inlet 54, and the air enters in the sulfur dioxide desorption tower 5 from the air inlet 53, thus the acidification slurry and air enter the sulfur dioxide desorption tower 5 The reverse contact in the absorption tower 5 is used to desorb _SO2 in the acidified slurry and obtain the desorbed _SO2 slurry, which is sent to the leaching system. At the same time, the sulfur dioxide gas discharged from the acidizing tank 4 and the sulfur dioxide desorption tower 5 is sent into the sulfuric acid system for acid production.

According to the zinc oxide desulfurization system of the embodiment of the present invention, calcined sand or zinc roasting smoke is used as an absorbent, and the final product can be returned to the wet leaching system of zinc smelting, so that no waste is discharged, and the absorption liquid With low solid content, it can solve the problem of pipeline and equipment blockage and scaling. In addition, compared with the traditional zinc oxide desulfurization system, the zinc oxide desulfurization system according to the embodiment of the utility model saves equipment such as oxidation fan, absorption tower side-entry agitator, filter press, etc., and no additional waste residue is generated in the desulfurization device , there is no need to arrange personnel to operate and transport slag, the power consumption, maintenance costs, and operating costs are lower, the equipment is simple, the process is short, the operation is convenient, and continuous operation can be realized. During the acidification process, the waste sulfuric acid of the whole plant can be treated Carry out comprehensive recycling, so that the overall process power consumption, operating costs, and overall investment are lower.

In the description of this specification, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific examples," or "some examples" are intended to mean that the implementation Specific features, structures, materials or characteristics described in an embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications, the scope of the present invention is defined by the claims and their equivalents.

Claims (10)

1. A zinc oxide desulfurization system, characterized in that, comprising: An absorption tower, the reaction chamber is defined inside the absorption tower, and the lower part of the side wall of the absorption tower is provided with an air inlet to send in sulfur-containing flue gas and the top of the absorption tower is provided with a gas outlet, the absorption tower The upper part of the side wall of the tower is provided with an absorption liquid inlet and the bottom of the absorption tower is provided with an absorption liquid outlet; A settling tank, the settling tank is communicated with the absorption liquid outlet to receive the absorption liquid output from the absorption liquid outlet and stir and settle the absorption liquid, the upper part of the settling tank is formed with a supernatant liquid outlet for the settled The supernatant overflows, and the bottom of the settling tank is formed with a solid-containing slurry outlet for discharging the settled slurry with a solid content of 30% to 50%; A slurrying tank, the slurrying tank is communicated with the settling tank to receive the supernatant overflowing from the settling tank, the top of the slurrying tank is provided with an absorbent inlet to add an absorbent containing zinc oxide, The absorbent is stirred with the supernatant and sent into the absorption tower; Acidification tank, the acidification tank is connected with the solid-containing slurry outlet of the settling tank to receive the slurry with a solid content of 30% to 50%, the top of the acidification tank is provided with a waste acid solution inlet and a gas outlet, and The lower part of the side wall of the acidizing tank is provided with an acidizing slurry outlet; Sulfur dioxide desorption tower, the sulfur dioxide desorption tower is an empty tower with a primary spray layer, the upper side of the desorption tower has an acidification slurry inlet connected to the acidification tank to receive the slurry flowing out after the reaction in the acidification tank, the said The top of the sulfur dioxide desorption tower is provided with a sulfur dioxide outlet, the bottom is provided with a slurry outlet, and the side wall is provided with an air inlet. 2. The zinc oxide desulfurization system according to claim 1, further comprising a first scraper assembly, the first scraper assembly comprising: a first scraper member, the first scraper member is rotatably arranged in the settling tank to scrape off the solid matter deposited on the bottom of the settling tank so that the solid matter can be discharged through the outlet of the solid-containing slurry; and A first driving device, the first driving device drives the first scraper to rotate. 3. The zinc oxide desulfurization system according to claim 2, wherein the settling tank comprises: columnar segment; and a conical section, the conical section is connected below the columnar section and formed in an inverted conical shape, wherein the solid-containing slurry outlet is formed at the bottom of the conical section. 4. The zinc oxide desulfurization system according to claim 1, further comprising: The first valve is arranged between the solid-containing slurry outlet of the settling tank and the acidification tank to control the flow of the slurry with a solid content of 30% to 50%. 5. The zinc oxide desulfurization system according to claim 2, further comprising a first stirring assembly, said first stirring assembly comprising: a first stirring member, the first stirring member is rotatably arranged in the slurry tank to stir the absorbent and the supernatant in the slurry tank; and A second driving device, the second driving device drives the first stirring member to be rotatable. 6. The zinc oxide desulfurization system according to claim 5, further comprising a second stirring assembly, the second stirring assembly comprising: a second stirring member, the second stirring member is rotatably arranged in the acidification tank to stir and react the solid impurities in the acidification tank with the spent acid solution; and A third driving device, the third driving device drives the second stirring member to be rotatable. 7. The zinc oxide desulfurization system according to claim 1, further comprising: The first pump, the first pump is connected downstream of the absorption tower to send a part of the absorption liquid in the absorption tower into the settling tank and another part of the absorption liquid is sent to the absorption tower through the absorption liquid inlet circulation Inside; a second pump connected between the slurrying tank and the absorption tower for sending fresh absorbent slurry into the absorption tower; and The third pump, the third pump is connected between the acidification tank and the sulfur dioxide desorption tower, and is used to send the slurry in the acidification tank to the sulfur dioxide desorption tower. 8. The zinc oxide desulfurization system according to claim 7, further comprising: A second valve, the second valve is arranged between the first pump and the settling tank. 9. The zinc oxide desulfurization system according to claim 7, further comprising: The fourth pump, the fourth pump is connected to the slurry outlet after removing free sulfur dioxide in the sulfur dioxide desorption tower to send out the slurry flowing out of the sulfur dioxide desorption tower. 10. The zinc oxide desulfurization system according to any one of claims 1-9, characterized in that the absorption tower is an empty tower.

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