Gold smelting waste gas treatment system
By designing a gold smelting waste gas treatment system, using catalytic oxidation and urea absorption technology to treat nitrogen oxides, and combining alkaline solution absorption and reverse nozzle structure to treat chlorine-containing waste gas and acid mist, the problem of waste gas being difficult to meet emission standards during the gold smelting process was solved, and an efficient and pollution-free waste gas treatment effect was achieved.
Patent Information
- Application Number
- CN202422077445.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-26
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-08-26
AI Technical Summary
During the gold smelting process, waste gases such as nitrogen oxides, chlorine-containing waste gas and acid mist are difficult to discharge in compliance with emission standards. In particular, the difficulty in treating high-concentration nitrogen oxides (NO) and chlorine lies in their low stability and absorption efficiency.
A gold smelting waste gas treatment system was designed, including nitrogen oxide and chlorine-containing waste gas treatment modules. Catalytic oxidation and urea absorption technologies were used to treat nitrogen oxides, and efficient removal was achieved through a multi-stage absorption tower and a urea circulation pump. For chlorine-containing waste gas and acid mist, an alkaline solution absorption and a washing tower with a reverse nozzle structure were used to achieve high-speed reverse contact between the gas and liquid phases to improve absorption efficiency.
It achieves efficient removal of waste gases such as nitrogen oxides, chlorine and acid mist generated during the gold smelting process, and achieves standard emissions of sulfur dioxide, hydrochloric acid mist, nitrogen oxides and chlorine, with high absorption efficiency and no secondary pollution.
Smart Images
Figure CN223324330U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of waste gas treatment, and in particular relates to a gold smelting waste gas treatment system. Background Art
[0002] In newly built gold production lines, renovated and expanded silver anode mud production lines, and silver electrolysis production lines, the instantaneous concentration of nitrogen oxides generated during the aqua regia dissolution of gold and the nitric acid dissolution of silver powder are high and difficult to treat. The flue gas generated during the sodium chlorate separation of silver anode mud is primarily chlorine-containing waste gas and acid mist. The reduction of the aqua regia solution and the chloride separation solution for these two materials also produces a certain amount of sulfur dioxide and acid mist. Therefore, it is necessary to design, manufacture, and install a nitrogen oxide and chlorine-containing waste gas absorption system to primarily treat the nitrogen oxides generated by the aqua regia dissolution of the gold production line, the chlorine-containing waste gas and acid mist generated by the silver anode mud production line, and the nitrogen oxides generated during the silver electrolysis liquid preparation process, thereby achieving standard emission of waste gas. Utility Model Content
[0003] In view of this, the technical problem to be solved by the present invention is to provide a gold smelting waste gas treatment system to effectively treat the waste gas generated in the gold smelting process so that it meets the emission standards.
[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:
[0005] The gold smelting waste gas treatment system includes: a nitrogen oxide waste gas treatment module and a chlorine-containing waste gas and acid mist waste gas treatment module. The nitrogen oxide waste gas treatment module includes: a catalytic unit, a nitrogen oxide waste gas absorption unit, a urea circulation unit, a first cooling unit and a urea supply unit. The air inlet of the catalytic unit is connected to the nitrogen oxide waste gas, and the air outlet of the catalytic unit is connected to the nitrogen oxide waste gas absorption unit. The nitrogen oxide waste gas absorption unit is connected to the urea absorption liquid tank through a liquid circulation pipeline. The urea supply unit and the first cooling unit are respectively connected to the urea absorption liquid tank. The air outlet of the nitrogen oxide waste gas absorption unit is connected to the first induced draft fan, and the chlorine-containing waste gas and acid mist waste gas treatment module includes: a chlorine-containing waste gas and acid mist waste gas absorption unit, an alkali solution circulation unit, a second cooling unit and an alkali solution supply unit. The chlorine-containing waste gas and acid mist waste gas absorption unit is connected to the alkali solution storage tank, and the second cooling unit and the alkali solution supply unit are respectively connected to the alkali solution storage tank. The air inlet of the chlorine-containing waste gas and acid mist waste gas absorption unit is respectively connected to the chlorine-containing waste gas and acid mist waste gas, and the air outlet of the first induced draft fan, and the air outlet of the chlorine-containing waste gas and acid mist waste gas absorption unit is connected to the second induced draft fan.
[0006] Optionally, the nitrogen oxide waste gas absorption unit includes: a first-stage absorption tower connected to the air outlet of the catalytic unit, the air outlet of the first-stage absorption tower is connected to the air inlet of the second-stage absorption tower, the air outlet of the second-stage absorption tower is connected to the air inlet of the third-stage absorption tower, and the air outlet of the third-stage absorption tower is connected to the first induced draft fan.
[0007] Optionally, the catalytic unit includes a catalytic reactor, in which a NO catalytic oxidant is arranged.
[0008] Optionally, the urea circulation unit includes: a first urea circulation pump connected to the primary absorption tower, a second urea circulation pump connected to the secondary absorption tower, and a third urea circulation pump connected to the tertiary absorption tower, and the first urea circulation pump, the second urea circulation pump and the third urea circulation pump are respectively connected to the urea absorption liquid tank.
[0009] Optionally, the chlorine-containing waste gas and acid mist waste gas absorption unit includes: a first-level feed pipe connected to the chlorine-containing waste gas and acid mist waste gas, the air outlet of the first induced draft fan is connected to the first-level feed pipe, the air outlet of the first-level feed pipe is connected to the air inlet of a first-level washing tower, the air outlet of the first-level washing tower is connected to the air inlet of a second-level feed pipe, the air outlet of the second-level feed pipe is connected to a second-level washing tower, and the air outlet of the second-level washing tower is connected to a second induced draft fan.
[0010] Optionally, the alkali liquid circulation unit includes: a first alkali liquid circulation pump connected to the primary washing tower, and a second alkali liquid circulation pump connected to the secondary washing tower, and the first alkali liquid circulation pump and the second alkali liquid circulation pump are respectively connected to the alkali liquid storage tank.
[0011] Optionally, the first-level feed pipe includes: an air inlet end, a convergent pipe connected to the air inlet end, an equal-diameter throat connected to the convergent pipe, a divergent pipe connected to the equal-diameter throat, and an equal-diameter connecting pipe connected to the divergent pipe, a nozzle is arranged in the equal-diameter connecting pipe, and the nozzle is facing the air inlet end.
[0012] Optionally, the structure of the secondary feed pipe is the same as that of the primary feed pipe.
[0013] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0014] The utility model provides a gold smelting waste gas treatment system based on the above technical solution, wherein the gold smelting waste gas mainly includes nitrogen oxides generated during the dissolution of gold alloy in aqua regia and the dissolution of silver powder in nitric acid, and chlorine-containing waste gas and acid mist generated during the gold separation process of silver anode mud with sodium chlorate. Through the treatment of this system, the emission of sulfur dioxide, hydrochloric acid mist, nitrogen oxides and chlorine gas that meet the standards can be achieved.
[0015] Among high concentrations of nitrogen oxides, NO is more difficult to remove than NO2 which is easily soluble in water due to its relatively stable nature. x During the treatment process, the key difficulty is to deal with NO. In this utility model, the high-concentration nitrogen oxide waste gas collected through the pipeline first enters the primary absorption tower and then the secondary absorption tower and the tertiary absorption tower in sequence. The primary absorption tower is an oxidation absorption tower, which uses a catalytic oxidant to oxidize NO in the waste gas into NO2 to improve the absorption efficiency. Then, it passes through the secondary and tertiary absorption towers, using urea as the absorption liquid to absorb NO in the waste gas. x The reaction removes it.
[0016] After absorption treatment, nitrogen oxide waste gas is mixed with acid mist, sulfur dioxide, and chlorine waste gas before entering the chlorine-containing waste gas and acid mist treatment module. The mixed waste gas first enters the primary feed pipe, where absorption liquid is injected into the airflow from bottom to top through a specially designed nozzle. This causes the gas and liquid phases to collide at high speeds in opposite directions. When the momentum of the two phases reaches equilibrium, a highly turbulent foam zone forms. Within this zone, the gas and liquid phases engage in high-speed turbulent contact, creating a large contact surface area that is constantly and rapidly renewed, achieving efficient absorption. The waste gas then enters the primary scrubber. The interaction of various forces, including the upward force of the high-speed airflow, the buoyancy of the liquid, and its own gravity, suspends the packing within the tower, creating turbulent rotation and collisions. This creates close contact between the gas and liquid, further promoting mass transfer and absorption. The waste gas is treated in a two-stage system and ultimately meets emission standards.
[0017] The treatment system of the utility model integrates a variety of treatment processes according to the characteristics of the waste gas generated by the project, selects and combines appropriate treatment units, so that the system has high absorption efficiency for each waste gas, stable operation, and does not generate secondary pollution. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 : A structural diagram of a gold smelting waste gas treatment system according to the present invention;
[0020] Figure 2 : Schematic diagram of the structure of the nitrogen oxide waste gas treatment module of the utility model;
[0021] Figure 3 : Schematic diagram of the structure of the first-level feed pipe / secondary feed pipe of the utility model;
[0022] Among them, 1. catalytic unit; 2. primary absorption tower; 3. secondary absorption tower; 4. tertiary absorption tower; 5. first induced draft fan; 6. first urea circulation pump; 7. second urea circulation pump; 8. third urea circulation pump; 9. primary feed pipe; 901. air inlet end; 902. convergent pipe; 903. equal-diameter throat pipe; 904. divergent pipe; 905. equal-diameter connecting pipe; 906. nozzle; 10. primary washing tower; 11. secondary feed pipe; 12. secondary washing tower; 13. second induced draft fan; 14. first alkali solution circulation pump; 15. second alkali solution circulation pump; 16. first cooling unit; 17. urea supply unit; 18. urea absorption liquid tank. DETAILED DESCRIPTION
[0023] To better understand the present invention, the following examples further illustrate the present invention. However, the present invention is not limited to the following examples. In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be practiced without one or more of these details.
[0024] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.
[0025] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and are not to be construed as limiting the present invention.
[0026] like Figure 1-3As shown, the gold smelting waste gas treatment system includes: a nitrogen oxide waste gas treatment module and a chlorine-containing waste gas and acid mist waste gas treatment module. The nitrogen oxide waste gas treatment module includes: a catalytic unit 1, a nitrogen oxide waste gas absorption unit, a urea circulation unit, a first cooling unit 16 and a urea supply unit 17. The air inlet of the catalytic unit 1 is connected to the nitrogen oxide waste gas, and the air outlet of the catalytic unit 1 is connected to the nitrogen oxide waste gas absorption unit. The nitrogen oxide waste gas absorption unit is connected to the urea absorption liquid tank 18 through a liquid circulation pipeline. The urea supply unit 17 and the first cooling unit 16 are respectively connected to the urea absorption liquid tank 18. The chlorine-containing waste gas and acid mist waste gas absorption unit is connected to the alkali storage tank, and the second cooling unit and the alkali supply unit are respectively connected to the alkali storage tank. The air inlet of the chlorine-containing waste gas and acid mist waste gas absorption unit is respectively connected to the chlorine-containing waste gas and acid mist waste gas, and the air outlet of the first induced draft fan 5, and the air outlet of the chlorine-containing waste gas and acid mist waste gas absorption unit is connected to the second induced draft fan 13.
[0027] like Figure 2 As shown, the nitrogen oxide waste gas absorption unit includes: a primary absorption tower 2 connected to the air outlet of the catalytic unit 1, the air outlet of the primary absorption tower 2 is connected to the air inlet of the secondary absorption tower 3, the air outlet of the secondary absorption tower 3 is connected to the air inlet of the tertiary absorption tower 4, and the air outlet of the tertiary absorption tower 4 is connected to the first induced draft fan 5 for treating nitrogen oxides.
[0028] The catalytic unit 1 includes a catalytic reactor in which a NO catalytic oxidant is arranged.
[0029] The urea circulation unit includes: a first urea circulation pump 6 connected to the primary absorption tower 2, a second urea circulation pump 7 connected to the secondary absorption tower 3, and a third urea circulation pump 8 connected to the tertiary absorption tower 4. The first urea circulation pump 6, the second urea circulation pump 7 and the third urea circulation pump 8 are respectively connected to the urea absorption liquid tank 18 to realize the recycling of urea solution.
[0030] The first cooling unit 16 includes a first cooling device for cooling the urea solution in the urea absorption tank 18 .
[0031] The urea supply unit 17 includes a urea preparation device for preparing urea to achieve continuous supply of urea.
[0032] Urea absorbs NO x The following reactions mainly occur:
[0033]
[0034]
[0035]
[0036]
[0037]
[0038]
[0039]
[0040]
[0041] Urea absorbs NO x The reaction process has no secondary pollution and is low in price. It can achieve good results in treating high-concentration nitrogen oxides and has good application prospects. However, its effect on NO x There are certain requirements for the oxidation degree of NO. If the oxidation degree is low, the removal effect is poor. For this reason, this system uses gaseous conditions to remove NO. x Using a hierarchical oxidation absorption method to treat NO x , oxidize and absorb it at high concentrations, along with NO x When the NO concentration is getting lower and lower, the NO x The residence time with the oxidant increases the NO x The oxidation degree of NO is then absorbed and graded. x Absorption treatment is carried out, and finally NO x Achieve standard emissions.
[0042] like Figure 1 As shown, the chlorine-containing waste gas and acid mist waste gas absorption unit includes: a first-level feed pipe 9 connected to the chlorine-containing waste gas and acid mist waste gas, the air outlet of the first induced draft fan 5 is connected to the first-level feed pipe 9, the air outlet of the first-level feed pipe 9 is connected to the air inlet of the first-level washing tower 10, the air outlet of the first-level washing tower 10 is connected to the air inlet of the second-level feed pipe 11, the air outlet of the second-level feed pipe 11 is connected to the second-level washing tower 12, and the air outlet of the second-level washing tower 12 is connected to the second induced draft fan 13, which is used to treat chlorine-containing waste gas and acid mist waste gas.
[0043] The alkali liquid circulation unit includes: a first alkali liquid circulation pump 14 connected to the primary washing tower 10, and a second alkali liquid circulation pump 15 connected to the secondary washing tower 12. The first alkali liquid circulation pump 14 and the second alkali liquid circulation pump 15 are respectively connected to the alkali liquid storage tank for realizing the recycling of the alkali liquid.
[0044] The second cooling unit includes: a second cooling device for cooling the alkali solution in the alkali solution storage tank.
[0045] The alkali solution supply unit includes: an alkali solution preparation device for preparing alkali solution, such as sodium hydroxide, to achieve continuous supply of alkali solution.
[0046] Principle of alkali absorption reaction:
[0047] Cl2 + 2NaOH = NaCl + NaClO 2+ H2O (cold water)
[0048] 6NaOH+3Cl2=5NaCl+3NaClO2+3H2O (hot water>70℃)
[0049] 2NaOH+SO2=NaSO3+H2O
[0050] NaOH + HCl = NaCl + H2O
[0051] like Figure 3 As shown, the first-level feed pipe 9 includes: an air inlet end 901, a convergent pipe 902 connected to the air inlet end 901, an equal-diameter throat pipe 903 connected to the convergent pipe 902, a divergent pipe 904 connected to the equal-diameter throat pipe 903, and an equal-diameter connecting pipe 905 connected to the divergent pipe 904. A nozzle 906 is arranged in the equal-diameter connecting pipe 905, and the nozzle 906 faces the air inlet end 901. The structure of the second-level feed pipe 11 is the same as that of the first-level feed pipe 9. After the exhaust gas enters the convergent tube 902 from the air inlet end 901, the cross-section through which the airflow passes gradually decreases, accelerating the airflow. The absorption liquid is sprayed upward through the atomizing nozzle 906 near the divergent tube 904, where it collides and condenses with the high-speed airflow at the constant-diameter throat 903. When the soda enters the divergent tube 904, the cross-section gradually expands, slowing the airflow. At this point, the airflow and the absorption liquid may collide and condense again. The gas-liquid mixture, after contact reaction in the primary feed pipe 9, enters the primary scrubber 10. After treatment in the primary scrubber 10, the exhaust gas enters the secondary feed pipe 11, where it enters the secondary scrubber 12 after gas-liquid mixing, and is further treated to meet emission standards.
[0052] This treatment system is used for a newly built gold alloy production line, a renovated and expanded silver anode mud production line and a silver electrolysis production line. The main parameters of high-concentration nitrogen oxides, chlorine, acid mist and sulfur dioxide waste gas in this production line are as follows:
[0053] (1) High concentration nitrogen oxide waste gas treatment volume: 3000m 3 / h, exhaust gas temperature: ≤80℃, average concentration 10000mg / m 3 . Absorbent: urea.
[0054] (2) Hydrochloric acid mist and sulfur dioxide waste gas treatment volume: 12000m 3 / h, exhaust gas temperature: ≤80℃, average concentration 1200mg / m3 . Absorbent: liquid alkali.
[0055] (3) Chlorine waste gas treatment volume: 9000m 3 / h, exhaust gas temperature: ≤80℃, average concentration 2500mg / m 3 . Absorbent: liquid alkali.
[0056] After being treated by this system, the emission concentrations of various waste gases are as follows:
[0057] (1) Sulfur dioxide emission concentration: <100mg / m 3 ;
[0058] (2) Hydrochloric acid mist emission concentration: <40mg / m 3 .
[0059] (3) Nitrogen oxide emission concentration: <150mg / m 3 .
[0060] (4) Chlorine emission concentration: <60mg / m 3 .
[0061] (5) No color gas comes out from the exhaust port.
[0062] It can be seen that after adopting this treatment system, the treatment efficiency of hydrochloric acid mist can reach 96.7%, the treatment efficiency of sulfur dioxide can reach 91.7%, the treatment efficiency of nitrogen oxides can reach 98.5%, and the treatment efficiency of chlorine can reach 97.6%. The comprehensive treatment effect is significant.
[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not limiting. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.
[0064] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. Gold smelting waste gas treatment system, characterized by: include: A nitrogen oxide waste gas treatment module and a chlorine-containing waste gas and acid mist waste gas treatment module, wherein the nitrogen oxide waste gas treatment module comprises: a catalytic unit, a nitrogen oxide waste gas absorption unit, a urea circulation unit, a first cooling unit and a urea supply unit, wherein the air inlet of the catalytic unit is connected to the nitrogen oxide waste gas, the air outlet of the catalytic unit is connected to the nitrogen oxide waste gas absorption unit, the nitrogen oxide waste gas absorption unit is connected to the urea absorption liquid tank through a liquid circulation pipeline, the urea supply unit and the first cooling unit are respectively connected to the urea absorption liquid tank, and the nitrogen oxide waste gas The air outlet of the absorption unit is connected to the first induced draft fan. The chlorine-containing waste gas and acid mist waste gas treatment module includes: a chlorine-containing waste gas and acid mist waste gas absorption unit, an alkali solution circulation unit, a second cooling unit and an alkali solution supply unit. The chlorine-containing waste gas and acid mist waste gas absorption unit is connected to the alkali solution storage tank, and the second cooling unit and the alkali solution supply unit are respectively connected to the alkali solution storage tank. The air inlet of the chlorine-containing waste gas and acid mist waste gas absorption unit is respectively connected to the chlorine-containing waste gas and acid mist waste gas, and the air outlet of the first induced draft fan, and the air outlet of the chlorine-containing waste gas and acid mist waste gas absorption unit is connected to the second induced draft fan.
2. The gold smelting waste gas treatment system according to claim 1, characterized in that: The nitrogen oxide waste gas absorption unit includes: a primary absorption tower connected to the air outlet of the catalytic unit, the air outlet of the primary absorption tower is connected to the air inlet of the secondary absorption tower, the air outlet of the secondary absorption tower is connected to the air inlet of the tertiary absorption tower, and the air outlet of the tertiary absorption tower is connected to a first induced draft fan.
3. The gold smelting waste gas treatment system according to claim 2, characterized in that: The catalytic unit includes a catalytic reactor, in which a NO catalytic oxidant is arranged.
4. The gold smelting waste gas treatment system according to claim 3, characterized in that: The urea circulation unit includes: a first urea circulation pump connected to the primary absorption tower, a second urea circulation pump connected to the secondary absorption tower, and a third urea circulation pump connected to the tertiary absorption tower. The first urea circulation pump, the second urea circulation pump and the third urea circulation pump are respectively connected to the urea absorption liquid tank.
5. The gold smelting waste gas treatment system according to claim 4, characterized in that: The chlorine-containing waste gas and acid mist waste gas absorption unit includes: a first-level feed pipe connected to the chlorine-containing waste gas and the acid mist waste gas, the air outlet of the first induced draft fan is connected to the first-level feed pipe, the air outlet of the first-level feed pipe is connected to the air inlet of the first-level washing tower, the air outlet of the first-level washing tower is connected to the air inlet of the second-level feed pipe, the air outlet of the second-level feed pipe is connected to the second-level washing tower, and the air outlet of the second-level washing tower is connected to the second induced draft fan.
6. The gold smelting waste gas treatment system according to claim 5, characterized in that: The alkali liquid circulation unit includes: a first alkali liquid circulation pump connected to the primary washing tower, and a second alkali liquid circulation pump connected to the secondary washing tower. The first alkali liquid circulation pump and the second alkali liquid circulation pump are respectively connected to the alkali liquid storage tank.
7. The gold smelting waste gas treatment system according to claim 6, characterized in that: The first-level feed pipe includes: an air inlet end, a convergent pipe connected to the air inlet end, an equal-diameter throat connected to the convergent pipe, an expander pipe connected to the equal-diameter throat, and an equal-diameter connecting pipe connected to the expander pipe. A nozzle is arranged in the equal-diameter connecting pipe, and the nozzle faces the air inlet end.
8. The gold smelting waste gas treatment system according to claim 7, characterized in that: The structure of the secondary feed pipe is the same as that of the primary feed pipe.