Nickel-cobalt smelting waste sulfuric acid concentration and fluorine and chlorine removal system

Abstract

The utility model discloses a system for concentrating and removing fluorine and chlorine from nickel-cobalt smelting waste sulfuric acid. The system comprises a preheating system, an evaporation concentration system, a desorption tower, an absorption tower and a vacuum system. According to the device, the waste dilute sulfuric acid can be subjected to concentration and defluorination rate operation, the treated sulfuric acid is high in concentration, the fluorine and chlorine recovery rate is high, and fluorine and chlorine separation can be completed in one step; in addition, the device is reasonable in design, energy-saving and environment-friendly in treatment process.

Description

TECHNICAL FIELD

[0001] The utility model relates to a waste sulfuric acid recovery treatment system, especially a nickel cobalt smelting waste sulfuric acid concentration defluorination and chlorine removal system. BACKGROUND

[0002] Cobalt nickel hydrometallurgy is usually composed of three steps of acid leaching dissolution, extraction impurity removal and cobalt nickel separation, and a large amount of dilute sulfuric acid with a concentration of 5-15% is produced in the production process, the concentration of F in the dilute sulfuric acid is 0.5-5g / L, the concentration of Cl is 0.5-12g / L, and the concentration of arsenic ion is 0.5-1g / L, and the concentration of other metal ions is 20-100mg / L (Zn, Fe, Ca, etc.).

[0003] Therefore, the waste sulfuric acid produced by cobalt nickel hydrometallurgy has great harmfulness, and the treatment cost is high, which has always been a big problem for cobalt nickel smelting enterprises.

[0004] Chinese patent CN108083231A introduces a method for separating hydrofluoric acid from fluorine-containing sulfuric acid, which is to continuously pass steam into the fluorine-containing sulfuric acid kettle, and the final residue in the kettle is fluorine-free sulfuric acid, and the generated gas is cooled to obtain hydrofluoric acid without sulfuric acid. Although this method can separate hydrofluoric acid, it has the following disadvantages: high treatment cost, high energy consumption, low concentration of produced sulfuric acid, low actual defluorination rate, and ineffective separation of chloride ions.

[0005] In order to improve the economy of waste sulfuric acid defluorination concentration, reduce the waste of sulfuric acid resources and fluorine-chlorine resources, and reduce the energy consumption of sulfuric acid defluorination concentration, it is necessary to improve the sulfuric acid defluorination concentration system. UTILITY MODEL CONTENT

[0006] In order to solve the above technical problems, the utility model provides a nickel cobalt smelting waste sulfuric acid concentration defluorination and chlorine removal system. The utility model can concentrate and defluorinate the waste dilute sulfuric acid, and the treated sulfuric acid has high concentration, high fluorine-chlorine recovery rate, and can separate fluorine and chlorine in one step. In addition, the utility model is reasonable in design, energy-saving and environmentally friendly in treatment process.

[0007] The technical scheme of the utility model comprises the following steps:

[0008] The application provides a nickel-cobalt smelting waste sulfuric acid concentration defluorination and dechlorination system.

[0009] The system of the application is a matching device for realizing the aforementioned process.

[0010] Preferably, the nickel-cobalt smelting waste sulfuric acid concentration defluorination and dechlorination system comprises a first-stage preheater and a second-stage preheater connected in series.

[0011] The preheating system of the application is composed of a first-stage preheater and a second-stage preheater connected in series.

[0012] Preferably, the nickel-cobalt smelting waste sulfuric acid concentration defluorination and dechlorination system comprises a first-stage preheater and a second-stage preheater connected in series.

[0013] The three groups of evaporation concentrators are connected in series to form the evaporation concentration system.

[0014] Preferably, the nickel-cobalt smelting waste sulfuric acid concentration defluorination and dechlorination system, the one-effect evaporation concentrator comprises a one-effect heater and a one-effect separation chamber; the two-effect evaporation concentrator comprises a two-effect heater and a two-effect separation chamber; the three-effect evaporation concentrator comprises a three-effect heater and a three-effect separation chamber respectively; the exhaust end of the one-effect separation chamber is connected with the service-side gas inlet of the two-effect heater, the exhaust end of the two-effect separation chamber is connected with the service-side gas inlet of the three-effect heater, and the exhaust end of the three-effect separation chamber is connected with the absorption tower.

[0015] The present scheme is more reasonable in design, more energy-saving, and lower in cost by taking the secondary steam of the separation chamber of the previous stage as the heat source of the heater of the next stage.

[0016] Preferably, the nickel-cobalt smelting waste sulfuric acid concentration defluorination and dechlorination system, the one-effect evaporation concentrator, the two-effect evaporation concentrator and the three-effect evaporation concentrator are all of forced circulation evaporation structure.

[0017] The evaporation concentrator of the present scheme is of forced circulation evaporation, and the effect of evaporation concentration can be further improved, and the concentration of sulfuric acid is higher.

[0018] Preferably, the nickel-cobalt smelting waste sulfuric acid concentration defluorination and dechlorination system, a condenser is arranged between the exhaust end of the three-effect separation chamber and the absorption tower, the service side of the condenser is provided with a condensed water upper water inlet and a condensed water lower water inlet, a waste water collecting tank is connected to the liquid discharge end of the condenser, and a waste water discharge pipe is arranged on the waste water collecting tank; the waste water collecting tank is connected with the service-side liquid discharge ports of the two-effect heater and the three-effect heater.

[0019] The present scheme is reasonable in design and environmentally friendly by arranging the condenser to condense the secondary steam of the evaporation concentration system and collecting the waste water in the condenser and the waste water in the two-effect heater and the three-effect heater by the waste water collecting tank.

[0020] The present scheme has the following beneficial effects:

[0021] 1. The system can realize concentration and defluorination and dechlorination of waste dilute sulfuric acid, and can respectively extract concentrated sulfuric acid, calcium fluoride and calcium chloride, and is reasonable in design and can be implemented in industrialization.

[0022] 2. The preheating system is composed of a primary preheater and a secondary preheater in series, the preheating effect is improved by two-stage preheating, the concentrated sulfuric acid and low-temperature steam discharged by the system are used as heat sources for the primary preheater and the secondary preheater respectively, energy loss is further reduced, energy consumption is saved, and processing cost is reduced.

[0023] 3. The utility model forms an evaporation and concentration system by adopting three groups of evaporation concentrators in series, which has higher evaporation and concentration efficiency, higher concentration and better concentration effect. At the same time, the utility model system uses the secondary steam of the separation chamber of the upper stage as the heat source of the heater of the lower stage, which is more reasonable in design, more energy-saving and lower in cost.

[0024] 4. The utility model system condenses the secondary steam of the evaporation concentration system by setting a condenser, and uses a wastewater collection tank to collect the wastewater in the condenser and the wastewater in the second-effect heater and the third-effect heater. The design is reasonable and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Attachment Fig. 1 It is a structural diagram of the system of the utility model;

[0026] Attachment Fig. 2 This is a structural diagram of the evaporation and concentration system of the utility model.

[0027] Explanation of the accompanying symbols: 1-waste sulfuric acid inlet, 2-preheating system, 3-evaporation and concentration system, 4-service side steam inlet, 5-desorption tower, 6-absorption tower, 7-vacuum system, 8-sodium hydroxide solution inlet, 9-air outlet, 10-filter press, 11-calcium fluoride extraction outlet, 12-calcium chloride solution outlet, 13-concentrated sulfuric acid outlet, 14-primary preheater, 15-secondary preheater, 16-condensate outlet, 17-condenser, 18-condensate upper water inlet, 19-condensate lower water inlet, 20-wastewater collection tank, 21-wastewater discharge pipe, 22-first-effect evaporation concentrator, 221-first-effect heater, 222-first-effect separation chamber, 23-second-effect evaporation concentrator, 231-second-effect heater, 232-second-effect separation chamber, 24-triple-effect evaporation concentrator, 241-triple-effect heater, 242-triple-effect separation chamber, 25-hot air inlet. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the embodiments, but they are not intended to limit the present invention.

[0029] Embodiments of the present utility model

[0030] A system for concentrating and defluorinating waste sulfuric acid from nickel and cobalt smelting, as shown in the attached Figs. 1-2 As shown, it includes a waste sulfuric acid inlet 1, which is connected to a waste sulfuric acid storage tank, the waste sulfuric acid inlet 1 is connected to a preheating system 2, the preheating system 2 is connected to an evaporation and concentration system 3, the evaporation and concentration system 3 is connected to a stripping tower 5, the stripping tower 5 is connected to an absorption tower 6, and the absorption tower 6 is connected to a vacuum system 7; wherein the preheating system 2, the evaporation and concentration system 3, the stripping tower 5 and the absorption tower 6 are sealed by pipelines, and a vacuum environment is provided inside by the vacuum system 7;

[0031] The evaporation concentration system 3 is provided with a service side steam inlet 4 connected with an external steam generator to provide high temperature steam for heating the evaporation concentration system 3. The liquid inlet of the evaporation concentration system 3 is connected with the liquid outlet of the preheating system 2, and the liquid outlet of the evaporation concentration system 3 is connected with the liquid inlet of the desorption tower 5.

[0032] The bottom of the desorption tower 5 is connected with a concentrated sulfuric acid outlet 13 and a hot air inlet 25 connected with an external hot air generator. The top of the desorption tower 5 is connected with the absorption tower 6.

[0033] The top of the absorption tower 6 is connected with a sodium hydroxide solution inlet 8 and an air outlet 9. The bottom of the absorption tower 6 is connected with a filter press 10 provided with a calcium fluoride outlet 11 and a calcium chloride solution outlet 12.

[0034] In use, the waste dilute sulfuric acid enters the preheating system 2 through the waste sulfuric acid inlet 1 to be heated to obtain preheated waste sulfuric acid. The preheated waste sulfuric acid is discharged from the preheating system 2 and enters the evaporation concentration system 3 through the pipeline. Under the action of the high temperature steam provided by the service side, the preheated waste sulfuric acid is further heated and most of the water in it is evaporated to obtain concentrated fluorine and chlorine containing sulfuric acid. The fluorine and chlorine containing concentrated sulfuric acid is discharged from the evaporation concentration system 3 and then sent to the top of the desorption tower 5 through the pipeline and sprayed downward through the conventional spray head. The bottom is sent to the dry hot air through the hot air inlet 25 to be blown and brushed, so that the fluorine and chlorine in the concentrated sulfuric acid is absorbed by the blowing gas. The pure concentrated sulfuric acid is discharged from the bottom. The hot air absorbing fluorine and chlorine is discharged from the top of the desorption tower 5 and then sent to the absorption tower 6 through the pipeline. The calcium hydroxide solution is sprayed into the absorption tower 6 from the sodium hydroxide solution inlet 8 at the top of the absorption tower 6. After the calcium hydroxide solution contacts with the gas in the absorption tower 6, absorption and reaction occur to generate calcium fluoride precipitate and calcium chloride solution. The absorbed air is directly discharged. The solid-liquid mixture below enters the filter press 10 to be filtered to obtain calcium fluoride solid and calcium chloride solution.

[0035] Further embodiments are shown in the accompanying drawings Figs. 1-2 The preheating system 2 is composed of a first preheater 14 and a second preheater 15 connected in series. The service side liquid inlet of the first preheater 14 is connected with the liquid outlet of the desorption tower 5. The concentrated sulfuric acid outlet 13 is connected with the service side liquid outlet of the first preheater 14. The service side gas inlet of the second preheater 15 is connected with the low temperature steam outlet of the evaporation concentration system 3. The service side gas outlet of the second preheater 15 is connected with the condensed water outlet 16.

[0036] In this embodiment, when the high-temperature concentrated sulfuric acid is discharged from the desorption tower 5, it firstly passes through the first-stage preheater 14, and the first preheating of the cold waste dilute sulfuric acid in the first-stage preheater 14 is performed to realize the recovery of the heat of the high-temperature concentrated sulfuric acid, and then the concentrated sulfuric acid is discharged through the concentrated sulfuric acid discharge port 13; and the low-temperature steam discharged from the evaporation and concentration system 3 enters the second-stage preheater 15 to perform the second preheating of the waste dilute sulfuric acid which has been subjected to the first preheating, so as to recover and utilize the heat in the low-temperature steam.

[0037] Further embodiments are illustrated in the accompanying Figs. 1-2 As shown in the accompanying drawings, the evaporation and concentration system 3 is composed of a one-stage evaporation concentrator 22, a two-stage evaporation concentrator 23 and a three-stage evaporation concentrator 24 which are connected in series.

[0038] In this embodiment, the one-stage evaporation concentrator 22, the two-stage evaporation concentrator 23 and the three-stage evaporation concentrator 24 are connected in series according to the connection mode of the conventional three-stage evaporation system.

[0039] Further embodiments are illustrated in the accompanying Figs. 1-2 As shown in the accompanying drawings, the one-stage evaporation concentrator 22 includes a one-stage heater 221 and a one-stage separation chamber 222; the two-stage evaporation concentrator 23 includes a two-stage heater 231 and a two-stage separation chamber 232; the three-stage evaporation concentrator 24 includes a three-stage heater 241 and a three-stage separation chamber 242 respectively; the exhaust end of the one-stage separation chamber 222 is connected with the service-side gas inlet of the two-stage heater 231, the exhaust end of the two-stage separation chamber 232 is connected with the service-side gas inlet of the three-stage heater 241, and the exhaust end of the three-stage separation chamber 242 is connected with the absorption tower 6.

[0040] In this embodiment, the heat source of the one-stage heater 221 is the high-temperature steam sent by the service-side steam inlet 4, and the heat sources of the two-stage heater 231 and the three-stage heater 241 are the secondary steam separated from the one-stage separation chamber 222 and the two-stage separation chamber 232 respectively.

[0041] Further embodiments are illustrated in the accompanying Figs. 1-2 As shown in the accompanying drawings, the one-stage evaporation concentrator 22, the two-stage evaporation concentrator 23 and the three-stage evaporation concentrator 24 are all forced circulation evaporation structures.

[0042] The forced circulation evaporation structure in this embodiment is the existing structure, and the function of forced circulation or liquid discharge is realized through the cooperation of the circulation pipeline and the valve body.

[0043] Further embodiments are illustrated in the accompanying Figs. 1-2As shown, the exhaust end of the three-effect separation chamber 242 is provided with a condenser 17 between the absorption tower 6, the service side of the condenser 17 is provided with a condensed water upper water inlet 18 and a condensed water lower water inlet 19, the exhaust end of the condenser 17 is connected with a waste water collecting tank 20, the waste water collecting tank 20 is provided with a waste water discharge pipe 21; the waste water collecting tank 20 is connected with the service side exhaust port of the two-effect heater 231 and the three-effect heater 241.

[0044] The waste water collecting tank 20 in the embodiment is mainly used for collecting the condensed water cooled by the steam heat source in the two-effect heater 231 and the three-effect heater 241, and the condensed water condensed after the secondary steam discharged by the three-effect separation chamber 242, so as to avoid pollution caused by the discharge of the condensed water.

[0045] The technical terms "desorption tower", "absorption tower", "vacuum system", "filter press", "preheater", "condenser", "waste water collecting tank", "heater" and "separation chamber" appearing in the embodiment of the utility model all belong to the conventional terms in the field, and the devices indicated by the above terms all adopt the commonly used devices in the field.

[0046] The above is only a preferable specific embodiment of the utility model creation, but the protection scope of the utility model creation is not limited to this, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the utility model concept of the utility model creation within the technical range disclosed by the utility model creation, which should be covered in the protection scope of the utility model creation.

Claims

1. A nickel-cobalt smelting waste sulfuric acid concentration defluorochlorination system characterized by: The waste sulfuric acid inlet (1) is connected with a preheating system (2), the preheating system (2) is connected with an evaporation concentration system (3), the evaporation concentration system (3) is connected with a desorption tower (5), the desorption tower (5) is connected with an absorption tower (6), and the absorption tower (6) is connected with a vacuum system (7); The evaporation concentration system (3) is provided with a service side steam inlet (4), the liquid inlet end of the evaporation concentration system (3) is connected with the liquid outlet end of the preheating system (2), and the liquid outlet end of the evaporation concentration system (3) is connected with the liquid inlet end of the desorption tower (5); The bottom of the desorption tower (5) is connected with a concentrated sulfuric acid discharge outlet (13) and a hot air inlet (25), and the top of the desorption tower (5) is connected with the absorption tower (6); The top of the absorption tower (6) is connected with a sodium hydroxide solution inlet (8) and an air discharge outlet (9), and the bottom is connected with a filter press (10), which is provided with a calcium fluoride outlet (11) and a calcium chloride solution discharge outlet (12).

2. The system for defluorochlorination of concentrated spent nickel-cobalt sulphuric acid according to claim 1, characterized in that: The preheating system (2) is composed of a first-stage preheater (14) and a second-stage preheater (15) connected in series; the service side liquid inlet of the first-stage preheater (14) is connected with the liquid discharge port of the desorption tower (5), and the concentrated sulfuric acid discharge outlet (13) is connected with the service side liquid outlet of the first-stage preheater (14); the service side gas inlet of the second-stage preheater (15) is connected with the low-temperature steam discharge outlet of the evaporation concentration system (3), and the service side gas outlet of the second-stage preheater (15) is connected with a condensed water discharge outlet (16).

3. The system for defluorochlorination of concentrated spent nickel-cobalt sulphuric acid according to claim 1, characterized in that: The evaporation concentration system (3) is composed of a one-effect evaporation concentrator (22), a two-effect evaporation concentrator (23) and a three-effect evaporation concentrator (24) connected in series.

4. The system for defluorochlorination of concentrated spent nickel-cobalt sulphuric acid according to claim 3, characterized in that: The one-effect evaporation concentrator (22) comprises a one-effect heater (221) and a one-effect separation chamber (222); the two-effect evaporation concentrator (23) comprises a two-effect heater (231) and a two-effect separation chamber (232); the three-effect evaporation concentrator (24) comprises a three-effect heater (241) and a three-effect separation chamber (242) respectively; the exhaust end of the one-effect separation chamber (222) is connected with the service side gas inlet of the two-effect heater (231), the exhaust end of the two-effect separation chamber (232) is connected with the service side gas inlet of the three-effect heater (241), and the exhaust end of the three-effect separation chamber (242) is connected with the absorption tower (6).

5. The system for defluorochlorination of concentrated spent nickel-cobalt sulphuric acid according to claim 4, characterized in that: The one-effect evaporation concentrator (22), the two-effect evaporation concentrator (23) and the three-effect evaporation concentrator (24) are all forced circulation evaporation structures.

6. The system for defluorochlorination of concentrated spent nickel-cobalt sulphuric acid according to claim 4, characterized in that: A condenser (17) is arranged between the exhaust end of the three-effect separation chamber (242) and the absorption tower (6), the service side of the condenser (17) is provided with a condensed water upper water inlet (18) and a condensed water lower water inlet (19), the liquid discharge end of the condenser (17) is connected with a waste water collection tank (20), the waste water collection tank (20) is provided with a waste water discharge pipe (21), and the service side liquid discharge ports of the two-effect heater (231) and the three-effect heater (241) are connected with the waste water collection tank (20).

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