Iron removal device for nickel-containing high-iron solution in nitric acid system

Abstract

The utility model discloses an iron removal device for a nickel-containing high-iron solution under a nitric acid system, which is characterized in that a temperature control system is arranged on a kettle body of a reaction kettle, and a stirring device, a gas phase thermometer, a liquid phase thermometer, a breather pipe, a water adding pipeline under pressure and an exhaust pipe are arranged on the reaction kettle. When the temperature detected by the gas-phase thermometer and the liquid-phase thermometer reaches a set value, inert gas is introduced into the kettle from the breather pipe and the exhaust pipe begins to exhaust gas, and in the process, generated nitric oxide is discharged out of the reaction kettle, so that nitric acid is prevented from being quickly formed, and decomposition reaction is inhibited; meanwhile, part of water vapor can be taken away in the exhaust process, and the solution is concentrated, so that water or the solution can be supplemented into the kettle body through the water adding pipeline under pressure, the concentration of the solution in the kettle is basically unchanged or the solution is not dried by burning, and the purpose of removing iron in the nickel-containing high-iron solution which is subjected to oxidation leaching by adopting a nitric acid system under normal pressure can be achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of wet leaching of nickel sulfide ore directly by using nitric acid under normal pressure, and particularly relates to an iron removal device for a nickel-containing high-iron solution in a nitric acid system. Background Art

[0002] In nature, nickel-containing deposits are all accompanied by iron. During the wet leaching process, iron enters the solution along with other metals such as nickel, cobalt, and manganese. Since trivalent iron ions are particularly easy to hydrolyze, they begin to hydrolyze to form iron hydroxide precipitation when the solution pH reaches 2.0. When the iron content in the solution is low (Fe≤1.0g / L), this method is mostly used to remove iron. However, when this method is used when the iron content is high, the amount of iron hydroxide precipitation is large, and the content of valuable metals such as nickel, cobalt, and copper entrained in the slag increases, resulting in a significant reduction in the recovery rate of valuable metals. Therefore, this method is not suitable.

[0003] The iron content in nickel-containing deposits in nature is mostly several times or even dozens of times that of heavy metals such as nickel and copper. If direct leaching is performed by wet method, the iron content in the solution can reach tens of grams per liter or even hundreds of grams per liter, and it is impossible to remove iron by hydrolysis. According to the extraction curve characteristics of various acidic extractants and actual production experience, acidic extractants are most likely to extract iron into the extractant, but it is not easy to wash. If the iron content in the solution is greater than 0.1g / L, after a period of circulation, the efficiency of the extractant is greatly reduced, and severe cases may even cause extractant poisoning.

[0004] At present, the basic method of nickel sulfide ore is to directly feed the mineral raw materials into the pyrometallurgical system for slag making. The pyrometallurgical slag making results in a large amount of slag and a low recovery rate of valuable metals such as nickel and cobalt. In addition, with the annual decrease in high-quality nickel sulfide ore resources, a large number of nickel sulfide ores with high magnesium content have appeared. Due to the high magnesium content, directly feeding into the pyrometallurgical system will increase equipment and operating costs.

[0005] In order to treat high-magnesium nickel sulfide ore, nitric acid is used to leach high-magnesium nickel sulfide ore under normal pressure, and metals such as nickel, cobalt, copper, iron, and magnesium enter the leachate in the form of nitrates. Then, thermal decomposition is used to remove iron to directly separate iron from the solution, and then refined nickel cobalt sulfate solution is finally prepared through extraction. At present, the equipment that can be used for heating reaction includes a reactor with a stirring device and a temperature control system, but the existing reactor cannot meet the process requirements of thermal decomposition and iron removal. For example, the nitrogen oxide gas generated by the decomposition of iron nitrate during the reaction needs to be quickly discharged from the reactor to avoid the rapid formation of nitric acid and inhibit the decomposition reaction. Therefore, it is necessary to make corresponding improvements on the existing reactor to meet the process requirements.

[0006] The decomposition temperature of ferric nitrate is ≥125℃, the decomposition temperature of ferric chloride is ≥315℃, and the decomposition temperature of ferric sulfate is ≥480℃. The decomposition temperature of ferric nitrate is lower than that of ferric chloride and ferric sulfate. The thermal stability of ferric nitrate is poor, and the energy consumption of ferric removal by thermal decomposition is low. The thermal decomposition reaction equation of ferric nitrate is: 4Fe(NO3)3→2Fe2O3+3O2↑+12NO2↑.

[0007] Therefore, this publication is mainly aimed at the research on removing iron from nickel-containing high-iron solution prepared by leaching nickel sulfide ore with nitric acid under normal pressure. Utility Model Content

[0008] The technical problem to be solved by the utility model is: in view of the defect in the prior art that the mineral raw materials of nickel sulfide ore are directly introduced into the pyrometallurgical system for slag formation, the utility model provides a method for removing iron from the nickel-containing high-iron solution oxidized and leached by a nitric acid system under normal pressure, so as to achieve the purpose of treating the nickel sulfide ore by directly adopting a wet method.

[0009] The technical solution adopted by the utility model is as follows:

[0010] A device for removing iron from a nickel-containing high-iron solution in a nitric acid system comprises a reactor, a temperature control system is arranged on the reactor body of the reactor, a stirring device is arranged on the reactor, a gas phase thermometer, a liquid phase thermometer, a vent pipe, a pressurized water supply pipeline and an exhaust pipe are arranged on the reactor, a valve one is arranged on the vent pipe, a water supply valve is arranged on the pressurized water supply pipeline, and a back pressure valve three is arranged on the exhaust pipe.

[0011] A further technical solution is that the pressurized water-filling pipeline is connected to the water outlet of the constant-pressure water-filling tank, and a water supply valve is connected between the pressurized water-filling pipeline and the water outlet of the constant-pressure water-filling tank, and a ventilation valve, a pressure gauge and a water-filling port are provided on the constant-pressure water-filling tank.

[0012] A further technical solution is that a constant pressure port is provided on the constant pressure water adding tank, and the constant pressure port is connected to a second pressure gauge via a constant pressure pipe.

[0013] A further technical solution is to provide a valve four on the constant pressure pipe.

[0014] A further technical solution is that the ventilation pipe is connected to the sampling buffer tank, a valve is arranged between the ventilation pipe and the sampling buffer tank, and a sampling valve is arranged at the outlet end of the sampling buffer tank.

[0015] A further technical solution is that a filter is arranged on the ventilation pipe, and valve one is a back pressure valve.

[0016] A further technical solution is that a pressure relief protection pipeline is arranged on the reactor, and valve five, an electric needle valve and valve six are arranged on the pressure relief protection pipeline in sequence.

[0017] A further technical solution is that the pressure relief protection pipeline, ventilation pipe, constant pressure pipe, pressurized water supply pipeline and exhaust pipe are all arranged on the kettle cover of the reactor. The reactor as a whole is arranged on a movable platform 29. A kettle body turning device and a lifting device are arranged on the platform 29. The kettle body turning device includes a turning bracket 25 and a turning drive 26 for driving the kettle body to turn over. The kettle body is rotatably connected to the turning bracket 25 by means of a support shaft. The lifting device includes a lifting bracket 27 and a lifting drive 28 for driving the kettle cover to rise and fall. The kettle cover is fixedly connected to the lifting bracket 27.

[0018] In summary, due to the adoption of the above technical scheme, the beneficial effects of the utility model are as follows: by arranging a temperature control system on the kettle body of the reactor, arranging a stirring device, a gas phase thermometer, a liquid phase thermometer, a vent pipe, a pressurized water adding pipeline and an exhaust pipe on the reactor, after the solution is loaded into the reactor, the temperature control system is started for heating, the stirring device is started for stirring, and when the temperature detected by the gas phase thermometer and the liquid phase thermometer reaches the set value, an inert gas is introduced into the kettle through the vent pipe, and exhaust is started through the exhaust pipe at the same time. During this process, the generated nitrogen oxides will be discharged from the reactor to avoid the rapid formation of nitric acid and inhibit the decomposition reaction. At the same time, the exhaust process will take away part of the water vapor, resulting in the concentration of the solution. For this reason, water or solution can be added to the kettle body through the pressurized water adding pipeline to ensure that the concentration of the solution in the kettle remains substantially unchanged or is not burned dry, thereby achieving the removal of iron in the nickel-containing high-iron solution oxidized and leached using a nitric acid system under normal pressure. The utility model directly adopts a wet method to achieve the purpose of treating nickel sulfide ore.

[0019] Taking advantage of the relatively low decomposition temperature of ferric nitrate, the ferric nitrate in the leachate is decomposed to generate Fe2O3 precipitation and gas. The precipitation is separated from the solution by filtration, and the iron in the high-iron solution is removed or reduced to about 1.0g / L. The nickel sulfide ore treatment process is greatly shortened and the production cost is reduced. The control of this device can realize remote automatic control through the PLC control system. The reaction temperature, pressure and other parameters can be observed and adjusted at any time, with high efficiency and easy operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0021] Figure 2 It is a schematic diagram of the structure on the kettle cover of the utility model;

[0022] Figure 3 It is a schematic diagram of the connection structure of the lifting drive and the lifting bracket of the utility model;

[0023] Figure 4 It is a schematic diagram of the connection of various components on the ventilation pipe of the utility model. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1-Figure 4 A device for removing iron from nickel-containing high-iron solution in a nitric acid system comprises a reactor 1, a temperature control system is arranged on the reactor body 2 of the reactor 1, a stirring device is arranged on the reactor 1, a gas phase thermometer 3, a liquid phase thermometer 4, a vent pipe 5, a pressurized water supply pipeline 6 and an exhaust pipe 7 are arranged on the reactor 1, a valve 8 is arranged on the vent pipe 5, a water supply valve 9 is arranged on the pressurized water supply pipeline 6, and a back pressure valve 10 is arranged on the exhaust pipe 7,

[0026] When in use, a reactor body 2 of the reactor 1 shown in the figure is made of Hastelloy with a thickness of 8 mm, and an inner bag coated with polytetrafluoro material inside and outside is made according to the size and placed in the reactor body 2 to achieve a double corrosion resistance effect. A coil 33 is added to the outer wall of the kettle body 2. The whole system of the coil 33 is connected to the high and low temperature integrated machine 34. The oil outlet of the high and low temperature integrated machine 34 is connected to the inlet of the coil 33, and the oil inlet of the high and low temperature integrated machine 34 is connected to the outlet of the coil 33, so as to form a circulating temperature rise and fall temperature control system. After the solution is loaded into the reactor 1, the temperature control system is started for heating, and the stirring device is started for stirring. When the temperature detected by the gas phase thermometer 3 and the liquid phase thermometer 4 reaches the set value, an inert gas is introduced into the kettle through the ventilation pipe 5, and exhaust is started through the exhaust pipe 7. In this process, the generated nitrogen oxides will be discharged from the reactor 1. The exhaust pipe 7 can be connected to the existing nitrogen oxide treatment equipment. At the same time, the exhaust process will take away part of the water vapor, resulting in the concentration of the solution. For this reason, water or solution can be added to the kettle body 2 through the pressurized water adding pipeline 6 to ensure that the concentration of the solution in the kettle remains substantially unchanged or is not burned dry, so as to achieve the removal of iron in the nickel-containing high-iron solution oxidized and leached by the nitric acid system under normal pressure.

[0027] The pressurized water-adding pipeline 6 is connected to the water outlet of the constant-pressure water-adding tank 11, and a water supply valve 9 is connected between the pressurized water-adding pipeline 6 and the water outlet of the constant-pressure water-adding tank 11. The constant-pressure water-adding tank 11 is provided with a vent valve 12, a pressure gauge 13 and a water-adding port 14. After the constant-pressure water-adding tank 11 is filled with water and the vent valve 12 is opened, when the internal pressure in the reactor 1 is reduced to the same as the pressure in the constant-pressure water-adding tank 11, the water in the constant-pressure water-adding tank 11 can enter the reactor 1.

[0028] The constant pressure water adding tank 11 is provided with a constant pressure port 15, and the constant pressure port 15 is connected to the pressure gauge 17 and the reactor 1 in sequence through the constant pressure pipe 16. The pressure value when the reactor 1 and the constant pressure water adding tank 11 are at constant pressure can be monitored through the constant pressure pipe 16 and the pressure gauge 17.

[0029] A valve 18 is provided on the constant pressure tube 16 to control the on and off of the constant pressure tube 16.

[0030] The vent pipe 5 is connected to the sampling buffer tank 19, a valve 8 is arranged between the vent pipe 5 and the sampling buffer tank 19, and a sampling valve 20 is arranged at the outlet end of the sampling buffer tank 19. After opening the valve 8, the liquid in the reactor 1 will enter the sampling buffer tank 19 along the vent pipe 5, thereby completing the sampling, and after the sampling, the valve 8 is closed, and the liquid will be discharged from the sampling buffer tank 19 after the sampling valve 20 is opened.

[0031] A filter is arranged on the ventilation pipe 5, and the valve 1 8 is a back pressure valve.

[0032] The reactor 1 is provided with a pressure relief protection pipeline, on which a valve five, an electric needle valve and a valve six are sequentially provided.

[0033] The pressure relief protection pipeline, the vent pipe 5, the constant pressure pipe 16, the pressurized water adding pipeline 6, and the exhaust pipe 7 are all arranged on the kettle cover 21 of the reactor 1. The reactor 1 is arranged as a whole on a movable platform 29. The platform 29 is provided with a kettle body 2 flipping device and a lifting device. The kettle body 2 flipping device includes a flipping bracket 25 and a flipping drive 26 for driving the kettle body 2 to flip. The kettle body 2 is rotatably connected to the flipping bracket 25 by means of a support shaft. The lifting device includes a lifting bracket 27 and a lifting drive 28 for driving the kettle cover 21 to lift and lower. The kettle cover 21 is fixedly connected to the lifting bracket 27. Other valves for auxiliary deflation to increase the deflation and pressure relief speed are also arranged on the kettle cover.

[0034] The utility model can be controlled by a PLC control system. When the temperature needs to be raised, the PLC control system is set to raise the temperature. When the reaction is completed and the temperature needs to be quickly lowered, it is set to refrigeration. The outside of the coil is an air insulation layer, and the outermost layer is a stable and scalding-proof layer. The entire kettle body 2 is connected to the rotating bracket by means of a support shaft. When the reaction is completed and it is necessary to discharge or clean, the support shaft and the kettle body 2 are driven to rotate by the flip drive 26, so as to adjust the angle of the kettle body 2, and the discharge or cleaning operation is performed when it is adjusted to an angle that is convenient for operation. The flip drive 26 can be driven by a motor or a hand wheel 39, and the motor or the hand wheel 39 is transmitted to the support shaft 32 by a worm gear 30 and a worm 31 transmission assembly. The worm 31 is coaxially fixed with the output shaft of the motor or the hand wheel 39, and the worm 31 is connected to the worm gear 30 by transmission, and the worm gear 30 is coaxially fixed with the support shaft 32. After the solution is loaded into the kettle body 2, the lifting drive is controlled to lower the lifting bracket 27, and the lifting drive 28 is a hydraulic cylinder. The kettle cover 21 is covered on the kettle body 2, and the main bolts and main nuts are connected and sealed. Then close the water supply valve 9, valve 1 8, and back pressure valve 3 10 on the exhaust pipe 7, and start the stirring system through the start button of the PLC control system. The stirring system is driven by the explosion-proof motor 38 with the help of belt drive 37 to drive the active end of the magnetic coupler 36 to rotate, and the driven end of the magnetic coupler 36 is connected to the stirrer 35, thereby driving the stirrer to rotate). Start the heating system to start heating, and the temperature in the reactor 1 is detected by the gas phase thermometer 3 and the liquid phase thermometer 4. The gas phase thermometer 3 is provided with a gas phase temperature measuring sleeve, and the liquid phase thermometer 4 is provided with a liquid phase temperature measuring sleeve. The gas phase thermometer 3 and the liquid phase thermometer 4 transmit the temperature signal to the PLC control system for recording and detection. When the temperature reaches the set temperature, inert gas can be introduced into the reactor through the ventilation pipe 5 according to the process requirements, and the back pressure valve is adjusted at the same time to start exhausting. Driven by the rapid airflow, the generated oxide gas is transported to the absorption system through the outlet of the back pressure valve. Since some water vapor will be brought into the process of exhaust, causing the solution to concentrate, the constant pressure water tank 11 can be used to control the water supply valve 9 to add water to the kettle body 2 to ensure that the concentration of the solution in the kettle remains roughly unchanged or is not burned dry. After the reaction is completed, the PLC control system is used to switch to the refrigeration system, and then the ventilation is turned off at a suitable temperature and the back pressure valve is closed. When cooled to room temperature, observe whether the pressure gauge returns to zero. After returning to zero, stop the stirring system. Remove the main nut, open the kettle cover 21 through the lifting bracket 27, control the kettle body 2 flip device to adjust to a suitable angle, pour out the reacted material, and then clean the kettle body 2 and return it to its original position for the next operation.

[0035] The above are only preferred embodiments of the present invention.

Claims

1. A device for removing iron from a nickel-containing high-iron solution in a nitric acid system, comprising a reactor (1), a temperature control system being arranged on a reactor body (2) of the reactor (1), and a stirring device being arranged on the reactor (1), characterized in that: The reactor (1) is provided with a gas phase thermometer (3), a liquid phase thermometer (4), a vent pipe (5), a pressurized water supply pipeline (6) and an exhaust pipe (7); a valve one (8) is provided on the vent pipe (5), a water supply valve (9) is provided on the pressurized water supply pipeline (6), and a back pressure valve three (10) is provided on the exhaust pipe (7).

2. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 1, characterized in that: The pressurized water-adding pipeline (6) is connected to the water outlet of the constant-pressure water-adding tank (11); the water supply valve (9) is connected between the pressurized water-adding pipeline (6) and the water outlet of the constant-pressure water-adding tank (11); and the constant-pressure water-adding tank (11) is provided with a vent valve (12), a pressure gauge (13) and a water-adding port (14).

3. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 2, characterized in that: The constant pressure water adding tank (11) is provided with a constant pressure port (15), and the constant pressure port (15) is connected to a second pressure gauge (17) via a constant pressure pipe (16).

4. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 3, characterized in that: A valve four (18) is provided on the constant pressure pipe (16).

5. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 4, characterized in that: The ventilation pipe (5) is connected to the sampling buffer tank (19), a valve 1 (8) is arranged between the ventilation pipe (5) and the sampling buffer tank (19), and a sampling valve (20) is arranged at the outlet end of the sampling buffer tank (19).

6. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 5, characterized in that: A filter is provided on the ventilation pipe (5), and valve one (8) is a back pressure valve.

7. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 6, characterized in that: The reactor (1) is provided with a pressure relief protection pipeline, on which a valve five, an electric needle valve and a valve six are sequentially provided.

8. The iron removal device for nickel-containing high-iron solution in a nitric acid system according to claim 7, characterized in that: The ventilation pipe (5), the constant pressure pipe (16), the pressurized water supply pipeline (6), and the exhaust pipe (7) are all arranged on the kettle cover (21) of the reaction kettle (1). The reaction kettle (1) is arranged as a whole on a movable platform (29). A kettle body (2) turning device and a lifting device are arranged on the platform (29). The kettle body (2) turning device comprises a turning bracket (25) and a turning drive (26) for driving the kettle body (2) to turn over. The kettle body (2) and the turning bracket (25) are rotatably connected by means of a support shaft. The lifting device comprises a lifting bracket (27) and a lifting drive (28) for driving the kettle cover (21) to move up and down. The kettle cover (21) and the lifting bracket (27) are fixedly connected.

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