System for preparing high-purity scandium oxide by hydrometallurgy

Abstract

The utility model relates to the technical field of hydrometallurgy, and specifically provides a system for preparing high-purity scandium oxide by hydrometallurgy, comprising: a pure water preparation unit; a cooling and drying unit; a pre-washing liquid preparation unit, the inlet of which is connected with the pure water preparation unit and a leaching acid pipeline; a scandium-containing acid solution preparation unit, the inlet of which is connected with the outlet of the pure water preparation unit and the leaching acid pipeline; a scandium-containing extraction stock solution preparation unit; a back-extraction agent preparation unit, the inlet of which is connected with the outlet of the pure water preparation unit; an extraction unit, the inlet of which is connected with the outlet of the scandium-containing extraction stock solution preparation unit, the outlet of the pre-washing liquid preparation unit, and the outlet of the back-extraction agent preparation unit; a washing unit; and a calcination unit. The utility model uses the extraction method to realize continuous production at a low equipment investment, improve production efficiency, and realize energy saving and consumption reduction by secondary utilization of waste heat generated in the production process through the series connection and parallel capacity matching of the equipment upstream and downstream.

Description

Technical Field

[0001] This utility model relates to the field of hydrometallurgical technology, and more specifically, to a system for preparing high-purity scandium oxide by hydrometallurgical processes. Background Technology

[0002] Scandium (Sc), a typical dispersed rare earth element, has an average crustal abundance of only 22-30 ppm and is extremely difficult to concentrate into minerals, resulting in a severe scarcity of natural scandium ore resources. Another major source of Sc is secondary sources, such as industrial byproducts or waste, including niobium tailings (Sc₂O₃ 200-300 ppm), waste acid from titanium dioxide production (Sc₃+ 10-20 mg / L), laterite nickel ore leaching solution (Sc 300-500 ppm), and dust from titanium slag chlorination processes (Sc 300-1200 ppm). With the rapid development of aerospace, military high-rise equipment, civilian high-end aluminum alloys, marine resource platform construction, solid oxide fuel cells, and 5G radio frequency front-ends, the strategic value of scandium is becoming increasingly prominent.

[0003] Existing hydrometallurgical systems for preparing high-purity scandium oxide suffer from drawbacks such as high investment costs and inability to achieve continuous production. This system adopts an extraction method and achieves continuous production with lower equipment investment by matching the capacity of upstream and downstream equipment in series and parallel connections. This improves production efficiency and enables energy conservation and consumption reduction through the secondary utilization of waste heat generated in the production process. Utility Model Content

[0004] To address the shortcomings of existing technologies, this invention provides a system for preparing high-purity scandium oxide via hydrometallurgy, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A system for preparing high-purity scandium oxide by hydrometallurgical process, comprising: The pure water preparation unit has its inlet connected to a tap water pipe and is used to prepare pure water. The cooling and drying unit has its inlet connected to the pure water preparation unit. It is used to cool the heat released by the chemical reaction during the acid leaching process and the preparation of the pre-wash solution, and to use the heat for heating and drying the washed product to achieve waste heat recovery. The pre-wash solution preparation unit has its inlet connected to the pure water preparation unit and the leaching acid pipeline, and its outer wall cavity inlet and outlet are connected to the inlet and outlet of the cooling and drying unit. It is used to prepare the extracted organic and purified back-extracted organic in the pre-wash solution washing and extraction process. The scandium acid solution preparation unit has its inlet connected to the outlet of the pure water preparation unit and the leaching acid pipeline, its outer wall cavity inlet and outlet connected to the inlet and outlet of the cooling and drying unit, and its exhaust port connected to the waste gas treatment system. It is used to leach and filter scandium-containing residue to obtain scandium acid solution. The scandium-containing extract preparation unit has its inlet connected to the outlet of the scandium-containing acid solution preparation unit, the outlet of the pure water preparation unit, and the leaching acid pipeline, and is used to adjust the pH of the scandium-containing acid solution to obtain the scandium-containing extract. The stripping agent preparation unit has its inlet connected to the outlet of the pure water preparation unit and is used to prepare the stripping agent; An extraction unit, the inlet of which is connected to the outlet of the scandium-containing extraction stock solution preparation unit, the outlet of the pre-wash solution preparation unit, and the outlet of the back-extraction agent preparation unit, is used for extraction and back-extraction to obtain scandium-containing intermediates; The washing unit has its inlet connected to the outlet of the extraction unit and the outlet of the pure water preparation unit, and its outlet connected to the sewage pipe. It is used to wash scandium-containing intermediates. The calcination unit is used to calcine the clean scandium-containing intermediate obtained from the washing unit to obtain high-purity scandium oxide.

[0006] Preferably, the outlet of the extraction unit is connected to the inlet of the scandium acid solution preparation unit and the sewage discharge pipe, so that the raffinate and washing liquid discharged from the extraction unit can be returned to the scandium acid solution preparation unit for recycling or direct discharge.

[0007] Preferably, the scandium-containing solution preparation unit consists of a cooling stirring tank, a water pump, and a filter tank connected in series; the pure water preparation unit consists of a pure water device and a storage tank connected in series; the pre-washing solution preparation unit consists of a cooling stirring tank and a water pump connected in series; the scandium-containing extraction stock solution preparation unit and the back-extraction agent preparation unit consist of a stirring tank and a water pump connected in series; the cooling and drying unit consists of an air-cooled heat exchanger and a water pump connected in series; the extraction unit consists of a reaction vessel; and the washing unit consists of a spin-drying tank.

[0008] Preferably, the outer wall of the cooling stirring tank is composed of a double-layered sealed cavity for the cooling water to circulate and cool within the cavity.

[0009] Preferably, the cooling mixing tank, mixing tank, storage tank, water pump reactor, and filter tank are one or more connected in parallel.

[0010] Preferably, the air-cooled heat exchanger consists of a heat exchange coil and a fan, used to cool the cooling water and heat the air to form hot air, which is used to dry the scandium-containing intermediate discharged from the washing unit, thereby realizing waste heat recovery.

[0011] Preferably, the cooling stirring tank, stirring tank, reaction vessel, storage tank, and filter tank are equipped with level gauges, the cooling stirring tank is equipped with an electronic thermometer, the cooling stirring tank, stirring tank, and reaction vessel are equipped with a stirrer and a timing device, and the spin-drying tank is equipped with a timing device.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model adopts the extraction method to achieve continuous production with low equipment investment by matching the capacity of upstream and downstream equipment in series and parallel. This improves production efficiency and achieves energy saving and consumption reduction by reusing the waste heat generated in the production process. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a system for preparing high-purity scandium oxide by hydrometallurgy according to this utility model.

[0014] 1. Pure water preparation unit 1; 2. Scandium acid solution preparation unit 2; 3. Cooling and drying unit 3; 4. Calcination unit 4; 5. Scandium-containing extract stock solution preparation unit 5; 6. Washing unit 6; 7. Extraction unit 7; 8. Back-extraction agent preparation unit 8; 9. Pre-wash solution preparation unit 9. Detailed Implementation

[0015] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0016] like Figure 1 As shown, a system for preparing high-purity scandium oxide by hydrometallurgy includes: Pure water preparation unit 1, whose inlet is connected to a tap water pipe, is used to prepare pure water; The cooling and drying unit 3 has its inlet connected to the pure water preparation unit 1. It is used to cool the heat released by the chemical reaction during the acid leaching process and the preparation of the pre-washing solution, and uses the heat to heat and dry the washed product to achieve waste heat recovery. The pre-washing solution preparation unit 9 has its inlet connected to the pure water preparation unit 1 and the leaching acid pipeline, and its outer wall cavity inlet and outlet are connected to the inlet and outlet of the cooling and drying unit 3. It is used to prepare the extracted organic and purified back-extracted organic in the pre-washing solution washing and extraction process. The scandium acid solution preparation unit 2 has its inlet connected to the outlet of the pure water preparation unit 1 and the leaching acid pipeline, its outer wall cavity inlet and outlet connected to the inlet and outlet of the cooling and drying unit 3, and its exhaust port connected to the waste gas treatment system. It is used to leach scandium-containing residue with acid and filter it to obtain scandium acid solution. The scandium-containing extract preparation unit 5 has its inlet connected to the outlet of the scandium-containing acid solution preparation unit 2, the outlet of the pure water preparation unit 1, and the leaching acid pipeline, and is used to adjust the pH of the scandium-containing acid solution to obtain the scandium-containing extract. The stripping agent preparation unit 8 has its inlet connected to the outlet of the pure water preparation unit 1 and is used to prepare the stripping agent. Extraction unit 7, whose inlet is connected to the outlet of scandium-containing extract stock solution preparation unit 5, the outlet of pre-wash solution preparation unit 9, and the outlet of back-extraction agent preparation unit 8, is used for extraction and back-extraction to obtain scandium-containing intermediates; The washing unit 6 has its inlet connected to the outlet of the extraction unit 7 and the outlet of the pure water preparation unit 1, and its outlet connected to the sewage pipe. It is used to clean scandium-containing intermediates. In the calcination unit 4, the clean scandium-containing intermediate obtained from the washing unit 6 is calcined to obtain high-purity scandium oxide.

[0017] The outlet of the extraction unit 7 is connected to the inlet of the scandium acid solution preparation unit 2 and the sewage discharge pipe, so that the raffinate and washing liquid discharged from the extraction unit 7 can be returned to the scandium acid solution preparation unit 2 for recycling or direct discharge.

[0018] The scandium-containing solution preparation unit 2 consists of a cooling stirring tank, a water pump, and a filter tank connected in series. The pure water preparation unit 1 consists of a pure water equipment and a storage tank connected in series. The pre-washing solution preparation unit 9 consists of a cooling stirring tank and a water pump connected in series. The scandium-containing extraction stock solution preparation unit 5 and the back-extraction agent preparation unit 8 consist of a stirring tank and a water pump connected in series. The cooling and drying unit 3 consists of an air-cooled heat exchanger and a water pump connected in series. The extraction unit 7 consists of a reaction vessel. The washing unit 6 consists of a spin-drying tank.

[0019] The outer wall of the cooling mixing tank is composed of a double-layered sealed cavity for the circulation of cooling water within the cavity.

[0020] The cooling mixing tank, mixing tank, storage tank, water pump reactor, and filter tank are composed of one or more units connected in parallel.

[0021] The air-cooled heat exchanger consists of a heat exchange coil and a fan, which is used to cool the cooling water and heat the air to form hot air. The hot air is used to dry the scandium-containing intermediate discharged from the washing unit 6, thereby realizing waste heat recovery.

[0022] The cooling and stirring tank, stirring tank, reaction vessel, storage tank, and filter tank are equipped with level gauges. The cooling and stirring tank is equipped with an electronic thermometer. The cooling and stirring tank, stirring tank, and reaction vessel are equipped with a stirrer and a timing device. The spin-drying tank is equipped with a timing device.

[0023] When the liquid level inside the cooling mixing tank, mixing tank, reaction vessel, storage tank, and filter tank reaches the upper limit value set by the liquid level gauge, the corresponding water pump is turned off; when the liquid level is lower than the lower limit value set by the liquid level gauge, the corresponding water pump and mixer are turned on to achieve continuous production. When the temperature of the electronic thermometer inside the cooling mixing tank is higher than the set upper limit, the water pump and fan of the cooling drying unit 3 are turned on; when the temperature of the electronic thermometer inside the cooling mixing tank is lower than the set lower limit, the water pump and fan of the cooling drying unit 3 are turned off. When the working time of the mixer and the spin dryer reaches the set value of the timer device, the mixer is turned off.

[0024] Follow these steps when using: (1) Acid leaching: The scandium-containing residue is fed into the cooling and stirring tank of the scandium-containing acid solution preparation unit 2. The water pump of the pure water preparation unit 1 and the switch of the leaching acid pipeline are turned on. At the same time, the agitator of the cooling and stirring tank is turned on. The concentrated sulfuric acid in the leaching acid pipeline and the pure water produced by the pure water preparation unit 1 are fed into the cooling and stirring tank of the scandium-containing acid solution preparation unit 2 according to the designed flow ratio. When the liquid level in the cooling and stirring tank is higher than the upper limit set by the level gauge, the water pump of the pure water preparation unit 1 and the switch of the leaching acid pipeline are turned off. When the temperature in the cooling and stirring tank is higher than the upper limit set by the electronic thermometer, the water pump of the cooling and drying unit 3 is turned on to cool the acid leaching process. When the temperature in the cooling and stirring tank is lower than the lower limit set by the electronic thermometer, the water pump of the cooling and drying unit 3 is turned off. When the working time of the agitator reaches the time set by the timer device, the agitator is turned off. The acid leaching process is thus completed, and the scandium-containing slurry is obtained.

[0025] (2) Filtration: When the liquid level in the filter tank is lower than the lower limit set by the level gauge, the water pump in front of the filter tank is turned on, and the scandium-containing slurry obtained in step (1) is pumped into the filter tank of the scandium-containing acid solution preparation unit 2 to separate the filter residue; when the liquid level in the filter tank is higher than the upper limit set by the level gauge, the water pump in front of the filter tank is turned off. The filtration process is thus completed, and the scandium-containing acid solution is obtained.

[0026] (3) pH adjustment: When the liquid level in the stirring tank of the scandium-containing extract preparation unit 5 is lower than the lower limit set by the level gauge, the water pump in front of the stirring tank and the agitator on the stirring tank are turned on. The scandium-containing acid solution obtained in the filter tank in step (2) is pumped into the stirring tank of the scandium-containing extract preparation unit 5 through the water pump, and concentrated sulfuric acid from the leaching acid pipeline and pure water produced by the pure water preparation unit 1 are introduced to adjust the pH to 3.5. When the liquid level in the stirring tank of the scandium-containing extract preparation unit 5 is higher than the upper limit set by the level gauge, the water pump in front of the stirring tank is turned off. When the working time of the agitator reaches the time set by the timer device, the agitator is turned off. The pH adjustment process is thus completed, and the scandium-containing extract is obtained.

[0027] (4) Extraction: Extractant and solvent oil are added to the reactor in the extraction unit 7 according to the design ratio to obtain the extracted organic; when the liquid level in the reactor is lower than the lower limit set by the level gauge, the water pump in front of the reactor and the agitator on the stirring tank are turned on, and the scandium-containing extractant obtained in step (3) is pumped into the reactor through the water pump and mixed with the extracted organic for extraction; when the liquid level in the reactor is lower than the lower limit set by the level gauge, the water pump in front of the reactor is turned off; when the working time of the agitator reaches the time set by the timer device, the agitator is turned off; after standing, the layers are obtained, the upper layer is the extracted organic and the lower layer is the raffinate. The raffinate is returned to the acid leaching in step (1) to form a multi-stage cyclic extraction to reduce the scandium loss in the extraction process; (5) Washing: When the liquid level in the cooling stirring tank of the pre-washing liquid preparation unit 9 is lower than the lower limit set by the level gauge, the leaching acid pipeline switch and the water pump of the pure water preparation unit 1 are turned on, and the stirrer is turned on at the same time. Concentrated sulfuric acid and pure water produced by the pure water preparation unit 1 are introduced into the cooling stirring tank of the pre-washing liquid preparation unit 9 according to the design ratio to obtain the pre-washing liquid; when the liquid level in the cooling stirring tank is higher than the upper limit set by the level gauge, the leaching acid pipeline switch and the water pump of the pure water preparation unit 1 are turned off; when the temperature in the cooling stirring tank is higher than the upper limit set by the electronic thermometer, the water pump of the cooling drying unit 3 is turned on to cool the acid leaching process; when the temperature in the cooling stirring tank is lower than the upper limit set by the electronic thermometer, the water pump of the cooling drying unit 3 is turned on to cool the acid leaching process. When the thermometer is set to the lower limit, the water pump of the cooling and drying unit 3 is turned off; when the liquid level gauge in the reactor of the extraction unit 7 is lower than the set lower limit, the water pump of the pre-wash liquid preparation unit 9 and the agitator in the reactor are turned on, and the pre-wash liquid is pumped into the reactor of the extraction unit 7 for stirring; when the liquid level in the reactor is higher than the set upper limit of the liquid level gauge, the water pump of the pre-wash liquid preparation unit 9 is turned off; when the working time of the agitator in the reactor reaches the set value, the agitator is turned off; after standing, the layers are separated again, the upper layer is the post-wash extracted organic, and the lower layer is the post-wash liquid containing impurities. The post-wash liquid is returned to the acid leaching in step (1) to achieve the reuse of acid and reduce the amount of wastewater discharged. (6) Back-extraction: Oxalic acid is added to the stirred tank in the back-extraction preparation unit according to the design value, and the water pump of the pure water preparation unit 1 is turned on to pump the pure water into the stirred tank in the back-extraction preparation unit. When the liquid level in the stirred tank in the back-extraction preparation unit is lower than the lower limit value set by the level gauge, the stirrer in the stirred tank is turned on. When the liquid level is higher than the upper limit value set by the level gauge, the stirrer in the stirred tank is turned off, and the back-extraction liquid is obtained. When the liquid level gauge in the reaction vessel of the extraction unit 7 is lower than the set lower limit value, the water pump in the back-extraction preparation unit and the stirrer in the reaction vessel are turned on to pump the back-extraction liquid into the reaction vessel of the extraction unit 7 and mix it with the washed and extracted organic obtained in step (5). When the liquid level in the reaction vessel is higher than the upper limit value set by the level gauge, the water pump in the back-extraction preparation unit is turned off. When the working time of the stirrer in the reaction vessel reaches the set value, the stirrer is turned off. After standing, the layers are separated. The upper layer is the back-extracted organic and the lower layer is the scandium-containing intermediate.

[0028] (7) Washing: The scandium-containing intermediate obtained in step (6) is discharged into the spin-drying tank of the washing unit 6, and the spin-drying tank is started simultaneously with the pure water produced in the pure water preparation unit 1; when the working time of the spin-drying tank reaches the time set by the customized device, the spin-drying tank is closed, and the dehydrated scandium-containing intermediate is obtained.

[0029] (8) Drying: The dehydrated scandium-containing intermediate obtained in step (7) is placed in a drying and cooling unit to obtain a dried scandium-containing intermediate; (9) Calcination: The scandium-containing intermediate obtained in step (8) is placed into the electric furnace in the calcination unit 4 and calcined at a set temperature to obtain high-purity scandium oxide with a purity of 99.9%.

[0030] (10) Organic purification: When the liquid level in the reactor of extraction unit 7 is lower than the lower limit set by the level gauge, the water pump in the pre-wash liquid preparation unit 9 and the agitator in the reactor are turned on, and the pre-wash liquid in the pre-wash liquid preparation unit 9 is pumped into the back-extracted organic obtained in step (6) for organic purification; when the liquid level in the reactor of extraction unit 7 is lower than the lower limit set by the level gauge, the water pump in the pre-wash liquid preparation unit 9 is turned off; when the working time of the reactor agitator reaches the time set by the customized device, the agitator in the reactor is turned off. After standing, it is divided into two layers: the upper layer is the washed organic and the lower layer is the washed liquid. The washed liquid is returned to the acid leaching in step (1) to realize the reuse of acid and reduce the amount of wastewater discharged. The washed organic is extracted in the next round of step (4).

[0031] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. Any obvious variations or modifications derived from the technical solutions of this utility model are still within the protection scope of this utility model.

Claims

1. A system for preparing high-purity scandium oxide by hydrometallurgical process, characterized in that, include: The pure water preparation unit (1) has its inlet connected to a tap water pipe and is used to prepare pure water. The cooling and drying unit (3) is connected to the pure water preparation unit (1) to cool the heat released by the chemical reaction during the acid leaching process and the preparation of the pre-wash liquid, and to use the heat for heating and drying of the washed product to achieve waste heat recovery. The pre-wash liquid preparation unit (9) has its inlet connected to the pure water preparation unit 1 (1) and the leaching acid pipeline, and its outer wall cavity inlet and outlet are connected to the inlet and outlet of the cooling and drying unit (3), which is used to prepare the extracted organic and purified back-extracted organic in the pre-wash liquid washing and extraction process. The scandium acid solution preparation unit (2) has its inlet connected to the outlet of the pure water preparation unit (1) and the leaching acid pipeline, its outer wall cavity inlet and outlet connected to the inlet and outlet of the cooling and drying unit (3), and its exhaust port connected to the waste gas treatment system. It is used to leach scandium residue with acid and filter it to obtain scandium acid solution. The scandium-containing extract preparation unit (5) has its inlet connected to the outlet of the scandium-containing acid solution preparation unit (2), the outlet of the pure water preparation unit (1), and the leaching acid pipeline, and is used to adjust the pH of the scandium-containing acid solution to obtain the scandium-containing extract. The stripping agent preparation unit (8) has its inlet connected to the outlet of the pure water preparation unit 1 (1) and is used to prepare the stripping agent; The extraction unit (7) has its inlet connected to the outlet of the scandium-containing extraction stock solution preparation unit (5), the outlet of the pre-wash solution preparation unit (9), and the outlet of the back-extraction agent preparation unit (8), and is used for extraction and back-extraction to obtain scandium-containing intermediates; The washing unit (6) has its inlet connected to the outlet of the extraction unit (7) and the outlet of the pure water preparation unit (1), and its outlet connected to the sewage pipe, and is used to clean scandium-containing intermediates; The clean scandium-containing intermediate obtained by the washing unit (6) is roasted in the roasting unit (4) to obtain high-purity scandium oxide.

2. The system for preparing high-purity scandium oxide by hydrometallurgical process as described in claim 1, characterized in that, The outlet of the extraction unit (7) is connected to the inlet of the scandium acid solution preparation unit (2) and the sewage pipe, so that the raffinate and washing liquid discharged from the extraction unit (7) can be returned to the scandium acid solution preparation unit (2) for recycling or direct discharge.

3. The system for preparing high-purity scandium oxide by hydrometallurgical process as described in claim 1, characterized in that, The scandium-containing solution preparation unit (2) consists of a cooling stirring tank, a water pump, and a filter tank connected in series. The pure water preparation unit (1) consists of a pure water equipment and a storage tank connected in series. The pre-washing solution preparation unit (9) consists of a cooling stirring tank and a water pump connected in series. The scandium-containing extraction stock solution preparation unit (5) and the back-extraction agent preparation unit (8) consist of a stirring tank and a water pump connected in series. The cooling and drying unit (3) consists of an air-cooled heat exchanger and a water pump connected in series. The extraction unit (7) consists of a reaction vessel. The washing unit (6) consists of a spin-drying tank.

4. The system for preparing high-purity scandium oxide by hydrometallurgical process as described in claim 3, characterized in that, The outer wall of the cooling mixing tank is composed of a double-layered sealed cavity for the circulation of cooling water within the cavity.

5. The system for preparing high-purity scandium oxide by hydrometallurgical process as described in claim 3, characterized in that, The cooling mixing tank, mixing tank, storage tank, water pump reactor, and filter tank are composed of one or more units connected in parallel.

6. The system for preparing high-purity scandium oxide by hydrometallurgical process as described in claim 3, characterized in that, The air-cooled heat exchanger consists of a heat exchange coil and a fan, which is used to cool the cooling water and heat the air to form hot air. The hot air is used to dry the scandium-containing intermediate discharged by the washing unit (6) to realize waste heat recovery.

7. The system for preparing high-purity scandium oxide by hydrometallurgical process as described in claim 3, characterized in that, The cooling and stirring tank, stirring tank, reaction vessel, storage tank, and filter tank are equipped with level gauges. The cooling and stirring tank is equipped with an electronic thermometer. The cooling and stirring tank, stirring tank, and reaction vessel are equipped with a stirrer and a timing device. The spin-drying tank is equipped with a timing device.

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