AU2019345538A1 - Centrifugal Stripping Device and Method for Stripping Scandium - Google Patents

Abstract

A centrifugal back-extracting apparatus and a scandium back-extracting method. The centrifugal back-extracting apparatus comprises: an outer shell (10), the outer shell (10) comprising a raw material inlet (11); an inner shell (20), the inner shell (20) being provided inside the outer shell (10), a gap being formed between the outer shell (10) and the inner shell (20), a material channel being provided at the bottom of the outer shell (10) and the bottom of the inner shell (20) to enable the material in the gap to enter the inner shell (20), a finished product channel (21) being provided at the bottom of the inner shell (20), the finished product channel (21) extending through the outer shell (10) to the exterior of the outer shell (10), a first discharge channel and a second discharge channel being provided at the upper part of the inner shell (20), and the first discharge channel being closer to one side of the inner shell than the second discharge channel; and a rotary shaft (30), the rotary shaft (30) being mounted on the outer shell (10) and located inside the inner shell (20), so that the rotary shaft (30) generates, when rotating, a centrifugal force to drive material to be separated and discharged respectively from the first discharge channel and the second discharge channel.

Description

Centrifugal Stripping Device and Method for Stripping Scandium

Technical Field The invention relates to a technical field of centrifugal extraction, in particular to a centrifugal stripping device and a method for stripping scandium.

Background When extracting scandium from a scandium-containing leachate, an organic extractant solution is usually used to extract the scandium to form a scandium-loaded organic phase. And then the scandium is stripped from the organic phase, mainly by adding a stripping agent such as an inorganic acid solution and the like, stripping the scandium into the stripping solution, and precipitating the scandium from the aqueous solution by adding a precipitating agent such as an oxalic acid solution and an alkali solution. The traditional extraction device in a related art is complex, and a large amount of raw materials such as water and the like are consumed during extraction.

Summary An embodiment of the invention provides a centrifugal stripping device and a method for stripping scandium so as to solve a problem that extraction device in a related art is complex. Some embodiments of the present invention provide a centrifugal stripping device, the centrifugal stripping device includes: an outer housing including a raw material inlet; an inner housing disposed in the outer housing, wherein a gap is formed between the outer housing and the inner housing, a material channel is formed in a bottom of the outer housing and a bottom of the inner housing to enable materials in the gap to enter the inner housing, the bottom of the inner housing is provided with a finished product channel, the finished product channel extends to an outside of the outer housing through the outer housing, an upper part of the inner housing is provided with a first discharge channel and a second discharge channel, and the first discharge channel is closer to a side of the inner housing than the second discharge channel; and a rotating shaft, the rotating shaft is disposed on the outer housing and positioned inside the inner housing, such that centrifugal force is generated when the rotating shaft rotates to drive the materials to be separated, and

1 PN132133NFGC the materials are respectively discharged through the first discharge channel and the second discharge channel. In an embodiment, a raw material inlet including a light phase inlet and a heavy phase inlet is provided in a middle of the outer housing, and the raw material inlet includes a light phase inlet and a heavy phase inlet. In an embodiment, the outer housing further includes a first discharge port and a second discharge port, the first discharge channel is communicated with the first discharge port, and the second discharge channel is communicated with the second discharge port. In an embodiment, the outer housing is of an inverted cone-shaped structure, the inner housing is of an inverted cone-shaped structure cooperated with the outer housing, a bottom end of the inner housing has a folded plate inwardly extending, a lower part of the rotating shaft has a baffle plate, a projection of the baffle plate overlaps with a projection of the folded plate in a vertical direction, and the baffle plate is higher than the folded plate. In an embodiment, a plurality of separating discs are disposed in the finished product channel, the separating discs are superimposed in a direction of product flow to form a plurality of sub-channels in the direction of product flow. According to some embodiments of the present invention, a method of stripping scandium is provided, the method includes: carrying out stripping precipitation reaction on an organic phase containing scandium through a precipitation stripping agent solution by utilizing a centrifugal stripping device, so as to obtain a precipitate containing scandium; carrying out solid-liquid separation by utilizing the centrifugal stripping device so as to separate the precipitate containing scandium obtained by the stripping precipitation reaction; the centrifugal stripping device is the above stripping device. In an embodiment, a light phase inlet is the above light phase inlet, a heavy phase inlet is the above heavy phase inlet, and a step of the stripping precipitation reaction includes the following steps: introducing the organic phase containing scandium into the light phase inlet, and introducing a precipitation stripping agent solution into the heavy phase inlet to perform a stripping precipitation reaction to obtain a precipitate containing scandium, a reacted precipitation stripping agent solution and a scandium-stripped organic phase; a solid-liquid separation step includes: under a driving action of the centrifugal force of the rotating shaft,

2 PN132133NFGC discharging the reacted precipitation stripping agent solution through the first discharge channel, discharging the scandium-stripped organic phase through the second discharge channel, and discharging the precipitate containing scandium through the finished product channel. In an embodiment, materials at the light phase inlet and materials at the heavy phase inlet are continuously fed, and a discharge of the finished product channel is intermittent. In an embodiment, a scandium-containing leachate is subjected to scandium extraction treatment by an organic extractant solution by means of the centrifugal stripping device so as to obtain the scandium-containing organic phase. In an embodiment, a concentration of the organic extractant solution is between 0.01 mol/L and 15 mol/L, and a concentration of the precipitation stripping agent solution is between 0.01 mol/L and 15 mol/L. In an embodiment, a volume ratio of a solution at the light phase inlet to a solution at the heavy phase inlet is between 1: 20 and 20: 1. According to the technical scheme provided by the invention, the required materials are extracted by cooperating the structures and parts in the centrifugal stripping device, and the extraction steps are reduced. For example, a finished product is produced in the finished product channel, heavier materials are discharged from the first discharge channel under an action of centrifugal force, lighter materials are discharged from the second discharge channel, and the device structure for realizing the separated materials is simple and only needs to be provided with the cooperation of the outer housing, the inner housing and the rotating shaft. The technical scheme of the invention effectively solves the problem of complex extraction device in a related art.

Brief Description of the Drawings The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and are not to be construed as unduly limiting the invention. In the drawings: Figure 1 shows a schematic structural view of an embodiment of a centrifugal stripping device according to the invention; Figure 2 shows a partially enlarged schematic view of the centrifugal stripping

3 PN132133NFGC device of figure 1; and Figure 3 shows a schematic flow diagram of a process for stripping scandium of the present invention. The above figures include the following reference numerals: 10, outer housing; 11, raw material inlet; 12, first discharge port; 13, second discharge port; 20, inner housing; 21, finished product channel; 22, folded plate; 30, rotating shaft; 31, baffle plate.

Detailed Description of the Embodiments It should be noted that the embodiments and features in the embodiments herein may be combined with one another without conflict. The present invention will now be described in detail, by way of example, with reference to the accompanying drawings. It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. For ease of description, spatially relative terms, such as "on", "above", "at an upper surface of...", "upper", and the like, may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It is to be understood that spatially relative terms are intended to encompass different orientations in use or operation in addition to the orientation of the device depicted in the figures. For example, if a device in the figures is turned over, devices described as "above" or "on" other devices or configurations would then be oriented "below" or "under" the other devices or configurations. Thus, the exemplary term " above" may include orientations of "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations) and the spatial relative description used herein will be explained accordingly. Exemplary embodiments according to the present application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. It should be understood that these embodiments are provided such that this disclosure will be

4 PN132133NFGC thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art, in which the thicknesses of layers and regions are expanded for clarity, and in which like reference numerals are used to designate like devices, and thus their description will be omitted. As shown in figures 1 to 3, the centrifugal stripping device of this embodiment includes: an outer housing 10, an inner housing 20 and a rotating shaft 30. The outer housing 10 includes a raw material inlet 11. The inner housing 20 is disposed in the outer housing 10, a gap is formed between the outer housing 10 and the inner housing 20, a bottom of the outer housing 10 and a bottom of the inner housing 20 are provided with material channels such that materials in the gap enter the inner housing 20, the bottom of the inner housing 20 is provided with a finished product channel 21, the finished product channel 21 extends to an outside of the outer housing 10 through the outer housing 10, and an upper part of the inner housing 20 are provided with a first discharge channel and a second discharge channel; the first discharge channel is closer to a side of the inner case 20 than the second discharge channel. The rotating shaft 30 is installed on the outer housing 10 and positioned inside the inner housing 20 such that the rotating shaft 30 generates centrifugal force when rotating to drive the materials to be separated and discharged from the first discharge channel and the second discharge channel, respectively. According to the technical scheme of the embodiment, the required materials are extracted through a cooperation of structures and parts in the centrifugal stripping device, and extraction steps are reduced. For example, a finished product is produced in the finished product channel, heavier materials are discharged from the first discharge channel under an action of centrifugal force, lighter materials are discharged from the second discharge channel, and a device structure for realizing the separated materials is simple and only needs to be provided with the cooperation of the outer housing, the inner housing and the rotating shaft. The technical scheme of the embodiment effectively solves the problem that extraction device in a related art is complex. Notably, the first discharge channel and the second discharge channel are artificially divided, by centrifugal force such that the first discharge channel passes the denser material, the second discharge channel passes the less dense material, and between the first discharge channel and the second discharge channel is a mixture of the denser and less dense material. As shown in figures 1 and 2, according to a technical scheme of an embodiment,

5 PN132133NFGC a raw material inlet 11 is disposed in a middle of the outer housing 10, and the raw material inlet 11 includes a light phase inlet and a heavy phase inlet. The separate arrangement of the light phase inlet and the heavy phase inlet facilitates mixing of the light phase material and the heavy phase material. As shown in figures 1 and 2, according to an embodiment, the outer housing 10 further includes a first discharge port 12 and a second discharge port 13, the first discharge channel communicating with the first discharge port 12, and the second discharge channel communicating with the second discharge port 13. The density of the material discharged from the first discharge port 12 is large, and density of the material discharged from the second discharge port 13 is small, such that the separation of the materials with different densities is facilitated. In some embodiments, the channel through which the first discharge port 12 communicates is positioned higher than the channel through which the second discharge port 13 communicates. The openings of the first discharge port 12 and the second discharge port 13 face downward. And the rotating shaft 30 is connected with a motor, the motor is fixed on the upper part of the housing 10, and the rotating shaft of the motor faces downwards. The rotation speed of the rotating shaft 30 is between 500 rpm and ,000 rpm. As shown in figures 1 and 2, in an embodiment, the outer housing 10 is of an inverted cone-shaped structure, the inner housing 20 is of an inverted cone-shaped structure cooperated with the outer housing 10, a bottom end of the inner housing 20 is provided with an inward extending folded plate 22, a lower part of the rotating shaft is provided with a baffle plate 31, a projection of the baffle plate 31 overlaps with a projection of the folded plate 22 in a vertical direction, and the baffle plate 31 is higher than the folded plate 22. The baffle plate 31 is arranged such that, on the one hand, the material which is not the finished product does not sink to influence the discharge of the finished product, and on the other hand, the baffle plate 31 has a certain rotating effect. The cooperation of the folded plate 22 and the baffle plate 31 reduces discharge of unfinished materials. As shown in figure 2, according to an embodiment of the invention, a plurality of separation discs are provided in the finished product channel 21, the separation discs are superimposed in a direction of product flow to form a plurality of sub-channels in the direction of product flow. In this way, the finished materials are pure when being discharged through the finished product channel 21, and other unfinished materials

6 PN132133NFGC are not discharged. The finished product outlet of the inner housing 20 is higher than the lowest of the finished product channel 21, such that the mixed phase is not discharged with the finished product. The embodiment of the invention also provides a method for stripping scandium, which includes the following steps: the scandium-containing leachate is subjected to scandium extraction treatment through an organic extractant solution by using a centrifugal stripping device so as to obtain an organic phase containing scandium. The scandium-containing organic phase is subjected to a stripping precipitation reaction by a precipitation stripping agent solution using a centrifugal stripping device so as to obtain a scandium-containing precipitate. Solid-liquid separation is carried out by using the centrifugal stripping device so as to separate the scandium-containing precipitate obtained by the stripping precipitation reaction. The centrifugal stripping device is the above stripping device. As shown in figures 1 to 3, according to the method for stripping scandium of an embodiment, a light phase inlet is the above light phase inlet, and a heavy phase inlet is the above heavy phase inlet. The flow of the stripping precipitation reaction includes the following steps: an organic phase containing scandium is introduced into a light phase inlet, and a precipitation stripping agent solution is introduced into a heavy phase inlet to perform a stripping precipitation reaction to obtain a precipitate containing scandium, a reacted precipitation stripping agent solution and a scandium-stripped organic phase. The solid-liquid separation flow includes the following steps: under a driving action of the centrifugal force of the rotating shaft, the reacted precipitation stripping agent solution is discharged through the first discharge channel, the scandium-stripped organic phase is discharged through the second discharge channel, and the precipitate containing scandium is discharged through the finished product channel. The precipitation stripping agent solution is: a mixed aqueous solution of one or more of sodium hydroxide, ammonia water, oxalic acid, hydrofluoric acid, phosphoric acid, sodium oxalate, sodium carbonate, sodium bicarbonate, sodium phosphate, sodium fluoride, ammonium oxalate and ammonium phosphate. In some embodiment of the present application, washing with the organic phase firstly, and the organic extractant (organic phase) is at least one selected from the group consisting of an organic phosphoric acid extractant, a neutral phosphorus extractant, an organic carboxylic acid extractant, an organic amine extractant and an organic chelating extractant. The organic extractant is at least one of alkanes (e.g.,

7 PN132133NFGC kerosene, n-heptane), aromatic hydrocarbons (e.g., benzene, toluene), organic alcohols (e.g., n-hexanol, isooctanol), and the like having a density less than water. The precipitation stripping agent solution can be one or more aqueous solutions of sodium hydroxide, ammonia water, oxalic acid, hydrofluoric acid, phosphoric acid, sodium oxalate, sodium carbonate, sodium bicarbonate, sodium phosphate, sodium fluoride, ammonium oxalate, ammonium phosphate and the like, and the concentration ranges from 0.01 mol/L to 15 mol/L. According to the method for stripping scandium in an embodiment, the material at the light phase inlet and the material at the heavy phase inlet are continuously fed, and the discharge of the finished product channel is intermittent. The material at the light phase inlet and the material at the heavy phase inlet are continuously fed, such that the extraction reaction is continuously carried out, and the discharge of the finished product channel is intermittent, such that the finished product is discharged outwards after being accumulated by a certain amount. According to the method for stripping scandium of an embodiment, the concentration of the organic extractant solution ranges from 0.01 mol/L to 15 mol/L, and the concentration of the precipitated stripper solution ranges from 0.01 mol/L to mol/L. According to the method for stripping scandium of an embodiment, a volume ratio of solution at the light phase inlet to solution at the heavy phase inlet is between 1: 20 and 20: 1. For example, scandium is extracted from a scandium-containing sulfuric acid solution with a kerosene solution containing 1 mol/L of an extractant P204 (di (2-ethylhexyl) phosphate), the scandium-loaded organic phase is washed with a 0.5 mol/L aqueous sulfuric acid solution, and the washed organic phase and a precipitation stripping agent solution containing 1 mol/L of NaOH are fed into a light phase inlet and a heavy phase inlet, respectively, of a centrifugal stripping precipitator. The liquid flow ratio at the light phase inlet and the heavy phase inlet is 5: 1, the centrifugal extractor is rotated at 3000 rpm, the resulting scandium hydroxide precipitate is finally discharged and collected through the slag phase outlet, the kerosene solution of the scandium-free extractant P204 is discharged and collected from the light phase outlet, and the NaOH solution having a concentration of about 0.2 mol/L is discharged and collected from the heavy phase outlet. For another example, scandium is extracted from a scandium-containing

8 PN132133NFGC hydrochloric acid feed liquid by using a toluene solution containing 1mol/L of a naphthenic acid extractant, and a scandium-loaded organic phase and a precipitation stripping agent solution containing 0.3 mol/L of oxalic acid are respectively input into a light phase inlet and a heavy phase inlet of a centrifugal stripping precipitator, wherein a liquid flow ratio of the light phase inlet to the heavy phase inlet is 1: 10, and the rotating speed of the centrifugal extractor is 8000 rpm; the resultant scandium hydroxide precipitate is finally discharged and collected through a slag phase outlet, a toluene solution of a naphthenic acid extractant, without scandium loading, is discharged and collected from a light phase outlet, and an oxalic acid solution having a concentration of about 0.01 mol/L is discharged and collected from a heavy phase outlet. The extraction of the present application may not be limited to scandium, but may also be 17 elements of lanthanum (La), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y), or may be metals such as magnesium (Mg), Aluminum (AI), calcium (Ca), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), titanium (Ti), zirconium (Zr), hafnium (Hf), barium (Ba), metals such as lead (Pb), tin (Sn), silver (Ag) and thorium (Th). It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the exemplary embodiments in accordance with the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising", when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof. It should be noted that the terms "first, second", and the like in the description and claims of the present application and in the above-mentioned drawings are used for distinguishing between similar objects and not necessarily for describing a particular order or sequential order. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprise", and " have", as well as any variations thereof, are intended to cover a non-exclusive

9 PN132133NFGC inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

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Claims (11)

1. What is claimed is: 1. A centrifugal stripping device, comprising: an outer housing (10) comprising a raw material inlet (11); an inner housing (20) disposed in the outer housing (10), wherein a gap is formed between the outer housing (10) and the inner housing (20), a bottom of the outer housing (10) and a bottom of the inner housing (20) are provided with a material channel to enable materials in the gap to enter the inner housing (20), and the bottom of the inner housing (20) is provided with a finished product channel (21); the finished product channel (21) extends to an outside of the outer housing (10) through the outer housing (10), an upper part of the inner housing (20) is provided with a first discharge channel and a second discharge channel, and the first discharge channel is closer to a side of the inner housing (20) than the second discharge channel; and a rotating shaft (30), wherein the rotating shaft (30) is disposed on the outer housing (10) and is positioned inside the inner housing (20), such that centrifugal force is generated when the rotating shaft (30) rotates to drive materials to be separated, and the materials are respectively discharged from the first discharge channel and the second discharge channel.
2. 2. The centrifugal stripping device according to claim 1, wherein the raw material inlet (11) is disposed in a middle of the outer housing (10), and the raw material inlet (11) comprises a light phase inlet and a heavy phase inlet.
3. 3. The centrifugal stripping device according to claim 1, wherein the outer housing (10) further comprises a first discharge port (12) and a second discharge port (13), the first discharge channel is communicated with the first discharge port (12), the second discharge channel is communicated with the second discharge port (13).
4. 4. The centrifugal stripping device according to claim 1, wherein the outer housing (10) is of an inverted cone-shaped structure, the inner housing (20) is of an inverted cone-shaped structure cooperated with the outer housing (10), a bottom end of the inner housing (20) has a folded plate (22) inwardly extending, and a lower portion of the shaft (30) has a baffle plate (31), a projection of the baffle plate (31) overlaps with a projection of the folded plate (22) in a vertical direction, and the baffle plate (31) is higher than the folded plate (22).
5. 5. The centrifugal stripping device according to claim 1, wherein a plurality of

   11 PN132133NFGC separation discs are disposed in the finished product channel (21), the separation discs are superimposed in a direction of product flow to form a plurality of sub-channels in the direction of product flow.
6. 6. A method for stripping scandium, characterized by comprising the following steps: carrying out stripping precipitation reaction on an organic phase containing scandium through a precipitation stripping agent solution by utilizing a centrifugal stripping device, so as to obtain a precipitate containing scandium; carrying out solid-liquid separation by utilizing the centrifugal stripping device, so as to separate the precipitate containing scandium obtained by the stripping precipitation reaction; wherein the centrifugal stripping device is the stripping device of any one of claims 1 to 5.
7. 7. The method for stripping scandium according to claim 6, wherein a light phase inlet is the light phase inlet of claim 2 and a heavy phase inlet is the heavy phase inlet of claim 2, and a step of the stripping the precipitation reaction comprises: introducing the organic phase containing scandium into the light phase inlet, and introducing the precipitation stripping agent solution into the heavy phase inlet to perform a stripping precipitation reaction to obtain the precipitate containing scandium, a reacted precipitation stripping agent solution and a scandium-stripped organic phase; a solid-liquid separation step comprises: under a driving action of the centrifugal force of the rotating shaft (30), discharging the reacted precipitation stripping agent solution through the first discharge channel, discharging the scandium-stripped organic phase through the second discharge channel, and discharging the precipitate containing scandium through the finished product channel (21).
8. 8. The method for stripping scandium according to claim 7, wherein materials at the light phase inlet and materials at the heavy phase inlet are fed continuously and a discharge of the finished product channel (21) is intermittent.
9. 9. The method for stripping scandium according to claim 6, wherein a scandium-containing leachate is subjected to scandium extraction treatment by means of an organic extractant solution using the centrifugal stripping device so as to obtain the scandium-containing organic phase.
10. 10. The method for stripping scandium according to claim 9, wherein a concentration of the organic extractant solution is between 0.01 mol/L and 15 mol/L,

    12 PN132133NFGC and a concentration of the precipitated stripper solution is between 0.01 mol/L and 15 mol/L.
11. 11. The method for stripping scandium according to claim 7, wherein a volume ratio of a solution at the light phase inlet to a solution at the heavy phase inlet is between 1: 20 and 20: 1.

    13 PN132133NFGC

    Fig 1

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    Fig 2

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    Scandium-containing material liquid

    Organic phase Solvent extraction of Scandium

    Scandium-containing organic phase

    washing

    Precipitating agent Precipitation and solution Stripping

    Scanidium Precipitation

    Fig 3

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