Scandium oxide and preparation method thereof

Abstract

The invention discloses scandium oxide and a preparation method thereof, and belongs to the technical field of scandium oxide materials. The method comprises the following steps: dissolving an acid-soluble scandium-containing extraction raw material by using a first inorganic acid to obtain an extraction stock solution; extracting the extraction stock solution by adopting an organic extraction reagent to obtain a scandium-containing loaded organic substance; the organic extraction reagent comprises HTTA, TOPO and a diluent; washing the scandium-containing loaded organic matter with a second inorganic acid, and then carrying out reverse extraction with a third inorganic acid to obtain a scandium-rich reverse extraction solution; and preparing scandium oxide from the scandium-rich strip liquor. By adopting HTTA and TOPO to synergistically extract scandium, the method has relatively high selectivity and extraction rate on scandium, and is beneficial to preparation of products meeting 3N international scandium oxide standards. In addition, the technological process is short, control points are few, scandium hydroxide is prevented from being generated in the whole preparation process after the raw materials are dissolved, and the problems of filter pressing difficulty and through filtration are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of scandium oxide materials, and in particular to scandium oxide and a preparation method thereof. Background Art

[0002] Scandium metal and its compounds are widely used in energy, electronic devices, medical, chemical, aerospace and other fields. At present, the scandium-related products in the market mainly include several products such as metal scandium, scandium oxide, aluminum-scandium master alloy and other scandium compounds. Among them, high-purity scandium oxide can be extended to metal scandium and aluminum-scandium master alloy in the scandium industry chain, and then used in laser, lighting, scandium-containing target materials, scandium-containing aluminum alloys and solid-state fuel cells.

[0003] Currently, the common methods for purifying scandium oxide are precipitation and extraction.

[0004] Among them, the precipitation method mainly dissolves crude scandium oxide in acid to obtain a metal solution, adjusts the pH and adds sulfate and organic acid to precipitate impurities in the crude scandium oxide, adds ammonia water to the filtrate for precipitation, washes, dissolves in acid, adds oxalic acid to precipitate scandium, and roasts to obtain the product. This method has low selectivity for impurities and is only suitable for the purification of crude scandium oxide with fewer impurities. In addition, scandium hydroxide is generated in the process, and filter pressing is extremely difficult in the actual production process, and filter penetration may occur.

[0005] The solvent extraction method mainly involves dissolving the crude scandium oxide in acid, extracting, precipitating scandium, and roasting. Existing solvent extraction methods often require high concentrations of alkaline substances for stripping, which is dangerous. In addition, the phase separation process after stripping is difficult to operate, and the filter press process is not easy to operate, and there may be a phenomenon of filter penetration.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The object of the present invention is to provide a scandium oxide and a preparation method thereof, so as to solve or improve the above technical problems.

[0008] The present invention can be implemented like this:

[0009] In a first aspect, the present invention provides a method for preparing scandium oxide, comprising: using a first inorganic acid to dissolve an acid-soluble scandium-containing extraction raw material to obtain an extraction stock solution;

[0010] The organic extraction reagent is used to extract the extraction stock solution to obtain the scandium-loaded organic; wherein the organic extraction reagent includes HTTA, TOPO and a diluent;

[0011] washing the scandium-containing organic material with a second inorganic acid to obtain a washed scandium-containing organic material;

[0012] Using a third inorganic acid to strip the washed scandium-containing organic matter to obtain a scandium-rich stripping solution;

[0013] Scandium oxide is prepared from the scandium-rich stripping solution.

[0014] In an alternative embodiment, the scandium content in the extraction feed does not exceed 35 wt %.

[0015] In an optional embodiment, the content of scandium in the extraction raw material is 20wt% to 35wt%.

[0016] In an alternative embodiment, the total content of nickel and cobalt in the extraction feed does not exceed 10 wt%.

[0017] In an alternative embodiment, the first inorganic acid comprises at least one of sulfuric acid and hydrochloric acid.

[0018] In an optional embodiment, the concentration of scandium in the extraction solution is 3 g / L to 5 g / L.

[0019] In an optional embodiment, the hydrogen ion concentration in the extraction solution is 0.1 mol / L to 0.5 mol / L.

[0020] In an optional embodiment, the organic extraction reagent contains 9% to 30% HTTA and 3% to 20% TOPO by volume, and the remainder is a diluent.

[0021] In an optional embodiment, the diluent includes 260# solvent oil.

[0022] In an optional embodiment, the extraction process has at least one of the following characteristics:

[0023] Feature 1: The volume ratio of the organic phase to the aqueous phase during the extraction process is 1:1 to 1:3;

[0024] Feature 2: Extraction time is 5min to 15min;

[0025] Feature 3: The phase separation time after extraction is 5min to 40min.

[0026] In an optional embodiment, the washing process has at least one of the following characteristics:

[0027] Feature 4: The second inorganic acid used for washing includes at least one of sulfuric acid and hydrochloric acid; optionally, the second inorganic acid is sulfuric acid; optionally, the concentration of the sulfuric acid used for washing is 0.1 mol / L to 0.5 mol / L;

[0028] Feature 5: The volume ratio of the organic phase to the aqueous phase during the washing process is 5:1 to 10:1;

[0029] Feature 6: Washing time is 5min to 15min;

[0030] Feature 7: The phase separation time after washing is 5 minutes to 20 minutes.

[0031] In an optional embodiment, the stripping process has at least one of the following characteristics:

[0032] Feature 8: The third inorganic acid used for stripping is hydrochloric acid; optionally, the concentration of the hydrochloric acid is 1 mol / L to 2 mol / L;

[0033] Feature 9: The volume ratio of the organic phase to the aqueous phase during the stripping process is 1:1 to 1:2;

[0034] Feature 10: Stripping time is 5min to 15min;

[0035] Feature 11: The phase separation time after stripping is 5 min to 20 min.

[0036] In an optional embodiment, preparing scandium oxide from a scandium-rich stripping solution comprises: reacting the scandium-rich stripping solution with oxalic acid to obtain scandium oxalate; calcining the scandium oxalate to obtain scandium oxide;

[0037] The amount of oxalic acid used is 1.25 to 2.5 times the amount of oxalic acid required for theoretically precipitating the scandium element in the scandium-rich stripping solution.

[0038] In an optional embodiment, the calcination temperature is 600° C. to 900° C., and / or the calcination time is 2 h to 3 h.

[0039] In a second aspect, the present invention provides scandium oxide, which is prepared by the preparation method of any one of the aforementioned embodiments.

[0040] In an optional embodiment, the scandium content in scandium oxide is not less than 58.5 wt %.

[0041] In an optional embodiment, the scandium content in the scandium oxide is 58.62 wt % to 62.31 wt %.

[0042] In a third aspect, the present invention provides a use of an organic extraction reagent in extracting scandium, wherein the organic extraction reagent comprises 9% to 30% HTTA and 3% to 20% TOPO in terms of mass percentage.

[0043] In an alternative embodiment, the organic extraction reagent further comprises a diluent.

[0044] In an optional embodiment, the concentration of scandium in the extraction solution to be extracted is 3 g / L to 5 g / L.

[0045] In an optional embodiment, the hydrogen ion concentration in the extraction solution to be extracted is 0.1 mol / L to 0.5 mol / L.

[0046] The beneficial effects of the present invention include:

[0047] The present invention uses HTTA and TOPO to extract scandium in a coordinated manner, has high selectivity for scandium, can improve the extraction rate of scandium, has low cost and is easy to operate. The scandium-containing organic material obtained by extraction can be directly stripped of the scandium therein using an inorganic acid, thereby avoiding the problems of the prior art that requires the use of alkaline substances for stripping and the generation of scandium hydroxide, which causes the difficulty of filter pressing and filtration. In addition, the process flow is short, the control points are few, and a product that meets the 3N international scandium oxide standard can be prepared. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0049] Figure 1 A process flow chart of the method for preparing scandium oxide provided by the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0051] The scandium oxide and the preparation method thereof provided by the present invention are specifically described below.

[0052] The present invention provides a method for preparing scandium oxide. Figure 1 , which comprises the following steps:

[0053] S1: using a first inorganic acid to dissolve an acid-soluble scandium-containing extraction raw material to obtain an extraction stock solution.

[0054] In some optional embodiments, the content of scandium in the extraction raw material does not exceed 35wt%, such as 35wt%, 30wt%, 25wt%, 20wt%, 15wt%, 10wt% or 5wt%, or other values ​​within the range of not more than 35wt%. In some more typical embodiments, the content of scandium in the extraction raw material is 20wt% to 35wt%, such as 20wt%, 22wt%, 25wt%, 28wt%, 30wt%, 32wt% or 35wt%, etc. The method provided by the present invention has a better extraction effect on the extraction raw material with a scandium content of 20wt% to 35wt%.

[0055] In some optional embodiments, the total content of nickel and cobalt in the extraction raw material does not exceed 10 wt % to avoid adverse effects on the extraction of scandium.

[0056] In some optional embodiments, the extraction raw material may be an extraction raw material containing scandium oxide, and the extraction raw material may illustratively be a concentrated underflow of P204 stripping liquid.

[0057] In some alternative embodiments, the first inorganic acid may include at least one of sulfuric acid and hydrochloric acid.

[0058] The concentration of hydrogen ions in the extraction solution after the first inorganic acid dissolution can be 0.1mol / L to 0.5mol / L, such as 0.1mol / L, 0.15mol / L, 0.2mol / L, 0.25mol / L, 0.3mol / L, 0.35mol / L, 0.4mol / L, 0.45mol / L or 0.5mol / L, etc., or other values ​​within the range of 0.1mol / L to 0.5mol / L. The concentration of scandium in the extraction solution can be 3g / L to 5g / L, such as 3g / L, 3.5g / L, 4g / L, 4.5g / L or 5g / L, etc., or other values ​​within the range of 3g / L to 5g / L.

[0059] That is, the hydrogen ion concentration of the first inorganic acid and the amount of the first inorganic acid used are not limited, as long as it can dissolve the extraction raw material and make the hydrogen ion concentration in the extraction stock solution 0.1 mol / L to 0.5 mol / L.

[0060] S2: extracting the original extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate; wherein the organic extraction reagent includes HTTA, TOPO and a diluent.

[0061] In some preferred embodiments, the organic extraction reagent is composed of HTTA, TOPO and a diluent, wherein HTTA is used as a chelating extractant and TOPO is used as a neutral phosphorus extractant. The diluent may exemplarily include 260# solvent oil.

[0062] In some optional embodiments, the organic extraction reagent contains 9% to 30% HTTA and 3% to 20% TOPO by volume, and the remainder is a diluent.

[0063] The content of HTTA may be 9%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28% or 30%, or other values ​​within the range of 9% to 30%.

[0064] The content of TOPO may be 3%, 5%, 8%, 10%, 12%, 15%, 18% or 20%, etc., or other values ​​within the range of 3% to 20%.

[0065] If the dosage of HTTA is too low, the organic extraction capacity of scandium is low; if the dosage of HTTA is too high, the extraction rate of iron by HTTA is high. Similarly, if the dosage of TOPO is too low, it is not conducive to inhibiting the extraction of Fe by HTTA; if the dosage of TOPO is too high, it will enhance the extraction of some metal ions coexisting in the aqueous solution.

[0066] It should be noted that the existing extractants used to extract scandium mostly use traditional extractants such as P204 and P507. Such extractants will form relatively stable extractants with scandium during the extraction process, and often require high concentrations of alkaline substances for stripping, which is dangerous. In the phase separation process after stripping, the organic phase is divided into two layers, the upper layer is the extractant layer, and the lower layer is the sulfonated coal oil layer. In the actual production phase separation process, manual operation is extremely difficult. If you are not careful, the extractant will be discharged together with the lower aqueous phase, affecting the subsequent extraction. In addition, the stripping process corresponding to the above method will also generate scandium hydroxide, which is more difficult to filter during pressure filtration and may cause filter penetration.

[0067] The present invention uses HTTA and TOPO to extract scandium in a coordinated manner, has high selectivity for scandium, can improve the extraction rate of scandium, and the extractant only needs to be used in conjunction with 260# solvent oil as a diluent, has low cost and is easy to operate. The scandium-containing loaded organic obtained by extraction can be directly stripped with inorganic acid, avoiding the problem of using alkaline substances for stripping in the prior art to produce scandium hydroxide.

[0068] In some optional embodiments, the volume ratio of the organic phase to the aqueous phase during the extraction process can be 1:1 to 1:3, such as 1:1, 1:1.5, 1:2, 1:2.5 or 1:3, or other values ​​within the range of 1:1 to 1:3.

[0069] The extraction time may be 5 min to 15 min, such as 5 min, 8 min, 10 min, 12 min or 15 min, etc., or other values ​​within the range of 5 min to 15 min.

[0070] The extraction can be carried out at a shaking speed of 100 r / min to 140 r / min (such as 100 r / min, 110 r / min, 120 r / min, 130 r / min or 140 r / min, etc.).

[0071] The phase separation time after extraction can be 5 min to 40 min, such as 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min or 40 min, or other values ​​within the range of 5 min to 40 min.

[0072] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0073] In some optional embodiments, the second inorganic acid used for washing may include at least one of sulfuric acid and hydrochloric acid. In some preferred embodiments, the second inorganic acid may be sulfuric acid, and its concentration may be 0.1mol / L to 0.5mol / L, such as 0.1mol / L, 0.2mol / L, 0.3mol / L, 0.4mol / L or 0.5mol / L, etc., or other values ​​within the range of 0.1mol / L to 0.5mol / L.

[0074] The volume ratio of the organic phase to the aqueous phase during the washing process can be 5:1 to 10:1, such as 5:1, 6:1, 7:1, 8:1, 9:1 or 10:1, or other values ​​within the range of 5:1 to 10:1.

[0075] The washing time may be 5 min to 15 min, such as 5 min, 8 min, 10 min, 12 min or 15 min, etc., or may be other values ​​within the range of 5 min to 15 min.

[0076] The phase separation time after washing can be 5 min to 20 min, such as 5 min, 8 min, 10 min, 12 min, 15 min, 18 min or 20 min, etc., or other values ​​within the range of 5 min to 20 min.

[0077] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0078] In some optional embodiments, the third inorganic acid used for stripping is hydrochloric acid, and its concentration can be 1mol / L to 2mol / L, such as 1mol / L, 1.2mol / L, 1.5mol / L, 1.8mol / L or 2mol / L, etc., or other values ​​within the range of 1mol / L to 2mol / L.

[0079] The volume ratio of the organic phase to the aqueous phase during the stripping process can be 1:1 to 1:2, such as 1:1, 1:1.5 or 1:2, or other values ​​within the range of 1:1 to 1:2.

[0080] The stripping time may be 5 min to 15 min, such as 5 min, 8 min, 10 min, 12 min or 15 min, etc., or may be other values ​​within the range of 5 min to 15 min.

[0081] The phase separation time after stripping can be 5 min to 20 min, such as 5 min, 10 min, 15 min or 20 min, etc., or other values ​​within the range of 5 min to 20 min.

[0082] The blank organic matter obtained in this step can be reused in the extraction step.

[0083] S5: preparing scandium oxide from the scandium-rich stripping solution.

[0084] In some optional embodiments, the scandium-rich stripping solution can be reacted with oxalic acid to obtain scandium oxalate, and the scandium oxalate can be roasted to obtain scandium oxide. In addition, other methods can be used to prepare scandium oxide from the scandium-rich stripping solution.

[0085] When the scandium-rich stripping solution reacts with oxalic acid, the amount of oxalic acid used is 1.25 to 2.5 times the amount of oxalic acid required for theoretical precipitation of the scandium element in the scandium-rich stripping solution, such as 1.25 times, 1.5 times, 2 times or 2.5 times, etc., and can also be other values ​​within the range of 1.25 to 2.5.

[0086] When scandium oxalate is calcined, the calcination temperature may be 600°C to 900°C, such as 600°C, 650°C, 700°C, 750°C, 800°C, 850°C or 900°C, or other values ​​within the range of 600°C to 900°C.

[0087] The calcination time may be 2 h to 3 h, such as 2 h, 2.5 h or 3 h, or other values ​​within the range of 2 h to 3 h.

[0088] Furthermore, the scandium oxide obtained by calcination may be washed with water.

[0089] As mentioned above, the preparation method of scandium oxide provided by the present invention has a shorter process and fewer control points, thereby avoiding the formation of scandium hydroxide in the preparation process, and further avoiding the difficulty of filter pressing and filtration problems; the extractant used in the method has a high selectivity for scandium; combined with low-acid extraction and high-acid stripping, the extraction rate of scandium can reach 83.0% to 99.9%, and the stripping rate of scandium can reach 97.0% to 99.4%, and scandium with higher purity can be obtained with a smaller amount of the third organic acid.

[0090] Correspondingly, the present invention also provides scandium oxide, which is prepared by the above preparation method.

[0091] In some optional embodiments, the scandium content in the scandium oxide is not less than 58.5 wt%, for example, it can be 58.62 wt% to 62.31 wt%.

[0092] In some optional embodiments, the purity of scandium oxide is not less than 99%.

[0093] This scandium oxide can meet the 3N international scandium oxide standard and can be further used in batteries and other fields.

[0094] In addition, the present invention also provides an application of an organic extraction reagent in the extraction of scandium, wherein the organic extraction reagent comprises 9% to 30% (such as 9%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28% or 30%) of HTTA and 3% to 20% (such as 3%, 5%, 8%, 10%, 12%, 15%, 18% or 20%) of TOPO in terms of mass percentage. Furthermore, the organic extraction reagent also comprises a diluent (such as 260# solvent oil, etc.).

[0095] In some optional embodiments, the concentration of scandium in the extraction solution to be extracted can be 3 g / L to 5 g / L (such as 3 g / L, 3.5 g / L, 4 g / L, 4.5 g / L or 5 g / L, etc.).

[0096] In some optional embodiments, the hydrogen ion concentration in the extraction solution to be extracted can be 0.1mol / L to 0.5mol / L (such as 0.1mol / L, 0.15mol / L, 0.2mol / L, 0.25mol / L, 0.3mol / L, 0.35mol / L, 0.4mol / L, 0.45mol / L or 0.5mol / L, etc.).

[0097] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0098] Example 1

[0099] This embodiment provides a method for preparing scandium oxide, comprising the following steps:

[0100] S1: dissolving the extraction raw material with sulfuric acid to obtain the extraction stock solution.

[0101] The extraction raw material is the concentrated bottom flow of P204 stripping liquid, the Sc content in the extraction raw material is 35wt%, and the total amount of Ni and Co is less than 10wt%.

[0102] The extracted solution obtained after dissolution contained 4.820 g / L Sc, 0.3511 g / L Ni, 0.6026 g / L Zn, 0.4313 g / L Co, 0.5588 g / L Cu, 0.0328 g / L Mn and 0.0328 g / L Fe. + The concentration is 0.1mol / L.

[0103] S2: extracting the above-mentioned extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate.

[0104] Calculated by volume percentage, the organic extraction reagent contains 10% HTTA and 10% TOPO, and the remainder is 260# solvent oil.

[0105] During the extraction process, the extraction phase ratio (that is, the volume ratio of the organic phase to the aqueous phase, the same below) was 1:1, the oscillation speed was 120 r / min, the extraction mixing time was 5 min, and the phase separation time was 20 min.

[0106] The loading amount of Sc in the scandium-containing organic material is 4.024 g / L, the loading amount of Ni is 0.0057 g / L, the loading amount of Co is 0.0052 g / L, and the loading amount of Fe is 0.0046 g / L. The extraction rate of Sc is 83.49%.

[0107] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0108] The second inorganic acid is a sulfuric acid solution with a concentration of 0.2 mol / L, the washing phase ratio is 5:1, the washing mixing time is 5 min, and the phase separation time is 10 min.

[0109] The content of Sc in the washing liquid was 0.1944 g / L, the content of Ni was 0.0044 g / L, the content of Zn was 0.0028 g / L, the content of Co was 0.0016 g / L, the content of Cu was 0.0012 g / L, the content of Mn was 0.0028 g / L, and the content of Fe was 0.0038 g / L.

[0110] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0111] Among them, the third inorganic acid is hydrochloric acid with a concentration of 2 mol / L, the stripping phase ratio is 1:1, the stripping mixing time is 5 min, and the phase separation time is 8 min.

[0112] The stripping rate of Sc is 97.29%, and the blank organic is returned to S2 for recycling.

[0113] S5: reacting the scandium-rich stripping solution with analytically pure oxalic acid to obtain a scandium oxalate precipitate.

[0114] The amount of analytically pure oxalic acid (diluted to a solution with a mass fraction of 10 wt%) is 1.5 times the amount of oxalic acid required for theoretical precipitation of the scandium element in the scandium-rich stripping solution.

[0115] S6: roasting the scandium oxalate to obtain scandium oxide; washing and drying the obtained scandium oxide.

[0116] The calcination temperature is 800°C and the calcination time is 2h.

[0117] The scandium grade of the scandium oxide after washing and drying reaches 58.62%.

[0118] Example 2

[0119] This embodiment provides a method for preparing scandium oxide, comprising the following steps:

[0120] S1: dissolving the extraction raw material with sulfuric acid to obtain the extraction stock solution.

[0121] The extraction raw material is the concentrated bottom flow of P204 stripping liquid, the Sc content in the extraction raw material is 35wt%, and the total amount of Ni and Co is less than 10wt%.

[0122] The extracted solution obtained after dissolution contained 4.820 g / L Sc, 0.3511 g / L Ni, 0.6026 g / L Zn, 0.4313 g / L Co, 0.5588 g / L Cu, 0.0328 g / L Mn and 0.0328 g / L Fe. + The concentration is 0.1mol / L.

[0123] S2: extracting the above-mentioned extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate.

[0124] Calculated by volume percentage, the organic extraction reagent contains 12% HTTA and 4% TOPO, and the remainder is 260# solvent oil.

[0125] During the extraction process, the extraction phase ratio (that is, the volume ratio of the organic phase to the aqueous phase, the same below) was 1:1, the oscillation speed was 120 r / min, the extraction mixing time was 5 min, and the phase separation time was 20 min.

[0126] The loading amount of Sc in the scandium-containing organic material is 4.785 g / L, the loading amount of Ni is 0.0045 g / L, the loading amount of Co is 0.0048 g / L, and the loading amount of Fe is 0.0059 g / L. The extraction rate of Sc is 99.27%.

[0127] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0128] The second inorganic acid is a sulfuric acid solution with a concentration of 0.3 mol / L, the washing phase ratio is 8:1, the washing mixing time is 5 min, and the phase separation time is 10 min.

[0129] The content of Sc in the washing liquid is 0.2394 / L, the content of Ni is 0.0032 g / L, the content of Zn is 0.0006 g / L, the content of Co is 0.0008 g / L, the content of Cu is 0.0023 g / L, the content of Mn is 0.0010 g / L, and the content of Fe is 0.064 g / L.

[0130] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0131] Among them, the third inorganic acid is hydrochloric acid with a concentration of 2 mol / L, the stripping phase ratio is 2:1, the stripping mixing time is 5 minutes, and the phase separation time is 8 minutes.

[0132] The stripping rate of Sc is 99.40%, and the blank organic is returned to S2 for recycling.

[0133] S5: reacting the scandium-rich stripping solution with analytically pure oxalic acid to obtain a scandium oxalate precipitate.

[0134] The amount of analytically pure oxalic acid (diluted to a solution with a mass fraction of 10 wt%) used is twice the amount of oxalic acid required for theoretically precipitating the scandium element in the scandium-rich stripping solution.

[0135] S6: roasting the scandium oxalate to obtain scandium oxide; washing and drying the obtained scandium oxide.

[0136] The calcination temperature is 900°C and the calcination time is 2h.

[0137] The scandium grade of the scandium oxide after washing and drying reaches 62.15%.

[0138] Example 3

[0139] This embodiment provides a method for preparing scandium oxide, comprising the following steps:

[0140] S1: dissolving the extraction raw material with sulfuric acid to obtain the extraction stock solution.

[0141] The extraction raw material is the concentrated bottom flow of P204 stripping liquid, the Sc content in the extraction raw material is 35wt%, and the total amount of Ni and Co is less than 10wt%.

[0142] The extracted solution obtained after dissolution contained 3.259 g / L Sc, 0.4138 g / L Ni, 0.0337 g / L Zn, 0.0196 g / L Co, 0.2132 g / L Cu, 0.0364 g / L Mn and 0.0451 g / L Fe. + The concentration is 0.3mol / L.

[0143] S2: extracting the above-mentioned extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate.

[0144] Calculated by volume percentage, the organic extraction reagent contains 10% HTTA and 5% TOPO, and the remainder is 260# solvent oil.

[0145] During the extraction process, the extraction phase ratio (that is, the volume ratio of the organic phase to the aqueous phase, the same below) was 1:2, the oscillation speed was 120 r / min, the extraction mixing time was 5 min, and the phase separation time was 20 min.

[0146] The loading amount of Sc in the scandium-containing organic material is 5.639 g / L, the loading amount of Ni is 0.0295 g / L, the loading amount of Co is 0.0023 g / L, and the loading amount of Fe is 0.0146 g / L. The extraction rate of Sc is 86.51%.

[0147] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0148] The second inorganic acid is a sulfuric acid solution with a concentration of 0.5 mol / L, the washing phase ratio is 10:1, the washing mixing time is 5 min, and the phase separation time is 10 min.

[0149] The content of Sc in the washing liquid is 0.2781 g / L, the content of Ni is 0.0378 g / L, the content of Zn is 0.0009 g / L, the content of Co is 0.0067 g / L, the content of Cu is 0.0032 g / L, the content of Mn is 0.0015 g / L, and the content of Fe is 0.0097 g / L.

[0150] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0151] Among them, the third inorganic acid is hydrochloric acid with a concentration of 1.5 mol / L, the stripping phase ratio is 1:1, the stripping mixing time is 5 minutes, and the phase separation time is 8 minutes.

[0152] The stripping rate of Sc is 97.03%, and the blank organic is returned to S2 for recycling.

[0153] S5: reacting the scandium-rich stripping solution with analytically pure oxalic acid to obtain a scandium oxalate precipitate.

[0154] The amount of analytically pure oxalic acid (diluted to a solution with a mass fraction of 10 wt%) used is 1.25 times the amount of oxalic acid required for theoretical precipitation of the scandium element in the scandium-rich stripping solution.

[0155] S6: roasting the scandium oxalate to obtain scandium oxide; washing and drying the obtained scandium oxide.

[0156] The calcination temperature is 600°C and the calcination time is 3h.

[0157] The scandium grade of the scandium oxide after washing and drying reaches 59.89%.

[0158] Example 4

[0159] This embodiment provides a method for preparing scandium oxide, comprising the following steps:

[0160] S1: dissolving the extraction raw material with sulfuric acid to obtain the extraction stock solution.

[0161] The extraction raw material is the concentrated bottom flow of P204 stripping liquid, the Sc content in the extraction raw material is 35wt%, and the total amount of Ni and Co is less than 10wt%.

[0162] The extracted solution obtained after dissolution contained 3.259 g / L Sc, 0.4138 g / L Ni, 0.0337 g / L Zn, 0.0196 g / L Co, 0.2132 g / L Cu, 0.0364 g / L Mn and 0.0451 g / L Fe. + The concentration is 0.3mol / L.

[0163] S2: extracting the above-mentioned extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate.

[0164] Calculated by volume percentage, the organic extraction reagent contains 9% HTTA and 3% TOPO, and the remainder is 260# solvent oil.

[0165] During the extraction process, the extraction phase ratio (that is, the volume ratio of the organic phase to the aqueous phase, the same below) was 1:2, the oscillation speed was 120 r / min, the extraction mixing time was 5 min, and the phase separation time was 20 min.

[0166] The loading amount of Sc in the scandium-containing organic material is 6.51 g / L, the loading amount of Ni is 0.0092 g / L, the loading amount of Co is 0.0019 g / L, and the loading amount of Fe is 0.0020 g / L. The extraction rate of Sc is 99.89%.

[0167] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0168] The second inorganic acid is a sulfuric acid solution with a concentration of 0.4 mol / L, the washing phase ratio is 5:1, the washing mixing time is 5 min, and the phase separation time is 10 min.

[0169] The content of Sc in the washing liquid is 0.1944 g / L, the content of Ni is 0.0239 g / L, the content of Zn is 0.010 g / L, the content of Co is 0.0087 g / L, the content of Cu is 0.0071 g / L, the content of Mn is 0.0058 g / L, and the content of Fe is 0.092 g / L.

[0170] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0171] Among them, the third inorganic acid is hydrochloric acid with a concentration of 1 mol / L, the stripping phase ratio is 1:2, the stripping mixing time is 5 minutes, and the phase separation time is 8 minutes.

[0172] The stripping rate of Sc is 97.29%, and the blank organic is returned to S2 for recycling.

[0173] S5: reacting the scandium-rich stripping solution with analytically pure oxalic acid to obtain a scandium oxalate precipitate.

[0174] The amount of analytically pure oxalic acid (diluted to a solution with a mass fraction of 10 wt%) is 2.5 times the amount of oxalic acid required for theoretical precipitation of the scandium element in the scandium-rich stripping solution.

[0175] S6: roasting the scandium oxalate to obtain scandium oxide; washing and drying the obtained scandium oxide.

[0176] The calcination temperature is 800°C and the calcination time is 2h.

[0177] The scandium grade of scandium oxide after washing and drying reaches 62.31%.

[0178] Example 5

[0179] This comparative example provides a method for preparing scandium oxide, comprising the following steps:

[0180] S1: dissolving the extraction raw material with sulfuric acid to obtain the extraction stock solution.

[0181] The extraction raw material is the concentrated bottom flow of P204 stripping liquid, the Sc content in the extraction raw material is 35wt%, and the total amount of Ni and Co is less than 10wt%.

[0182] The extracted solution obtained after dissolution contained 19.83 g / L Sc, 5.901 g / L Ni, 0.1495 g / L Zn, 0.2956 g / L Co, 0.8824 g / L Cu, 0.4668 g / L Mn and 0.0472 g / L Fe. + The concentration is 0.1mol / L.

[0183] S2: extracting the above-mentioned extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate.

[0184] Calculated by volume percentage, the organic extraction reagent contains 12% HTTA and 4% TOPO, and the remainder is 260# solvent oil.

[0185] During the extraction process, the extraction phase ratio (that is, the volume ratio of the organic phase to the aqueous phase, the same below) was 1:1, the oscillation speed was 120 r / min, the extraction mixing time was 5 min, and the phase separation time was 55 min.

[0186] The loading amount of Sc in the scandium-containing organic material is 5.237 g / L, the loading amount of Ni is 0.0457 g / L, the loading amount of Co is 0.0072 g / L, and the loading amount of Fe is 0.0059 g / L. The extraction rate of Sc is 26.40%.

[0187] It should be noted that, compared with Example 2, the scandium content in the extraction solution of this embodiment is higher, the organic Sc ​​loading is in a saturated state, and the extraction rate is calculated as (loading amount in the organic phase ÷ amount of the extracted substance in the two phases) × 100%. The loading amounts of the two are roughly the same, but the denominator in the calculation formula of this embodiment is larger, so the calculated extraction rate is lower.

[0188] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0189] The second inorganic acid is a sulfuric acid solution with a concentration of 0.3 mol / L, the washing phase ratio is 8:1, the washing mixing time is 5 min, and the phase separation time is 10 min.

[0190] The content of Sc in the washing liquid is 0.2761 g / L, the content of Ni is 0.0176 / L, the content of Zn is 0.0038 g / L, the content of Co is 0.0082 g / L, the content of Cu is 0.0074 g / L, the content of Mn is 0.066 g / L, and the content of Fe is 0.069 g / L.

[0191] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0192] Among them, the third inorganic acid is hydrochloric acid with a concentration of 2 mol / L, the stripping phase ratio is 2:1, the stripping mixing time is 5 minutes, and the phase separation time is 8 minutes.

[0193] The stripping rate of Sc is 98.62%, and the blank organic is returned to S2 for recycling.

[0194] S5: reacting the scandium-rich stripping solution with analytically pure oxalic acid to obtain a scandium oxalate precipitate.

[0195] The amount of analytically pure oxalic acid (diluted to a solution with a mass fraction of 10 wt%) used is twice the amount of oxalic acid required for theoretically precipitating the scandium element in the scandium-rich stripping solution.

[0196] S6: roasting the scandium oxalate to obtain scandium oxide; washing and drying the obtained scandium oxide.

[0197] The calcination temperature is 900°C and the calcination time is 2h.

[0198] The scandium grade of the scandium oxide after washing and drying reaches 60.39%.

[0199] Comparative Example 1

[0200] The difference between this comparative example and Example 1 is that, by volume percentage, the organic extraction reagent contains 10% HTTA and the remainder is 260# solvent oil. The phase separation time in S2 is 25 minutes.

[0201] In the scandium-containing organic material extracted in this comparative example, the loading amount of Sc is 3.421 g / L, the loading amount of Ni is 0.0068 g / L, the loading amount of Co is 0.0047 g / L, and the loading amount of Fe is 0.0325 g / L. The extraction rate of Sc is 70.98%.

[0202] The washed scandium-containing organic material has a Sc content of 0.1546 g / L, a Ni content of 0.0058 g / L, a Zn content of 0.0006 g / L, a Co content of 0.0052 g / L, a Cu content of 0.0031 g / L, a Mn content of 0.0031 g / L, and a Fe content of 0.0044 g / L.

[0203] The stripping rate of Sc was 97.29%, and the stripping rate of Fe was 98%.

[0204] The scandium grade of the scandium oxide after washing and drying is 53.32%, but the Fe element exceeds the standard, and the prepared scandium oxide does not meet the 3N national standard scandium oxide.

[0205] Comparative Example 2

[0206] The difference between this comparative example and Example 1 is that, by volume percentage, the organic extraction reagent contains 10% TOPO and the remainder is 260# solvent oil. The phase separation time in S2 is 40 minutes.

[0207] In the scandium-containing organic material extracted in this comparative example, the loading amount of Sc is 2.865 g / L, the loading amount of Ni is 0.0753 g / L, the loading amount of Co is 0.0369 g / L, and the loading amount of Fe is 0.0044 g / L. The extraction rate of Sc is 59.43%.

[0208] The washed scandium-containing organic material has a Sc content of 0.1132 g / L, a Ni content of 0.0878 g / L, a Zn content of 0.0091 g / L, a Co content of 0.0088 g / L, a Cu content of 0.0231 g / L, a Mn content of 0.0027 g / L, and a Fe content of 0.0068 g / L.

[0209] The stripping rate of Sc was 79.05%.

[0210] The scandium grade of the scandium oxide obtained after roasting is 53.33%.

[0211] Comparative Example 3

[0212] This comparative example provides a method for preparing scandium oxide, comprising the following steps:

[0213] S1: dissolving the extraction raw material with sulfuric acid to obtain the extraction stock solution.

[0214] The extraction raw material is the concentrated bottom flow of P204 stripping liquid, the Sc content in the extraction raw material is 35wt%, and the total amount of Ni and Co is less than 10wt%.

[0215] The extracted solution obtained after dissolution contained 3.259 g / L Sc, 0.4138 g / L Ni, 0.0337 g / L Zn, 0.0196 g / L Co, 0.2132 g / L Cu, 0.0364 g / L Mn and 0.0451 g / L Fe. + The concentration is 0.3mol / L.

[0216] S2: extracting the above-mentioned extraction solution with an organic extraction reagent to obtain scandium-loaded organic and raffinate.

[0217] Calculated by volume percentage, the organic extraction reagent contains 9% HTTA and 3% TOPO, and the remainder is 260# solvent oil.

[0218] During the extraction process, the extraction phase ratio (that is, the volume ratio of the organic phase to the aqueous phase, the same below) was 1:2, the oscillation speed was 120 r / min, the extraction mixing time was 5 min, and the phase separation time was 20 min.

[0219] The loading amount of Sc in the scandium-containing organic material is 6.438 g / L, the loading amount of Ni is 0.0100 g / L, the loading amount of Co is 0.0017 g / L, and the loading amount of Fe is 0.0019 g / L. The extraction rate of Sc is 98.78%.

[0220] S3: washing the scandium-containing organic material with a second inorganic acid to obtain the washed scandium-containing organic material and a washing liquid.

[0221] The second inorganic acid is a sulfuric acid solution with a concentration of 0.4 mol / L, the washing phase ratio is 5:1, the washing mixing time is 5 min, and the phase separation time is 10 min.

[0222] The content of Sc in the washing liquid is 0.2011 g / L, the content of Ni is 0.0212 g / L, the content of Zn is 0.0009 g / L, the content of Co is 0.0094 g / L, the content of Cu is 0.0083 g / L, the content of Mn is 0.0058 g / L, and the content of Fe is 0.0115 g / L.

[0223] S4: stripping the washed scandium-containing organic solution with a third inorganic acid to obtain a scandium-rich stripping solution and a blank organic solution.

[0224] Among them, the third inorganic acid is hydrochloric acid with a concentration of 0.7 mol / L, the stripping phase ratio is 1:2, the stripping mixing time is 5 minutes, and the phase separation time is 8 minutes.

[0225] The stripping rate of Sc is 62.68%, and the blank organic is returned to S2 for recycling.

[0226] S5: reacting the scandium-rich stripping solution with analytically pure oxalic acid to obtain a scandium oxalate precipitate.

[0227] The amount of analytically pure oxalic acid (diluted to a solution with a mass fraction of 10 wt%) is 2.5 times the amount of oxalic acid required for theoretical precipitation of the scandium element in the scandium-rich stripping solution.

[0228] Since the Sc stripping rate of this comparative example is too low, the subsequent calcination process is not performed.

[0229] For the convenience of comparison, some effect data of the above embodiments and comparative examples are summarized in Table 1.

[0230] Table 1 Comparison data

[0231] Extraction rate of Sc (%) Stripping rate of Sc (%) Scandium grade (%) Example 1 83.49 97.29 58.62 Example 2 99.27 99.40 62.15 Example 3 86.51 97.03 59.89 Example 4 99.89 97.29 62.31 Example 5 26.40 98.62 60.39 Comparative Example 1 70.98 97.29 53.32 Comparative Example 2 59.43 79.05 53.33 Comparative Example 3 98.78 62.68 -

[0232] By comparing the above examples and comparative examples, it can be seen that all examples can effectively extract scandium with a high extraction rate, and only a small amount of hydrochloric acid is needed in the stripping process to strip out scandium. In addition, compared with using a single HTTA extractant, by combining HTTA with TOPO, the extraction rate of Sc can be increased while suppressing the extraction of Fe by HTTA.

[0233] In summary, the present invention uses HTTA and TOPO to extract scandium in a coordinated manner, which has high selectivity and extraction rate for scandium, and is conducive to preparing products that meet the 3N international scandium oxide standard. In addition, the process flow is short, with fewer control points, and the entire preparation process after dissolving the raw materials avoids the formation of scandium hydroxide, avoiding the difficulty of filter pressing and the problem of filter penetration.

[0234] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing scandium oxide, characterized in that: include: Using a first inorganic acid to dissolve an acid-soluble scandium-containing extraction raw material to obtain an extraction stock solution; The extraction stock solution is extracted with an organic extraction reagent to obtain a scandium-loaded organic; wherein the organic extraction reagent comprises HTTA, TOPO and a diluent; washing the scandium-containing organic material with a second inorganic acid to obtain a washed scandium-containing organic material; Using a third inorganic acid to strip the washed scandium-containing organic matter to obtain a scandium-rich stripping solution; The scandium-rich stripping solution is used to prepare scandium oxide.

2. The preparation method according to claim 1, characterized in that: The content of scandium in the extraction raw material does not exceed 35wt%; Optionally, the content of scandium in the extraction raw material is 20wt% to 35wt%; Optionally, the total content of nickel and cobalt in the extraction raw material does not exceed 10wt%.

3. The preparation method according to claim 1, characterized in that: The first inorganic acid comprises at least one of sulfuric acid and hydrochloric acid; Optionally, the concentration of scandium in the extraction solution is 3 g / L to 5 g / L; Optionally, the hydrogen ion concentration in the extraction stock solution is 0.1 mol / L to 0.5 mol / L.

4. The preparation method according to any one of claims 1 to 3, characterized in that: In terms of volume percentage, the organic extraction reagent contains 9% to 30% of the HTTA and 3% to 20% of the TOPO, and the remainder is the diluent; Optionally, the diluent includes 260# solvent oil.

5. The preparation method according to claim 4, characterized in that: The extraction process has at least one of the following characteristics: Feature 1: The volume ratio of the organic phase to the aqueous phase during the extraction process is 1:1 to 1:3; Feature 2: Extraction time is 5min to 15min; Feature 3: The phase separation time after extraction is 5min to 40min.

6. The preparation method according to claim 1, characterized in that: The washing process has at least one of the following characteristics: Feature 4: The second inorganic acid used for washing includes at least one of sulfuric acid and hydrochloric acid; optionally, the second inorganic acid is sulfuric acid; optionally, the concentration of the sulfuric acid used for washing is 0.1 mol / L to 0.5 mol / L; Feature 5: The volume ratio of the organic phase to the aqueous phase during the washing process is 5:1 to 10:1; Feature 6: Washing time is 5min to 15min; Feature 7: The phase separation time after washing is 5 minutes to 20 minutes.

7. The preparation method according to claim 1, characterized in that: The stripping process has at least one of the following characteristics: Feature 8: The third inorganic acid used for stripping is hydrochloric acid; optionally, the concentration of the hydrochloric acid is 1 mol / L to 2 mol / L; Feature 9: The volume ratio of the organic phase to the aqueous phase during the stripping process is 1:1 to 1:2; Feature 10: Stripping time is 5min to 15min; Feature 11: The phase separation time after stripping is 5 min to 20 min.

8. The preparation method according to claim 1, characterized in that: The method of preparing scandium oxide from the scandium-rich stripping solution comprises: reacting the scandium-rich stripping solution with oxalic acid to obtain scandium oxalate; calcining the scandium oxalate to obtain scandium oxide; The amount of oxalic acid used is 1.25 to 2.5 times the amount of oxalic acid theoretically required to precipitate the scandium element in the scandium-rich stripping solution.

9. The preparation method according to claim 8, characterized in that: The calcination temperature is 600° C. to 900° C., and / or the calcination time is 2 h to 3 h.

10. A scandium oxide, characterized in that: The scandium oxide is prepared by the preparation method according to any one of claims 1 to 9; Optionally, the scandium content in the scandium oxide is not less than 58.5wt%; Optionally, the scandium content in the scandium oxide is 58.62wt% to 62.31wt%.

11. Use of an organic extraction reagent in extracting scandium, characterized in that: In terms of mass percentage, the organic extraction reagent includes 9% to 30% HTTA and 3% to 20% TOPO; Optionally, the organic extraction reagent further comprises a diluent; Optionally, the concentration of scandium in the extraction solution to be extracted is 3 g / L to 5 g / L; Optionally, the hydrogen ion concentration in the extraction stock solution to be extracted is 0.1 mol / L to 0.5 mol / L.

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