A method for determining scandium and niobium in beneficiation and smelting tailings

Abstract

The invention discloses a method for determining scandium and niobium in the tailings of Baotou Bayan Obo ore dressing and smelting, which includes: weighing a sample in a porcelain ash dish, placing it in a muffle furnace for burning, completely burning and decomposing carbon and carbides in the tailings, then transferring it into a platinum crucible, adding dilute sulfuric acid and hydrofluoric acid, heating to dissolve the sample, removing it when sulfuric acid fumes, cooling, adding a certain amount of potassium pyrosulfate, then placing it in a muffle furnace for melting, dissolving salts with dilute hydrochloric acid, adding a small amount of tartaric acid solution, transferring it into a volumetric flask, and using ICP-MS to determine scandium and niobium. The method of the invention has high sensitivity, fast determination speed, simple operation, less interference compared with other methods, and good selectivity at the same time; using rhodium as an internal standard to improve the determination stability, and can provide accurate data for controlling the process of comprehensive utilization of tailings recovery.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgical analysis, and particularly relates to a method for determining scandium and niobium in the tailings of Baotou Bayan Obo ore dressing and smelting. Background Art

[0002] Scandium and niobium are widely used in industries such as electronics, metallurgy, aerospace, and military. Bayan Obo ore is an iron, rare earth, niobium, and scandium polymetallic associated deposit, containing 71 elements. After iron is selected from Bayan Obo ore and discharged into the tailings dam, the scandium content in the tailings is about 0.050%, and the niobium content is higher than 0.070%. Its value is very objective. Accurately determining the contents of scandium and niobium in the tailings is very important for the recycling and utilization of the tailings of Baotou Steel.

[0003] At present, the main methods for determining scandium and niobium include chemical methods, spectrophotometry, inductively coupled plasma atomic emission spectrometry, etc. In chemical methods, the gravimetric method can determine niobium with a mass fraction of up to 50%, but the coexistence and separation of niobium and tantalum are difficult, the operation process is complex, and the results are on the high side; although spectrophotometry can determine niobium at about 0.01%, tantalum is also determined simultaneously; the intensity of niobium determined by inductively coupled plasma emission spectrometry is low, and the determination accuracy is low. In recent years, inductively coupled plasma emission spectrometry has mostly been used to determine scandium. For example, Pang Xueyong discussed "Determination of Scandium in the Tailings of Bayan Obo Iron Ore by ICP - AES Method", but there is no standard method and literature report on the simultaneous determination of scandium and niobium in the tailings of Baotou Bayan Obo ore dressing and smelting by ICP - MS method. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for determining scandium and niobium in the tailings of Baotou Bayan Obo ore dressing and smelting, which has high sensitivity, fast determination speed, simple operation, less interference compared with other methods, and good selectivity; using rhodium as an internal standard to improve the determination stability, and can provide accurate data for the control process of the comprehensive utilization of tailings recycling.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for determining scandium and niobium in the tailings of Baotou Bayan Obo ore dressing and smelting according to the present invention includes: weighing a sample in a porcelain ash dish, placing it in a muffle furnace for burning, completely burning and decomposing carbon and carbides in the tailings and then transferring it to a platinum crucible, adding dilute sulfuric acid and hydrofluoric acid to heat and dissolve the sample, removing it after sulfuric acid fumes and cooling, adding a certain amount of potassium pyrosulfate and then placing it in a muffle furnace for melting, dissolving salts with dilute hydrochloric acid, adding a small amount of tartaric acid solution, transferring it to a volumetric flask, and using ICP - MS to determine scandium and niobium;

[0007] Specifically, it includes:

[0008] Step 1: Weigh the sample into a washed porcelain ash dish, place it in a muffle furnace and burn until the carbon and carbides are completely decomposed by burning. Take it out and cool to room temperature.

[0009] Step 2: Sweep the burned sample into a platinum crucible, add (1+1) sulfuric acid L and hydrofluoric acid, heat and decompose it at low temperature and evaporate until sulfuric acid fumes are emitted. Take it off and cool to room temperature.

[0010] Step 3: Weigh a certain amount of potassium pyrosulfate into the above platinum crucible, put the platinum crucible into a muffle furnace, continue to heat the muffle furnace to 700 °C, melt for a certain time at this temperature, take it out and cool to room temperature.

[0011] Step 4: Put the above platinum crucible into a beaker, add hot water, hydrochloric acid and tartaric acid, heat and extract at low temperature to dissolve the frit, transfer the solution to a volumetric flask, and make up the volume with high-purity water.

[0012] Preparation of blank sample solution: Take another platinum crucible, add (1+1) sulfuric acid and hydrofluoric acid, heat and decompose it at low temperature and evaporate until sulfuric acid fumes are emitted. Take it off and cool to room temperature; continue to operate according to Step 2, Step 3 and Step 4 in sequence. This is the blank sample.

[0013] Step 5: When the scandium and niobium contents in the sample are <0.025%, the above solution is directly measured; when the scandium and niobium contents in the sample are >0.025%, take aliquots of the above solution into a volumetric flask, add hydrochloric acid and tartaric acid, make up the volume with high-purity water, shake well; measure on the machine; operate on the blank sample solution synchronously.

[0014] Step 6: Preparation of standard calibration curve solution

[0015] Niobium single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Substances Center; Scandium single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Substances Center; Aluminum single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Substances Center; Calcium single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Substances Center; Iron single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Substances Center.

[0016] Gradually dilute the niobium and scandium single-element standard solutions to 5.00 μg / mL respectively.

[0017] Take 0, 0.500 mL, 1.00 mL, 2.00 mL, 3.00 mL, and 5.00 mL of niobium and scandium standard solutions at 5.00 μg / mL respectively into 250 mL volumetric flasks. Add single-element standard solutions of iron, calcium, and aluminum to prepare solutions containing 10.00% Fe, 8.00% Ca, and 3.00% Al that match the sample matrix. Add 10 mL of hydrochloric acid and 5 mL of tartaric acid, and make up to the mark with high-purity water. Shake well; this solution is used to prepare the standard curve; the concentrations of scandium and niobium in this standard series are 0, 10.00 ng / mL, 20.00 ng / mL, 40.00 ng / mL, 60.00 ng / mL, and 100.00 ng / mL respectively;

[0018] Step 7: Select the internal standard element

[0019] The measuring instrument is an iCAP RQ type inductively coupled plasma mass spectrometer;

[0020] Use rhodium Rh 103 as the internal standard element; rhodium single-element standard solution: with a concentration of 1000 μg / mL, sourced from the National Standard Substances Center; gradually diluted to a concentration of 10 μg / L and added online simultaneously with the sample solution;

[0021] The content of each element in the sample is calculated according to the following formula:

[0022] W% = (W i - W0) × f

[0023] Where: W - mass percentage of the element in the sample;

[0024] W0 - mass percentage of the element in the blank solution to be measured;

[0025] W i - mass percentage of the element in the sample to be measured;

[0026] f - dilution factor.

[0027] Furthermore, the concentration of tartaric acid is 50 g / L.

[0028] Furthermore, the detection range of this method: Sc 0.0005 at~0.30 at%; Nb 0.0005 at~0.30 at%.

[0029] Furthermore, in step 3, put the platinum crucible into a muffle furnace at 200 °C.

[0030] Furthermore, in step 1, the burning temperature of the muffle furnace is 750 °C and the burning time is 30 min.

[0031] Compared with the prior art, the beneficial technical effects of the present invention:

[0032] The method for determining scandium and niobium in the beneficiation and smelting tailings of Bayan Obo in Baotou of the present invention;

[0033] Since the carbon content in the beneficiation and smelting tailings of Bayan Obo in Baotou fluctuates greatly, usually between 1.0% and 20.0%, the high content of carbon will corrode the platinum crucible. Therefore, in the present invention, the sample is pre-burned in a muffle furnace at 750°C for 30 minutes. After the carbon and carbides in the tailings are completely burned and decomposed, they are transferred into a platinum crucible, which can avoid corroding the platinum crucible.

[0034] Secondly, in the present invention, 1 mL of (1+1) sulfuric acid and 5 mL of hydrofluoric acid are used for the pretreatment of the sample, so that silicon and boron in the sample can form fluorides and escape, thereby avoiding the interference of silicon and boron on the determination of scandium. Then, 1.50 g of potassium pyrosulfate is used to treat the residue, and 10 mL of hydrochloric acid and 5 mL of tartaric acid (50 g / L) are used to leach the frit. Less chemical reagents are used, which is more material-saving; the operation of the present invention is simple, and scandium and niobium can be simultaneously determined within 6 hours. The sample is directly decomposed and then determined without separation. The method is simple, rapid and has high accuracy.

[0035] The present invention utilizes the characteristic that potassium pyrosulfate decomposes to produce sulfate at 300°C, which can better react with scandium and niobium compounds to form corresponding sulfates that are easily soluble in water. Especially when leaching the frit subsequently, the hydrolysis of niobium can be avoided. After adding potassium pyrosulfate to the platinum crucible, the platinum crucible is placed in a muffle furnace at 200°C, and the muffle furnace is then heated to 700°C. Thus, potassium pyrosulfate decomposes slowly, enabling potassium pyrosulfate to react fully with the sample, and the sample is completely decomposed at 700°C within 10 minutes.

[0036] By adopting the method of on-line adding rhodium (Rh) internal standard, the measurement stability is improved, and the measurement result has high sensitivity and more accurate result.

[0037] Using ICP-MS to determine scandium and niobium in the beneficiation and smelting tailings of Bayan Obo in Baotou, the detection range: Sc 0.0005 at~0.30 at%; Nb 0.0005 at~0.30 at%.

[0038] Through multiple inspections of the beneficiation and smelting tailings samples of Bayan Obo in Baotou, the present invention has good application effects. The present invention adopts matrix matching to eliminate matrix interference, and has the characteristics of wide linear range, high sensitivity, simple operation, accurate and reliable analysis results, providing reliable data for the detection of scandium and niobium in the beneficiation and smelting tailings of Bayan Obo in Baotou; at the same time, it supplements the method for simultaneously determining scandium and niobium in the beneficiation and smelting tailings of Bayan Obo in Baotou by ICP-MS. Specific embodiments

[0039] In the embodiments of the present invention, the preferred reagents used are:

[0040] Potassium pyrosulfate, tartaric acid: analytically pure;

[0041] Sulfuric acid, hydrochloric acid, hydrofluoric acid of guaranteed reagent grade;

[0042] Scandium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Niobium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Rhodium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Aluminum single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Calcium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Iron single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Rhodium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center;

[0043] Argon: argon purity ≥ 99.9%; Compressed air.

[0044] iCAP RQ type inductively coupled plasma mass spectrometer (Thermo Fisher Scientific, USA).

[0045] Sample analysis

[0046] Weigh 0.1000 g of the sample into a washed porcelain ash dish, place it in a muffle furnace at 750 °C and burn for 30 minutes, take it out and cool to room temperature. Sweep the burned sample into a platinum crucible, add 1 mL of (1+1) sulfuric acid and 5 mL of hydrofluoric acid, decompose by heating at low temperature and evaporate until sulfuric acid fumes are evolved, take it off and cool to room temperature. Weigh 1.50 g of potassium pyrosulfate into the platinum crucible, put the platinum crucible into a muffle furnace at 200 °C, continue to heat the muffle furnace to 700 °C, melt at this temperature for 10 minutes, take it out and cool to room temperature. Put the platinum crucible into a 300 mL beaker, add 100 mL of hot water, 10 mL of hydrochloric acid, 5 mL of (50 g / L) tartaric acid, extract and dissolve the frit by heating at low temperature, transfer the solution to a 250 mL volumetric flask, and make up the volume with high-purity water.

[0047] Preparation of blank sample solution: Take another platinum crucible, add 1 mL of (1+1) sulfuric acid and 5 mL of hydrofluoric acid, and perform the same operations as above to make a blank sample.

[0048] Liquid separation: When the content of scandium and niobium in the sample > 0.025%, take 20 mL of the above solution and transfer it to a 250 mL volumetric flask, add 8 mL of hydrochloric acid and 5 mL of (50 g / L) tartaric acid, make up the volume with high-purity water, shake well. Measure on the machine. Perform the same operations on the blank sample solution.

[0049] Preparation of standard calibration curve solution

[0050] Niobium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Scandium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Aluminum single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Calcium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; Iron single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center;

[0051] Gradually dilute the niobium and scandium single-element standard solutions to 5.00 μg / mL respectively;

[0052] Respectively take 0, 0.500 mL, 1.00 mL, 2.00 mL, 3.00 mL, 5.00 mL of the 5.00 μg / mL niobium and scandium standard solutions into 250 mL volumetric flasks, add iron, calcium, and aluminum single-element standard solutions, and prepare solutions with Fe 10.00%, Ca 8.00%, and Al 3.00% matching the sample matrix. Add 10 mL of hydrochloric acid and 5 mL of (50 g / L) tartaric acid, and make up to the mark with high-purity water, then shake well. This solution is used to make the standard curve. The concentrations of scandium and niobium in this standard series are 0, 10.00 ng / mL, 20.00 ng / mL, 40.00 ng / mL, 60.00 ng / mL, and 100.00 ng / mL respectively.

[0053] This method uses rhodium (Rh 103 ) as the internal standard element. Rhodium single-element standard solution: concentration is 1000 μg / mL, sourced from the National Standard Material Center; gradually dilute to a concentration of 10 μg / L and add it online simultaneously with the sample solution.

[0054] The content of each element in the sample is calculated according to the following formula:

[0055] W% = (W i - W0) × f

[0056] Where: W - mass percentage of the element in the sample;

[0057] W0 - mass percentage of the element in the blank solution to be measured;

[0058] Wi - mass percentage of the element in the sample to be measured;

[0059] f - dilution factor;

[0060] The detection range of this method: Sc 0.0005 at~0.30 at%; Nb 0.0005 at~0.30 at%.

[0061] Example 1

[0062] Prepare the working curve according to the above method. The correlation coefficients r of the curves for scandium and niobium are both greater than 0.9999. Prepare 11 blank solutions according to the experimental method and perform the determination in 3 batches. According to the detection limit formula C L = 3S b / k (S b is the standard deviation of the blank, and k is the slope of the corresponding calibration curve), the detection limits of the method for scandium and niobium are calculated to be 0.00002% and 0.00003% respectively.

[0063] Example 2

[0064] Weigh the sediment (CAN LKSD-1), (JLK-1), (SRM8704) and the standard sample of Baotou ore (R715) and perform the determination according to the above method. The results are shown in Table 1.

[0065] Table 1 Determination results of standard samples %

[0066]

[0067]

[0068] Example 3

[0069] Weigh 2 portions of the sediment (CAN LKSD-1) and (JLK-1) respectively, add different amounts of scandium and niobium standard solutions, perform the determination according to the above method, and conduct the standard addition recovery experiment. The results are shown in Table 2.

[0070] Table 2 Standard addition recovery experiment %

[0071] Sample number Scandium scalar added Recovery rate Niobium scalar added Recovery rate CAN LKSD-1 0.010 98.8 0.010 99.1 CAN LKSD-1 0.050 100.3 0.050 99.8 JLK-1 0.100 101.2 0.100 101.3 JLK-1 0.300 99.8 0.300 100.7

[0072] Example 4

[0073] Weigh the tailings samples of Baiyun Ebo concentrator and smelter in Baotou 1 # 、2 # respectively perform the determination according to the above method and conduct the standard addition recovery experiment. The results are shown in Table 4.

[0074] Table 4 Determination results of the tailings samples of Baiyun Ebo concentrator and smelter in Baotou %

[0075]

[0076]

[0077] Therefore, through the verification of the above examples, it can be seen that the method for scandium and niobium described in the present invention adopts the method of on-line adding rhodium (Rh) internal standard to improve the determination stability, making the determination results highly sensitive and more accurate.

[0078] Determination of scandium and niobium in the beneficiation tailings of Bayan Obo in Baotou by ICP-MS, detection range: Sc 0.0005at~0.30at%; Nb 0.0005at~0.30at%.

[0079] Through multiple inspections of the beneficiation tailings samples of Bayan Obo in Baotou, the present invention has good application effects. The present invention adopts matrix matching to eliminate matrix interference, and has the characteristics of wide linear range, high sensitivity, simple operation, accurate and reliable analysis results, providing reliable data for the detection of scandium and niobium in the beneficiation tailings of Bayan Obo in Baotou; at the same time, it supplements the method for simultaneous determination of scandium and niobium in the beneficiation tailings of Bayan Obo in Baotou by ICP-MS.

[0080] The embodiments described above are only descriptions of the preferred modes of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for determining scandium and niobium in ore dressing tailings, characterized in that: Including: Weigh the sample in a porcelain ash dish, place it in a muffle furnace for burning. After completely burning and decomposing the carbon and carbides in the tailings, transfer it to a platinum crucible. Add dilute sulfuric acid and hydrofluoric acid, heat to dissolve the sample, remove it when sulfuric acid fumes, cool it, add a certain amount of potassium pyrosulfate, then place it in the muffle furnace for melting. After dissolving the salts with dilute hydrochloric acid, add a small amount of tartaric acid solution, transfer it to a volumetric flask, and use ICP-MS to determine scandium and niobium; Specifically including: Step 1: Weigh the sample in a washed porcelain ash dish, place it in the muffle furnace for burning until the carbon and carbides are completely burned and decomposed, take it out and cool to room temperature; Step 2: Sweep the burned sample into a platinum crucible, add 1+1 sulfuric acid and hydrofluoric acid, decompose it by heating at low temperature and evaporate until sulfuric acid fumes, take it out and cool to room temperature; Step 3: Weigh a certain amount of potassium pyrosulfate into the above platinum crucible, put the platinum crucible into the muffle furnace, continue to heat the muffle furnace to 700°C, melt it at this temperature for a certain time, take it out and cool to room temperature; Step 4: Put the above platinum crucible into a beaker, add hot water, hydrochloric acid, and tartaric acid, extract and dissolve the frit by heating at low temperature, transfer the solution to a volumetric flask, and make up the volume with high-purity water; Preparation of blank sample solution: Take another platinum crucible, add 1+1 sulfuric acid and hydrofluoric acid, decompose it by heating at low temperature and evaporate until sulfuric acid fumes, take it out and cool to room temperature; continue to operate according to Step 2, Step 3, and Step 4 in sequence, and this is the blank sample; Step 5: When the content of scandium and niobium in the sample < 0.025%, the above solution is directly measured; when the content of scandium and niobium in the sample > 0.025%, take aliquots of the above solution into a volumetric flask, add hydrochloric acid and tartaric acid, make up the volume with high-purity water, shake well; measure on the machine; Perform the same operation on the blank sample solution; Step 6: Preparation of standard calibration curve solution Niobium single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Material Center; Scandium single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Material Center; Aluminum single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Material Center; Calcium single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Material Center; Iron single-element standard solution: Concentration is 1000 μg / mL, sourced from the National Standard Material Center; Gradually dilute the niobium and scandium single-element standard solutions to 5.00 μg / mL respectively; Respectively take 0, 0.500 mL, 1.00 mL, 2.00 mL, 3.00 mL, 5.00 mL of the 5.00 μg / mL niobium and scandium standard solutions into 250 mL volumetric flasks, add iron, calcium, and aluminum single-element standard solutions, prepare solutions with Fe 10.00%, Ca 8.00%, and Al 3.00% matching the sample matrix, add 10 mL of hydrochloric acid and 5 mL of tartaric acid, make up the volume with high-purity water, and shake well; this solution is used to make the standard curve; the concentrations of scandium and niobium in this standard series are 0, 10.00 ng / mL, 20.00 ng / mL, 40.00 ng / mL, 60.00 ng / mL, 100.00 ng / mL respectively; Step 7: Select internal standard elements The measuring instrument is an iCAP RQ type inductively coupled plasma mass spectrometer; Using rhodium Rh 103 as the internal standard element; Rh single-element standard solution: with a concentration of 1000 μg / mL, sourced from the National Standard Material Center; gradually diluted to a concentration of 10 μg / L and added online simultaneously with the sample solution; The content of each element in the sample is calculated according to the following formula: W%=(W i -W0)×f Where: W - the mass percentage of the element in the sample; W0 - the mass percentage of the element in the blank solution to be measured; W i - mass percentage of the element in the sample to be measured; f - the dilution factor.

2. The method for determining scandium and niobium in ore dressing and metallurgy tailings according to claim 1, wherein: The concentration of tartaric acid is 50 g / L.

3. The method for determining scandium and niobium in ore dressing tailings according to claim 1, characterized in that: The detection range of this method: Sc 0.0005 at~0.30 at%; Nb 0.0005 at~0.30 at%.

4. The method for determining scandium and niobium in ore dressing tailings according to claim 1, characterized in that: In step 3, the platinum crucible is placed in a muffle furnace at 200 °C.

5. The method for determining scandium and niobium in ore dressing tailings according to claim 1, wherein: In step 1, the burning temperature of the muffle furnace is 750 °C and the burning time is 30 min.

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