Method for analyzing content of thorium in iron ore

Abstract

The invention discloses a method for analyzing the content of thorium in iron ore, which is characterized by comprising the following steps of: putting a weighed sample into a polytetrafluoroethylene beaker, adding concentrated hydrochloric acid and hydrofluoric acid, heating on an electric heating plate, adding perchloric acid when the volume of the solution is a certain amount, and completely drying to form wet salt; taking down, cooling, adding concentrated hydrochloric acid to dissolve salts, transferring to a constant volume in a volumetric flask, uniformly shaking, and measuring the thorium content by adopting an inductively coupled plasma emission spectrometer. The method can accurately determine the content of thorium in the iron ore, is simple and rapid to operate, can meet the production detection requirements, provides accurate data for efficient development of thorium resources, is suitable for the green and environment-friendly detection requirements of the modern metallurgical industry, and has good popularization and application values.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgical analysis, and particularly relates to a method for analyzing the thorium content in iron ore. Background Art

[0002] The reserves of thorium in the earth's crust are more than three times that of uranium, and China is one of the countries with the richest thorium resources in the world. Compared with traditional uranium-based nuclear energy, thorium energy exhibits multiple advantages: thorium reactors can theoretically achieve "inherent safety", and the molten salt reactor technology can avoid the risk of core meltdown; its nuclear waste has a half-life of only a few hundred years, far lower than the tens of thousands of years of uranium waste; in addition, thorium has a higher utilization efficiency, and the power generation of 1 ton of thorium is equivalent to that of 200 tons of uranium or 3.5 million tons of coal. This characteristic makes thorium regarded as the key to cracking the nuclear power safety anxiety and realizing "zero-carbon energy".

[0003] The Bayan Obo Mine is the largest rare earth mine in the world. It was first discovered by Chinese geologist Ding Daoheng in 1927 and contains more than 41% of the world's proven total reserves of rare earth minerals and 175 mineral resources such as iron, niobium, manganese, phosphorus, and fluorite. Recently, a thorium deposit with rich reserves has been discovered through exploration, which not only injects new growth momentum into the local area, but also may give birth to a high-end industrial chain covering thorium ore mining, molten salt reactor research and development, nuclear fuel preparation, and equipment manufacturing.

[0004] In order to ensure the reasonable development and utilization of thorium resources, the determination of thorium content in iron ore is particularly important. At present, the determination of thorium content in iron ore usually follows the national standard GB / T 6730.89-2024. It uses hydrochloric acid, hydrofluoric acid, and perchloric acid to dissolve the sample, extracts it with a butyl acetate solution of PMBP, and then back-extracts it with hydrochloric acid to separate thorium from other interfering elements. Finally, arsenazo is used as a chromogenic agent, and the absorbance is measured at 660 nm to calculate the thorium content. Its determination process is long and complicated, requiring the use of a variety of chemical reagents. Among them, the use of organic reagents for extraction to improve the sensitivity of thorium content determination requires subsequent recovery or treatment of the organic reagents, increasing the analysis cost and harm to the human body. When using inductively coupled plasma emission spectrometry to measure the thorium content in iron ore, only need to process the iron ore into a solution, and directly measure it with an inductively coupled plasma emission spectrometer to obtain the thorium content, and then convert it into the content of thorium dioxide. The process is simple to operate, uses fewer types of reagents, has high accuracy and sensitivity, and is suitable for the development direction of rapid and accurate detection in the modern metallurgical industry with green environmental protection. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for analyzing the thorium content in iron ore. By using inductively coupled plasma emission spectrometry to determine the thorium content in iron ore, the work efficiency is improved, and the environmental pollution is reduced. This method has been used in production practice, and the determination process is simple, fast, and accurate.

[0006] To solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for analyzing the thorium content in iron ore of the present invention places the weighed sample in a polytetrafluoroethylene beaker, adds concentrated hydrochloric acid and hydrofluoric acid, places it on a hot plate for heating. When the volume of the solution reaches a certain amount, perchloric acid is added to fume until it becomes dry and forms a wet salt state. After taking it down and cooling, concentrated hydrochloric acid is added to dissolve the salts, and then it is transferred and fixed in a volumetric flask. After shaking well, an inductively coupled plasma emission spectrometer is used to measure the thorium content.

[0008] Furthermore, it also includes drawing a working curve with a standard solution: Weigh six portions of 0.06 g of high-purity iron (equivalent to 30% of the iron content in the sample) and place them in a 150 mL beaker as a base. Dissolve them according to the method and transfer them to a 100 mL volumetric flask. Respectively add calcium standard solutions equivalent to 0.00%, 0.010%, 0.05%, 0.100%, 0.250%, and 0.500% of the thorium content in the sample, dilute with water to the scale and shake well. Draw a working curve with the intensity as the ordinate and the thorium content as the abscissa.

[0009] Furthermore, place 0.2 mg of the weighed sample in a 150 mL polytetrafluoroethylene beaker, add 10 mL of concentrated hydrochloric acid and 5 mL of hydrofluoric acid, place it on a hot plate for heating. When the volume of the solution is 4.5 - 5.5 mL, add 5 mL of perchloric acid to fume until it becomes dry and forms a wet salt state. After taking it down and cooling, add 10 mL of concentrated hydrochloric acid to dissolve the salts, and then transfer and fix it in a 100 mL volumetric flask. After shaking well, an inductively coupled plasma emission spectrometer is used to measure the thorium content.

[0010] Furthermore, a blank test is conducted along with the sample.

[0011] Furthermore, the inductively coupled plasma emission spectrometer uses an Optima5300DV type plasma emission spectrometer.

[0012] Furthermore, the main working parameters of the instrument:

[0013] High-frequency frequency: 40.68 MHz; Power: 1300 W;

[0014] Cooling gas flow rate: 15 L / min Auxiliary gas flow rate: 0.2 L / min Carrier gas flow rate: 0.8 L / min;

[0015] Solution lift amount: 1.5 mL / min Flushing time: 8 s;

[0016] Observation method: Axial Background deduction method: Single-point integration method: Peak height;

[0017] Analysis wavelength: 401.962 nm.

[0018] Furthermore, thorium dioxide content (%) = thorium content (%) × 1.1379, wherein 1.1379 is a coefficient for converting thorium element content into thorium dioxide content.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are:

[0020] The invention can realize the rapid detection of thorium content in iron ore, and is advanced, scientific and accurate, and provides an accurate and rapid instrumental analysis method for the utilization and development of thorium resources in Bayan Obo mine. DETAILED DESCRIPTION

[0021] A method for analyzing thorium content in iron ore, comprising:

[0022] 1 Scope

[0023] This method specifies the use of hydrochloric acid, hydrofluoric acid and perchloric acid to dissolve the sample and the use of inductively coupled plasma optical emission spectrometry to determine the thorium content in the iron ore.

[0024] 2 Principle

[0025] After the sample is heated and dissolved with hydrochloric acid and hydrofluoric acid, perchloric acid is added to remove fluorine, and the volume is transferred to a 100 ml volumetric flask. After shaking, the solution is introduced into an inductively coupled plasma emission spectrometer to determine the thorium content.

[0026] 3 Main instruments and reagents

[0027] Hydrochloric acid: high purity ρ≈1.19 g / mL.

[0028] Hydrofluoric acid: high purity ρ≈1.15g / mL.

[0029] Perchloric acid: high purity ρ≈1.68g / mL.

[0030] Optima5300DV plasma emission spectrometer.

[0031] Thorium standard solution (100 μg / mL) mL.

[0032] Deionized water.

[0033] 4. Instrument Preparation

[0034] 4.1 Main operating parameters of the instrument

[0035] High frequency: 40.68MHZ Power: 1300W

[0036] Cooling gas flow rate: 15L / min Auxiliary gas flow rate: 0.2L / min Carrier gas flow rate: 0.8L / min

[0037] Solution elevation: 1.5 mL / min Flushing time: 8 s

[0038] Observation method: Axial Background subtraction method: Single-point integration method: Peak height

[0039] Analysis wavelength: 401.962 nm

[0040] 4.2 Instrument working curve plotting

[0041] 4.2.1 Standard solution for plotting the working curve

[0042] Weigh six portions of 0.06 g of high-purity iron (equivalent to 30% iron content in the sample) and place them in a 150 mL beaker. Dissolve them according to the determination method in 5.3, transfer to a 100 mL volumetric flask, and add calcium standard solutions equivalent to 0.00%, 0.010%, 0.05%, 0.100%, 0.250%, and 0.500% thorium content in the sample respectively. Dilute with water to the mark and shake well. Plot the working curve with intensity as the ordinate and thorium content as the abscissa.

[0043] 4.2.2 Standard substance for plotting the working curve

[0044] Select standard substances of iron ore with different thorium contents, and plot the working curve after synchronous operation according to the determination method in 5.3.

[0045] 5 Analysis steps

[0046] 5.1 Sample amount

[0047] Weigh 0.2 g of the sample, accurate to 1 mg.

[0048] 5.2 Blank test

[0049] Perform a blank test along with the sample

[0050] 5.3 Determination

[0051] Place the weighed sample in a 150 mL polytetrafluoroethylene beaker, add 10 mL of concentrated hydrochloric acid and 5 mL of hydrofluoric acid, heat on a hot plate. When the solution volume is about 5 mL, add 5 mL of perchloric acid and fume until dry to form a wet salt. After cooling, add 10 mL of concentrated hydrochloric acid to dissolve the salts and then transfer and dilute to the mark in a 100 mL volumetric flask. After shaking well, determine the thorium content using an inductively coupled plasma emission spectrometer.

[0052] 6 Calculation of thorium dioxide content

[0053] Thorium dioxide content (%) = Thorium content (%) × 1.1379

[0054] 1.1379 is the coefficient for converting thorium element content to thorium dioxide content

[0055] 7 Tolerance

[0056]

[0057] 8 Results and Discussion

[0058] 8.1 Sample Precision Experiment

[0059] The standard reference material of Baotou ore numbered R715 was measured 6 times. The relative standard deviation (RSD) of this method was less than 5%, indicating good precision. The experimental results are shown in Table 1:

[0060] Table 1 Precision Experiment (n = 6)

[0061]

[0062] 8.2 Sample Accuracy Experiment

[0063] The thorium dioxide content in the Baotou ore numbered R715, the B-K-1 raw ore, and the B-K-3 rare earth concentrate was measured. The standard values and the measured values were in good agreement, so it had good accuracy. The experimental results are shown in Table 2:

[0064] Table 2 Method Accuracy Experiment (%)

[0065]

[0066] 9 Conclusions

[0067] Using this method, the thorium content in iron ore can be accurately determined. The operation is simple and rapid, which can meet the production detection requirements, provide accurate data for the efficient development of thorium resources, and meet the requirements of green environmental protection detection in the modern metallurgical industry, having good popularization and application value.

[0068] 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 analyzing the thorium content in iron ore, characterized in that: Weigh the sample and place it in a polytetrafluoroethylene beaker. Add concentrated hydrochloric acid and hydrofluoric acid, and heat it on a hot plate. When the volume of the solution reaches a certain amount, add perchloric acid until fuming to dryness to form a wet salt state. After removing and cooling, add concentrated hydrochloric acid to dissolve the salts, then transfer and make up the volume to a volumetric flask. After shaking well, use an inductively coupled plasma emission spectrometer to determine the thorium content.

2. The method for analyzing the thorium content in iron ore according to claim 1, wherein: It also includes preparing a working curve with standard solutions: Weigh six portions of 0.06 g of high-purity iron and place them in 150 mL beakers. Dissolve them according to the method, transfer to 100 mL volumetric flasks, and add calcium standard solutions equivalent to 0.00%, 0.010%, 0.05%, 0.100%, 0.250%, and 0.500% of the thorium content in the sample respectively. Dilute with water to the mark and shake well. Use the intensity as the ordinate and the thorium content as the abscissa to prepare a working curve.

3. The method for analyzing the thorium content in iron ore according to claim 1, wherein: Specifically, it includes: Weigh 0.2 mg of the sample and place it in a 150 mL polytetrafluoroethylene beaker. Add 10 mL of concentrated hydrochloric acid and 5 mL of hydrofluoric acid, and heat it on a hot plate. When the volume of the solution is 4.5 - 5.5 mL, add 5 mL of perchloric acid until fuming to dryness to form a wet salt state. After removing and cooling, add 10 mL of concentrated hydrochloric acid to dissolve the salts, then transfer and make up the volume to a 100 mL volumetric flask. After shaking well, use an inductively coupled plasma emission spectrometer to determine the thorium content.

4. The method for analyzing the thorium content in iron ore according to any one of claims 1-3, characterized in that: Perform a blank test along with the sample.

5. The method for analyzing the thorium content in iron ore according to claim 1, wherein: The inductively coupled plasma emission spectrometer used is the Optima5300DV type plasma emission spectrometer.

6. The analysis method for thorium content in iron ore according to claim 5, wherein: Main working parameters of the instrument: High-frequency frequency: 40.68 MHz; Power: 1300 W; Cooling gas flow rate: 15 L / min Auxiliary gas flow rate: 0.2 L / min Carrier gas flow rate: 0.8 L / min; Solution uptake rate: 1.5 mL / min Flushing time: 8 s; Observation mode: Axial Background subtraction mode: Single-point integration mode: Peak height; Analysis wavelength: 401.962 nm.

7. The method for analyzing the thorium content in iron ore according to claim 1, wherein: The content percentage of thorium dioxide = the content percentage of thorium × 1.1379, where 1.1379 is the coefficient for converting the thorium element content to the thorium dioxide content.

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