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This article is about studying GB-T 6730.84-2023 Determination of total rare earth content in iron ore by inductively coupled plasma atomic emission spectrometry. I have compiled study notes and shared them in the hope that more people will benefit. If there is any infringement, please contact us in time.
1 Scope
This document describes a method for the determination of total rare earth content by inductively coupled plasma atomic emission spectrometry.
This document is applicable to the determination of the total rare earth content in iron ore, iron concentrate, sinter, and pellet mineral products. Measuring range (mass fraction):
0.10%～15.00%。
2 Normative reference documents
The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, for dated referenced documents
, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to this document.
this document.
GB/T 6379.1 Accuracy of measurement methods and results (correctness and precision) Part 1: General principles and definitions
GB/T 6379.2 Accuracy of measurement methods and results (correctness and precision)
Part 2: Determining the repetition of standard measurement methods
Basic methods of sex and reproducibility
GB/T 6682 Specifications and test methods for water used in analytical laboratories
GB/T 6730.1 Preparation of pre-dried samples for iron ore analysis
GB/T 8170 Numerical rounding rules and representation and determination of limit values
GB/T 10322.1 Iron ore sampling and sample preparation methods
GB/T 12806 Laboratory glassware single-marked volumetric flasks
GB/T 12807 Graduated pipettes for laboratory glass instruments
GB/T 12808 Single-marked pipette for laboratory glass instruments
JJG 768 emission spectrometer
JY/T 0567 General principles for inductively coupled plasma emission spectroscopy analysis methods
3 Terms and definitions
There are no terms or definitions to be defined in this document.
4 Principles
The sample is melted with sodium hydroxide and sodium peroxide, and leached with triethanolamine with a volume ratio of (5+95). In the presence of hydroxylamine hydrochloride and ascorbic acid,
EDTA
complexing is used to separate interfering elements such as iron, manganese, aluminum, and calcium. The precipitate was filtered and acidified with hydrochloric acid. In dilute acid medium, directly use argon, etc.
The ion light source is used to excite and the spectrum is measured. The measured content of each rare earth element is calculated to obtain the total rare earth content.
GB/T 6730.84—2023
5 Reagents and materials
Unless otherwise stated, only use approved analytical grade reagents and
secondary water that meets the requirements of GB/T 6682 or water of equivalent purity.
5.1 Sodium hydroxide (dry out moisture in advance).
5.2 Sodium peroxide.
5.3 Disodium ethylenediaminetetraacetate (EDTA).
5.4 Ascorbic acid.
5.5 Hydroxylamine Hydrochloride.
5.6 Hydrochloric acid, p≈1.19 g/mL.
5.7 Hydrochloric acid, 1+1.
5.8 Hydrochloric acid, 5+95.
5.9 Nitric acid, p≈1.42 g/mL.
5.10 Nitric acid, 1+1.
5.11 Hydrogen peroxide, 30%.
5.12 Sodium hydroxide lotion, 20 g/L.
Weigh 2 g of sodium hydroxide and dissolve it in 100 mL of water.
5.13 Triethanolamine, 5+95.
Measure 5 mL of triethanolamine, add 95 mL of water and mix well.
5.14 Yttrium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of yttrium oxide [w(Y₂O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 h, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.15 Lanthanum oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
lanthanum oxide [w(La₂O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.16 Cerium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of cerium oxide [w(CeO2/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 h, and place it in a
In a 100 mL beaker, add 10 mL
nitric acid (see 5.10), heat at low temperature, and dropwise add hydrogen peroxide (see 5.11) until completely dissolved, cool to
room temperature , transfer to a 100 mL volumetric flask, dilute to volume with water, and mix .
5.17 Praseodymium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of praseodymium oxide [w(PrsOn/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 hour, and place it in a
Add 10 mL hydrochloric
acid (see 5.7) to a 100 mL beaker, heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask,
dilute to volume with water, and mix.
5.18 Neodymium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
neodymium oxide [w(Nd2O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.19 Samarium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
samarium oxide [w(Sm2O3/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
GB/T 6730.84—2023
5.20 Europium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of europium oxide [w(Eu₂O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 h, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.21 Gadolinium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
gadolinium oxide [w(Gd2O3/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.22 Terbium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
terbium oxide [w(Tb;O₇/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 hour, and place it
In a 100 mL beaker, add 10 mL
nitric acid (see 5.10), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.23 Dysprosium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
dysprosium oxide [w(Dy₂O3/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 h, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.24 Holmium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of holmium oxide [w(Ho₂O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.25 Erbium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of erbium oxide [w(Er₂O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950°C for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.26 Thulium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000g of
thulium oxide [w(Tm2O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 hour, and place it
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.27 Ytterbium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g
of ytterbium oxide [w(Yb2O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 h, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.28 Lutetium oxide standard storage solution, 1 mg/mL.
Weigh 0.1000 g of
lutetium oxide [w(Lu₂O₃/REO)≥99.99%, w(REO)≥99.5%] that has been burned at 950℃ for 1 hour, and place it in a
In a 100 mL beaker, add 10 mL
hydrochloric acid (see 5.7), heat at low temperature until complete dissolution, cool to room temperature, transfer to a 100 mL volumetric flask, and use
Dilute to volume with water and mix well.
5.29
Series standard solutions: Use standard storage solutions (see 5.14~5.28) or certified standard samples to prepare a series of standard solutions. The medium is hydrochloric acid
(see 5.8).
5.30 Argon gas, volume fraction ≥99.99%.
6 Instruments and equipment
Unless otherwise specified, use usual laboratory equipment. Single-marked volumetric flasks, graduated pipettes and single-marked pipettes shall comply with
GB/T 6730.84—2023
The provisions of GB/T 12806, GB/T 12807 and GB/T 12808
. The corundum crucibles, beakers, volumetric flasks, etc. used in the experiment are all made of hydrochloric acid solution (see
5.8) Soak for more than 24 hours, rinse with water, dry and set aside.
6.1 Inductively coupled plasma atomic emission spectrometer should meet the following requirements:
a) The resolution is less than 0.008 nm (at 200nm);
b) Comply with the emission spectrometer calibration procedures and technical indicators required in JJG 768.
6.2 Electric hot plate: temperature control range 50℃~350℃.
6.3 Muffle furnace: temperature control range 500℃~800℃.
6.4 Analytical balance: sensitivity 0.1 mg.
6.5 Corundum crucible.
7 Sampling and sample preparation
7.1 Laboratory samples
Sampling and preparation shall be carried out in accordance with GB/T10322.1. Generally, the sample particle size is less than 100 μm.
If the sample contains combined water or easy oxides,
When the amount is high, the particle size should be less than 160 μm.
The regulations for high combined water and easy oxidation content are in accordance with GB/T 6730.1.
7.2 Preparation of pre-dried samples
Thoroughly mix the laboratory samples and take samples using the aliquot method. According to the provisions of GB/T6730.1
, dry at a temperature of 105℃±2℃
Dry the sample and cool it to room temperature in a desiccator for later use.
8 Analysis steps
8.1 Number of measurements
According to Appendix B, the same pre-dried sample shall be measured independently at least twice.
Note: "Independent" means that the results of the second and subsequent measurements are not affected by the results of the previous measurements. In this analysis method, this condition means that in the same laboratory
, the same operator uses the same equipment and follows the same test method to independently perform repeated measurements on the same measured object in a short period of time, including
including the use of appropriate recalibration.
8.2 Sample size
Weigh approximately 0.50 g of pre-dried sample (see 7.2), accurate to 0.0001 g.
The sample weighing operation should be carried out as quickly as possible to prevent the sample from absorbing moisture again.
8.3 Blank test and verification test
8.3.1 Blank test
A blank test is performed along with the sample analysis, and all reagents should be taken from the same reagent bottle.
8.3.2 Verification test
Along with the sample, standard samples of the same type are analyzed for verification tests.
8.4 Determination
8.4.1 Decomposition of specimens
Place the sample (see 8.2) in a
corundum crucible containing 3 g to 4 g of sodium hydroxide (see 5.1) that has been pre-baked to remove moisture, mix evenly, and add 4 g
GB/T 6730.84—2023
Cover it with sodium peroxide (see 5.2), place it in a muffle furnace (see 6.3) and gradually heat it from low temperature to 750°C until it melts until red and transparent for 5
to 10 minutes. Shake twice in the middle and take it out to cool.
8.4.2 Preparation of analytical solution
8.4.2.1 Move the cooled corundum crucible into a 400 mL beaker containing 100 mL
triethanolamine (see 5.13), 1g EDTA (see 5.3), 1 g ascorbic acid (see 5.4) and 1g hydroxylamine
hydrochloride (see 5.5)
, and wait until After the violent reaction stops, heat to boiling, remove, and wash out the crucible. Boil
the solution for several minutes, cool it slightly, filter it with quantitative medium-speed filter paper, and wash the beaker and sediment 6 to 7 times with sodium hydroxide washing solution (see 5.12).
Dissolve the precipitate on the filter paper with 5 mL
hydrochloric acid (see 5.7), and filter it into the volumetric flask. After the precipitate is dissolved, wash the filter paper with dilute hydrochloric acid (see 5.8) 8 to 10 times. The filtrate is added to the volumetric flask,
and Dilute to volume with water and mix well.
8.4.2.2 Pipette the test solution (see 8.4.2.1) into a 50 mL
volumetric flask according to Table 1, add 5 mL hydrochloric acid (see 5.7), dilute to the mark with water, mix well, and wait for testing.
Table 1 Total rare earth content and fractionated volume
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8.4.3 Adjusting the spectrometer
8.4.3.1 Test preparation
Adjust the spectrometer according to the conditions provided by the instrument manufacturer and laboratory practice, select the appropriate torque tube and atomizer, and adjust the power and gas flow.
Amount, observation height, lifting rate, etc. The recommended analysis lines for each element are shown in Table 2.
Table 2 Recommended analysis lines
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8.4.3.2 Performance test
Performance testing is performed to optimize the spectrometer with sufficient sensitivity and precision to allow comparison of the data produced.
GB/T 6730.84—2023
The parameters involved in the performance test include detection limit (DL), background correction concentration (BEC), and short-term accuracy (RSDN). The
specific evaluation is based on JJG 768 and
Carry out in accordance with the provisions of JY/T 0567.
8.4.4 Drawing of calibration curve
Establish the analysis program according to the instrument instructions, establish the working parameters of the inductively coupled plasma spectrometer, refer to Table 2 to select the elements to be measured
and the corresponding analysis lines, measure the series of standard solutions in order from low to high concentration, and use the signal of each element to be measured Intensity is the ordinate,
Concentration is the abscissa to draw a calibration curve. The recommended calibration curve series standard solution concentrations are shown in Table 3.
Table 3 Series standard solution concentrations
Units are micrograms per milliliter
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8.4.5 Determination of sample solution
Measure the blank solution (see 8.3.1) and the sample solution to be tested (see 8.4.2) in sequence. The concentration found from the calibration curve is
The concentration of oxides of each element in the test solution.
Further reading
More information can be found in GB-T 6730.84-2023 Determination of total rare earth content in iron ore by inductively coupled plasma atomic emission spectrometry. Further study