GB/T 6730.76-2017 in English

1. Standard range

This standard specifies the method for determining the content of potassium, sodium, vanadium, copper, zinc, lead, chromium, nickel and cobalt in iron ore by inductively coupled plasma optical emission spectrometry (ICP-OES), which is applicable to iron ore, iron concentrate, sintered ore and pelletized ore. The content range of the measured elements is shown in Table 1. 0.001 ~ 0.4 Zn 0.002 ~ 0.4 N 0.0007 ~ 0.4 Zn 0.001 ~ 0.4 N 0.0007 ~ 0.4 Cu 0.001 ~ 0.4 0.001 ~ 0.06 Pb 0.006 ~ 0.06 Cr 0.001 ~ 0.06 Ni 0.004 ~ 0.06 Co 0.001 ~ 0.06

2. Background of Standardization

With the increase of global demand for iron ore, accurate determination of the content of trace elements in it is crucial for quality control of the smelting process. Traditional methods such as atomic absorption spectroscopy (AAS) are less efficient when detecting multiple elements, while ICP-OES technology has the advantages of high sensitivity and simultaneous detection of multiple elements, so it has become the standard method for iron ore analysis.

3. Analysis of technological evolution

Early metal element determination mainly relied on chemical wet decomposition and spectrophotometer. With the development of ICP-OES technology, the detection speed and accuracy have been significantly improved. Modern instruments are also equipped with high-salt and hydrofluoric acid resistant atomizers, which further improve the adaptability to complex samples.

4. Detailed explanation of analysis steps

1. Sample decomposition:Weigh about 1.0 g of pre-dried sample and add mixed acid (hydrochloric acid, hydrofluoric acid, nitric acid and perchloric acid) to dissolve.
2. Blank test:Use high-purity iron as a control sample to ensure the purity of the reagents and the accuracy of the method.
3. Calibration curve: Prepare standard solutions of different concentrations according to Table C.1, and draw calibration curves to determine the content of the elements to be measured.
4. Spectral interference correction: Eliminate background interference between spectral lines by synthesizing standard solutions and regression analysis.

5. Comparison of precision between laboratories

Table 3 gives the repeatability limits (r) and reproducibility limits (R) of different elements, ensuring the reliability and consistency of the method.

6. Implementation Suggestions

To ensure the accuracy of the analysis results, it is recommended to:

• Calibrate the instrument regularly and optimize the operating parameters (such as power, nebulizer type).
• Use certified standard samples (CRM or RM) for verification to ensure the validity of the method.
• Pay attention to the recording and analysis of blank tests and abnormal results to avoid systematic errors.