Method for improving accuracy and precision of trace amount antimony in metal lead measuring

Abstract

The invention belongs to the field of nonferrous metallurgy, in particular to a method for improving the accuracy and precision of trace amount antimony in metal lead measuring. The method comprises the following steps: (1), preparing the following solution; (2), drawing the standard solution working curve; and (3), analyzing samples and finding out corresponding antimony concentration from the working curve. The method has the following advantages: (1), a technology is provided for improving the accuracy and precision of trace amount antimony in metal lead measuring; (2), full amount extraction is realized; (3), the method has high result accuracy, high precision and good repeatability; no light absorption value variation triggered by diversity of the extraction sequence or storage period during the measurement between standard curve series point solution and sample solution is caused; (4), the method is also suitable for the measurement of antimony in lead alloy; and (5), only simple and convenient spectrophotometer is used, the cost is low, and the method is particularly suitable for production units.

Description

technical field [0001] The invention belongs to the field of nonferrous metallurgy, and in particular relates to a method for improving the accuracy and precision of determining trace antimony in metallic lead. Background technique [0002] The content of antimony in metallic lead is very small, usually in the range of 0.000X to 0.0X%. At present, the main methods of determination are direct reading spectroscopy, plasma emission spectrometry, hydride-atomic fluorescence method, spectrophotometry and so on. Although the results of direct reading spectroscopy and plasma emission spectroscopy are relatively accurate, the equipment is expensive, and high-purity nitrogen gas is required, which is high in cost; although the hydride-atomic fluorescence method has high sensitivity and precision of measurement results, the results are reliable, but it requires It is equipped with a hydride generating device, and the operation is tedious and the cost of use is high; the latest effect...

AI Technical Summary

Problems solved by technology

Although the results of direct reading spectroscopy and plasma emission spectroscopy are relatively accurate, the equipment is expensive, and high-purity nitrogen gas is required, which is high in cost; although the hydride-atomic fluorescence method has high sensitivity and precision of measurement results, the results are reliable, but it requires It is equipped with a hydride generating device, and the operation is tedious and the cost of use is high; the latest effective national testing standard GB / T4103.2-2000 is the crystal violet spectrophotometric method, which uses [SbCl 6 ] - Based on the color strength of the blue complex formed with crystal violet, but due to [SbCl 6 ] - And its crystal violet complex is easy to decompose in acidic medium, resulting in unstable color of the blue complex. In addition, the difference in operation details of different personnel often leads to poor reproducibility of measurement results by different personnel or even the same personnel, sometimes even The difference is several times, and it is mainly because of: 1. A small amount of HCl remaining in the antimony organic phase cannot be completely removed, which makes the organic complex easy to decompose. The national standard adopts the method of adding anhydrous sodium sulfate in the organic phase to remove Residual hydrochloric acid, but the effect is still unsatisfactory; 2. The temperature of the solution after adding urea and shaking and the storage time before extraction have a great influence on the extraction, but the operating standard has not been clearly described in detail; 3. The chromogenic agent and its relationship with [SbCl 6 ] - The complex compound is unstable in hydrochloric acid medium, and lacks corresponding control means

4. The combined effect of the first three factors, even if the standard curve series points are measured immediately after extraction, the absorbance value of the same series of points will be significantly reduced within 2 minutes, which directly causes the linearity of the standard curve to be poor. If you have to wait for the sample solution After extraction and at the same time as the standard curve series points, the absorbance value changes more

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