Lead assay in mining concentrates is an important process to determine the commercial value of a mining project. The analysis of lead is typically performed using atomic absorption spectroscopy, inductively coupled plasma optical emission spectroscopy, or inductively coupled plasma mass spectrometry. These methods provide a working range from parts per million to percent levels of lead in the sample, depending on the complexity of the sample. Sample preparation is a critical step in the lead assay process, as interferences from other elements present in the sample can affect the accuracy of the results. Understanding the sample matrix and implementing appropriate sample preparation techniques are crucial to obtain accurate and precise results. Accurate and precise results are essential for making informed decisions about the mining project’s economic viability. The accuracy and precision of the lead assay are critical to provide reliable information to stakeholders in the mining industry.

Atomic Absorption Spectrometry (AAS): This method involves dissolving the sample in acid and then measuring the amount of lead present using a flame or graphite furnace to atomize the lead. The working range for lead in this method is typically 0.01-100 ppm.

Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES): This method involves dissolving the sample in acid and then measuring the amount of lead present using a plasma to excite the atoms and then measuring the light emitted by the atoms. The working range for lead in this method is typically 0.01-100 ppm.

The titration method with EDTA (ethylene diamine tetra acetic acid) is a commonly used method for the assay of lead in mining concentrates. The method involves adding a known amount of EDTA solution to a sample of the concentrate containing lead. The EDTA reacts with the lead in the sample to form a complex, which is then back-titrated with a solution of a metal ion, typically zinc, using a suitable indicator. The endpoint of the titration is the point at which all the lead has reacted with the EDTA, and excess EDTA is detected by the indicator.

The working range of the titration method with EDTA for the assay of lead in mining concentrates is typically in the range of 25-80% lead.