Preparation of high purity compact galena bulk by hot pressed sintering

By using PbS powder as raw materials, high-purity compact and machinable galena bulk was successfully prepared by sintering method under high pressure and temperature for the first time. The hot pressed sintering was performed at 0.9 GPa and 550 °C for 1 h. The as-prepared products were characterized by powder X-ray diffraction (XRD), Electron Probe Microanalysis (EPMA), Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), Carbon and Sulfur Analyzer, and optical microscopy, respectively. XRD results show that the as-prepared samples have a cubic structure and were identified as galena without any impurity. Based on microscopic observations and element analyses, only galena was identified, and it is consistent with the results of XRD analysis. The density of galena bulk was measured and it is equal to the theoretical value. It is machinable and can be processed into fixed shape.