Evaluation of Mineralogical Characteristics and Flowsheet Improvements for Carbon-Bearing Lead-Zinc Ore

Abstract

The chemical and process mineralogical characteristics of carbon-bearing lead–zinc ore in Sanguikou, Inner Mongolia, China, were investigated. The study aimed to identify the mineral characterizations and distribution of lead, zinc, and carbon. X-ray fluorescence and chemical analysis showed lead, zinc, and carbon grades of 0.58%, 2.44%, and 5.33%, respectively. X-ray diffraction, polarizing microscopy, and mineral liberation analysis revealed lead and zinc mainly occur as galena and marmatite, with carbon as graphite. The particle sizes are small and symbiotic relationships complex. Additionally, the characteristic features of carbon-bearing lead–zinc ore were summarized, and the current plant flowsheet and outcomes were assessed. The improved flowsheet includes X-ray sorting before grinding and a flotation column in zinc flotation to treat the regrinding middling separately. This approach achieved a Pb grade of 65.34% with a recovery of 70.64% and a Zn grade of 45.61% with a recovery of 89.98%. The Sanguikou plant processes 5000 t/day, producing 23.58 t of lead concentrate and 105.41 t of zinc concentrate daily. The new flowsheet enhances the grade and recovery of lead and zinc concentrates. The proposed flowsheet is a promising comprehensive recovery method and cleaner production process for this unique lead–zinc resource.