Water used by mining enterprises needs to be comprehensively recovered and utilized to achieve clean production. This requires the effective treatment of mineral processing wastewater. Wastewater produced during non-ferrous metal mineral processing contains a complex mixture of pollutants at high concentrations, making comprehensive treatment difficult. Here, the sources of and hazards posed by wastewater produced during non-ferrous metal mineral processing are introduced and the techniques for removing heavy metal ions and organic chemicals are reviewed. Chemical precipitation and adsorption methods are often used to remove heavy metal ions. Chemical precipitation methods can be divided into hydroxide and sulfide precipitation methods. Organic chemicals are mainly removed using oxidation methods, including electrochemical oxidation, photocatalytic oxidation, and ultrasonic synergistic oxidation. External and internal cyclic utilization methods for treating wastewater produced by mineral processing plants are introduced, and a feasibility analysis is performed.

Chloride ions were found to potentially increase activity of cerussite surfaces. Dissolution experiments, zeta potential measurements, X-ray photoelectron spectroscopy (XPS) studies, and density functional theory (DFT) computation were conducted in this study. Dissolution experiments showed that the lead ion concentrations in the NaCl solution system were lower than those in the deionized water system and that the lead ion concentrations in NaCl + Na₂S aqueous systems decreased by approximately one order of magnitude compared with that in the Na₂S system alone. Results of zeta potential measurements revealed that the pretreatment with chloride ions of cerussite caused a more positive zeta potential than that without chloride ions. XPS analysis results indicated that the number of lead ions on the mineral surface increased after cerussite was treated with chloride ions. Results of DFT computation implied that the number of lead atoms on the mineral surface increased and that the activity improved after PbCl⁺ was adsorbed onto the cerussite surface. The contribution of chloride ions to the activity on the mineral surface is attributed to the increase in the number of active sites and enhancement in the activity of these sites, resulting in improved sulfidization and flotation performance.

The beneficiation of low-grade oxidized lead and zinc ore from the Lanping mine has attracted extensive interest in the mineral processing field due to the extremely rich resource reserves and the challenge in lead and zinc recovery. This study’s objective is to analyze the process mineralogy characteristics and to conduct the flotation optimization of this ore. Mineralogy parameters of the ore, such as mineral composition, mineral liberation degree, and intergrowth relationship, were investigated using an X-ray fluorescence spectrometer (XRF), an X-ray powder diffractometer (XRD), and an electronic probe microanalyzer (EPMA). The effect of the main experimental factors on the lead and zinc flotation is determined and compared. The results confirm that the low content of lead and zinc and the complex co-occurrence relationships between minerals bring a challenge to the efficient separation of the ore. Furthermore, a flow sheet consisting of “lead preferred flotation-zinc flotation” is performed, and an all-open flotation process consisted of “two-times lead rougher-one-time lead cleaner-two-times zinc rougher-one-time zinc cleaner” is finally employed for the beneficiation of this ore with the aids of mixed depressants and cationic-anionic collectors for zinc recovery. The Pb grade in the lead rougher concentrate is 2.83%, and the Pb recovery is 57.56%. The Zn grade reaches 28.64% with a recovery of 83.45%. Thus, the findings provide important technical supports for the processing of similar ores.

Tungsten is a commercially important metal element that usually coexists with a variety of non-ferrous metals, which makes its extraction difficult. Scheelite is a commonly occurring tungsten-containing ore with the formula CaWO₄. Improving the surface properties of scheelite to increase its adsorption of the collector for flotation separation is the focus of our current research. In this paper, the effects of manganese ions on scheelite flotation in benzohydroxamic acid (BHA) system were studied by micro-flotation tests, adsorption tests, fourier transform infrared spectroscopy (FTIR), zeta potential, and X-ray photoelectron spectroscopy (XPS) analysis. The addition of Mn²⁺ was found to improve the recovery of scheelite. The addition of Mn²⁺ greatly improved the recovery of scheelite. Infrared spectroscopy, adsorption tests, zeta potential measurements and XPS analysis all confirmed that BHA had a higher adsorption capacity and a stronger bond to the surface of scheelite after the addition of manganese ions, increasing the floatability of scheelite particles. Therefore, Mn²⁺ shows great potential for the improvement of the flotation index of scheelite in a system with BHA.