Treatment of Highly Concentrated Fluoride Wastewater from the Semiconductor Industry by CaCl₂ based on the Adjustment of ζ-Potential

Efficient recovery of highly pure CaF2 from fluorine-containing wastewater using an icy lime solution

“…For instance, Zhai et al (Zhai et al 2013) reported that direct addition of lime to fluorine-containing wastewater resulted in treated water with significantly higher concentrations of fluoride ions ranging from 30 to 50 mg/L than the required discharge limits. In addition, the low purity (only 20-40% (Zhou et al 2023)) of recovered calcium fluoride needs to be further purified prior to use, thereby inevitably increasing the subsequent processing steps and costs. This indicates that the efficiency of lime treatment of fluorine-containing wastewater should be further improved.…”

Economic Feasibility Evaluation of Bioleaching-Based Tungsten Recycling of Semiconductor Industry Waste

“…This necessity aligns with the principles of green chemical engineering and is driven by considerations of global warming and environmental impacts. − Notably, wastewater generated from semiconductor manufacturing processes contains environmentally hazardous materials, such as tungsten, fluorine, copper, cadmium, and lead. The development of technologies to recover metal resources from wastewater in semiconductor manufacturing is gaining attention as a solution to environmental pollution and resource depletion issues. − Tungsten, recognized for its essential metallic properties, is widely employed in various sectors. This extensive usage establishes tungsten as a critical raw material for manufacturing processes .…”