A Chemical Recovery System is an integrated arrangement of process equipment, instrumentation, and control systems specifically designed to capture, treat, purify, and recycle chemical reagents from spent process solutions or waste streams back into active production circuits. In contrast to individual unit operations, a chemical recovery system encompasses the complete cycle of collection, treatment, and return of chemicals, representing a closed-loop or near-closed-loop approach to reagent management. In bauxite and alumina refining, the chemical recovery system for caustic soda (NaOH) typically comprises evaporators (multi-effect or mechanical vapor recompression types), flash tanks, heat exchangers, desilication reactors, and associated pumping and piping infrastructure. The system processes large volumes of spent liquor continuously and must handle scaling tendencies, sodium oxalate crystallization, and corrosion from hot concentrated caustic solutions. In gold processing, chemical recovery systems for cyanide incorporate the SART process (Sulfidization, Acidification, Recycling, and Thickening), which precipitates copper sulfide from cyanide-copper complexes and releases free cyanide for return to the leach circuit, along with associated reactors, thickeners, and filtration equipment. In diamond processing plants, ferrosilicon dense media recovery systems include magnetic separators, drain-and-rinse screens, and demagnetization circuits to reclaim ferrosilicon from product and waste streams. The performance of a chemical recovery system is measured by recovery efficiency (percentage of chemical reclaimed), reagent losses to tailings or effluent, energy consumption of the recovery process, and overall operating cost per unit of chemical recovered. Capital investment in robust chemical recovery systems is typically justified through rapid payback from reduced fresh reagent consumption and improved environmental compliance.
