There are not only many harmful substances, but also a lot of valuable substances in waste circuit boards. Generally, waste circuit boards contain 30% plastics, 30% inert oxides and 40% metals (by weight), of which base metals (copper, lead, zinc, etc.) about 30% and precious metals (gold, silver, platinum, palladium, etc.) account for about 0.3%~0.4%. Therefore, recycling metals, especially precious metals, is the main driving force for recycling of waste PCB. If it is not recycled, the metal in the waste circuit board may cause the pollution of soil and groundwater. Therefore, no matter from the perspective of environmental protection or resource utilization, the metal in waste PCB should be recycled.
Put the copper containing material into the reactor to leach the copper, then after filtered, the copper is extracted by the extraction method. The solvent extraction is tributyl phosphate, the diluent is sulfonated kerosene, the ratio of extractant: diluent=1:1, then sent to the electrowinning tank for electrowinning extraction.
CWL-M centrifugal extractor can be used as the core extraction equipment for copper extraction. This series of centrifugal extractors is an efficient extraction equipment that uses centrifugal force to achieve liquid-liquid two-phase extraction and separation. It can realize liquid-liquid two-phase mixing mass transfer, reaction, extraction, washing, separation and other functions. Compared with the traditional box type and tower type extraction equipment, the centrifugal extractor has the advantages of short stage retention time, rapid phase separation and wide flow ratio range; Liquid materials with different densities and viscosities can be met by changing weir plates and frequency conversion speed regulation, with strong adaptability.