Metal surface treatment liquid recycling system and operation method thereof

• Main Authors: LIAO, PEI-NUO, LIAO, CHONG-HENG
• Format: Patent
• Language: Chinese; English
• Published: 01.07.2023
• Subjects: CHEMISTRY; METALLURGY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING; TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE

A metal surface treatment liquid recycling system includes a treatment liquid collecting tank, a pre-treatment device, a nanofiltration device and a vacuum distillation device, all of which are connected sequentially. The nanofiltration device includes a feed tank, a first-stage nanofiltration membrane unit, and a second-stage nanofiltration membrane unit. Treatment wastewater in the treatment liquid collecting tank is fed into the pre-treatment device to filter out suspended solids and then enter the feed tank. The wastewater in the feed tank is filtered by the first-stage nanofiltration membrane unit and transformed to a first-stage concentrated waste liquid and first-stage infiltration fluids. The first-stage infiltration fluids are fed into and re-filtered by the second-stage nanofiltration membrane unit and transformed to a second-stage concentrated waste liquid and second-stage infiltration fluids. The second-stage infiltration fluids are evaporated and concentrated by the vacuum distillation device for