Zero liquid discharge (ZLD) is an engineering approach to water treatment where all water is recovered and contaminants are reduced to solid waste.
Two Zero Liquid Discharge Treatment Plants Headed to Sub-Arctic Mine
Saltworks Technologies has been chosen to deliver two full-scale saline water treatment systems for a precious metals mine in the Canadian North. The zero liquid discharge (ZLD) plants will desalinate mine shaft water, and enable the site to achieve their treatment goals.
After a year-long pilot and competitive selection process, the client chose Saltworks’ SaltMaker Evaporator Crystallizer and supporting process plant. Pilot results demonstrated that the treated water met stringent arctic discharge requirements, including aquatic life tests, while producing zero liquid discharge salts. Some of the salts may be reused inside the mine shaft for de-icing.
The modular plants are being delivered on a rapid schedule as a series of ISO shipping container blocks. The multi-effect evaporator crystallizer process can be driven by waste heat due to its energy efficient design, and has built-in intelligent controls for self-cleaning and automated operation.
“Contributing to an important mining development is a great way to start 2018. Many modern innovations rely on mined precious metals – cell phones, electric cars, computers. Zero liquid discharge represents the future of mine water management, and we are thrilled to be a part of it,” said Saltworks CEO, Ben Sparrow.
The many options for managing brine, a term for saline wastewater from industrial processes, fall under two categories: brine treatment and brine disposal. Brine treatment involves desalinating the brine for reuse and producing a concentrated brine (lower liquid waste volume), or residual solids (zero liquid discharge).
Convention teaches that ZLD requires energy-intensive boiling to produce solids. Our engineers recently broke that convention and helped a mining client achieve solid salt production in a novel membrane-chiller hybrid plant using UHP-RO.