emew Smart SystemTM

Conventional electrowinning involves placing an anode and cathode into a bath of slowly circulating or stagnant electrolyte. The metal ions eventually make their way to the cathode via diffusion to be plated. With emew electrowinning, the electrolyte is circulated rapidly past the anode and cathode at a very high flow rate, significantly enhancing mass transfer and allowing for improvements in efficiency and recovery.

“Novel electrochemical cell designs are emerging as alternative process units for various applications in industry. Most of the advances in electrochemical cell design are in the field of improving mass transfer. Improved mass transfer allows increased specific production capacity, reduced footprint, increased selectivity, and plating from lower concentrations. One of the designs gaining acceptance in industry is the annular/tubular/cylindrical electrochemical cell. It is concluded that swirl flow significantly improves mass transfer over axial flow in annular electrochemical cells due to the slower formation of the diffusion layer.”

Source: Mass Transfer in Annular Cylindrical Electrochemical Cells, Etienne Roux

emew Plate

The emew Plate cell is used for more concentrated electrolytes generally when the target metal concentration is greater than 10 g/L. The emew Plate cell is often used for recovering copper, nickel and tin cathode in a variety of applications including mining, refining, and recycling. The emew Plate cells can also be paired with solvent extraction (SX) and ion exchange (IX) when pre-concentration of the target metal is necessary.

emew Powder

The fully automated emew Powder cells use the same basic philosophy as emew Plate cells, however, they are designed to produce a metal powder.  The emew Powder cells generally operate at lower target metal concentrations (<5 g/L), higher current density and lower flow rate than their plating cell counterparts.  The metal powder formed on the cathode surface is automatically harvested using a flush-through methodology.

The closed nature of these cells coupled with automated flushing makes them ideally suited for precious metals applications such as silver, silver-gold and palladium.  Having a single collection point for the precious metal enhances security, reduces losses and facilitates metallurgical accounting.  In addition to precious metals, emewPowder systems are also used to produce specialty powders such as electrolytic copper and nickel powders, as well as bismuth and copper arsenide.

emew Polish

Direct electrowinning is pushed to the extreme with emew Polish. Using the same concept of high-efficiency emew electrowinning equipped with a sophisticated, proprietary high surface area cathode, this type of emew cell can recover metals down to less than 5ppm. Not possible with conventional electrowinning technology, the emew Polish cell is ideal for recovering metals from dilute concentration bleed streams, wastewater or any industrial process stream with low metals concentration.

Applications for emew Polish include:

   • Silver refineries looking for an alternative to AgCl to treat bleed streams and spent electrolyte

   • Zinc refineries looking to minimize zinc dust usage to remove copper, cadmium, bismuth, and others during zinc electrolyte purification

   • Any industrial wastewater that is too dilute to be treated by conventional means

emew Clean

A unique fusion of emew cell designs, emew Clean is specifically formulated for environmental applications.  This proprietary hybrid technology uses emew high surface area ‘3D’ cathode in combination with emew Plate technology to recover metals from dilute streams and produce high purity cathode.  This innovative, additive approach further expands the capability of emew electrowinning technology so that the sum truly is greater than the individual components.  The result is an advanced metal recovery system that can recover metals to less than 5ppm while also producing cathode for reuse or sale.

Applications for emew Clean include:

     • Copper waste from semiconductor fabrication plants

     • Rinse baths and drag out from electroplating facilities

     • Any industrial wastewater that is too dilute to be treated by conventional means

The emew Group has assembled a suite of complementary technologies that go beyond electrowinning to provide clean technology solutions for environmental stewardship, metal recovery, energy efficiency and waste water treatment.

Digestion/Leaching

Very often the most difficult part of effective metals recovery from sludges and solid materials is getting into a solution for separation and selective recovery. A range of effective digestion and leaching technologies are offered by emew along with the know-how for getting various difficult to process metals into a solution for separation and production as saleable metals.

Ion Exchange (IX)

Ion Exchange (IX) processes allow for purification and concentration of targeted ions from solutions for selective recovery. Examples include separation of nickel from cobalt, separation of palladium from silver, copper from chlorides or mine waste waters and nickel from electroless nickel solutions. In most cases the Ion Exchange units are self-contained, skid mounted and controlled by PLC.  The relatively simple operation of ion exchange on a small scale vs solvent extraction makes the technology ideally suited for rapid set up in small to medium sized operations.
Variations such as continuous IX and fluid bed IX offer advantages over conventional fixed bed IX for solutions with suspended solids and minimizing rinse waters used in the ion exchange process.

Solvent Extraction (SX)

Solvent Extraction (SX) has been used for over 50 years in the copper industry for concentration and purification of copper and other solutions prior to electrowinning. Solvent Extraction is common for treating complex, low grade electrolytes for separation, purification, enrichment, and recovery.

Solvent extraction plants are closed loop in concert with leaching and electrowinning with optimum recycling of reagents to produce metal cathode. SX can also be used to extract and separate nickel and cobalt from chloride, ammoniacal, and sulphate solutions. Low cost, modular SX plants offered by emew are ideal for small scale mining and capital sensitive projects.