​Mech-Chem offers Electrodialysis lab test units for the testing and verification for the following application:

• Removal of Salt Brine from Water.
• Concentration of Metal Salts from Dragout and Rinses for Recycling to Plating Baths.
• Salt Maintenance on Fume Scrubbing Systems
• Electroless Nickel Purifications 

Electrodialysis is an electrically driven ion-exchange process which utilizes alternating sequences of cation exchange membranes and anion exchange membranes to effect the separation and concentration of dissolved salts from various solutions. Selectively permeable ions are transported from one side of a membrane, through the membrane, to the other side of the membrane. These salts are concentrated, collected, and removed from the unit.

​With the proper selection and configuration of permselective membranes between a positively charged, inert anode, and a negatively charged cathode, electric deionization is accomplished. Such a configuration of membranes, hydraulic spacers, and electrodes is termed an Electrodialysis stack.

An Electrodialysis system is comprised of an Electrodialysis stack, circulation pumps, solution holding tanks, a power supply, pressure gauges and ancillary controls. Optional controls may also include particulate filters and conductivity control. 

What is Sulfuric Acid Anodizing?
The Anodizing process produces oxide film on the surface of an aluminum substrate. This acid film produces a hard corrosion and abrasion resistant coating, with excellent wear properties. Various electrolyte solutions can be employed, but the most commonly used is Sulfuric acid.

By controlling the electrolyte and the anodizing conditions, such as temperature, current density and air agitation, one can produce Aluminum coatings with almost any desired property.

Why should I use Diffusion Dialysis with my Sulfuric Acid Anodizing process?

Diffusion Dialysis is ideally suited for the recycling of sulfuric acid anodizing solutions. Diffusion Dialysis provides improved anodize quality, consistent anodized color and consistent anodic thicknesses, cooler and less energy demanding baths, while eliminating production down-time associated with the dumping and remaking of the anodize bath.

The passive, continuous Diffusion Dialysis process enables the anodizer to efficiently remove and control the dissolved aluminum content in the bath while recovering and returning a high percentage of the sulfuric acid back into the process bath. The Diffusion Dialysis process also removes and controls other contaminant buildup in the anodize bath, such as : copper, iron, lead, magnesium, manganese, phosphate, silicon and zinc, while producing a minimum of rejected waste by –product for subsequent treatment and disposal.

Acid Purification System Model Number
Based upon 24hours per day/ seven days per week of operation. Actual calculation: bath volume divided by calendar days of bath life equals gallons per day required.

**Large Scale AP Systems Are Available (Systems greater than 300 Gallons Per Day)**

The Acid Purification Systems manufactured by Mech-Chem Associates, Inc. are tailored to the client’s needs with respect to materials of construction and operating capacity required. ​