Every Day, Asterion works to help our clients become more efficient, more productive and, most importantly, more profitable. As part of our efforts, we work with our clients to help them discover better methods to manage and control their plating baths.
Over time we have learned quite a bit about the struggles our customers have in managing carbonates in alkaline plating baths. Accumulation of carbonates in alkaline plating baths is a continuous problem and can lead to a number of issues affecting quality and plating efficiency.
The primary cause of formation of sodium carbonate is a naturally occurring phenomenon when sodium hydroxide is electrolyzed. Another cause is our atmosphere, which contains carbon dioxide. Carbon dioxide combines with water to create a form of carbonic acid, H2CO3. The carbonic acid reacts with the alkaline solution to form carbonates. Air agitation or vigorous mixing will make the problem worse.
Finally, a smaller but important cause can be the formation of oxygen at the anode. The oxygen can react with organic materials that may be present in the plating bath as additives, this reaction forms carbonates.
Typically, a new plating bath will have about 8oz./gal of carbonate contamination. But over time carbonates build in plating baths and when carbonate concentrations reach 12 oz./ gal. a number of problems will begin to occur. These problems include but are not limited to slower plating speeds, reduced throwing power, increased brightener consumption, grainy or burned deposits in high current density areas, plating roughness and in extreme cases organics that begin to “oil” out or float. Needless to say no plating professional wants to work with a bath that contains a high concentration of sodium carbonates.
Asterion™ is offering a solution to the problem associated with carbonate build-up in alkaline plating solutions.
Traditional methods for reducing carbonates in alkaline plating baths in solution involved shutting down production, decanting a portion of the working bath and pumping the solution to totes and placing in an environment with temperatures less than 32 ⁰F waiting for crystals to form, which can take up to 48 hours, and then manually removing the sludge. This is a time consuming and costly procedure that is inexact and often results in a substantial loss of the working bath volume.
Asterion’s “Carbo-Dry™” unit offers a unique system for reducing carbonates with the capability to produce almost solid crystals utilizing a simple and relatively maintenance free skid mounted system. The “Carbo-Dry™” automatically treats 50 gallons in a batch process producing roughly 70 pounds of dry crystal residue as a result of a 2 step cycle that includes both a chilling cycle and a centrifuge process. The treated solution is transferred back to the plating line eliminating the need to shut down production or the need to have additional plating solution for an off-line treatment. This reduces time spent by manual labor filtering a slush, it virtually eliminates loss of plating solution and greatly reduces waste treatment cost. Total cycle time in most cases is three to five hours with a starting plating solution temperature of 80⁰F-140⁰F.
To learn more about this process, download our FREE guide.
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