Page 43 - PCMI Summer Journal 2021
P. 43
An Overview of the Operation of Ferric Chloride Regeneration Systems in Photochemical Etching Machines
Presented by: Kirk Lauver, the Marketing Specialist, Chemcut Corporation, US
24
25
7/27/21
• Add additional cells to increase capacity
• Adding storage tanks increase the etchant
volume which flattens the FeCl3 depletion
curve.
• More Information: https://www.k-s-d.de
info@k-s-d.de
• Most popular regeneration for new installations
• Known in Europe as BEAC
• Lowest cost regeneration to install
• Sodium Chlorate breaks hydrochloric acid into water and chlorine
• Fe0 + 2FeCl3 = 3FeCl2 Etching Reaction
• 3FeCl2 + 0.5NaClO3 + 3HCl = 3FeCl3 + 1.5H2O + 0.5NaCl Regeneration Reaction • Etching 1 Kg of metal requires:
• 1.96 Kg HCl (100%), 20°Be’ 6.22 Kg(5.36 ltr), 22°Be’ 5.6 Kg(4.75 ltr) H2O = 4.26 Kg or 3.64 Kg The total HCl need will be higher due to system losses
• 0.95 Kg NaClO3 (100%) At 46% 2.07 Kg(1.48 ltr) H2O = 1.12 Kg
• Water produced in the regeneration reaction = 0.48 Kg
• Total water added when regenerating 1 Kg of metal = 5.86 Kg (20° HCl) or 5.24 Kg (22° HCl)
• Water per Kg of metal in 40° Be’ FeCl3 is 4.98 Kg, No Baume’ adjusting water required, unless there is significant evaporation from the etcher.
• Sodium chlorate regeneration produces more reaction heat than chlorine gas, additional cooling load.
Issue 137 August 2021 PCMI Journal 43
