Patent ID: 6171409
Filing Date: 2001-01-09
Classification: C23C,C23G

Abstract:
A process for chemical treatment of a metal surface comprising:contacting said metal surface with a process bath solution in a container, said process bath solution being comprised of a plurality of components in aqueous solution and having a composition maintained within a given range by addition of at least one solution or gas, wherein said process bath solution is circulated via a first line and a circulating pump and said solution or gas to be added is fed into said process bath solution at a point where vigorous thorough mixing of the solution or gas with the process bath solution occurs,wherein said first line has an end which is above the surface of the process bath solution in the container,wherein a portion of the process bath solution is recycled via a heat exchanger into the process bath and the process includes the step of heating the recycled portion of the process bath solution by means of said heat exchanger.