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Economic Evaluation of a Method to Regenerate Waste Chromic Acid- sulfuric Acid Etchants.

Authors
Spotts-DA
Source
MISSING :7 pages
Link
NIOSHTIC No.
10002820
Abstract
Researchers at the Bureau of Mines have developed a technique for regenerating chromic acid-sulfuric acid etching solutions used in metal surface treatment operations. The technique utilizes a diaphragm cell equipped with a cation-selective membrane to oxidize cr3+ to cr6+ at the anode and to remove copper, the major metallic contaminant, at the cathode. Normally, spent etchant is discarded after approximately 3 days of use. Using the electrolytic cell, the etchant can be used for a year without replacement. From data obtained from industrial-scale cells, the installation of a regeneration cell with a 1,000-gal catholyte-holding tank has been estimated to save at least $240 per day. The payback period for the investment is estimated to be about 10 mo or less. Because the magnitude of these cost savings will vary at different locations, several graphs are presented to aid in calculating payback for a specific site. Using these graphs and the capital costs presented in this study, the payback period can be determined for installing a regeneration cell with a 500- or a 1,000-gal catholyte-holding tank in an existing surface treatment plant.
Publication Date
19830101
Document Type
IH; Information Circular;
Fiscal Year
1983
NTIS Accession No.
NTIS Price
Identifying No.
IC 8931
NIOSH Division
AVRC;
Source Name
MISSING
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