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AssigneeSMS Schloemann-Siemag Aktiengesellschaft
InventorsJoachim Kuhlmann, Ulrich Glasker
Estimating the term…
A method and a plant for regenerating zinc sulfate electrolyte in steel strip electrogalvanizing processes by precipitating dissolved iron from electrolyte circulating through a coating cell. A partial quantity of the circulating electrolyte to be regenerated is removed from the coating cell and the dissolved iron is oxidized to Fe.sup.3+ by a redox-controlled addition of oxidizing agents. Subsequently, by raising the pH value to the precipitation limit of Fe.sup.3+ by a controlled addition of a ZnO/water suspension or a ZnCO.sub.3 /water suspension, the dissolved iron is precipitated as sludge. Any excess ZnO or ZnCO.sub.3 is then dissolved by adding fresh electrolyte. The precipitated iron sludge is conducted through a suitable filter such as a filter press, a filter belt, a decanter, etc., and the precipitated iron is filtered out in this manner. Subsequently, the purified partial quantity of the electrolyte is returned to the coating cell.
A method of regenerating zinc sulfate electrolyte in a steel strip electrogalvanizing process by precipitating dissolved iron from electrolyte circulating through a coating cell, the method comprising the steps of:
A plant for regenerating zinc sulfate electrolyte in a steel strip electrogalvanizing process by precipitating dissolved iron from electrolyte circulating through a coating cell, the plant comprising at least one coating cell and means for feeding a steel strip to be coated through the coating cell, and means for producing the circulation of the electrolyte through the coating cell, the plant further comprising a reaction vessel and a stirring apparatus mounted in the reaction vessel, wherein the reaction vessel is in communication with the electrolyte in the coating cell through a discharge line and a return line, further comprising a first supplementary vessel for oxidizing agent in communication with the reaction vessel through a connecting line and a first metering pump, and a second supplementary vessel for a ZnO/water suspension or ZnCO.sub.3 /water suspension in communication with the reaction vessel through a second connecting line and a second metering pump, wherein the second metering pump is in connection with a pH value sensor and the first metering pump is in connection with a measuring unit for determining the oxygen content in the electrolyte, and wherein a filter for filtering solids is mounted in the return line.
Dependencies are inferred from the claim text.