Abstract: Phosphorus furnace slag is used as a ladle flux and/or as a tundish flux in the continuous casting of steel. The phosphorus furnace slag uniquely combines the properties of thermal insulation, oxidation protection and inclusion absorption necessary to function satisfactorily as a ladle flux and/or as a tundish flux.
Type:
Grant
Filed:
April 7, 1987
Date of Patent:
April 19, 1988
Assignee:
Tenneco Canada Inc. (ERCO division)
Inventors:
Alexander McLean, Iain D. Sommerville, Paul S. Timmons, Michael S. Krugel
Abstract: The extent of delignification of chemical pulps by oxygen-containing chemicals, preferably hydrogen peroxide, is enhanced by demethylating the pulp prior to such oxidative delignification, to a degree of demethylation of at least about 30%, preferably at least about 50%. Demethylation may be achieved by chemical treatment of the already-formed pulp or by modification to the pulping process to result in demethylated pulp.
Abstract: Dichromate values, or other soluble hexavalent chromium values, are removed from cell liquor or other aqueous media containing the same by cathodically reducing the same to trivalent chromium, which deposits on the cathode as chromium hydroxide. The cathode has a high surface area three-dimensional structure which exposes the electrolyte to electrolysis for a relatively long period of time. An electrode potential of about 0 volts vs. SCE is applied to the cathode.
Abstract: Dissolved arsenic (III) contaminant is removed from mineral acids, such as hydrochloric acid, by electrolysis using a high surface area cathode having a three-dimensional electrolyte-contacting surface which exposes the electrolyte to electrolysis for a relatively long period of time. The dissolved arsenic is reduced to arsenic metal, which then plates out on the cathode. Dissolved concentrations of arsenic of less than 1 ppm can be achieved using the invention.
Abstract: Chlorine dioxide is transferred by membrane pervaporation from one chamber filled with aqueous chlorine dioxide-generating reactants or other chlorine dioxide donor medium across a gas-permeable hydrophobic membrane to a recipient aqueous medium filling a second chamber. The recipient medium may be water, pulp suspension or sodium chlorite solution. The membrane typically is expanded polytetrafluoroethylene.
Type:
Grant
Filed:
December 24, 1985
Date of Patent:
July 28, 1987
Assignee:
Tenneco Canada Inc. (ERCO division)
Inventors:
Zbigniew Twardowski, James D. McGilvery