American Can Company

Niranjan M Parikh

Carl F Bauer

Ronald E Beese

Benny Langston

James H Hussey

An improved flux used for the recovery of metallic aluminum from dross in a reverberatory furnace. The flux is an alloyed mixture of sodium chloride and potassium chloride in approximately equal parts by weight which has been preheated and then cooled to form an alloyed mixture. A small amount of cryolite can be added to the liquid mixture before cooling to improve the recovery of metal obtained than when the salt and potash flux mixture is used alone.

Flux in recovery of aluminum in reverberatory furnace and method of

This invention pertains to fluxes used in recovery operations for secondary aluminum. The flux herein is formulated in order to minimize the amount of chloride in the slag whereby it can be used as land fill without an adverse impact on the environment or in lieu of bauxite in the manufacture of aluminum or as source of aluminum oxide for the manufacture of aluminum or aluminum salts. The flux uses a combination of sodium chloride and aluminum chloride which form a double salt having vapor pressure sufficiently low to permit the aluminum chloride sublimation, without rapid sublimation, however, sufficiently high to permit the evaporation of chloride salts to provide low chloride slag. The improved flux also permits the heat cycle to be shortened by 10 to 20 percent thereby giving a measurable energy savings.

Flux

A technique for controlling severe chemical reactions which occur when salt containing furnace slags from secondary aluminum melting operations are brought in contact with water is provided. The technique which retards the formation and evolution of hydrogen gas resulting from the reaction of aluminum metal fines with water in the presence of chloride and the formation and evoluation of ammonia gas from the reaction of aluminum nitride with water is accomplished by controlling the pH of the water-solid slurry to be around 8. Consequently, the formation and gaseous evolution of hydrogen is controlled and the evolution of ammonia is eliminated with a concomitant elimination of explosion and fire hazards associated with the uncontrolled chemical reactions.

pH Control during leaching of aluminum slags

Zinc or iron sacrificial anodes, or the cathodic current from a DC current source applied through a platinum electrode, provide stainless steel protection from pitting corrosion particularly in the interior of long narrow stainless steel tubes exposed to hot concentrated chloride brine. The invention is characterized by the placing of an anode in a brine solution near one end and electrically connected to a stainless steel tube, thereby protecting the interior of the stainless steel tube along its entire length from pitting corrosion by the brine.

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Winnetka, IL, United States of America

Niranjan M Parikh