Aluminum Company of America

Alcoa Inc.

Roy A Christini

Kenneth A Bowman

Marlyn D Ballain

Eric L Clark

Robert K Dawless

Rolf Rolles

Robert D Girt

Kenneth P Frizzell

The present invention is directed to methods for preheating a molten salt electrolysis cell having inert anodes ( ) using recuperative gas heating by combusting a first gas outside the cell chamber ( ) in a combustion chamber ( ) and using to heat a second gas in recuperator ( ) which second gas us passed to the cell chamber ( ). The inert anode can be a cermet inert anode.

Use of recuperative heating for start-up of electrolytic cells with inert anodes

The present invention is directed to methods for applying a protective layer ( ) to the cathode ( ) of an electrolysis cell ( ), where the cell also contains inert anodes ( ) and the protective layer ( ) can comprise a plurality of layers ( ) with an inner layer ( ) of TiB being preferred, and the protective layer ( ) protects the cathode ( )from hot gases ( ) used to pre-heat the cell ( ).

Method for protecting electrodes during electrolysis cell start-up

A method of producing magnesium vapor at substantially atmospheric pressure. The method comprises feeding into the reaction zone of a reduction furnace magnesium-oxide containing materials and metal reductants and then heating the magnesium-oxide containing materials and the metal reductants in the reaction zone to an operating temperature to create a slag composition. The slag composition has a phase diagram including a two-phase liquid and solid region. The feeding of the magnesium-oxide containing material and the metal reductant into the furnace bath are controlled such that the slag composition at the operating temperature is within the two-phase liquid and solid region of the phase diagram. In this way, reactions occur to produce magnesium vapor at substantially atmospheric pressure. A method of producing magnesium metal is also disclosed.

Method of producing magnesium vapor at atmospheric pressure

The present invention provides a process for purifying aluminum and lithium including recovering aluminum and lithium through layered electrolysis through a lithium transport cell to form purified lithium metal and residual aluminum and purifying the residual aluminum through a second stage layered electrolysis through a second stage lithium transport cell to form purified aluminum metal. In one aspect, the process provides the second stage step for purifying the residual aluminum by chlorinating the residual aluminum to form a purified aluminum. In one aspect, layered electrolysis is provided by a three-layered electrolysis cell including an end layer of molten aluminum-lithium alloy, a middle layer of molten salt electrolyte, and an opposite end layer of molten lithium.

Two stage lithium transport process

The present invention provides an apparatus for producing lithium from an aluminum-lithium alloy scrap comprising (a) a dryer for removing moisture from solid aluminum-lithium alloy; (b) a reservoir for heating and holding molten aluminum-lithium alloy; (c) a three-layered electrolysis cell comprising a most dense lowest layer of molten aluminum-lithium alloy, a middle layer of molten salt electrolyte, and an uppermost layer of molten lithium; and (d) a reactive gas fluxing unit to remove water present in the molten salt.

Process and apparatus for producing lithium from aluminum-lithium alloy

The present invention provides a process for recovering lithium from an aluminum-lithium alloy scrap including heating a lithium chloride-potassium chloride-lithium fluoride salt mixture in a separate bath melter vessel to form a molten salt bath reservoir; fluxing the molten salt with chlorine or hydrogen chloride gas to remove moisture; drying the aluminum-lithium scrap; heating the dried aluminum-lithium alloy scrap to form a molten reservoir of aluminum-lithium alloy; feeding low moisture molten salt and aluminum-lithium alloy to a three-layered electrolysis cell comprising a most dense lowest layer of molten aluminum-lithium alloy, a middle layer of molten salt electrolyte, and an uppermost layer of molten lithium; passing direct current through the cell with the aluminum-lithium alloy anodic; reducing lithium ions to lithium metal at a cathode suspended in the molten salt electrolyte; and removing lithium from said uppermost layer in said three-layered electrolysis cell.

Lithium transport cell process

Disclosed is a process for refining magnesium crude containing between about 0.7 and 1.5 wt. % calcium. The process includes mixing a flux containing from about 55 to 85 wt. % magnesium chloride and 45 to 15 wt. % alkali chlorides into a molten body of the crude. Refined magnesium is thereby produced, as well as a sludge containing calcium chloride which never has a liquidus exceeding the temperature of the molten body. The refined magnesium is then separated from the sludge.

Magnesium refining process

Calcium is produced by a thermal reduction process in a reaction-condensation system having a reaction zone and a condensation zone. According to the process, a reducing agent is contacted or reacted in the reaction zone with at least a partially molten slag to produce calcium vapor. The calcium vapor is transported from the reaction zone to the condensation zone and condensed therein.

Thermal reduction process for production of calcium using aluminum as a

Magnesium is produced by a thermal reduction process in a reaction-condensation system having a reaction zone and a condensation zone. According to this process, a reducing agent containing a mixture of ferrosilicon and at least 25 wt. % aluminum skim is contacted or reacted in the reaction zone with a calcium-silicon-aluminum-magnesium oxide slag to produce magnesium vapor. The magnesium vapor is transported from the reaction zone to the condensation zone and condensed therein.

Thermal reduction process for production of magnesium using aluminum

Magnesium is produced by a thermal reduction process in a reaction-condensation system having a reaction zone and a condensation zone. According to this process, a reducing agent containing ferrosilicon and at least 25 wt. % aluminum is contacted in the reaction zone with a calcium-silicon-aluminum-magnesium oxide slag to produce magnesium vapor. The magnesium vapor is transported from the reaction zone to the condensation zone and condensed therein. The slag is maintained to contain from 1 to 8 wt. % MgO, at least 9 wt. % Al.sub.2 O.sub.3, and have a CaO/SiO.sub.2 weight ratio no less than that provided by the formula 2.1+0.03 (wt. % Al.sub.2 O.sub.3 -9). The slag is also maintained so as to decrepitate upon cooling.

Growing community of inventors

Apollo, PA, United States of America

Roy A Christini