Alcoa Inc.

Aluminum Company of America

R Lee Troup

Siba P Ray

Robert K Dawless

Alfred F LaCamera

Leroy E D'Astolfo

Gerald E Carkin

Robert B Hosler

Don R Careatti

An improved electrical connection between an inert anode and a conductor rod is disclosed. The conductor rod has a smaller diameter than a hole in the anode such that a gap is provided between the conductor rod and the anode. The gap is filled with an electrically conductive particulate material, such as Cu, Ni and/or Ag. The particulate conductor material is at least partially sintered before or during operation of the anode. To ensure a good connection between the conductor rod and the anode, the particle size distribution of the particulate connector material may be controlled.

Inert anode electrical connection

This invention relates to the use of bubble-driven flow to enhance the dissolution and distribution of alumina in an aluminum electrolysis cell operating with inert anodes. By harnessing the driving force of bubbles rising along the sides of a sloped anode to induce circulation in a cell and by using a group of anodes to amplify the effect, alumina distribution can be maintained close to or at saturation without formation of muck/sludge. Alumina fed through point feeders at specific locations can be distributed throughout the entire cell rather than sinking to the bottom of the cell below the feed location. For a given circulation pattern, feeder locations can be optimized.

Alumina distribution in electrolysis cells including inert anodes using bubble-driven bath circulation

An electrolytic cell for reduction of a metal oxide to a metal and oxygen has an inert anode and an upwardly angled roof covering the inert mode. The angled roof diverts oxygen bubbles into an upcomer channel, thereby agitating a molten salt bath in the upcomer channel and improving dissolution of a metal oxide in the molten salt bath. The molten salt bath has a lower velocity adjacent the inert anode in order to minimize corrosion by substances in the bath. A particularly preferred cell produces aluminum by electrolysis of alumina in a molten salt bath containing aluminum fluoride and sodium fluoride.

Molten salt bath circulation design for an electrolytic cell

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Murrysville, PA, United States of America

R Lee Troup