Abstract: An electrolysis cell (10) contains a number of carbon anodes (12) having top, bottom and side surfaces, operating in molten electrolyte (17) in an aluminum electrolysis cell (10), where gas bubbles (28) are generated at the anode surfaces and where alumina particles (20) are added to the top of the molten electrolyte, where the carbon anodes (12) have at least two inward slots (21) passing through the carbon anode (12) along the longitudinal axis 40 of the carbon anode and also passing through only one front surface (25) of the carbon anode, where the height (32) of the slots (21) is from about 45% to 80% of the anodes thickness and the slotted front surfaces (25) are disposed toward the center of the electrolysis cell so that generated gas bubbles (28) are directed to the alumina particles.

Abstract: An electrolysis cell (10) contains a number of carbon anodes (12) having top, bottom and side surfaces, operating in molten electrolyte (17) in an aluminum electrolysis cell (10), where gas bubbles (28) are generated at the anode surfaces and where alumina particles (20) are added to the top of the molten electrolyte, where the carbon anodes (12) have one inward slot (21) passing through the carbon anode (12) along the longitudinal axis 40 of the carbon anode and also passing through only one front surface (25) of the carbon anode, where the height (32) of the slot (21) is from about 45% to 80% of the anodes thickness and the slotted front surfaces (25) are disposed toward the center of the electrolysis cell so that generated gas bubbles (28) are directed to the alumina particles.

Abstract: An electrolysis cell (10) contains a number of carbon anodes (12) having top, bottom and side surfaces, operating in molten electrolyte (17) in an aluminum electrolysis cell (10), where gas bubbles (28) are generated at the anode surfaces and where alumina particles (20) are added to the top of the molten electrolyte, where the carbon anodes (12) have at least two inward slots (21) passing through the carbon anode (12) along the longitudinal axis 40 of the carbon anode and also passing through only one front surface (25) of the carbon anode, where the height (32) of the slots (21) is from about 45% to 80% of the anodes thickness and the slotted front surfaces (25) are disposed toward the center of the electrolysis cell so that generated gas bubbles (28) are directed to the alumina particles.

Abstract: A method and apparatus for accurately measuring superheat, bath ratio and alumina concentration in an aluminum smelting bath. In one embodiment, a reusable probe determines the bath temperature and bath sample superheat. In other embodiments, the probe also determines bath composition including bath cryolite ratio and alumina concentration.

Abstract: A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

Abstract: A cermet composite material is made by treating at an elevated temperature a mixture comprising a compound of iron and a compound of at least one other metal, together with an alloy or mixture of copper and a noble metal. The alloy or mixture preferably comprises particles having an interior portion containing more copper than noble metal and an exterior portion containing more noble metal than copper. The noble metal is preferably silver. The cermet composite material preferably includes alloy phase portions and a ceramic phase portion. At least part of the ceramic phase portion preferably has a spinel structure.

Abstract: Aluminum is produced by electrolytic reduction of alumina in a cell having a cathode, an inert anode and a molten salt bath containing metal fluorides and alumina. The inert anode preferably contains copper, silver and oxides of iron and nickel. Reducing the molten salt bath temperature to about 900-950.degree. C. lowers corrosion on the inert anode constituents.

Abstract: 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.

Abstract: An inert electrode material is made by reacting at an elevated temperature a mixture preferably comprising iron oxide, at least one other metal oxide, copper and silver. The reaction produces a material having ceramic phase portions and alloy phase portions, wherein the alloy phase portions have copper-rich interior portions and silver-rich exterior portions. Inert anodes made with a reaction mixture containing copper and silver have lower wear rates than inert anodes made with copper and no silver.