Abstract: Method and apparatus for controlling the temperature of a molten salt, electrolytic demagging cell wherein an operating condition of the cell (e.g., current, temperature, etc.) is measured and a cathode immersed in the cell's electrolyte is moved to and fro the aluminum melt in the cell in response to the measured condition to vary the heat input to the cell.

Abstract: Dealuminizing cast iron by contacting it with free-flowing flux particles having a solid silica core and a molten silica shell wherein said flux comprises silica and about 1% to about 5% calcium fluoride.

Abstract: Recontaminating cast iron by contacting it with a molten flux consisting essentially of silicon dioxide and calcium fluoride.

Abstract: Probe for the electrochemical determination of the hydrogen content of molten aluminum comprising: a catalytic metal membrane hydrogen electrode; a Ca-CaH.sub.2 counterelectrode; a solid-state electrolyte such as calcium hydride, calcium hydrochloride and strontium hydrochloride; a porous barrier separating the aluminum from the hydrogen electrode; and a hydrogen accumulation chamber adjacent the catalytic membrane.

Abstract: An electrochemical concentration cell adapted for immersion in a melt of aluminum-magnesium alloy for determining the concentration of the Mg on an ongoing basis (e.g., during demagging). The cell includes a first probe comprising a housing having a cavity therein containing a Mg-ion-rich molten salt electrolyte. An opening in the housing exposes the electrolyte to the melt via a porous ceramic frit wetted by the electrolyte. A hollow capsule containing a Mg-rich reference material is immersed in the electrolyte and the reference material electrically coupled to the melt via second probe immersed therein. Containment of the reference material within the capsule beneath the melt prevents attack of the housing by the reference material and evaporative loss thereof.