Abstract: A method for determining a length parameter of an electrode during operation of an electric arc furnace. An internal duct extends through the length of the electrode and is open at its lower end. A waveguide having a solid core is received in the internal duct and comprises a material having a low dielectric constant and high temperature resistance. The solid core of the waveguide includes at least one target. An electromagnetic radiation signal is emitted from a source and transmitted through the waveguide and the signal is diffracted and/or reflected from at least one target to produce at least one return signal which is transmitted back through the waveguide. A time or frequency difference between the emitted signal and the return signal is measured and the length parameter is calculated based on this difference.

Abstract: A method for recovering metal values from a molten slag composition includes atomizing the slag with an oxygen-containing gas in a gas atomization apparatus, to produce solid slag granules. Oxygen in the atomizing gas converts metals to magnetic metal compounds, thereby magnetizing the metal-containing slag granules. These metal-containing slag granules are then magnetically separated. Larger amounts of metals may be removed by passing the molten slag through a pre-settling pan with an adjustable base, and/or discontinuing atomization where the metal content of the slag exceeds a predetermined amount. Solid slag granules produced by atomization may be charged to a recovery unit for recovery of one or more metal by-products. An apparatus for recovering metal values from molten slag includes a gas atomization apparatus, a flow control device for controlling the flow of atomizing gas, a control system, and one or more sensors to detect metal values in the slag.

Abstract: A method for determining a length parameter of an electrode during operation of an electric arc furnace. An internal duct extends through the length of the electrode and is open at its lower end. A waveguide having a solid core is received in the internal duct and comprises a material having a low dielectric constant and high temperature resistance. The solid core of the waveguide includes at least one target. An electromagnetic radiation signal is emitted from a source and transmitted through the waveguide and the signal is diffracted and/or reflected from at least one target to produce at least one return signal which is transmitted back through the waveguide. A time or frequency difference between the emitted signal and the return signal is measured and the length parameter is calculated based on this difference.

Abstract: A method for recovering metal values from a molten slag composition includes atomizing the slag with an oxygen-containing gas in a gas atomization apparatus, to produce solid slag granules. Oxygen in the atomizing gas converts metals to magnetic metal compounds, thereby magnetizing the metal-containing slag granules. These metal-containing slag granules are then magnetically separated. Larger amounts of metals may be removed by passing the molten slag through a pre-settling pan with an adjustable base, and/or discontinuing atomization where the metal content of the slag exceeds a predetermined amount. Solid slag granules produced by atomization may be charged to a recovery unit for recovery of one or more metal by-products. An apparatus for recovering metal values from molten slag includes a gas atomization apparatus, a flow control device for controlling the flow of atomizing gas, a control system, and one or more sensors to detect metal values in the slag.