초록 ▼

This invention teaches a control to be used in smelting aluminum by the electrolysis breakdown of alumina (A12O3) in a molten electrolyte heated to approximately 950°-1000°C. The invention provides a sonic resonator and control that can accurately detect the resonant frequency of the resonator in th

This invention teaches a control to be used in smelting aluminum by the electrolysis breakdown of alumina (A12O3) in a molten electrolyte heated to approximately 950°-1000°C. The invention provides a sonic resonator and control that can accurately detect the resonant frequency of the resonator in the molten electrolyte. The resonator preferably is made with tubular side wall ¼of the sonic wavelength, or is a quarter wave resonator. A wave generator inputs a signal having a range of frequencies that includes the resonant frequency, so that a peak resonant output at the resonant frequency can be detected on an oscilloscope or like detector. This instantaneous resonant frequency is then checked against an accurate data base correlating the resonant frequencies of the resonator in the electrolyte at specific alumina concentrations normally experienced throughout the electrolysis cycle. The electrolysis cycle can thus be controlled and recharged at any predetermined low alumina concentration greater than where the anode effect phase of the cycle normally might begin.

대표청구항 ▼

In the smelting of aluminum by electrolysis of a molten electrolyte at temperatures between 950°and 1000°C., where alumina would normally start at 6-7 wt.% concentration of the electrolyte and decline to 2.2-0.5 wt.% concentration near the end of the cycle where an anode effect would begin, a method

In the smelting of aluminum by electrolysis of a molten electrolyte at temperatures between 950°and 1000°C., where alumina would normally start at 6-7 wt.% concentration of the electrolyte and decline to 2.2-0.5 wt.% concentration near the end of the cycle where an anode effect would begin, a method for accurately determining when a predetermined alumina concentration of the order of 2.7-2.5 wt.% is reached to provide for recharging the electrolyte with alumina before any anode effort might actually begin, comprising the steps of submerging a sonic resonator in the electrolyte at a representative level thereof, periodically exciting the resonator throughout a range of frequencies through and including the resonant frequency of the resonator in the electrolyte, detecting for each excitation of the resonator the instantaneous resonant frequency thereof, correlating this against a data base calibration of the resonator at known alumina concentration throughout the smelting cycle, whereby the instantaneous resonant frequency effectively can provide the instantaneous alumina concentrations during the smelting cycle so as to allow the identification thereof when said alumina concentration reaches said predetermined alumina concentration.