METHOD OF ALUMINA CONCENTRATION ESTIMATE IN CRYOLITE-ALUMINA MELT AND FACILITY FOR IMPLEMENTATION OF THIS METHOD Russian patent published in 2009 - IPC C25C3/06 C25C3/20 

FIELD: metallurgy.

SUBSTANCE: method consists in immersion of sensor into cryolite-alumina melt, in measuring current strength on sensor at forced linear change of voltage on sensor by means of controlled voltage source, in plotting volt-ampere curve on obtained values of current strength and voltage, in evaluation of current strength of peak on plotted volt-ampere curve corresponding to start of anode effect on anode of sensor and in evaluation of alumina concentration by gauge dependence. Simultaneously with measurement of current strength on the sensor, resistance between anode and cathode of the sensor is measured at superposition of alternate pulse voltage of 10-100 kHz frequency and variable component of current strength of corresponding frequency is registered; also ohm component is evaluated; volt-ampere curve is plotted less ohm component of voltage. The facility consists of the sensor with cathode and anode arranged coaxially to each other and insulated from each other with insulation out of pyrolytic boron nitride; also insulation of not less 1 mm thickness is applied on side surface of anode by method of chemical sedimentation out of gas phase producing insulating coating; further, the facility consists of an electronic control and registration unit with autonomous electric power source, of a controlled voltage source, of a recorder of current strength and voltage and of a controlled generator of alternate high frequency signals. Anode is placed inside cathode and is made out of graphite. Output of the unit is connected with anode of the sensor, while input is connected to the controlled source of voltage.

EFFECT: compensation of ohm component of voltage and elimination of outflow of cryolite-alumina melt between anode and pyrolytic boron nitride.

3 cl, 2 tbl, 6 dwg