| Autor: |
Rudenko, A. V., Tkacheva, O. Yu., Kataev, A. A. |
| Zdroj: |
Russian Metallurgy (Metally); Aug2023, Vol. 2023 Issue 8, p1069-1075, 7p |
| Abstrakt: |
The electrolytic production of Al–Y and Al–Sc alloys in an electrolyte based on the KF–NaF (10 wt %)–AlF3 potassium cryolite with a cryolite ratio (CR) of 1.5 containing Al2O3, Sc2O3, or Y2O3 oxides in a cell with vertical electrodes is studied. An Fe–Ni–Cu alloy serves as an inert anode. The wettable cathode is a graphite plate coated with aluminum diboride. Electrolysis is carried out at 830°C and a cathode current density of 0.2 A/cm2. The weight of an Al2O3 additive is calculated at a current efficiency of 60%. A Sc2O3 additive is introduced into a melt in an amount of 1 wt %. The weight of an Y2O3 additive is chosen on the basis of its solubility in the melt under study. For this purpose, the influence of Y2O3 additives on the liquidus temperature of a quasi-binary mixture [KF–NaF (10 wt %)–AlF3 (CR = 1.5)]–Y2O3 is determined. Unlike Sc2O3 additives decreasing the liquidus temperature of the cryolite melt, small Y2O3 additives lead to a sharp increase in the liquidus temperature. The efficiency of the electrolytic reduction of Y2O3 is an order of magnitude higher than that of aluminothermic reduction. Under other equivalent conditions, the efficiency of the electrolytic reduction of Y2O3 is higher than that of Sc2O3. Al–Y and Al–Sc alloys with a 0.6 wt % REM are formed. However, the time to reach the maximum reduction of yttrium significantly exceeds the time to reduce scandium. Metallographic studies of the prepared alloys indicate the presence of the Al3Sc and Al2Y intermetallic compounds. A conclusion is made about a principal possibility of the low-temperature electrolytic production of Al–REM alloys in cryolite melts based on potassium cryolite in vertical cells with an inert metallic anode and a wettable cathode. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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