Enlarged laboratory skull electrolyzer with the current load up to 100 A for testing novel electrolytes, electrode and construction materials as well as protection coatings of cathodes for primary aluminium electrolytic production has been developed and tested.
Test electrolyzer provides the following areas of research:
1) study of new cryolite-alumina molten salt stability during the aluminum electrolysis;
2) detection of resistant salt skull formation conditions from researched melts;
3) study of electrode material durability at the electrolyzer start up and the following operation, study of the corrosion mechanisms and destructive processes of electrode materials under these conditions;
4) study of protective coatings durability for electrolyzer and its accessory electrode and construction materials.
Electrolyzer successfully withstood the 96-hours testing:
- Starting and operating regimes of electrolyzer were defined and resistant skull layer was formed.
- Anodes made of different construction materials (graphite and special alloys) were tested.
- Carbonate mechanism of the cathode graphite heath filling was detected.
- Modified cryolite-alumina melt with improved electric conductivity was recommended as the electrolyte for semi-industrial tests.
- Developed test electrolyzer allows performing long-scale tests under operation conditions which are closely approximated to that of the industrial electrolyzers for primary aluminum production.
