POLYAKOV ELECTROLYSIS CELL FOR PRODUCING ALUMINIUM Russian patent published in 2010 - IPC C25C3/06 

FIELD: chemistry.

SUBSTANCE: in the electrolysis cell, the anode part of bipolar electrodes is consumable, while the electrodes themselves are movable with possibility of adjusting the inter-electrode distance. The end electrode is inert and partially consumable. The movable bipolar electrodes and one of the end electrodes are mounted on rollers made from material which is resistant to aluminium or electrolyte, e.g. silicon carbide. The anodes are inclined to the horizontal at an angle of 1-45°, and there are grooves on the anode side of the bipolar electrode. One of the end anodes can be replaced by a new one. The cathode side of the bipolar electrode is made from material which can be soaked with aluminium, e.g. titanium diboride, having layer thickness of 0.1-5 mm. The system of electrodes has holders which are resistant to the electrolyte and metal, e.g. silicon carbide. The bottom is inclined, can be soaked with aluminium and has a receiver and a false bottom under which metal collects. Temperature of the inner surface of the lining of the electrolysis cell is higher than liquidus temperature of the electrolyte by 3-50°C. The distance between the bottom end of the electrodes and the receiver and between the top end of the bipolar electrodes and the surface of the electrolyte is not more than 5 cm. The electrolysis cell is fitted with caissons containing a coolant and is lined with material which is resistant to aluminium and the electrolyte, e.g. silicon carbide, high-alumina concrete or magnesite, a removable roof for releasing exhaust gases, alumina and fluoride loading systems, and a gas trapping device. The system for feeding alumina in the roof of the electrolysis cell can continuously supply alumina using compressed air. Electrolytes based on sodium, potassium, lithium and aluminium fluorides are used.

EFFECT: reduced overall dimensions of the electrolysis cell, higher current output, easier use of the electrolysis cell and improved environmental setting.

19 cl, 4 dwg