The present invention relates to a system for superimposing alternating current on direct current flowing through one or more electrolytic cells, for electro-winning or electro-refining processes, in which the terminals of an alternating current source are connected to the first and last electrode of a cell or a group of cells.

The invention relates to a non-consumable anode for electrolysis that contains carbon. Said anode is made of pyrocarbon (pyrographite). The pyrocarbon (pyrographite) anode is stable even in nitrate electrolytes and does not contaminate the electrolyte with erosion products.

A regenerator cell for regenerating metallic particles is provided. The regenerator cell includes: a housing for containing a quantity of electrolyte; an anode; a cathode; a cavity at least partially defined by the housing, the cathode and the anode; an inlet port for supplying electrolyte to the cell, the inlet port in fluid communication with the cavity; and an outlet port for expelling electrolyte, particles and/or gas from the cell, the outlet port in fluid communication with the cavity.

A regenerator cell for regenerating metallic particles is provided. The regenerator cell includes: a housing for containing a quantity of electrolyte; an anode; a cathode; a cavity at least partially defined by the housing, the cathode and the anode; an inlet port for supplying electrolyte to the cell, the inlet port in fluid communication with the cavity; and an outlet port for expelling electrolyte, particles and/or gas from the cell, the outlet port in fluid communication with the cavity.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

In this disclosure, a process of recycling acid, base and the salt reagents required in the Li recovery process is introduced. A membrane electrolysis cell which incorporates an oxygen depolarized cathode is implemented to generate the required chemicals onsite. The system can utilize a portion of the salar brine or other lithium-containing brine or solid waste to generate hydrochloric or sulfuric acid, sodium hydroxide and carbonate salts. Simultaneous generation of acid and base allows for taking advantage of both chemicals during the conventional Li recovery from brines and mineral rocks. The desalinated water can also be used for the washing steps on the recovery process or returned into the evaporation ponds. The method also can be used for the direct conversion of lithium salts to the high value LiOH product. The method does not produce any solid effluent which makes it easy-to-adopt for use in existing industrial Li recovery plants.

A preparation method of gradient high-silicon steel by molten salt electrolysis includes: weighing the inorganic fluoride salt and the inorganic silicon salt, mixing them uniformly and then drying; heating the electrolysis container over the melting point of the electrolyte, passing the inert gas through the electrolysis container, and connecting the electrode to the power supply to perform constant current electrolysis, after the electrolysis is finished, the cathode is taken out, washed and dried, placing the dried cathode in a constant temperature region of an annealing furnace; under a protective gas atmosphere, heating the cathode to the target temperature, and maintaining the temperature for a period of time; after the heat treatment, cooling the cathode to the room temperature, during which the cathode is always placed in the furnace.

A preparation method of gradient high-silicon steel by molten salt electrolysis includes: weighing the inorganic fluoride salt and the inorganic silicon salt, mixing them uniformly and then drying; heating the electrolysis container over the melting point of the electrolyte, passing the inert gas through the electrolysis container, and connecting the electrode to the power supply to perform constant current electrolysis, after the electrolysis is finished, the cathode is taken out, washed and dried, placing the dried cathode in a constant temperature region of an annealing furnace; under a protective gas atmosphere, heating the cathode to the target temperature, and maintaining the temperature for a period of time; after the heat treatment, cooling the cathode to the room temperature, during which the cathode is always placed in the furnace.

A cathode assembly for an electrolytic cell including a cathode block having a second surface and a first surface. The cathode block also including at least one sealing groove opening onto its first surface and a plurality of electrical contact plugs mounted in electrical contact with the first surface of the cathode block. The cathode assembly includes at least one current supply plate in electrical contact with at least one electrical contact plug, and is connected to at least one unit for connection to an electric current source. The cathode assembly includes at least one current supply bar having a coefficient of thermal expansion substantially identical to the coefficient of thermal expansion of the current supply plate and is sealed within the at least one sealing groove while being fastened to at least one current supply plate.

New copper-coated titanium diboride electrodes are disclosed. The copper-coated titanium diboride electrodes may be used in an aluminum electrolysis cell. In one embodiment, a method includes installing the copper-coated titanium diboride electrode in the aluminum electrolysis cell and operating the aluminum electrolysis cell. During start-up, the aluminum electrolysis cell may be preheated and a bath may be formed from a molten electrolyte. Alumina (Al.sub.2O.sub.3) may in the added to the bath and reduced to aluminum metal. At least some of the copper film of the copper-coated titanium diboride electrode may be replaced by an aluminum film, thereby forming an aluminum-wetted titanium diboride electrode.