Development and Industrial Application of Wettable Inert TiB2 Cathodic Composite Coating for Aluminum Electrolysis
|School||Central South University|
|Keywords||Aluminum electrolytic TiB2 Composite cathode coating Room temperature curing Industrial applications Energy saving Extend bath life|
In order to overcome our Prebake Aluminum slot is too short-lived severe drawbacks, and the development of new aluminum reduction cell with an inert the wettability cathode material, an extensive literature survey and on the basis of previous work, of TiB composite cathode coating materials and technology, in-depth research. (1) a more comprehensive study of TiB 2 powder raw materials of nature and TiB 2 cathode coating performance. Elect a better TiB 2 powder raw material; determine TiB 2 cathode coating heat curing, carbonization variable temperature heating system; discussed TiB 2 sub > the cathode overcoat resistivity variation of temperature, and found that the TiB 2 cathode coating matrix can cathodes resistivity becomes small in a certain degree; coating of TiB 2 on the content of the coating resistivity, resistance to sodium permeability and wettability with molten aluminum. Numerical concise characterization of aluminum electrolytic cathode material is resistant sodium permeability of ideas; establish a sodium penetration mathematical model: In (ΔL) / L) = Ina-(b / t), looking to digitize characterization of the cathode material resistant sodium permeability factor, namely a and Q (= a / b), and use a large number of experimental data verify the resistance to sodium permeability can be characterized by a, Q cathode material. (2) to explore the mechanism of TiB 2 cathode coating reinforced. Studied the content of the carbon fibers in the coating, the size of the carbon fiber surface oxidation treatment method, the surface of the carbon fibers the number of oxygen-containing group, a furan resin viscosity average molecular weight TiB 2 cathode coating tensile strength, the relationship between bond strength and other properties. TiB 2 cathode coating material further optimization. The oxidation treatment process of the carbon fiber surface of the liquid phase method. (3) in the laboratory to detect the optimized TiB 2 the cathode coating materials performance results show that the performance targets were met or exceeded the GB8744-88 aluminum electrolytic with semi-graphite Ph.D. Dissertation. Summary of the cathodes requirements; simulated industrial coating the cathode layer coke preheating and the electrolysis process, Coke Preheating after carbonization coating does not crack, not hierarchical, electrolysis for 12 hours after the coating the cathode is equally full, intact. TIB: the cathode coating technology applied in 160kA large Prebake of slot and assessment of the coating slot indicators show started roasting, TIB: the cathode coating does not come off, in good working condition of the coating slot, furnace tacticity, hearth clean, uniform current distribution; compare and contrast groove, cathode lining for reducing the absorption of sodium, sodium permeation rate slowed drop reduces the hearth (mean reduction 39mV), the current efficiency (average increase of 0.41%); coating life of 38 months. (4) at room temperature curing TIB: the concept of the cathode coating; developed at room temperature the curing TIBZ composite cathode coating material, and to detect its performance; 160kA and 75 recognized pre-baked anode, respectively, the application of room temperature curing TIB: composite the cathode coating technology, and room temperature curing coating trough assessment. Application practice shows room temperature curable coating technology to simplify the construction process of high-temperature curing coating, high temperature curing coating savings required heat curing equipment investment, shorten coating construction time, greatly reduce application costs, TIB: cathode coating promote the application of the technology has played a catalytic role. Room temperature curing coating the cathode performance, its performance and high temperature curing coating cathode and exceeded the requirements of GB8744-88 semi-graphite cathodes for aluminum electrolysis, have applied to the basic conditions for production of aluminum. Room temperature curing coating slots assessment, and high temperature curing coating slot cathode lining reducing the absorption of sodium and sodium penetration slowed to reduce sodium expansion hazards, reduce doctorate abstract aluminum reduction cell early damage the chance; starts, room temperature curing coating does not fall off, and also has good adhesive properties; compare and contrast groove, room temperature curing coating trough normal production after the cathode surface clean and smooth, no precipitation or crusts regular furnace The cathode, anode current distribution, hearth drop reduces (average reduced 11.smv), current efficiency (average increase of 1.48%); coating in electrolyzer memory in time can be up to 44 months or more; room temperature curing coating The layer can also serve to improve the electrolyzer work status, save energy, extend the life of the slot role.