Method for preparing aluminum-scandium intermediate alloy by using elpasolite molten salt sinking cathode electrolysis

Abstract

The invention discloses a method for preparing an aluminum-scandium intermediate alloy by using elpasolite molten salt sinking cathode electrolysis. The method comprises the following steps of (1), respectively weighing raw materials, specially, a K3AIF6 (KF and AIF3) ), a and an aluminum ingot; (2), putting the K3AIF6 in the step (1) into an electrolytic cell, and heating to increase temperature,adding the aluminum ingot after the K3AIF6 is completely molten, and adding and melting the Sc2O3 after the aluminum ingot is molten; (3), carrying out molten salt electrolysis, a cathode of the molten salt electrolysis is liquid aluminum, an anode is graphite, and sinking a prepared aluminum-scandium intermediate alloy to the bottom of the electrolytic cell. According to the method for preparingthe aluminum-scandium intermediate alloy, a potassium cryolite molten salt system (K3AIF6) is adopted, harmful gas cannot be generated, and the method is relatively environment-protecting; and the method adopts the cheap and easily-available Sc2O3 as an electrolysis raw material, the production cost can be greatly saved, the prepared aluminum-scandium intermediate alloy is sunk to the bottom of the molten salt, and the method is suitable for industrial mass production application.

Description

technical field [0001] The invention relates to the technology in the field of metal materials, in particular to a method for preparing an aluminum-scandium master alloy by sinking cathode electrolysis of potassium cryolite molten salt. Background technique [0002] Scandium (Sc) is a light rare earth metal, which has the same period as transition elements and the same main group as rare earth elements. Therefore, Sc element has some physical and chemical properties of the two types of elements but is superior to these two types of elements. The density of Sc is 2.99 g / cm 3 , with a density of Al of 2.70 g / cm 3 The difference is not much, and it can refine the grain of aluminum, increase the recrystallization temperature, and enhance the corrosion resistance, strength and plasticity of the alloy. The melting point of Sc (1540 °C) is much higher than that of Al (660 °C), but the two can form Al after alloying 3 Sc co-precipitated phase, Al 3 The existence of Sc phase make...

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Problems solved by technology

Due to the high cost and uneven alloy structure, the application range of the smelting method is small, such as the patent with the application number CN201610862283.X and the patent with the patent number CN201410850893.9

The vacuum aluminothermic reduction method is a widely used and researched Al-Sc alloy preparation technology, such as the patent No. CN201110288762.2; there are also improved technologies by adding flux, such as the patent No. CN201610848014.8, but There are still problems in continuous production, etc.

The process technology for preparing Al-Sc alloy by molten salt electrolysis has the advantages of low cost, uniform alloy structure and high production efficiency, but there are still deficiencies in the selection of molten salt system and the determination of process parameters;

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