Method for preparing aluminum-scandium alloy by segmental countercurrent reduction method

Abstract

The invention discloses a method for preparing aluminum-scandium alloy by adopting a segmented counter-current reduction method. According to the method, the whole reaction process is divided into multiple sections; and scandium-containing alloy and scandium-containing raw material (slag phase or molten salt ) are reversely moved in the whole process so as to ensure that high-scandium-content rawmaterial is used for reducing high-scandium-content alloy, low-scandium-content raw material is used for reducing low-scandium-content alloy, on one hand, the alloy material meeting the required scandium content can be obtained, and on the other hand, scandium content in the final waste slag (or the molten salt) can be reduced to the largest extent so that the actual yield of scandium can be greatly improved; and the alloy containing active metals such as magnesium and calcium can be used as the raw material in a primary stage reaction, the scandium in the raw material can be reduced to the maximum extent, and the content of the scandium in the waste slag (or the molten salt) is reduced to the minimum, meanwhile, due to the fact that calcium and magnesium are more active than aluminum andscandium, the residual extremely small amount of calcium and magnesium impurities can also be oxidized into the slag phase (or the molten salt) in the later reduction reaction and are finally discharged from the alloy, and components of a final product is prevented from being influenced.

Description

technical field [0001] The invention relates to a method for preparing an aluminum-scandium alloy, in particular to a method for preparing an aluminum-scandium alloy by adopting a segmented countercurrent reduction method. Background technique [0002] Scandium (Sc) is a soft, silvery-white transition metal that is produced in very small quantities, accounting for about 0.0005% of the earth's crust. Scandium is known to be the most effective grain refiner for aluminum alloys. Only a small amount of Sc (usually 0.2%) needs to be added to aluminum alloys to greatly improve the strength, heat resistance, weldability and stress resistance of the alloy Corrosion ability, etc., have broad application prospects in high-tech fields such as ships, aviation, aerospace industry, rockets, missiles, and nuclear energy. However, due to the sparse resources of scandium, the price of scandium and its compounds is too expensive (currently the price of scandium oxide is about 6,000 yuan / kg, ...

AI Technical Summary

Problems solved by technology

[0018] Sc is more active than Al, so to reduce and prepare aluminum-scandium alloys with sufficient scandium content, more scandium compounds remain in the reduction slag, resulting in a low recovery rate of scandium

Adding active metals such as magnesium, calcium, strontium, and sodium to aluminum can greatly reduce the content of scandium in the slag, reduce losses, and increase yields. However, the residual magnesium, calcium and other elements in the alloy limit the application range of aluminum scandium master alloys. Restricted and cannot be used where there are strict restrictions on the above elements

[0019] Among the above methods, the non-vacuum aluminothermic reduction or aluminum-magnesium alloy reduction method is currently the main method for preparing aluminum-scandium alloys, but the yield of scandium by the aluminothermic reduction method is low, and the application range of products obtained by the aluminum-magnesium alloy reduction method is limited.

However, other Al-Sc alloy preparation methods either require expensive raw materials, or require a high-temperature vacuum environment, or the yield of scandium is not high, and there is a common problem of high production costs.

Images