A kind of method that uses fly ash to prepare aluminum-magnesium alloy

Abstract

The invention belongs to the field of nonferrous metallurgy and relates to a method for preparing aluminum-magnesium alloys with fly ash. The technical solution of the present invention is to first adopt fly ash acid leaching to produce aluminum chloride, and then the electrolyte system used is composed of flux, melt and additives, wherein the composition of the flux is: NaCl: 0-60%, KCl : 25-75%, MgCl2: 0-66%, then add the melt AlCl3 that accounts for 5-50% of the flux quality, the additive LiCl, 0-5% additive KF, 0-5% additive that account for 0-5% of the flux quality MgF2 or 0-5% additive AlF3, in which molten AlCl3 is added from the bottom of the electrolytic cell, the inter-electrode voltage is controlled at 2.3-3.3V, the cathode current density is 0.5-1.5A / cm2, the electrolysis temperature is 450-500°C, during the electrolysis process Chlorine gas is generated on the anode side, which is recycled and reused, and solidified aluminum-magnesium alloy is deposited on the cathode side. The method of the invention has low power consumption, low electrolysis temperature, and low production cost, solves the problems of aluminum chloride evaporation and dendrite generation by electrolysis, has no environmental pollution, and is easy to implement.

Description

technical field [0001] The invention belongs to the field of nonferrous metallurgy and relates to a method for preparing aluminum-magnesium alloys with fly ash. Background technique [0002] The traditional metal aluminum production method is the Hall-Heroult (Hall-Heroult) method. In 1886, American Hall and Frenchman Herout simultaneously invented the cryolite-alumina molten salt electrolysis method to produce aluminum, that is, using carbon Plain material is used as electrode material, cryolite is used as solvent, alumina is used as solute, and the method for producing aluminum by molten salt electrolysis at a temperature of 950-1000°C. The source of alumina so far is mainly obtained by alkali leaching, that is, using alkali (industrial caustic soda NaOH or soda ash Na 2 CO 3 ) to process bauxite so that the alumina in the ore becomes soluble sodium aluminate. The purified sodium aluminate solution is analyzed to separate out aluminum hydroxide, and after separation, wa...

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Problems solved by technology

The main features of these two methods are that the electrolysis temperature is low, and the aluminum chloride vapor is easy to control, but the metal is in the state of crystal particles, which is difficult to collect. In addition, the easy formation of dendrites is the biggest defect of this method.

[0006] In the early research on aluminum chloride electrolysis, most of the sources of aluminum chloride were obtained through the chlorination of alumina. The production cost was relatively high, coupled with some difficulties in engineering, it has not been applied industrially.

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