Method for the production of high-concentration manganese mini-tablets for alloying aluminum baths and device for implementing said method

Abstract

The method has the aim of obtaining Mn mini-tablets with a concentration of the metal ranging between 90 and 98%, Al particles being the binding element. The method is based on the use of ground electrolytic Mn from shales with a chemical purity of 99.7% or higher. The product is screened with a mesh of less than 450 micra, wherein the fine powder content should be less than 15%. Moreover, atomized powder Al obtained by mechanical processes with a granulometry of between 100 and 800 micra and with over 80% of the powder being between 350 and 720 micra should be used in the method. The method is carried out in a device having a storage hopper (1), a diffuser (4) of the product in the hopper (1), a hopper for compacting and shaping the mini-tablets in molds (9) in combination with pressing punches (7 and 8) and with the aid of an alveolar and dosing valve (10) mounted between the feed chamber (5) and the compacting chamber (6).

Description

OBJECT OF THE INVENTION [0001] The present invention refers to a procedure for the manufacture of high concentration manganese (Mn) minitablets for aluminium (Al) bath alloying, the purpose of which is to produce Mn minitablets with a 90-98% concentration of this metal, for adding in Al smelting. [0002] The object of the invention is to produce a minitablet product composed of Mn and Al powder whose first component is obtained by electrolysis and grinding, while the second component is an atomized powder produced by means of mechanical processes, both components being them mixed and compacted to form minitablets with a high Mn concentration. [0003] A further object of the invention is the device for the execution of the above-mentioned procedure, the device where the loading, dispensing, compacting and final forming of the minitablets take place. BACKGROUND OF THE INVENTION [0004] The alloying of aluminium baths with manganese has changed substantially in recent times, and from the ...

AI Technical Summary

Benefits of technology

[0001] The present invention refers to a procedure for the manufacture of high concentration manganese (Mn) minitablets for aluminium (Al) bath alloying, the purpose of which is to produce Mn minitablets with a 90-98% concentration of this metal, for adding in Al smelting.

[0002] The object of the invention i...

Problems solved by technology

Furthermore, parent alloys usually contain 75 to 90% second smelting aluminium, which could give rise to problems in the molten metal, besides calling for a stock 4 times higher than that of compacted powder alloying agents.

In this respect, no materials are available on the market that contain a percentage above 85% Mn, due mainly to the problems of compactibility of Mn, an abrasive and non-ductile material.

Lastly, we have to consider that the founder / user is not interested in adding a material (Al powder) to his furnace that he is able to sell himself and which, moreover, has a value added due to atomisation, which is lost when smelting it again.

Despite these financial advantages, no compact Mn materials have appeared on the market with a concentration of 90% or more.

The attainment of this objective raises a series of scientific challenges when it comes to flow production of these materials.

Although it would be desirable to have this concentration available in standard sized tablets as well, the need to apply high pressures to the material means that the study is complicated if the size of the compact diameter is larger than 40 mm.

On the other hand, fluxes were initially rejected in this study insofar as they are materials whose binding action is considerably inferior to that of Al powder.

With regard to the raw materials to be used, Mn is the first limitation of the study.

At present electrolytic Mn is only produced in the Republic of South Africa and the People's Republic of China, which reduces the possibilities of finding materials with different specifications.

This fact means that again the production of a material of specific characteristics for the compacting of Mn tablets is skewed or subject to production conditions independent of the application that this study sets out to examine.

This represents a problem at industrial level, as smaller diameter minitablets give rise to lower productivity (minitablets weigh less).

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