RU2561948C1 - Flux for refinement of aluminium alloys - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: flux is production waste - slime of salty hardening baths.

EFFECT: invention allows to create flux for high cleaning of molten aluminium from impurity and non-metallic inclusions with keeping of high mechanical characteristics of the produced aluminium alloy.

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Description

The invention relates to foundry and can be used for refining aluminum alloys from hydrogen impurities and non-metallic inclusions.

The known composition of the flux for refining aluminum alloys from magnesium [1], containing sodium chloride (15-25 wt.%), Potassium chloride (15-25 wt.%), Sodium silicofluoride (10-25 wt.%), A mixture of cryolite and aluminum fluoride (60-25 wt.%), each introduced onto the surface of the molten metal.

A decrease in the amount of magnesium in the alloy and a specific consumption of flux per 1 kg of magnesium were noted.

The flux has drawbacks, in particular, the long processing time of the melt due to the introduction and melting of each component separately and the high cost of the flux due to the use of pure materials. Known flux for processing aluminum alloys [2].

The flux for refining aluminum alloys contains sodium chloride and potassium chloride, in order to ensure more complete removal of non-metallic inclusions from the alloy, it additionally contains basalt in the following ratio of components, wt.%:

Sodium chloride 30-35 Basalt 30-40 Potassium chloride Rest

Flux has a high cost due to the use of pure materials. The use of industrial waste in the manufacture of flux is known. For example, RF patent No. 2010882, C22C 1/06, C22B 9/10, publ. 04/15/1994 - prototype - flux for aluminum and its alloys is protected, containing, wt.%: Carnallite 60-85 and coal foam 15-40 - waste generated during the electrolysis of aluminum. The prototype aims to reduce the duration of smelting, energy consumption and flux while maintaining refining properties (flux is loaded onto the melt surface at 780 ° C), reducing labor costs for cleaning the furnace and reducing the cost of flux.

The flux has a two-component composition, and its preparation in a crucible at a temperature of 780 ° C for 2.5 hours is associated with certain energy and time consumption. Carnallite is a mineral whose use is also associated with material costs.

These shortcomings are eliminated by the proposed solution.

The claimed invention is aimed at solving the problem of creating a flux for processing aluminum alloys from materials of low cost, expanding the raw material base and the range of materials used.

The technical result is the creation of a flux for high purification of metal from non-metallic inclusions with high mechanical characteristics of the resulting alloy.

This technical result is achieved in that the flux for refining aluminum alloys based on industrial waste as industrial waste contains slurry of salt quenching baths of the following composition, wt.%:

Iron metal, oxide 22.50-23.50 Sodium chloride 9.50-10.50 Potassium chloride 9.50-10.50 Magnesium chloride 9.00-10.00 Charcoal 9.50-10.50 Chromium oxide 0.02-0.03 Water 0.06-0.07 Manganese Oxide 0.08-0.09 Barium carbonate Rest

The difference of the claimed invention is the use of salt quenching baths, which in its composition contains sodium, potassium, magnesium chlorides and other components that have a refining effect on aluminum melt in the flux of pure materials from pure materials (federal waste classification catalog 5150000000000).

Sludge from salt quenching baths is a waste of production and the cost of it, as a material, is minimal, even taking into account its preliminary preparation, in addition, the consistency of the flux allows using it in a filling funnel, which increases the purity of the alloy

The flux is prepared as follows.

Sludge of salt quenching baths is pre-crushed to a granule size of 7.5-10 mm (corresponding to the mesh size of the filter into which it will be filled for a melt mass of 200-500 kg) and dried at a temperature of 200 ° C for 1-1.5 hours .

The flux is poured at 1/3 of the height into the filling funnels located on the mold, and when pouring with the melt, batch refining of the metal takes place. As a result, the aluminum melt, being cleaned of impurities and non-metallic inclusions, is more ductile and has high mechanical characteristics.

Example

For comparison, a flux of the proposed composition and prototype was manufactured.

The optimum thickness of the backfill layer is 20–40 mm with heating of the filter layer to a temperature of 300–350 ° C for 15 minutes with a gas burner.

For laboratory tests, samples (4 pcs.) Were made from AK5M2 GOST 1583 alloy, poured into a sand-clay form by raw at an alloy temperature of 750 ° C. Samples No. 1, 2 were made using the prototype flux at average values: carnallite 70%, coal foam 30% directly into the mold, samples No. 3, 4 were poured into the mold through a granular filter based on sludge from salt quenching baths. Additionally, tests were carried out on samples of AK9ch alloy obtained using the proposed flux (samples No. 5, 6 in the table).

The table shows that the relative elongation increases by an average of 3.2%; tensile strength increased by 4.9%; the fracture force increased by 7%, which corresponds to the AK5M2 alloy GOST 1583. Additional tests of the mechanical properties of AK9ch are not lower than GOST 1583, which indicates a high purity of the melt from non-metallic inclusions.

The analysis of analogues shows that the proposed solution meets the criterion of "novelty", the technical result obtained, provided by a combination of essential features, indicates an inventive step, and tests carried out in a production environment confirm industrial applicability.

Information sources

1. RF patent 2368674, cl. C22B 9/10, publ. 09/27/2009.

2. USSR copyright certificate 1196400, cl. C22B 9/10, C 22 C 1/06, publ. 12/07/1985.

3. RF patent No. 2010882, cl. C22C 1/06, C22B 9/10, publ. 04/15/1994.

Claims (1)

Flux for refining aluminum alloys based on production waste, characterized in that the waste of production is used as a slurry of salt quenching baths having the following composition, wt.%:
iron oxide
metal 22.50-23.50 sodium chloride 9.50-10.50 potassium chloride 9.50-10.50 magnesium chloride 9.00-10.00 charcoal 9.50-10.50 chromium oxide 0.02-0.03 water 0.06-0.07 manganese oxide 0.08-0.09 barium carbonate rest