RU2038398C1 - Method for production of aluminium alloy - Google Patents

Abstract

FIELD: production of aluminium and silicon base alloys. SUBSTANCE: introduction of refractory transition metals into jet of molten silicon with temperature of 1450-1750 C ensures reduction of losses of alloying refractory transition metals. EFFECT: higher efficiency. 1 tbl

Description

 The invention relates to non-ferrous metallurgy, and in particular to a technology for the production of alloys based on aluminum and silicon containing one or more elements from the group of refractory transition metals.

 A known method of producing alloys for the production of aluminum alloys, including the melting of aluminum, the introduction of a transition metal into the melt, carried out in the form of a briquetted thermal mixture of it with aluminum (ed. St. USSR N 1759930, class C 22 C, 1992).

 The disadvantages of this method are the high consumption of aluminum, significant costs for the preparation of briquettes, which leads to an increase in the cost of the alloy.

A method of producing an aluminum-silicon alloys comprising chromium hypereutectic silikoalyuminiya smelting, alloying with aluminum and its introduction copper and / or nickel in hypereutectic silikoalyuminy at a temperature of 900-1400 ^C. in the form of an alloy with zinc (SU, USSR N 1286638, cl. C 22 C, 1987).

 The disadvantage of this method is that for the preparation of copper and / or nickel-zinc alloys used to introduce them into silicoaluminum, additional costs are required. In addition, the use of this method is limited by the need for zinc in the resulting alloy.

Closest to the proposed is a method for producing alloys based on aluminum, comprising dissolving alloying elements in a preheated aluminum melt, introduced in the form of alloys or pure metals. So, for example, manganese is introduced in the form of pieces with sizes of 30-40 mm across at a melt temperature of 900-1000 ^о С, copper in the form of sheets at a temperature of 800-850 ^о С, nickel in the form of plates and granules at a temperature of 950-1000 ^о S, etc. (M.B. Altman et al. Smelting and casting of aluminum alloys. M. Metallurgy, 1970, p. 161-163).

 The disadvantage of this method is the low degree of assimilation of alloying refractory transition metals, which leads to significant losses of these metals. Due to the low dissolution rate of these components in the aluminum melt, the melting time increases, which reduces the performance of the foundry-smelting unit and, due to this, the cost of the alloy.

 The aim of the invention is to reduce losses of alloying refractory transition metals by increasing the degree of assimilation, reducing the duration of smelting and reducing the cost of the alloy.

The object is achieved in that the method for producing aluminum alloy comprising alloying molten silicon and refractory transition metals with stirring, cooling and casting, the refractory transition metals are introduced into the stream of molten silicon at a temperature ^of 1450-1750 C, fed into a melt of aluminum or an alloy thereof.

Introduction of refractory transition metals into a spray of molten silicon at a temperature ^of 1450-1750 C, fed into a melt of aluminum or an alloy thereof, provides a reduction of losses of alloying refractory transition metal by raising the degree of digestion, reducing the duration of the smelting and reducing alloy costs.

Increased assimilation alloying refractory transition metals is achieved by intensive mixing of these metals into the silicon liquid jet and the high velocity of dissolution in molten silicon at a temperature ^of 1450-1750 C. The molten aluminum or its alloy jet enters the liquid silicon with refractory transitional dissolved therein metals. The high dissolution rate and the effective absorption of refractory transition metals in a silicon liquid stream at given temperatures and further in the molten aluminum or its alloy provides a significant reduction in the melting time, which leads to an increase in the productivity of the melting-distributing unit and, therefore, to reduce the cost of the alloy. This also contributes to a reduction in the losses of alloying refractory transition metals from an increase in the degree of their assimilation. Despite the increase in the temperature of the melt after the introduction of molten silicon into it, the metal loss from oxidation of the melt does not increase, since the melting time is sharply reduced.

 The selected conditions are limited by the following factors.

Reducing the silicon liquid jet temperature less than 1450 ^{° C} is not possible due to the convergence of the jet temperature and the melting temperature of silicon, and an increase ^of more than 1,750 C is impractical due to an increase of metal loss by oxidation of the melt.

 As a result of a search in the patent and scientific and technical literature, no technical solutions with features distinguishing the proposed invention from the prototype were found, namely: allowing using a silicon liquid jet to carry out effective dissolution with stirring of refractory transition metals introduced into the jet.

 The implementation of the method is carried out in the preparation of aluminum-silicon alloys containing one or more components from the group of refractory transition metals. To obtain the alloy, a silicon liquid stream is used when it is released from an RKO-25KrI-type ore reduction furnace after melting silicon. As alloying refractory transition metals, manganese is used in the form of pieces with sizes of 30-40 mm in diameter, copper in the form of sheet cathodes and nickel in the form of plates and granules.

EXAMPLE EXAMPLE 1 The ladle with molten and heated to 750 ^{° C} the aluminum in an amount of 3955 kg (by calculation), the chute is introduced stream of silicon at a temperature ^of 1450 C., which is administered in the source trench refractory transition metal manganese in the amount of 36.3 kg per heat. Total silicon injected 1105 kg. Get 5000 kg of alloy with a silicon content of 21% and 0.7% manganese which is poured after cooling. The degree of assimilation of manganese is 97.0%
In examples 2 and 3, the Al-Si-Mn alloy is obtained analogously to example 1 with the following parameters.

PRI me R 2. The temperature of the silicon jet 1600 ^about C.

PRI me R 3. The temperature of the silicon jet 1750 ^about C.

 In example 4, the alloy is obtained analogously to examples 1-3 beyond the upper limit of the claimed interval.

 Get a similar alloy by a known method (example 5).

 In examples 6-9, an Al-Si-Cu alloy is obtained in the same manner as in examples 1-4.

 Get a similar alloy by a known method (example 10).

 In examples (11-14), an Al-Si-Ni alloy is obtained analogously to examples 1-4 and 6-9.

 Get a similar alloy by a known method (example 15).

 In examples 16-19 receive alloy Al-Si-Mn-Cu-Ni (AK-21) similarly to examples 1-3, 6-9 and 11-14.

 Get a similar alloy by a known method (example 20).

 The test results are shown in the table.

 From the table it is seen that the use of the proposed method for producing aluminum alloys provides an increase in the degree of assimilation of refractory transition metals by an average of 7.5 abs. and due to this, a reduction in their losses by an average of 5.5 times. The preparation time of an aluminum-based alloy with additives of refractory transition metals is reduced by 39%. Due to an increase in the process productivity and a reduction in alloying refractory transition metals, the cost of the alloy is reduced.

Claims (1)

METHOD FOR PRODUCING ALUMINUM ALLOYS, including alloying a melt of aluminum and its alloys with silicon and refractory transition metals with stirring, characterized in that the alloying is carried out with a molten silicon stream with a temperature of 1450 1750 ^o C, and refractory transition metals are subjected to additional mixing in a molten silicon stream.

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