SU1180396A1 - Method of producing aluminium-silicon alloys - Google Patents

Abstract

A METHOD FOR MANUFACTURING ALUMINUM-SILICON ALLOYS, including loading silicon on the bottom of the furnace, pouring molten aluminum and mixing the melt mainly with tangential flows created by the channel-type magnetohydrodynamic pump, which is designed to reduce the temperature of the shaft-type pump, in order to improve the homogeneity of the alloy and reduce the loss of water, the shaft can be covered with a channel-type pump, in order to improve the homogeneity of the alloy and to reduce the loss of water, the channel can be used to reduce the temperature of the pump. These streams are reversed with the frequency of changing the direction of said streams, as defined by the formula Wj -j-Et. where n is the frequency of changing the direction of metal flow in channel -1 (L of pump, h VJ. is the linear velocity K of metal flow in the pump channel, FK is the cross-sectional area of the pump channel, m, Vp is the melt volume, m 00 about WITH; about Od

Description

 . The invention relates to metallurgy of aluminum-silicon alloys and can be used in the preparation of silumin. The purpose of the invention is to improve the homogeneity of aluminum-silicon alloys and reduce the loss of alloy components. When the melt is stirred in a jammed volume of tangential flows of one direction over time, zones at different points of this volume are created, the nature of the melt movement in which differs from the general nature of flow movement, and therefore the rate of saturation of aluminum with silicon in these zones will be different. . Therefore, in order to equalize the chemical composition of the alloy throughout the volume, it is necessary to reverse the direction of the velocity vector at each of its points. However, an arbitrary choice of the frequency of the change in the direction of movement the flow slows down the equalization of the chemical composition simultaneously at all points of the melt volume, because at an arbitrarily chosen frequency, the total volume of the melt during its movement through the MHD pump channel in one direction may not flow velocity vector directions at all points of the melt volume. Calculations show that the frequency of changing the direction of movement of the metal flow should be no less than the value of n -, -. Performing a VP of this condition ensures that the flow of the entire volume of the melt flows tangentially during the passage through the channel in one direction, which leads to acceleration of silicon concentration throughout the volume of the bath, therefore, when casting the finished alloy, fluctuations in silicon content decrease. with a change in the direction of flow of the stream with a frequency established by the ratio indicated, it also reduces the loss of metals in the preparation of the alloy. This is due to an increase in the rate of silicon dissolution in the volume of the melt, leading to a decrease in the rate of transition of the slime into the slag. 96 Example, The proposed method is carried out under industrial conditions in a 15 ton mixer. To create predominantly tangential melt flows in a mixer, a magnetohydrodynamic pump with a horizontally arranged channel is used. Preparation of silumin are as follows. Silicon in the form of lumps is loaded onto the mixer bottom based on the preparation of an alloy with a content of crusts of not more than 11.5 wt.%. Then pour the estimated amount of liquid aluminum. Melt mixing is carried out by switching on the MHD pump. Since the pump channel is located horizontally, by turning on the MHD pump, a directed metal flow is created, which has a predominantly tangential character of movement in the channel and mixer. The frequency of changing the direction of flow is set equal to 10 times per hour from the ratio n ------, based on the following data: linear speed of flow in the channel 0.3 m / s or 1080 m / h, channel cross section 0.054 m, volume melt in a mixer 5.8 m. To evaluate the effectiveness of the proposed method, the slag formed during the preparation of the alloy is weighed and analyzed for the content of aluminum and silicon. The results are presented in Table. 1, for comparison, the results achieved using the known method are given. It follows from the above data that when using the proposed method, the loss of aluminum with shpak is reduced from 9.0 to 7.6 kg / t, and silicon from 4.9 to 2.6 kg / t. In the implementation of the known and proposed ci; oco6oB, samples are taken to determine the average silicon content by volume of the molten bath at nine points: at the corners of the bath, in the middle of each side and in the center of the bath. The results are presented in Table. 2. From the above data it follows that using the proposed method significantly improves the homogeneity of the chemical composition of the alloy (the root-mean-square deviation of the silicon concentration over the entire bath volume decreases by 3 rags), which ensures the quality of the finished alloy. When implementing the proposed method, the effect of the frequency of changing the direction of movement of the metal flow on the homogeneity of the chemical composition of the melt is studied. In this case, in one case, the alloy is prepared, setting the frequency by the proposed method, and in the other, the frequency is chosen arbitrarily. The duration of the melt mixing in all cases is 60 minutes. The results obtained are presented in Table. 3. From the data presented, it follows that the melt is more homogeneous in chemical composition in the case of 964 hours, if the frequency is established. -. , 0. from the ratio n This conclusion is also confirmed by the results of the chemical composition of the finished alloy ingots. The proposed method for the preparation of aluminum-silicon alloys has the following technical and economic advantages in comparison with the known method: it reduces the metal loss, accelerates the dissolution of silicon, increases the leveling rate of the chemical composition of the alloy, ensures its uniformity in the volume of the entire molten bath. The economic effect of using the proposed method is taught by reducing the loss of aluminium and silicon from the slag and reducing the chemical composition of the waste. Table 1

Loaded batch

aluminum

silicon

1 ton of finished aluminum

silicon Received ready

aluminum silicon

Per 1 ton of finished aluminum

silicon slag obtained,

aluminum silicon

Per 1 ton of finished aluminum

silicon

31081

82546 4425 10708

00,6

894.5 13.7 116.0

81814

426611

at

10467 52077

886,6

891.2 113, A 108.8

701

4307 237 2328

7,6

9.0 2.6 4.9

The method of preparation of the alloy

Famous Offered

Average content

and change the direction of the silicon in the flow stream

- (ve, wt.%

h 8

11.08

10 13 11.13 11.06

table 2

Table 3

Standard deviation

0,0029

11.3 11.3 0.0023 0.0034 11.3

Claims (1)

METHOD FOR MANUFACTURING ALUMINUM-SILICON ALLOYS, including loading silicon onto the hearth of a furnace, pouring aluminum melt and mixing the melt with predominantly tangential flows created by a channel-type magnetohydrodynamic pump, characterized in that, in order to increase the uniformity of the alloy and reduce the loss of melt component, during mixing these flows are reversed with the frequency of the change of direction of these flows, determined by the formula where η is the frequency of the change of direction metal flows into the pump channel, h '\ Wg - linear velocity of the metal flow in the pump canap, m ^-1 ', F _K - the cross-sectional area of the pump channel, m ² ·, Vp is the melt volume, m ³ .