SU791258A3 - Crucible for aluminium production - Google Patents

Abstract

1498198 Metallurgical vessels UNION CARBIDE CORP 19 March 1975 [23 Dec 1974] 11345/75 Heading F4B A metallurgical vessel having a cast iron shell 31 is protect against attack by the molten metal contained in the vessel by lining the inside of the shell with self-supporting refractory plates 45, which are inert to the molten metal and arranged to be free to move relative to each other and to the shell upon thermal expansion, the molten metal being permitted to penetrate behind the lining through joints opened by the expansion to combine with the iron of the shell and form a solid refractory layer which prevents further contact between the molten metal and the cast iron shell. The molten metal may be aluminium or an alloy of it, and the refractory layer formed consists of FeAl 3 or Fe 3 SiAl 12 if the alloy or cast iron contains silicon. If the cast iron contains chromium a solid phase CrAl 7 may be formed. The refractory plates may be of graphite, or silicon carbide or some of each of these materials.

Description

one

The invention relates to non-ferrous metallurgy, in particular, to devices for producing aluminum and its alloys.

A crucible is known for producing aluminum, containing a lining made of an inert with respect to the melt material, such as graphite, inside the iron body.

A disadvantage of the known crucible is the impossibility of eliminating the interaction of the cast iron body with molten aluminum, which leads to a decrease in the service life of the crucible and an increase in the contamination of the finished metal.

The purpose of the invention is to increase crucible service life.

The goal is achieved by the fact that a coating of the intermetallic compound FeAtj is made on the inner surface of the body, and the lining consists of removable plates.

FIG. 1 shows a crucible; vertical section; in fig. 2 - FeABj coating made on the inner surface of the housing; in fig. 3 shows a crucible version, vertical section; in fig. 4 - the same in terms of.

The crucible consists of a cast-iron cord 1, inside which is installed a wiper 2, made of a material that is inert to aluminum and its alloy, such as graphite. An intermetallic compound 3 is applied to the inner surface of the housing 1 (Fig. 2). The crucible is placed in a lined bath 4, relative to which it is installed with a gap to accommodate heaters (not shown). A crucible on top ;, covered with a lid 5, on which is mounted a rotating nozzle 6 for feeding into

15 melt inert gas. On one of the walls of the crucible body 1, a channel 7 is made to feed the melt, and on the opposite wall, a hole 3 and a channel 9 are made

20 products.

The arrow shows the direction of movement of the melt in the crucible.

The crucible works as follows.

Channel 7 enters the crucible

25 is a molten aluminum which is heated by 4 heaters located in the gap between the body of the bath.

The inert gas supplied through the rotating nozzle 6 mixes

thirty

melt, its composition and temperature are average.

The finished, refined aluminum through the hole 8 and the channel 9 is withdrawn from the crucible for casting.

In the aluminum refining process, the graphite lining of the 2k cast iron body 1 expands, and due to the fact that the degree of thermal expansion of the iron is higher than that of graphite, the lining plates 2 are freely displaced relative to each other, which prevents the formation of cracks on the surface of the plates.

The aluminum penetrating through the gaps between the liner plates 2 cannot contact with the housing 1, since the latter is protected over the entire surface by a layer of intermetallic compound REHE, whose composition corresponds to the state of aluminum penetration by aluminum, i.e. corresponds to the state of equilibrium between aluminum and iron.

FIG. 3 and 4 one of possible options of installation of crucible is shown.

As in the above embodiment, the crucible comprises body 1, lining 2, intermetallic layer 3, cover 5 and nozzles 6. However, the crucible is divided by a partition 10 into two halves (each with its nozzle 6).

. Channel 7 for melt feed and channel 9 for the output of the finished product

are located at different levels on the common wall of the housing 1, and a pipe 11 is installed to supply the melt to the channel 9.

The inner lining is 2 crucibles, and J also the partition wall 10 can also be made of silicon carbide, which is also melt-inert and is a good heat insulator.

Intermetallic compound 0 - acts as a buffer between

the body of the crucible and the melt penetrating through the slots of the plates of the lining, and serves as a reliable barrier to the highly reactive melt, which eliminates contamination of the resulting product and increases the resistance of the crucibles.

Claims (1)

1. US Patent No. 3743263, cl. 266 34A, published. 1973. 1