SU768813A1 - Method and device for separating slag from cast iron - Google Patents

Description

gutter after the end of the extrusion of the products of melting and closure of the log iron letkk.

The known method and; the device makes it possible to prevent slag from entering the iron buckets, however they have significant drawbacks, which consist in the large capacity of the auxiliary bucket and the need to increase the loading capacity of the yard yard.

This is due to the fact that up to 25 tons of pig iron can remain in the main chute of the blast furnace. Taking into account the cast iron deposited from the slag during the release of smelting products, as well as taking into account some remaining amount in the auxiliary slag ladle, the capacity of the auxiliary ladle should be 25-30 tons, and the carrying capacity of the foundry yard (taking into account the weight of the empty lined auxiliary bucket) - respectively 40-50t.

The use of such a large bucket as an accessory for such a large capacity (t) makes it difficult to transport it and turn it over to the casting yard, and also increases the total duration of operations for the production of melted products, which can lead to disruption of the production schedule and, as a result, cast iron production losses .

On blast furnaces, the load capacity of the casting yard is usually 2; 5-30 g. The casting yard capacity of a casting yard up to 40-60 tons requires large capital expenditures to strengthen the building structures of the casting yard and existing blast furnaces with significant technical.

In addition, it is difficult to carry out the conventional method, and in myogic cases it is impossible to carry out on blast furnaces — with bucket cleaning and single-numbered slag casting due to an excessively large height difference along the route — a transport chute for draining iron and slag residues — an auxiliary bucket — stationary Slag chute - swinging chute for slag casting (taking into account the need to cascade the listed elements).

The purpose of the invention is to prevent slag from falling into cast iron buckets while reducing the amount of cast iron being drained into an auxiliary ladle.

This task is solved by creating a method for separating slag from cast iron, into which a layer of cast iron 50–100 mm high, which is in the main trough under the slag, is poured into the auxiliary ladle together with the slag, and the rest of the cast iron is made into cast iron dams.

A device for carrying out the pre-conditions of the side wall of which, before the skimmer, an additional hole is made, while the lower edge of the additional hole is located below the level of the pass for the cast iron by (0.3-0.4) Lf (50-1) / 1Sh, where h is the difference heights between the pass for the iron and the pass for the slag.

FIG. 1 shows a diagram of the gutters of the foundry. Of the yard with two cast-iron tap-holes; in fig. 2 - main chute, longitudinal section.

The device includes the main chute 1, with 1 opening to the cast-iron notch 2 of the blast furnace 3. The main chute, / is equipped with a 4 cast iron bridge and a pass 5 for slag, between which there is a skimmer 6. In the main chute / at the level of its bottom between the pass 4 for cast iron and skimmers 6, a hole 7 was made to release the cast iron from the main trough / into the cast iron carriers. 8. In the side wall of the main trough / before the skimmer 6, an additional hole 9 was made, the lower edge of which is located below the level of the pass 4 for cast iron on (0 , 3-0.4) / g-b (50-100) mm, where / I - differential heights between pass 4 for cast iron and pass 5 for slag. The gutter adjoins to pass 4 for cast iron

10 for the removal of pig iron, under the drain toe of which a swinging trough P is installed for pouring iron into the pig iron-carrying ladle 8. A passage 12 for the removal of slag is adjacent to the slag pass 5 under the drain

the toe of which is installed the swinging chute 13 for pouring slag into the slag ladles 14. iB the location of the outlet 7 to the main chute / adjoins the chute 15, which is then connected to the chute 10. At the location of the additional opening 9 to the main chute 1 adjoins the chute 1.6, under the drain. Of which in the foundry yard, an auxiliary bucket was installed / 7.

The method is as follows.

The release of smelting products from the blast furnace 3 cast iron and slag through the cast iron tap-hole 2 enters the main chute / where they are separated. .Wherein

The slag is retained by the skimmer 6 and through the pass 5 for the slag along the chute .12 enters the swinging chute 13 and further into the slag-carrying buckets .14, and the iron passes under the skimmer € and through the pass 4 for the cast iron along the chute 10 enters the "swinging chute 11 and further in pig-iron co.vshi 8. At the time of release of the products of smelting from the blast furnace 3 hole 7 and. extra hole 9 in the main groove /

Hardened by fireproof mass.

After the end of the production of smelting products in the main chute, 1 remains iron and slag. If it is necessary to empty the main gutter 1, for example, for its re 4 pt, open the additional hole 9 and drain the eye gutter / total slag and the underlying iron layer 50-100 mm in height along the chute 16 to the auxiliary bucket 17. Then open the hole 7 at the level of the bottom of the main chute / and release the left in the main chute / cast iron through the chute 1/5 and further along the chute 10 and the swing chute // into the cast-iron ladles 8.

The contents of the auxiliary scoop 17 (cast iron and slag) are poured into the same main chute / after its repair or into the main chute d at another cast-iron notch 2 by means of a crane 18 of the casting yard. This operation is preferable to be done after the end of the next production of I13 blast furnace 5 .

The location of the additional hole in the main chute is chosen in such a way as to ensure that all the remaining slag in the main chute and the minimum amount of cast iron are drained into the auxiliary bucket. This requirement, under actual operating conditions, corresponds to the height of the cast iron bed from 50 to 100 mm.

The distance from the level of the pass for the cast iron to the lower edge of the additional hole is determined from the hydrostatic equilibrium equation of the liquid melting products located in the main channel on opposite sides of the okimmer:

(a + / g- / gh) -rsh.

op

where a is the distance from the pass level for the cast iron to the lower edge of the additional hole, in mm; h is the height difference between the pass for the cast iron and the pass for the slag in mm;

cp is the height of the iron layer from the lower edge of the additional hole to the level of the interface between the iron and the slag from the main channel, in mm; Рш - Zddelka weight, rc - specific weight of cast iron, g / sl. Substituting, in the equation / 1h 50-100 MJM ,, ,, 0 g / slg, RCh 7.0 g / slg and solving it with respect to a, we get:

a (: 0, 4) / g + (50-100) lsh.

Other uses of the invention are possible. For example, for two main troughs located on the same foundry yard, one common auxiliary bucket can be installed. The invention can also be applied in the presence of one related to the furnace.

a main gutter (bath) serving two cast-iron tap-holes, which in this case are connected to the main gutter by means of transport chutes.

The advantages of the invention are that it ensures that slag does not get into the cast-iron ladles when it is reduced (by a factor) by reducing the amount of the slag to the auxiliary ladle and the corresponding

reducing the capacity of the auxiliary bucket. As a result, there is no need to increase the carrying capacity of the casting yard crane, which requires large capital expenditures; Facilitating transport and tilting of an auxiliary goat with a crane of the casting yard, reducing the overall duration of operations for the production of smelting products.

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Claims (2)

1. A method of separating slag from cast iron, comprising draining the iron and slag from the main trough of the blast furnace after finishing the output of smelting products and closing the iron notch into the auxiliary ladle, followed by emptying the auxiliary ladle into the main chute, characterized in that slag falling into iron buckets with a decrease in the amount of pig iron poured into the auxiliary Koeni, into the auxiliary bucket together with the slag poured a layer of pig iron located in the main trough under the slime 50 mm high, and the rest of the iron is poured into the iron pigs. 2. A device for carrying out the method according to claim 1, comprising a main chute with a skimmer, a pass for the iron and a slag, characterized in that an additional hole is made in the side wall of the main trough to the skimmer, the lower edge of which is located below the level of the pass for the iron by (0.3-0.4) L + + (50 -100) mm, where ft is the height difference between the passes for the iron and the slag. The source of information taken into account in the examination: 1. US Patent No. 3689252, cl. 75-46, 1974 (prototype). ; 5 12