RU2491148C1 - Method of producing synthetic composite for metallurgical conversion (versions) and casting machine to this end - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to metallurgy. Solid filler is fed into belt conveyor moulds, poured with iron and pigs are cooled at casting machine. Said solid filler is fed into said molds in two successive steps whereat it is poured with iron. After pouring, cast iron is cooled in moulds by feeding water in amount of 0.025-1.000 kg per kg of cast iron.

EFFECT: more uniform distribution of filler over pig volume.

5 cl, 2 dwg, 2 ex

Description

The invention relates to ferrous metallurgy, and in particular to methods for producing charge materials for steelmaking, known as synthetic composite materials for smelting steel and alloys.

A known method of producing a synthetic composite material, implemented in the production of a billet for metallurgical processing, in which the iron ore part of the charge (oxide bulk material, filler) is poured into the molds (molds, molds) and cast iron [Description of the invention to the patent of the Russian Federation No. 2092573 from 26.05 .1995, IPC ⁶ C21C 5/52, C21C 5/28, B22D 5/00, publ. 10/10/1997]. The oxide material used is iron ore pellets, iron ore, metal concentrate, scale, sinter, pulverized wastes and slag from sintering production, blast furnace dust.

Also known is a method of producing a billet of billets for steelmaking, including pre-loading dried to a relative humidity of not more than 2% solid oxidizing agents with a fraction of a certain size into the molds of a casting machine and their subsequent pouring with liquid cast iron with a temperature of 1250-1380 ° C [Description of the invention to the RF patent No. 2094480 dated 11/21/1995, IPC ⁶ C21C 5/52, C22B 1/24, publ. 10/27/1997]. The ingots of the blanks are cooled in natural conditions on a filling machine.

Among the disadvantages of both known methods, it should be noted that due to the delay of iron trucks at the furnace at the outlet, the delay in the delivery of ladles from the furnace to the casting, the preparation of the casting machine for casting, etc. the temperature of cast iron decreases to 1250 ° C and lower and, as a result, its viscosity increases.

Due to the increase in the viscosity of cast iron during casting, there is a local clutter of the gutters with frozen metal, it is difficult to mix the filler with cast iron, which leads to an unsatisfactory coating of the filler with metal. The consequence of this is the destruction of the obtained billets during loading and transportation, which ultimately leads to a decrease in the yield of castings by 15-20%.

In the method for producing a semi-finished product for metallurgical processing, which involves pouring liquid fillers previously loaded into the tinplate with liquid metal having a density lower than the density of cast iron and then cooling them, immediately after the casting is completed, the solid fillers in the trough are additionally subjected to mechanical force to force the “return” of the surfaced fillers in the volume of more ductile iron [Description of the invention to the patent of the Russian Federation No. 2075366 from 07.20.1993, IPC ⁶ B22D 5/00, C21C 5/52, C22B 1/24, publ. 03/20/1997]. This achieves a homogeneous heterogeneous system in the volume of ingots (castings, ingots) and the homogeneous structure of the semi-finished product.

The disadvantage of this method is the difficulty of ensuring the interconnection of such technological parameters as the temperature of the liquid metal, its flow rate, the cooling rate of the semi-finished product, the time of onset of mechanical action and the amount of coolant to obtain stable quality castings.

The closest in technical essence to the present invention is a method for producing a semi-finished product (synthetic composite material) for metallurgical processing, in which the molds are pre-filled with solid additives and then cast with cast iron in two stages: first, the mold is filled with solid additives and 10-50% of the volume is filled the melt required to completely fill the mold, and then fill in the remaining amount of the melt after 1-10 seconds [Description of the invention to the patent of the Russian Federation No. 2031965 from 09/21/1992, IPC ⁶ C22B 1/24, C21C 5/52, publ. 03/27/1995]. The yield of castings suitable for geometric dimensions in this case increases by 11-14%.

The disadvantage of this method is the low productivity, insufficient and unstable quality of the resulting semi-finished products due to the uneven distribution of solid additives in the volume of ingots. As a rule, solid additives, due to their lower density in comparison with cast iron, are collected in the upper part of the ingots instead of a uniform distribution over their volume.

The task of the group solved by the first and second inventions and the technical result achieved are to create the next methods for producing synthetic composite materials for metallurgical processing, simplify them, to improve the quality of castings by achieving a more uniform distribution of fillers in their volume and increasing the productivity of the process.

To solve the problem and achieve the claimed technical result in the method for producing a synthetic composite material for metallurgical redistribution according to the first embodiment, which includes supplying solid filler to the conveyor molds of the conveyor belt, pouring it with cast iron from an iron ladle through the gutter socks, and cooling ingots on the casting machine, pouring the filler with cast iron is carried out in two steps, and after each pouring, the cast iron is cooled by supplying water to its surface in the amount of 0.025-1,000 kg / kg of cast iron. As a filler, iron ore pellets or iron ore, or metal concentrate, or scale, or agglomerate, or pulverized waste and sintering slag, or blast furnace dust, or a combination thereof, are used.

In the method according to the second embodiment, comprising supplying solid filler to the conveyor belt of the casting machine, pouring it with cast iron from the iron ladle through the socks of the trough and cooling the ingots on the casting machine, filling the filler with cast iron is carried out in several stages, while the solid filler is fed into the molds of the filling machine sequentially, at least in two stages, at least one of which is preliminary and in each of which it is cast at least once with cast iron, and after that zhdoy pouring cast iron filler further cooling is carried out in iron by feeding troughs on the surface of water in an amount of 0,025-1,000 kg / kg of the cast iron. As a filler, iron ore pellets or iron ore, or metal concentrate, or scale, or agglomerate, or pulverized waste and sintering slag, or blast furnace dust, or a combination thereof, are used.

All of the above methods for producing synthetic composite materials are implemented on typical filling equipment [see Description of the invention to the patent of the Russian Federation No. 2075366], which includes a bucket with a trough and socks, a conveyor belt with molds and a hopper of solid fillers with a dispenser.

The disadvantage of this equipment is low productivity, insufficient and unstable quality of the resulting semi-finished products, and in addition, mechanical stirring significantly complicates the design of the device and accelerates the wear of the conveyor.

The task of the group solved by the third inventions and the technical result achieved is to create a filling machine for producing synthetic composite materials for metallurgical processing, to constructively simplify it and increase productivity, as well as to improve the quality of ingots (castings) by achieving a more uniform distribution of fillers in their volume.

To solve the problem and achieve the claimed technical result in a casting machine for producing a synthetic composite material for metallurgical processing, including a cast-iron ladle with liquid metal, a chute with socks, a conveyor belt with molds (molds, foundry molds) and at least one hopper solid fillers with a dispenser, along the gutter after each toe along the conveyor belt mounted spray with water dispensers.

The invention is illustrated by drawings, where:

- figure 1 shows a General view of a filling machine that implements the first version of the method for producing a synthetic composite material for metallurgical processing - the simplest modernization of existing equipment;

- figure 2 shows a General view of a filling machine that implements the second variant of the method.

The method for producing a synthetic composite material for metallurgical processing according to the first embodiment can be implemented on a casting machine, including a ladle 1 of molten metal with a groove 2 and socks 3, a conveyor belt 4 with molds (molds, casting molds) 5 and one working hopper 6 of solid fillers 7 with a dispenser 8, while along the trough 2 after each toe 3 in the direction of the conveyor 4 installed spray 9 with dispensers 10 for water supply.

The present method includes feeding into the molds 5 of the conveyor belt 4 of a filling machine 7 of solid filler 7, pouring it with cast iron from an iron ladle 1 through socks 3 of the chute 2 and cooling the ingots (castings, ingots) 11 on the filling machine, filling the filler with cast iron is carried out in two stages, after each filling of filler with 7 cast iron, cooling of cast iron is additionally carried out by supplying water 12,025-1,000 kg / kg of cast iron to its surface 12.

The method for producing a synthetic composite material for metallurgical redistribution according to the second embodiment can be implemented on a casting machine, including a bucket 1 with a groove 2 and socks 3, a belt conveyor 4 with troughs 5 and two or more successive solid filler working bins 6 installed in the direction of the conveyor 4 7 with their own dispensers 8, while along the trough 2 after each toe 3 along the conveyor 4 are installed spray 9 with dispensers 10 for supplying water.

This method includes feeding into the molds 5 of the conveyor belt 4 of the filling machine a solid filler 7, pouring it with cast iron from an iron ladle 1 through socks 3 of the chute 2 and cooling the pigs 11 on a filling machine, filling the filler with cast iron is carried out in several stages, while the solid filler 7 is fed into the molds 5 of the casting machine in series in two or more stages, the first of which is preliminary, and at each stage the filler 7 is cast at least once with cast iron, and after each filling, Itel cast iron additionally carry out cooling of cast iron in troughs by supplying water 12,025-1,000 kg / kg of cast iron to its surface 12.

Let us analyze the essential features of inventions.

The cooling of molten iron with water after the first filling of filler 7 allows us to fix in the volume of the future ingot 11 the location of the floated fractions of filler 7 to one degree or another. The next casting of cast iron into tins 5 finally closes the protruding fractions of filler 7. serve water. As a result, they receive pig 11 with a “filling” made of filler 7 hidden under a metal layer. This gives significant advantages in the conversion of such castings to steel and alloys with normalized physicochemical properties.

A more pronounced effect can be obtained when the solid filler 7 is fed into the molds 5 of the filling machine in series: filler 7 — liquid metal — cooling; again filler 7 - again liquid metal - again cooling. As a result, a “flaky” casting is obtained with “fillings” from filler 7 hidden under a metal layer. There can be two or more such layers of filler 7 in the volume of ingots 11. Structurally obtained casting will be closer to “theoretical” - when the filler 7 is evenly distributed throughout its entire volume. Such a synthetic composite material (semi-finished product) is most preferred for further metallurgical processing.

The amount of process water used to cool the surface of molten iron 12 is selected for reasons of guaranteed fixation of the surfaced fractions of the filler 7 in the volume of the future casting (ingots 11 ') and in the ingot 11. The contact of the molten metal with the filler 7 promotes the formation of a primary metal crust. When water is supplied to the first, as well as to subsequent portions of liquid with a crust of metal, its complete evaporation should occur, excluding the possibility of contact of the remaining water in tin 5 with the next (or last) portion of liquid metal. Intensive evaporation of water and, accordingly, the formation of a dense metal surface begins even before it comes into contact with water. At the very first stage of filling the filler with metal, it is possible to completely cool the entire volume of the metal to a solid state - it all depends on the amount of water supplied. An amount of water less than 0.025 kg / kg of cast iron will not allow cooling the metal to the proper extent - as the conveyor 4 moves, the hardened crust will melt again, especially when the next portion of the molten metal is fed, and the filler 7 will definitely float. An amount of water equal to 1,000 kg / kg of cast iron is guaranteed to evaporate from the metal surface if it is sprayed over it and, in no case, is supplied by a thick stream. The amount of water greater than 1,000 kg / kg of cast iron will lead to its unreasonable cost overruns, coupled with the possibility of contact with the next portion of liquid metal, which is unacceptable.

Structurally, the implementation of the methods is achieved by the fact that along the trough 2 after each toe 3 along the conveyor 4 there are installed sprinklers 9 with dispensers 10 for supplying water - regardless of the chosen technology for producing ingots 11 - to form one or more layers of filler 7.

The implementation of the inventions will consider the following examples.

Example 1. Obtaining castings with one layer of filler

From the beginning of the movement of the conveyor belt 4 from the hopper 6 with the dispenser 8, a portion of the solid filler 7 is loaded into each mold 5 — approximately 40-60% of the volume of the mold 5. The filler (oxide material) 7 uses iron ore pellets, iron ore, metal concentrate, scale, agglomerate, pulverized wastes and slag from sintering production, as well as blast furnace dust.

Upon receipt of the mold 5 to the second position, fill the solid filler 7 with hot cast iron for 50% of the volume of the mold 5 with spraying the metal surface 12 with water from a spray of 9 with a water flow rate, for example, 0.07 kg / kg of cast iron.

On the surface of the metal 12 in a mold (mold 5) a dense surface is formed, preventing the emergence of the filler 7.

In the third position, the mold 5 is filled with molten cast iron to the full volume and watered with water from the next downstream conveyor 4 sprayed 9 with a water flow rate, for example, 0.7 kg / kg of cast iron to form a solid strong crust, providing an output of ingots of 11 to 92%. Next, the troughs 5 enter the zone of their filling with water and cooling the castings (pigs 11).

The performance of the casting machine upon receipt of the synthetic composite material in the form of ingots 11 for metallurgical processing reaches the performance of the casting machine for casting iron.

The process is ongoing.

Example 2. Obtaining castings with two (or more) layers of filler

This Example is similar to Example 1 with the only difference that, for example, half of a portion of solid filler 7 is loaded into each tin 5 — approximately 20-30% of the volume of the tin 5.

Upon receipt of the mold 5 to the second position, fill the solid filler 7 with hot cast iron for 33% of the volume of the mold 5 with spraying the surface of the metal 12 with water from a spray of 9 with a flow rate of, for example, 0.07 kg / kg of cast iron.

An artificial seal is formed on the surface 12 of the metal, preventing the filling of the filler 7.

In the third position, the remainder of the filler 7 is loaded into the mold 5.

The fourth 33% of the volume of molten cast iron is added to the fourth position in the mold 5 and again the molten metal is poured with water from the spray 9 with a water flow rate, for example, 0.12 kg / kg of cast iron to form the next dense surface, preventing the second portion of the filler 7 from floating up.

In the fifth position, the mold 5 is filled with molten cast iron to the full volume and watered with water from the latter along the conveyor 4 sprayed 9 with a water flow rate, for example, 0.7 kg / kg of cast iron to form a solid, durable crust, providing a yield of castings up to 95% and more, which depends on the number of portions of filler filled with liquid metal 7. Next, the troughs 5 enter the zone of their filling with water and cooling ingots (castings) 11.

The process also goes on continuously.

As a result of the use of inventions, high-performance and at the same time simple methods for producing synthetic composite materials for metallurgical processing were created, the corresponding equipment for their implementation was created, which made it possible to improve the quality of castings by achieving a more uniform distribution of fillers in their volume by structurally simple methods.

Claims (5)

1. A method of producing a synthetic composite material for metallurgical processing, comprising supplying solid filler to the conveyor belt of a casting machine, pouring it with cast iron from an iron ladle through the gutter socks and cooling the ingots on a casting machine, characterized in that the filler is filled with cast iron in two steps, after each pouring, cooling of cast iron is carried out by supplying water to its surface in an amount of 0.025-1,000 kg / kg of cast iron. 2. The method according to claim 1, characterized in that the filler uses iron ore pellets or iron ore, or metal concentrate, or scale, or sinter, or pulverized wastes and slag from sintering production, or blast furnace dust, or a combination thereof. 3. A method for producing a synthetic composite material for metallurgical processing, including feeding solid filler into the conveyor belts of a casting machine, casting it with cast iron from an iron ladle through the gutter socks and cooling the ingots on a casting machine, characterized in that the filler is filled with cast iron in several stages, wherein the solid filler is fed into the molds of the filling machine sequentially in at least two stages, at least one of which is preliminary in each of which it at least once poured cast iron, wherein after each pouring filler cast iron cooling the cast iron is carried in the trough by applying to the surface of the water in an amount of 0,025-1,000 kg / kg of the cast iron. 4. The method according to claim 3, characterized in that the filler uses iron ore pellets or iron ore, or metal concentrate, or scale, or sinter, or pulverized waste and slag from sintering production, or blast furnace dust, or a combination thereof. 5. A filling machine for producing a synthetic composite material for metallurgical processing, including a cast-iron ladle with liquid metal, a chute with socks, a conveyor belt with molds and at least one hopper of solid fillers with a dispenser, characterized in that along the chute after each sock in the direction of the conveyor installed squirting with water dispensers.

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