SU713919A1 - Charge for iron flux production and its preparation method - Google Patents

Description

I

The invention relates to the field of preparation of metallurgical raw materials and can be used, for example, for agglomeration of iron flux for blast-furnace smelting.

There is a known method of using metallurgical production wastes in blast smelting, according to which oxygen-converter slag is introduced into a blast furnace together with the ore component of charge 1.

The disadvantages of the method are the impossibility of using in the smelting of other metallurgical wastes, the need to sort the slag according to the crushiness and the low stability of the granules, the slag during their storage.

The closest to the proposed technical essence is a method involving the work of cold fine raw materials (iimaKa steelmaking, pyrite ogarkov, metallurgical dust) in the presence of 3-7 wt.% CaSC or oxide of ferric chloride, or calcium hydroxide (oxide) of calcium to obtain raw pellets with their subsequent drying and heating on a neutralizing furnace in a neutral or

oxidizing atmosphere at 900-1100 ° C and roasting at a temperature of 1250 ° C 2.

The disadvantages of the method are the complexity of the technology, the considerable costs of heat for the process, the need to sort the steelmaking slag according to size in order to remove fines from it, the need to use additives that are not waste from the metallurgical process (ferric chloride, CaClj, etc.).

The aim of the invention is the disposal of metallurgical production wastes and heat of the slag melt, as well as the simplification of technology.

This goal is achieved by the introduction of scale and sintering of agglomerate and pellets at the following ratios, wt%: as iron supplements.

Steelmill grade 30-50

Okalina10-20

Elimination of agglomerate and

pellets fraction

0.1-3.5 mmEverything else

3.7

In addition, mixing is carried out in a to-parabolic or parabolic vessel with a central {m DO1-WN hole by way of) keg of eos-containing additives along the center of the vessel into a hot melt with a temperature of 1520-1600 ° C and a viscosity of 2-6 P, From height to height: slag layer to the diameter of the outflowing jet 1.2-2.5,

. In blast furnace smelting, the following wastes may be used. Oxygen onvergorny (or open-hearth) slag, having, for example, at the Krivorozhstal plant, has a spelled composition, wt.%:

Fe.24-22

; MpO7-2

SzO.40-52

MDO4-7

F0-3

SiOj12-20

AI OS-3-4

resulting in a volume of 145 kg / t steel; podreshegny product rassevaaglomerat and pellets in a volume of up to 125 kg / t of iron with an iron content of up to 56%; The scale generated in the rolling process in the amount of up to 30-40 kg / t of rolled products with an iron content of 68-72% is usually abundantly oiled (the oil content in the form of a film on the scale reaches 8 wt.%).

The use of these wastes by way of direct loading them into the furnace is impossible, since this will sharply deteriorate the characteristics of the charge.

A liquid donkey with pulverized and small additives is mixed in a rotating vortex formed when a slag flows out of the hole. At the same time, heat of the slag melt is utilized, which is spent on the smelting of iron flux.

The uniform mixing of the donkey, the ocanine, and the minutiae of the agglomerate and okah necks is carried out as follows.

The slag (melt) is fed to a vessel with an open hole. When fluid flows out (in a bowl: a case of slag), a hole of rotation with an internal cavity is formed from the hole. In order to form a highly turbulent spin funnel with slag outflow, the height of the free slag surface above the bottom opening must be 1.8 hole diameters. Bulk additives are fed to the center of the spin funnel. Due to the intensive rotation of the laadosti in the area of the aperture, the motion turbulence is high. Due to this, liquor1 (penetration) of the particles of the hard product into the liquid occurs, npHleM due to the difference in specific weights during rotation, the light parts are concentrated in the center of the hole and more severely move to the periphery. Because

194

ul.eln yu carried jelly-containing additives above the specific weight of the scale, then a part of the solid waste supplied to the center from itcHTpa to the ger ”from the center, - pp-tya, is distributed.

At the expense of u koltisnchy gepla obtained during the combustion of mill scale due to the addition of preheating, the vessel in the orifice zone remains high, and the mixture in the Q; V5pC1 zone is liquid1) one; og

-OcfiODHhie nusaKii, having xopoiuyKi current Irl High temperature, hot air has very high HHrepBajie temperatures (5 degrees prior1) and tsago1 ;;; | s TBspayjo: .iaccy, mine minus) Oy; Therefore, 1: pH rapid cooling of the floor of Shyugsk Grag-Ul is rather large (20-32 mm). Introduction to the donkey melt of powdered FeO privo / scht at about

20 melting the melt to stabilize it and increase the mechanical strength of the granules.

The drawing shows schematically ifpouecc of the mixing of slag melt with additives and the formation of grapules.

7-5 Ylak enters the suck.;. 1 of the device 2, and iron-containing additives - from the hopper 3.

A melt of a cockverter cell at that time after the expiration of the ICM is 0 °: power supply unit (t i550 - j60uC) has a viscosity of /. I. gb)

30 outflow from the hole di; GLS7RL 50: chm: npi ratio of 1.2 --- 2, with / ichulspopoiiKj; vryi, enn, sposabstnuetgpagu ..iii.HOMy sgchssshkvaipyu.

On the other hand, with -V- - 0.4-0.6 ppc, i5 xxto it is a whirlwind (cavity BOpOHKiE of rotation) in the B1 opening. At the same time, t ;, the fluid flow rate in the area of the oil supply increases, but the flow rate of the expiration becomes liecTable.

The composition of steelmaking slags and their basicity, even in one enterprise, fluctuates within 5–120 bounds, therefore the melt temperature and its viscosity are necessary within 1 bore bounds of the cobalt.

45 Conducted studies showed that the presence of fluorine compounds in the slag reduces the viscosity of the attack at 1520-1550 ° C to 2P, and the increased content increases the viscosity of up to 7 P.

To form a funnel, the ottoshe -2- is within 1.2, S, and the gemper-gorae is 1520-1-1600 ° C.

The rate of expiration of the mixture from the outlet during the experiment is in the range of 0.45-1-0.48 m / s, averaging V - 2.4 ha m / s.

The melt with additives to the solid state transition at a temperature on the surface of the sample} 380-1460.

A model with a vessel capacity of 0.42 m was made to obtain samples of iron flux. Based on the converter slag of the Krivorozhstal plant, the sifting of pellets, sinter (fraction 0-3.5 mm) and scale, six mixtures are made, differing from each other in the proportions of the ingredients (slag, sifting, scale).

The characteristics and chemical analysis of the samples of the iron flux obtained on the basis of these mixtures are given in the table.

The receiving vessel has a bottom hole with a diameter of 35 mm, and the maximum size of the samples obtained is 32 mm. The strength test of iron-flux is carried out by crushing the samples on an IM-40 machine. Tested samples of round shape with a diameter of 28-30 mm.

The cited data was obtained at-1.7-1.8; the temperature of the mixture is 1560-1580 ° C; 1 2-4.5 P; V 0.45-0.48 m / s, the vessel has the shape of a truncated cone with a smaller diameter D main meters. 140, big D osn. b 680mm

Thus, for effective mixing of the slag melt with additives, it is necessary that when the slag (mixture) is drained, a rotational funnel is formed, and the movement of the mixture in the orifice zone must be highly turbulent (150).

Analysis of this research

shows that laughter is effective when

n 2 2.5 and viscosity of donkey up to 3 10 m / s.

With these parameters after the donkey is flowing out: I, a spinning funnel is formed and the turbulence in the hole zone is sufficient to mix the slag melt with iron-containing additives.

The use of the invention makes it possible to obtain metallurgical raw materials, utilize metallurgical production wastes, open the ways for expanding the use of steel-smelting donks, whose use is extremely limited at present, use the heat that exists during slag cooling, and improve the gas-dynamic parameters of the blast-furnace charge by increasing it material fractions of 20-32 mm, open paths for using strong low-axis agglomerates.

The iron flux is not inferior to the agglomerate in its strength, has a high basicity and its grain composition provides a high gas permeability of the layer.

Iron-flux with the specified properties can be applied instead of the viewbased basic additives (limestones) in the blast furnace process.

Claims (2)

Claim 1. The mixture for the production of iron flux, containing steelmaking rods and iron-containing additives, characterized by the fact that, in order to utilize metallurgical waste and increase the strength of the granules, the mixture contains iron oxide and sinter and pellet screening as iron additives in the following ratios components, wt.%: Steelmaking slag ‘30-50 Dross 10-20 Screening of agglomerate and pellets • fractions of 0.1-3.5 mm Else. 2. A method of producing iron flux from a mixture of π. 1, including mixing slag with iron-containing additives, characterized in that, in order to simplify the technology and utilize the heat of the slag, mixing is carried out in a conical or parabolic vessel 5 with a central outlet by supplying iron-containing additives in the center of the vessel into slag melt with a temperature of '1520-1600 ° C and a viscosity of 2-6 P, while the ratio of the height of the slag layer to the diameter of the effluent is 1.2-2.5.