RU2333264C2 - Production line for metallurgical charge material preparation - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention concerns ferrous metallurgy. Particularly, it concerns preparation of flux ingredients burning wastes for feeding in metallurgical charge. Production line includes facility for trapping of small-fractional limestone burning wastes in the shape of aspiration lime of removed from aggregate gas burning and tank for lime collection, system of briquet forming, consisting of feed gear and briquetting gear. Production line is outfitted by one or more reactor, comprised as mixer and outfitted by water batcher, of capacity for iron-containing wastes of metallurgy reception and by solidification post. Reactor/reactors are connected with iron-containing wastes receiving tank and tank for lime collection by batching and transportation facilities conformably iron-containing wastes and lime and also connected with system of briquette forming be feeding facilities of received in reactor/reactors mixture of slaked lime and iron-containing wastes. In the capacity of material briquetting it contains vibropress. Invention provides aspiration lime utilisation at the place of its formation, possibility of joint treatment of small-fractional limestone burning wastes and iron-containing wastes of metallurgy into slag-forming iron-containing briquettes, which are used as lime substitute while cast steel and steel making process.

EFFECT: aspiration lime utilisation at the place of its formation, possibility of joint treatment of small-fractional limestone burning wastes and iron-containing wastes of metallurgy into slag-forming iron-containing briquettes.

2 cl, 1 dwg

Description

The invention relates to ferrous metallurgy, in particular to the preparation of waste products for calcining fluxing components for feeding into a metallurgical charge by production of iron-containing slag-forming briquettes used as a substitute for lime in the production of iron and steel.

A device for dedusting exhaust gas from a rotary kiln designed for calcining limestone is provided, comprising a chamber with bag filters located on the loading end of the kiln and a dust collecting bin (see AS USSR No. 1649227, MKI 5 F27B 7/20, publ. 15.05 .91, Bull. No. 18).

The essential features of the invention, common with the essential features of the claimed technical solution, are: a device for dust removal of exhaust gases, containing a hopper for collecting dust.

The disadvantage of this device is the inability to dispose of a significant amount of suction dust at the place of its formation. Therefore, lime dust collected by the rotary kiln dust removal device is accumulated in the hopper, and then transported by truck or other means of transport to the sinter preparation section of the sinter plant, and in enterprises where there is no sinter plant, it is dumped or transferred to construction enterprises.

Taking into account the physical properties of dust (fineness, increased activity in the open air, dust emission during overloads, etc.), its transfer and use away from the place of formation causes additional difficulties (use of special vehicles, aspiration of loading and unloading places, limited storage time, etc.).

A known line for the preparation and supply of material of a metallurgical charge, including bunkers installed during the technological process and connected by material transfer mechanisms, a mill, weighing devices, a firing unit system, coolers and an aspiration system, while a small fraction of limestone firing product caught by electrostatic precipitators is fed to bunkers and further pelletizing (agglomeration) (see Ukrainian patent No. 6439 C1, MKI 5 C22B 1/00, publ. 12/29/94, Bull. No. 8-1). This decision was made as an analogue.

The essential features of the analogue, which coincide with the essential features of the claimed technical solution, are: a device for dust removal of exhaust gases, a dust collection bin.

The disadvantage of the analogue is the lack of lime slaking, which leads to its limited consumption in sinter charge due to emissions proportionally to the increasing amount of toxic toxic dust fractions formed when it is quenched at the moment of contact with moist concentrate and water, large losses of lime (up to 5%) as a result ablation of its small classes with steam, which is intensively formed during the quenching period, incomplete use of the intensifying ability of lime due to insufficient contact of lime with the concentrate. Therefore, the process of "extinguishing" individual particles of lime does not have time to end and proceeds when pelletizing the mixture and laying it on an agglomerate. Since the process of slaking lime is accompanied by an increase in its volume, this leads to the destruction of the already formed granules of the mixture.

A known line for the preparation of the material of the metallurgical charge, namely converter lime (see AS USSR No. 1505902 A1, MKI 4 C04B 2/02, published on 09/07/1989, Bull. No. 33), adopted as a prototype.

In accordance with the prototype, limestone is fired in a multi-zone fluidized-bed furnace and, in the form of soft-burnt lime with a particle size of 3-20 mm, is sent to a chilled lime conveyor, then it is fed to a two-day screen, where it is divided into two classes of particle size: 8-20 and 3-8 mm. Lime with a particle size of 8-20 mm is fed without further processing to the converter shop. Lime with a particle size of 3-8 mm and pulverized lime with a particle size of 0-1 mm, caught in the gas treatment system and in process cyclones, are fed to a mixing device. The mixture is fed into a roller briquette press and briquetted. Ready briquettes are transported by special transport to the converter shop.

The essential features of the prototype, which coincide with the essential features of the claimed technical solution, is the availability of a device for trapping fine-grained limestone firing waste in the form of suction dust from the exhaust gases from the firing unit, a lime collecting tank, and also a briquette forming system consisting of feeding and briquetting mechanisms.

The disadvantage of the prototype is the lack of means for supplying iron-containing waste from metallurgical production to the briquetting mixture, i.e. the impossibility of obtaining iron-containing slag-forming briquettes.

The basis of the invention is the task to improve the line of preparation of the material of the metallurgical charge by expanding its technological capabilities by introducing new links into it, which provide the possibility of co-processing small-fraction waste of calcining limestone and iron-containing waste of metallurgical production into slag-forming iron briquettes.

The problem is solved in that the line for the preparation of the material of the metallurgical charge, including a device for collecting fine-grained limestone calcining waste in the form of suction lime from the exhaust gases from the calcining unit, and a lime collecting tank, a briquette forming system consisting of feeding and briquetting mechanisms, characterized in that contains one or more reactors, made in the form of a mixer and equipped with a water dispenser, a container for receiving iron-containing waste of metallurgical production hardening stations, and the reactor (or reactors) is connected with a container for receiving iron-containing waste and a capacity for collecting lime by means of dosing and transporting lime and iron-containing waste, and with a briquette forming system by means of supplying slaked lime mixture obtained in the reactor (or reactors) and iron waste.

In addition, the line as a briquetting mechanism of the material contains a vibrating press.

The causal relationship between the set of essential features of the invention and the achieved technical result is as follows.

The introduction of one or more reactors, made in the form of mixers and equipped with a water dispenser, and their combination by means of dosing and transportation with a container for collecting lime and a container for receiving iron-containing waste from metallurgical production allows combining the performance of two functions in one device - the function of the reactor and the function of the mixer, namely, to "quench" lime and mix it with iron-containing waste in one device, and to ensure their communication by means of feed the mixture of slaked lime and iron-containing waste in the reactors with the briquette forming system allows to obtain iron-containing slag-forming briquettes, used instead of lime in the production of iron and steel, as a substitute for burnt lime.

The installation of two mixers operating in cycles (during operation of the first mixer, the second is loaded and vice versa) ensures the continuity of the “quenching” mode and the entire cycle as a whole. In case of market demand for lime test, the addition of iron-containing waste from metallurgical production is excluded from the technological process and briquettes are not formed. Ready lime dough directly from the mixer is unloaded into a truck or packed in plastic bags using a packaging machine. Mixers can be both gravitational and forced action.

The invention is illustrated in the drawing, which shows the technological scheme of the line.

The line for preparing the material of the metallurgical charge comprises a device 1 for collecting fine-grained limestone calcining waste in the form of suction lime from the exhaust gases from the calcining unit 2 and a lime collecting tank 3, as well as a briquette forming system 7 consisting of feeding mechanisms 10 and briquetting 11. The line equipped with two reactors 4, made in the form of mixers and equipped with a water dispenser 5, a capacity of 6 for receiving iron-containing waste from metallurgical production and contains hardening posts, and reactors 4 are connected with a capacity 6 for receiving iron-containing waste and a capacity 3 for collecting lime by means of dosing 9 and transporting 12 lime and iron-containing waste and with a briquette forming system 7 by means of 8 supplying a mixture of slaked lime and iron-containing waste obtained in reactors 4.

A vibrating press is installed as a briquetting mechanism.

The line works as follows.

The crushed material (limestone) is sent to the firing unit 2. After firing, the material enters (not shown) in precipitators and is cooled, and the gas stream containing fine-grained suction lime is sent to the device 1 for collecting fine-grained lime roasting waste in the form of suction lime and subjected cleaning up. The purified gas is discharged into the atmosphere by means of a fan and a pipe, and the aspiration lime trapped in the device 1 is sent to a container 3 for collecting lime, and then it is fed by means of dosing 9 and transportation 12 to one of the mixing reactors 4 (gravity or forced mixing) where water is dispensed by dispenser 5 and mixed until the lime is completely "quenched".

In order to ensure continuity of the cycle and to ensure the mode of "blanking" in the line, it is planned to install two reactors 4, made in the form of mixers, operating cyclically - during operation of the first reactor-mixer, the second is loaded and vice versa.

Reception of iron-containing waste of metallurgical production is carried out in a container 6 for receiving iron-containing waste of metallurgical production, from which transport means 12 transmit in a predetermined ratio, taking into account the preparation of the mixture with a moisture content of 8-10%.

The total preparation time of the batch is 5-6 minutes.

The prepared semi-dry mixture by means of feed 8, for example, by a conveyor belt, is fed into the briquette formation system 7, consisting of feeding mechanisms 10 and briquetting 11.

After forming, raw briquettes on technological pallets are placed in containers and transferred to hardening stations. After 12-14 hours, the briquettes are unloaded into the hopper and from the hopper, as they accumulate, into the dump truck and transported to the consumer (blast furnace or steel workshop).

The use of the invention provides the disposal of aspiration lime directly at the place of its formation, which eliminates the negative impact of dust on the environment, reduces the cost of transporting dust, eliminates the use of special delivery vehicles, and also allows you to get a product with new consumer properties - iron-containing slag-forming briquettes used in metallurgical process as a substitute for burnt lime. This allows you to reduce production costs in the production of cast iron or steel by replacing some of the components with waste briquettes, and reduce the cost of waste disposal.

Claims (2)

1. The line for preparing the material of the metallurgical charge, including a device for collecting fine-grained limestone calcining waste in the form of suction lime from the exhaust gases from the calcining unit and a lime collecting tank, a briquette forming system consisting of feeding and briquetting mechanisms, characterized in that it contains one or more reactors in the form of a mixer with a water dispenser, a container for receiving iron-containing waste from metallurgical production and hardening stations, the reactor / reactors being connected / connected anes with a container for receiving the iron-containing waste and the container for collecting lime dosing and conveying means, respectively, and iron-containing waste with lime forming system briquettes supply means resulting in a reactor / reactors a mixture of slaked lime and iron-containing wastes. 2. The line according to claim 1, characterized in that as a mechanism for briquetting the material contains a vibrating press.