RU2010874C1 - Agglomeration production method - Google Patents

Abstract

FIELD: ferrous metallurgy technology. SUBSTANCE: sintering material is cooling at furnace top grill after grinding at temperature 900 C. Agglomerate is caking by sinter burden firing in blast regime. Carbon oxide of waste gas is firing by pure oxygen mixing by gas blasting. EFFECT: more effective processing. 1 dwg

Description

 The invention relates to metallurgy, in particular to methods for pretreatment of ore fines by sintering on a grate.

 A technical solution is known in accordance with (1), characterized in that a cold bed, an agglomeration charge and a hot bed removed after sintering the sinter charge are laid on a moving grate.

The disadvantages of the described method are that:
temperature hot bed layer does not exceed 600 ^{° C,} so it can not serve as an igniter layer had to spend fuel in the hearth sintering machine;
flue gases are not cleaned from gas pollution.

 There is also a known method for the production of agglomerate, adopted as a prototype, characterized in that an agglomeration charge with a non-sintering layer is laid on the outside of the heated ignition layer, by which agglomerate is then divided into cold and hot streams. The cold agglomerate is crushed, and the hot agglomerate is crushed and cooled.

The disadvantages of the prototype are as follows:
high fuel consumption spent on heating the ignition layer;
the heat of sinter is not utilized;
in sinter gas, carbon oxides are not neutralized.

 The aim of the invention is to improve the quality of the sinter, saving fuel and improving the environmental situation.

This goal is achieved by the fact that in the method for the production of sinter, including laying on a moving grate the ignition layer and the sinter layer, sintering the mixture, separate unloading the ignition layer and sinter cake, crushing and screening and cleaning the exhaust gases, sinter after crushing with a temperature of more than 900 ^o C is cooled on the grate, using as the ignition layer, while carbon monoxide in the exhaust gases is burned by mixing with O ₂ -containing gases.

 The drawing shows the implementation of the proposed method.

The method is as follows. In the hopper 1 serves crushed agglomerate fraction 0-100 mm at a temperature of more than 900 ^about With the help of technology used, for example, for dry quenching of coke. The agglomerate is laid on the movable grate 2 so that segregation of pieces of material takes place and large pieces appear from below, and fines from above. Then, agglomerate 6 is fed to agglomerate layer 3 from bunker 4 with a chisel 5. Layers 3 and 6 are blown from below by air supplied by exhauster 7 rigidly connected to movable blast chambers 8 and grate 2. As a result, the crushed agglomerate is cooled, and the agglomerate is sintered. The layers of the cake and the ignition layer are separated by a knife 9. The cake is passed through a crusher 10 and crushed to a piece size of less than 100 mm, loaded into a lined carriage 11, delivered to the lift 12, lifted and put into the hopper 1.

 Partially chilled agglomerate of layer 3 is passed through a screen 13, separated into fractions +10 and -10 mm, fractions are separately cooled: coarse on a linear cooler 14, and fine in a drum 15. Chilled agglomerate of a fraction +10 mm is fed to a blast furnace, and fractions are fed 10 mm - into the charge compartment 16.

Sintering gases above the bed 6 is collected in a gas collecting chamber 17 and directed to the afterburner chamber 18. The secondary blast is introduced last 19. As a result of intensive mixing CO-containing gas with air at a gas temperature of 850 ^{° C} carbon monoxide and other organic compounds - impurities burn .

Then sintering gas is sent to a heat exchanger, which is, for example, a two-chamber layered lime kiln. The original limestone is fed from the hopper 20 by the dispenser 21 into the firing chamber. In it, hot gases from chamber 18 are filtered through limestone-irrigation fractions of 15-30 mm and the raw materials are decarbonized. The products of firing are sucked off by a smoke exhauster 22 through a pipe 23, a waste heat boiler 24 and a gas purification 25. Lime is lowered in a layer into the cooling chamber 26, where air is blown through a layer of lump lime with a fan 27, which is then also taken through the pipe 28 to a waste heat boiler 24. During firing lime sulfur oxides contained in sintering gas are bound to sulfates at a temperature of 900-1050 ^о С.

 The shelter chamber of the crusher 10 is aspirated, the suction is removed by the exhaust fan 29 through a gas treatment 30.

An example implementation of the method. The movable grate serves 125.3 t / h agglomerate fraction 0-100 mm at a temperature of 1000 ^C. On the agglomerate stack 143 t / h sinter mix (dry basis) moisture 7.4%, containing 5.17% carbon. Agglomerate and charge are blown from below with air with a flow rate of 60 thousand m ³ / h. After 18 min crushed agglomerate is cooled to an average of 231 ^C and sintered agloshihta, wherein the sinter temperature is 1020 ° ^C and igniting Aglospek layer separated, after which the crushed material is passed through a screen and classify Grains 10 mm. Major fraction (100 t / h) and a fines fraction (25.3 t / h) are separately cooled to 50-70 ^° C Aglospek crushed and is cooled on the lattice.

Sintering gases leaving the bed have a temperature of ^about 1000 C. Their intensively mixed with the secondary air flow rate is equal to 10% by volume aglogazov (1.0074 m ³ / kg sinter). As a result, the oxygen content is raised to 5.16% and carbon oxide (2.49% by weight) was burned, and gas temperature rises up to 1153 ^C. They were fed to heat exchanger and is cooled in a known manner. If sintering gases are used for calcining lime, then they are purified from sulfur dioxide.

The advantages of the offer are due to the following:
sinter cooling on the grate of the sinter machine allows to reduce heat loss with cake from 32 to 8.65%;
utilized heat of burning of sulfur and carbon, oxidation of iron during cooling of the sinter;
environmental pollution is prevented due to the cooling of the sinter;
the quality of the agglomerate, which is slowly cooled at high temperatures on the grate;
increase the heat recovery and the degree of its transfer cake aglogazam raises their temperature on leaving the bed of 500-550 ^o C to 1000 ^o C, this creates the possibility of afterburning of carbon monoxide in aglogazah without consuming additional fuel;
it becomes possible to use any low-sulfur coals in the sinter charge instead of coke, since volatile and tar will be burned together with CO;
a waste heat boiler or a waste heat due to increase of exhaust gas temperature is effectively used from ^about 450-550 C to 450-550 ^C;
a powerful igniting layer prevents the formation of channels in the sinter charge, since the sinter acts as a throttle that evens out the air flow over the cross-section of the grate;
dust carried out from the ignition layer is captured in the sinter charge. (56) Copyright certificate of the USSR N 931769, cl. C 22 B 1/16, 1980.

Claims (1)

METHOD FOR PRODUCING Agglomerate, including laying on a moving grate the ignition layer and the sinter layer, sintering the mixture in the blast mode, separate unloading the ignition layer and the sinter layer, crushing, screening and cleaning the exhaust gases, characterized in that, in order to improve the quality of the sinter , fuel economy and environmental improvement, after crushing the agglomerate to a temperature of 900 ^o C is cooled on the grate, using as the ignition layer, wherein the oxide uglero and afterburning in flue gases by mixing them with O ₂ -containing gas.

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