SU894007A1 - Method of agglomerating iron-containing materials - Google Patents

Description

The method is carried out as follows. Carbonaceous dust, in particular koloshnikov,. its preliminary preparation is not used as a component of the charge, but as an additional coolant (from burning carbon of the fuel) supplied to the mixture with an oxygen-containing agent to the zone of the highest temperature of the hearth. Koloshnikov dust contains in its composition 15-20% of carbon solid fuel and oxides of metals, mainly iron. The fine dispersion of dust makes it possible to ensure complete combustion of the carbon of the fuel at the ignition stage, heating and expansion of the iron-containing part of the dust with subsequent layering of the melted droplets on the surface layer of the charge. In addition, the supply of the top part under the incendiary horn will significantly reduce the consumption of gaseous fuel required to ignite the charge. The removal of flue dust from the sintering mixture provides a high degree of pelletizing of the charge and good t. : One gas-dynamic conditions of the process. One of the distinguishing features of the proposed method is to feed a mixture of top dust and oxygen-enriched air into the zone of the maximum temperature of the incendiary hearth. The zone of the highest temperature of the coolant (1 ° C) from the combustion of gaseous fuel (a mixture of blast furnace gas and industrial gas) is located at a distance of 60–40 mm from the surface layer of the mixture. On other furnaces equipped with flat-flame burners, the distribution of the temperature field along the height of the torch is almost the same, with the exception of areas located in close proximity to the surface of the charge. For complete and efficient combustion of carbon from flue dust. In the ignition zone, a certain period of time is necessary, due to the place where the mixture of dust and oxidant is blown into the ignition zone and so. By the main coolant circuit, for ordinary incendiary furnaces, the greatest effect is achieved, and the combustion of the blast dust from carbon is achieved when it is fed to the zone of maximum temperatures. For horns equipped with flat-flame burners, the place of supply of the top furnace should be located at a distance of 20О-ZOO mm from the surface layer of the charge. The location of the entry of a mixture of flue dust and an oxidizing gas is a necessary, but not sufficient condition for increasing the efficiency of disposal of food and for more complete burning of carbon in the fuel. The completeness of the combustion of carbon from flue dust, which ensures the preset ignition temperature, is achieved only if oxygen is enriched with air, and the content of the latter should be 50-60%. A decrease in the concentration of oxygen in the air leads to a decrease in calorimetric temperature and temperature above the charge layer, which violates the conditions of the thermal conditions of the furnace, leads to an increase in gas consumption and deterioration in the quality of the top of the cake. An excessive increase in oxygen requires the development of new design solutions for a gas-burning device and high capital costs. J Another distinguishing feature of the proposed (Lagged method is the ratio between the consumption of gaseous fuel and carbon flue dust, expressed by the amount of heat supplied from each coolant. This ratio is closely interrelated with both oxygen depletion in the air and the incendiary hearth. The optimum amount of flue dust blown in a mixture with oxygen-enriched air should be 6-12 kg / g sinter (0.6-1.2 t / h), while the amount of heat from burning 15% of the carbon in the dust is O, 1.4 10 O kcal / h. With the total amount of heat supplied to the ignition of the charge equal to (3.5–3.6) x1 O kcal / h, the ratio between heat from burning gaseous and solid fuels is 1: (0,2-O, 4). The introduction of top dust in the amount of 6-12 kg / ton of sinter (0.6-1.2 t / h) reduces the consumption of natural gas at 31-32. At the same time, the ignition temperature remains at a predetermined level and is. A reduction in the flue dust consumption below optimal values does not lead to an improvement in the technical and economic indices of the process due to the fact that, firstly, the cost of enrichment with oxygen is not compensated by a slight decrease in the consumption of natural gas.

gas by blowing in flue dust and, secondly, the return yield from the upper layers of the cake remains at the same level. In addition, the use of flue dust as an additional coolant is not balanced with respect to the output in the blast furnace smelting process. Therefore, the bulk of flue dust (about 7%) must be introduced into the charge.

An excessive increase in the consumption of colds {1IKOVA dust accompanied by a decrease in the resistance of the hearth due to burning of particles and melting of iron oxides on the surface of the lining of the hearth, the development of liquid phase transformations and shielding the surface of the charge melt, worsening gas dynamic conditions of the process, as well as high oxygen consumption. the development of a fundamentally new incendiary horn design.

Example. Studies on the use of flue dust as an additional coolant were carried out under industrial conditions on an sintering machine. For this purpose between the mountain and the reflection sheet at a height of 1.6 m from

Indicator

the surface of the charge set capacity of 0.6 m in which the flue dust is manually loaded. containing,%: carbon 12,15; a37.3;

CaO 8.13; 5 Oa 9.17; AtpOa 0.69 and M & A 1.52.

The lower conical part of the vessel is connected via a pipeline with an ejection device, working on

mixture of oxygen and compressed air. Possessing high fluidity, the blast furnace dust enters the ejector, is captured by the air flow and blown under the incendiary horn. The opening angle of the ejector ensures an even distribution of dust across the width of the hearth.

The consumption of top dust varies within 3,6,9,12,15 kg / t sinter

in increments of 3. Compressed air is supplied with oxygen up to 50-60%. Each experimental period after the stabilization of the dust supplying mode lasts for 1 hour. At the same time, samples of the sinter are taken and the performance of the sintering tape is recorded.

The research results are presented in the table.

Flue dust consumption per ignition

Output class 1.6 mm after the second drum

Reduced gas consumption for ignition,

Ignition temperature, “С

The yield of sinter,%

Performance,

T (/ H

Drum sample,%

An analysis of the data in the table shows that the removal of all top dust from the charge (columns 4–6) allows for 29,228.3 17.9 12.4 12.3 12.3

O 6.0 31 48 62 62

125О 1200 1250 125О 1250 12ОО

57, O57.3 67.8 68.0 68, O 67.5

1.51.51 1.62 1.62 1.63 1.60

19,319.0 14.2 14.3 14.0 14.1

Claims (1)

to improve the technical and economic indicators of the preparation and sintering of the charge. The quality of pelletizing is improved, the yield: the 1.6 mm class is reduced compared to the base period (1) by 11-16 a6ci%. Significantly reduced. gas flow at an eaigigate increases the yield of the suitable one (due to the higher strength of the top of the cake) and the specific productivity by 7.3-7.9%. The strength of the sinter increases by 4-5 abs.%. Claims method with aggly ashga and sand-containing materials, including using carbon dust, dosing of components, mixing them, wetting, pelletizing, igniting carbon fuel and the main gaseous coolant and sintering it, characterized in that, with the efficiency chain, the furnace head and converter will be sintering, characterized in that with an efficiency head chain and a sintering sintering chain, which uses an open furnace head and a sintering chain, characterized in that, with the efficiency chain, the furnace head and converter will be sintering, characterized in that with an efficiency chain, the furnace head and converter will be sintering, characterized in that it uses a brazed furnace and a sintering chain to increase the efficiency of using a brass furnace and a sintering unit, characterized in that it uses a head furnace and a sintering chain, which increases efficiency and uses a furnace head and a sintering unit, which is characterized in that it uses a head furnace and a sintering chain in order to increase the efficiency of using a brazier and converter. and improving product quality, carbonaceous dust is blown into the zone of maximum temperature of the main heat carrier at the ignition stage, while simultaneously entering into zone at the oxidant gas, the amount of heat from the additional teplonsitel osnoshgogo and maintained in the range 1: (0.2-0.4) and the information sources, the received note in the examination № 1. Australian Patent 297787, cl. 184, 1968.