SU692856A1 - Method of sintering iron ore materials - Google Patents

Description

(54) METHOD FOR DIVIDING IRON ORE MATERIALS

The invention relates to the iron ore raw material for the production of iron and steel and can be used mainly in the sintering of iron ore materials. Known methods of sintering the mixture with sucking oxygen-enriched gas or air (1. The disadvantages of these methods are that they only affect the sintering process by changing the composition of the suction gas-gas phase without associating with the parameters of the physicomechanical structure of the layer. As a result , when sintering the mixture according to the indicated method, oxygen is used inefficiently to intensify the sintering and to improve the quality of the agglomerate. and the achieved result is a method of agglomeration of iron ore materials, which reduces the supply of oxygen from the beginning to the end of the sintering process. However, this method of increasing gas permeability is associated with the deceleration of the burning rate of the fuel, since the degree of enrichment of air with oxygen is minimized (0.02 MVM). The aim of the invention is to increase the specific productivity of the specular aggregates and to improve the quality of the agglomerate. The goal is achieved by the fact that for each percent increase in the oxygen content in the mixture in excess of 4-10%, the initial charge size is 1.4-1.8 mm, increase by 0.07-0.1 mm, and when heat is supplied from an external source in excess of 12000 kcal / m, the particle size of the charge is further increased by 0.02-0.05 mm for every 5000 kcal / m, while reducing the consumption of solid fuel by 0.25-0.5% (abs.). When sintering a two-layer mixture for each percent increase in the oxygen content in the mixture, the particle size of the lower layer is increased by 0.0 5-0.07 mm, and the top layer by 0.09-0.11 mm, and

with an increase in the heat supply from an external source in excess of 12000 kcal / m, in addition to increasing the size of the pelleted charge, the fuel content in the upper layer charge is reduced by 0.25: 0.75% (abs.) for every 5000 kcal / m of heat input,

; The criterion that establishes the correspondence between the oxygen concentration in the gas that is sucked through the layer and the crucible of the charge is the temperature-heat sintering regime according to the height of the layer. The optimal sintering mode is such that it ensures the same heating and cooling conditions at all horizons of the bed. The technological parameters of the sintering process must ensure constant temperature conditions throughout the entire high-baking layer. This is achieved by the fact that at a given oxygen concentration in the heated gas-air mixture, the parameters of the pelletizing mode, for example, the moisture content of the charge, the amount of lime and fuel supplied by rolling on the pre-pelletized charge, are set such that the pelletized charge size satisfies the heat transfer condition. The effect of the coarse load of the charge on the velocity of the heat wave and the distribution of temperature fields is caused by the dependence of the total heat transfer coefficient on these two specified values. The maximum temperature at any Horizon of the sintered layer at the hot point. Experimental sintering of the charge from, magical concentrates into agro-ores in ratios 1: 0 0.5: 6.5; 0: 1 at a constant e & hold a return of 20% and the basis

These conditions depend on the speed of the heat wave. As the gas filtration rate increases, the maximum temperature at the bottom of the bed decreases to a greater extent than at the top of the bed. Consequently, the oxygen content in the gas-air phase of the heating devices (s; fiery furnace, additional gas-burning device), the amount of heat from these devices, and the amount of solid fuel consumed and the particle size of the blended mixture are effective factors for controlling the temperature-heat mode of the sintering process. In theory and practice of sinter production, it is known about the relationship between the consumption of solid fuel for sintering and the degree of oxygen enrichment of the gas to be sucked. Under production conditions, the grain size of the pelleted charge can be determined by the equivalent diameter, calculated as the average harmonic value according to the particle size distribution of the charge, or by a continuous method, by measuring the gas permeability of the charge column in the feed hopper.

Table 1 presents the experimental data of the initial parameters and the optimal oxygen content in the heated gas-air mixture, which satisfies the condition of constant temperature-heat regime along the height tslO For various sizes of the bath mixture:.:.;. :,. ...;

T a b l. and c a 1

equal to 1.2. The data of experiments on the sintering of the mixture containing 100% of the Lebedinsky GOK concentrate in the iron ore part are given in Table 2.-g In the initial mode 1 (generally accepted sintering technology), the OjB content of the gas-air mixtures was left at 7.2%. Modes P and ly fijO with the prototype of a love) reflect the effect of 5 o with oxygen, when the charge capacity is constant - mm. In order to obtain comparative data, parallel studies were carried out with the addition of the charge size to 2.4 and 3.2 mm (modes W and W, according to the curve). Modes 1U and U are different from each other (they eat the heat of your source, they were determined at their own stage. sa and indicators of the strength properties of the sinter .. As can be seen from the table, the proposed method provides maximum performance with high product strength. Use the proposed method of snapping iron ore materials ivaet compared to existing methods the following advantages: the ability to obtain high speed sintering and specific productivity by 24% during sintering;

Claims (2)

Table 2 and a reduction in fuel consumption by 6%; increase the strength of suitable sinter; which almost doubles the efficiency of using oxygen to increase the specific productivity of aggregates and improve the quality of the agglomerate. The economic effect from the implementation of this method at the Novo-Lipetsk metallurgical plant is estimated at a calculation of 4,795,000 rubles / year. Claims 1. Method of bite iron ore materials, including mixing, pelletizing with the addition of water, rolling fuel and lime and sintering one or two layers with suction of gases and air enriched with oxygen using heat from an external source Since in order to increase the Specific productivity of the sintering units and improve the quality of the sinter, for each percent increase in the oxygen content in the mixture in excess of 4–10%, the size of the initial mixture equal to 1.4–1.8 mm increases at 0.07–0.1 mm, and when Heat is supplied from an external source in excess of 12,000 kcal / m, the charge size is further increased by 0.02–5 0.05 mm for every 5000 kcal / m, while reducing the consumption of solid fuel by 0.25-0.5% (abs.), 2 The method according to p. 1, about tl and h and yats and the fact that during sintering two-Yichny imkhty Per kgikdyy percentage increase in the oxygen content in the mixture the size of the lower the layer is increased by 0.05-0.07 mm, and the top one by 0.09-0.11 mm, and with an increase in the heat supply from an external source of 12000 kcal / m, the particle size of the charge additionally increases by 0.02-0.05 mm and lowers the fuel content in the upper layer on the charge 0.25-0.75% (abs.) per 5000 kcal / m Incoming heat. Sources of information taken into account in the examination 1. USSR author's certificate 346340, cl. From 21 To 1/06, 1972, 2. USSR author's certificate 502965, cl. From 21 to 1/16, 1976.