SU597718A1 - Method of blast furnace smelting - Google Patents

Description

(54) METHOD OF BLANKING BLASTING undergone aggregative changes. The blast furnace shaft, the difference between gas and charge temperatures is minimal, is called the zone of slow heat exchange and is located at a height of 4O-5O% of the furnace height from the level of air tuyeres to the level of rash. The value of the gas injection level, which is more than 5% of the height, refers to furnaces operating at atmospheric pressure and 4% to furnaces operating with an increase in the oxygen concentration in the blast, and with an increase in the enrichment rate of oxygen blowing, the height of the zone of slow heat exchange decreases; the gas in this zone is close to equilibrium with respect to iron oxide (the degree of equilibrium with carbon monoxide is about 8%; hydrogen is about 10%) and contains about 10% carbon dioxide and water vapor. If it is assumed that the gas flow in the shaft is about BS. or and m / min of carbon dioxide and water vapor, and each lance supplies hydrocarbons per m, according to the equation about the cue CH + C02 (H20) -2CO (CO) + 2H. (3N) 3 you can serve 6 m / min methane per lance, this produces 4 times more reducing gas than methane is supplied. The gas mixture formed here will have much more CO and hydrogen than the original kiln gas, and its reduction potential increases as the use of reducing agents improves and the degree of indirect reduction increases, which ensures a reduction in coke consumption. Example. Experienced melting wire. on a blast furnace of 1719 Krivorozhstal plant. In this furnace, the zone of slow heat exchange is at a level of approximately 0.4 to 5 of the height of the furnace from the level of air to the level of grist. The diameter of the mine at this level is 894 mm; Mine tuyeres are introduced to a depth of about 165 mm. Through them serves 15OO2OOO m / h of natural gas. The results of melting without the supply of natural gas to the mine (comparable period) and with its supply in the amount of 150О-2ООО m / H (experimental period) are given in the table. As follows from the above data, due to the improved utilization of the reducing energy of the gas, the productivity of the furnace increases by about 2%, and the coke consumption is reduced by 6.8%.

Performance accounting data, tons / day

Capacity, reduced to the same conditions, t / day

Coke consumption, kg / t of pig iron

Guna

ABOUT

Oxygen consumption, m / cast iron

Temperature blow, ° C

Downtime,%

Silent moves,%

Reduced coke consumption, kg / t

cast iron

Change in coke consumption, kg / t of pig iron

Productivity change, t / day

The oxygen content in the blast,%

3 Consumption blow, m / min

ZOOZ.b 289O, 5

3063.6

ZOOZ.b 487 527

491.0 -36.0

+ 6O, O

44.9 2786 5 "

Claims (1)

Claims of the invention of coke, natural gas is fed into the blast furnace smelting process, including the radius of the mine. supply of natural gas to the kiln’s shaft above Level of air tuyeres, I distinguish-5 mania during examination: yi and with the fact that, in order to raise I. Japan Patent No. 334О7, the degree of use of gas in the furnace and eco-class. Since 21B, 1972. 597718 that furnace at a depth of 0, 3-O, 4 internal