SU855037A1 - Charge for producing fluxed pellets - Google Patents

Description

The invention relates to ferrous metallurgy and can be used for the production of spore pellets. The known charge for the production of pellets, containing iron ore material, flux, carbon, binder and alumina iron ore in an amount of from 2 to 15% by weight of the dry mixture. Raw pellets are characterized by increased strength of li 1. The disadvantage of this mixture is the low degree of sulfur removal during roasting due to the increased fuel content ... The closest to the invented technical essence is that for the production of fluxed tatters 2, consisting of iron ore concentrate, lime, siderite ore and magnesium chloride in the following ratio of components, wt.%: Lime 2-8 Siderite ore 5 LASTY magnesium 0, 2-1.0 Iron ore end nitrate Remaining The disadvantages of this charge are low sulfur removal during roasting, due to the secondary formation of calcium sulfate (60-75%) and increased abrasion of the calcined pellets during recovery. The purpose of the invention is to increase the degree of sulfur removal and decrease octogenic acidity during reduction. The goal is achieved by the fact that the charge additionally contains solid fuel at the following ratio of components, wt.%: Known to 4.5-12.0 Sideritic ore 0.8-5.6 Solid fuel 0.9-3.0 Iron ore concentrate-lower Lower and the upper (i.e., 4.5 and 12%) limits of limestone content in the mixture are determined by the minimum and maximum content in iron ore, silicon dioxide concentrates while maintaining the CaO / SiO2 ratio in the 1X 1.0-1.2 limit. The lower limit of content in the charge of siderite ore, i.e. 0.8% depends on the concentration of sulfur in the iron ore material and provides high strength pellets and the degree of sulfur removal of at least 80%. Upper limit of siderite ore content, 5.6%, depends on the content of MDO

in iron ore concentrate and provides a CaO + MgO / SiO ratio of no more than 1.5. With a higher content of siderite ore, the indicators of blast-smelting deteriorate at 100% pellets in the charge.

The lower limit of the content in the solid fuel mixture, i.e. 0.9% is due to the production of pellets with a magnetite structure during roasting, which is a necessary condition for reducing the abrasion of the pellets. With a smaller consumption of solid fuel in the pellets, hematite is produced, which leads to a sharp deterioration in the strength properties and decreases the degree of sulfur removal, the upper limit of the solid fuel content, i.e. 3.0%, due to „production of pellets with wustite structure. With a higher content of solid fuel, the degree of removal decreases.

sulfur.

Example. I make pellets

of the proposed charge components (Table 1) in a drum granulator with a diameter of 350 mm. As a solid fuel, a sinter coking fraction of 0.1 mm is used. Raw pellets are burned on a bowl-horn installation with a bowl diameter of 450 mm at 300–1300 C. Burned pellets are tested for durability according to GOST 1957574 and the content of residual sulfur and FeO are determined by chemical analysis. The test results are shown in Table. 2

As the results show, the proposed composition of the charge improves the degree of sulfur removal in the pellets from 74.3 to 80.2-93.6% and reduces the rate of abrasion during reduction (output of cells 0.5-0.0 mm) from 17.2 up to 10.1-2.2%. Thus, the invention makes it possible to significantly improve the metallurgical properties of fluxed pellets.

The mixture can be used for the production of fluxed wusite-magnetite pellets at the Sokolovsko-Sarbai and other GOKs ,.

Table 1

Iron ore

concentrate I 66.40 28.3 63.5 1.16

Iron ore

4.01 1.24 1.00 0.39 0.56

table 2

Claims (2)

1. Authors certificate of USSR 260641, class, C 22 V 1/24, 1967. 2. Authorship certificate of the USSR 635148, cl. From 22 to 1/243, 1976.