SU870466A1 - Method of charge preparation for sintering - Google Patents

Description

(54) METHOD OF PREPARATION OF CHARGE TO SINTERING

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The invention relates to the field of preparation of ores and concentrates for smelting and can be used in ferrous and non-ferrous metallurgy during agglomeration.

The known method of preparing the sintering mixture by two-stage mixing and preliminary ozero. In the first mixing stage, a group of components is supplied, consisting of a larger share of the ore part of the charge (ore, return, limestone) without fuel and all the water necessary to obtain the optimum moisture content of the total charge, and pelletized to obtain waterlogged grains charge. In the second stage of mixing, the moistened grains (lumps) of the charge are introduced, the remaining fraction of the ore charge, the wet moisture and pelletized

The disadvantage of this method is the deterioration of the granulometric composition of the charge, due to the deliberate overwetting of its most part in the primary mixer-pelletizer, which is difficult to fix in the secondary sanifier-oxide collector.

The closest in technical essence and achieved 1 result

is a method of preparing the sinter charge for sintering, according to which the components of the charge are separated. on two groups on durability received -. These granules from this mixture, with a strength of more than 140 and less than 120 g / pellet, respectively, moreover, the weight ratio of groups of components is maintained in the range of 60-40: 40-60. Komlokentg

10 each group is metered onto conveyors, mixed separately and pelletized at optimum moisture content of the components of the group, with greater granule strength, and at a moisture content of up to 3%

15 less optimal for the entire charge of moisture content in the other group of components, then both groups are combined and finished and mixed and mixed at optimum humidity. First group

The 20 components, which include the concentrate and limestone in the ratio of 7525: 62, 5-37.5, are moistened to 9.0-9.5% with the supply of 1.3-2.6% water. The second group of components, which includes

25 concentrate, sludge, agglode, return, fuel, practically not moistened when mixed 23

The disadvantages of the method are the reduction of the gas permeability of the sintered

30 layers and a decrease in the specific productivity due to the deterioration of the granulometric composition of the charge, as well as a decrease in the quality of the agglomerate due to the deterioration of the distribution in the mixture of fuel and lime. Thus, an increase in the moisture content of the first group of components by 1.3–2.6%, which is mainly represented by a concentrate with a moisture content of 10%, leads to its overwetting, deterioration of the particle size distribution and distribution of limestone in it. At the same time, the presence in the second group of such wet materials as a concentrate with moisture 10%, fuel with moisture up to 15%, sludge with moisture up to 25%, even without water supply when mixed, leads to uneven distribution of moisture in this group of components the formation of large (more than 10–15 mm) cores with fuel rolled up inside them. At the same time, the combination of two groups of components in the secondary mixer with additional moistening cannot significantly improve the particle size distribution of the total mixture and the distribution of fuel and lime in it. The aim of the invention is to improve the gas permeability of the sintered layer and increase the specific productivity of the sintering process. The goal is achieved by the fact that in the method including separate dosing ,. mixing, moistening and pelletizing of the charge components, combining, mixing and refining of the entire charge, dividing the components of the iron ore flux part of the charge into two groups. Produce at a rate of wetting with water, respectively, at intervals of 1.3-0.64 "U and 0.6 -0.25 CMVceK-10 and the weight ratio of groups of components is within (32-50) :( 68-50), after which the components of the first group are metered, mixed and moistened to 4-5%, the components of the second group are dosed, mixed and pelletized to the size of the components of the first group at the optimum for rh NOSTA caking and coke fines are introduced after combining groups of components when dookomko Vania. The proposed method was tested on the two most common types of iron ore sinter charge: a multicomponent and a single component. Example 1. A multicomponent agglomeration mixture consisted of the following components,%: Concentrate of SSGOK Concentrate of Kacharsky GOK Aglorud Margantsev ore Known to Koksik Return, Preparation of the charge was, in the following. Components of the charge on the basis of the rate of wetting with water (see tab.1) were divided into two groups. The wetting rate of the charge materials was determined by the method of capillary suction of a layer of dry material with a particle size of less than 0.2 mm in a known Buzago instrument, with horizontal movement of water. The first group included agglome, limestone, manganese ore and return. In the second group - concentrates of Sokolovsky-Sarbai and Kacharsko) -. , GOKOV. The ratio of groups of components tov was 50:50. The components of the first group were separately metered and mixed for 1.0 min., In the mixer when humidified, up to 5.0%. The components of the second group were separately metered, mixed in 1.0 min and pelleted for 1.5 min, and the optimum moisture content for pelletizing (8.7–9.3%) to the size of the components of the first group, i.e. up to a maximum size of 6-7 mm. Then, the first and second groups of components were combined, mixed, and refined for 1, O min at the optimum moisture content of the charge (6.77, 0%) -; The fuel was introduced by combining the groups at the end of the pelletizing. The rest of the procedure for experimenting remained unchanged. The sintering of the prepared mixture was carried out at the sintering plant, which allows sintering of the charge in an amount of 50 kg in a 300 mm layer at a time under vacuum under the grate up to 1400-1450 mm water column. Indicators of sintering the mixture of the same composition, prepared by the prototype and the proposed method are given in table. 2. The results of the study indicate that the preparation of the mixture according to the proposed method made it possible to improve the granulometric composition of the mixture, for example, the content of the class + 5 mm was reduced twice from 20.8 to 10.2%, the class 1-0 mm by 6.8% from 26.0 to 19.2%, in connection with which the gas permeability of the sintered layer increased (the value of the average and maximum value of the vacuum under the grate decreased). The specific productivity increased by 10% from 1.05 to 1.16 tons. Example 2. A single-component (by iron ore) sintering mixture consisted of. The following components, ponentov,% Concentrate Kachkanarsky GOKa 65.0 Known k6.0 Koksik4.0 Return 25.0. Preparation of the charge was as follows. According to the magnitude of the siaking rate (see Table 3), the components of the charge were divided into two groups. The first group entered known and return, the second - Kachkanarsky concentrate. The ratio of groups of components was 32:68. The components of the first group were separately dosed and mixed for 1 minute at a temperature of 4.0-5.0%. The concentrate was dosed and pelleted to a size of 5-6 mm for 1.5 minutes at an optimum moisture content of 8.8-9.2%. Then, the first and second groups of components were combined, mixed, and made up to the optimum moisture content of the total Chihuah (6.46, 7% 4. Otherwise, the experiments were carried out similarly to Example 1. The sintering parameters of the same composition prepared using the Sokolov concentrate Concentrates

table 2

Prototype

The proposed method and the proposed method are presented in Table 4 ... Preparing a one-component mixture for sintering according to the proposed method allows to improve the particle size distribution of the mixture, thus reducing the content of the class + 5 mm from 20.2 to 9.5%, i.e. 2.1 times, due to which the gas permeability of the sintered layer has increased ( the value of the average and maximum vacuum values under the grate was reduced.) The specific sintering process productivity increased from 0.8 to 0.92 t / m, i.e. by 15%. Thus, the proposed method of preparation of the charge makes it possible to increase the gas permeability of the sintered layer and the specific productivity of the process by 10–15% due to an improvement in the composition of the charge: a decrease. class output +5 2 times and class 1-0 mm 1.3 times. I T a b l i-c a 1

Concentrate Kachkanarskohche

GOKa.0,60,55

Vls1zhnost charge%

Granulometric composition +10 mm of the charge, the output of classes,%,

10-5 mm

5-1 mm

1-0.5 m

-0.5 mm

Specific performance

The vacuum under the grate, mm.vod.st.

Claims (2)

The invention of the method of preparation of the charge k sintering, including separate dosing, mixing, wetting and pelletizing KoivinoHeHTOB charge, the subsequent merging of the groups of components into a common charge. mixing and finishing it, about t-60 characterized by the fact that, in order to increase the gas permeability of the sintered layer and increase the specific productivity, separation of the components of the iron ore flux part 65 Table 3 0.480.42 Table 4 6.5 1.0 8.0 65.4 18.4 6.7 0.92 The charges are produced in two goopps with a rate of wetting with water, respectively, in intervals of 1.3-0.64 cmK 0.6-0.2 cm VceK .. 10-, and. the weight ratio of the groups of components is maintained within (32-50):: (68-50), after which the components of the first group are moistened to 4-5%, the components of the second group are pelletized to the size of the components of the first group at optimum moisture content, and. coking is introduced after combining 987046610 no groups of components for dookokom- 1. Patent of England 967004, Vania .. C1A, 1962. Information sources, 2. USSR author's certificate (taken into account during the examination. 5.84048, -kl. from 22 in 1X13, 1975.