RU2365640C2 - Briquette for obtaining zinc half-finished product during cast iron smelting - Google Patents

Abstract

FIELD: metallurgy. ^ SUBSTANCE: invention relates to ferrous metallurgy, namely to the composition of the briquette for cast iron smelting for obtaining zinc half-finished product. The briquette contains slurry of the blast furnace gas cleaner as carbonaceous, ferriferous and zinc-containing material with cement being a binding substance. The components in the briquette are in the following ratio, wt %: slurry of the blast furnace gas cleaner - 82-96, cement - 4-18. ^ EFFECT: output of the zinc half-finished product as collected dust with a high content of zinc. ^ 1 tbl

Description

The invention relates to ferrous metallurgy, and specifically to the composition of a briquette for smelting cast iron to produce an intermediate for the zinc industry.

Known as a prototype [1] charge for the production of carbon-containing iron ore briquettes, including sludge from metallurgical industries and blast furnace dust, characterized in that it contains components in the following ratio, wt.%:

sludge of metallurgical industries 70-95 blast furnace dust 5-30

Significant disadvantages of this mixture are:

- low mechanical strength of the briquette due to the lack of ligaments;

- low content of zinc components in the briquette to obtain an intermediate for the zinc industry.

There is also known a method of processing and obtaining raw materials for the production of zinc [2], the main source for which are sulfide polymetallic copper-lead-zinc, lead-zinc and copper-zinc ores. A significant disadvantage of this method is the high cost of production of raw materials due to mining, complex processing and processing of ore components.

The desired technical results of the invention are:

- obtaining an intermediate for the zinc industry in the form of trapped dust with a high zinc content;

- efficient disposal of industrial waste.

For this purpose, we propose a briquette for producing a zinc intermediate in the smelting of pig iron, including carbon-containing, iron-containing and zinc-containing materials, as well as a binder, in which blast-furnace gas treatment slurries are used as carbon-containing, iron-containing and zinc-containing materials, and cement is used as a binder in the following ratio of components, wt .%:

blast furnace slurry 82-96 cement 4-18

The claimed limits are selected experimentally.

Blast furnace gas treatment sludges are also introduced into the briquette as iron-carbon and zinc-containing components, and when using less than 82%, the unit’s useful coefficient decreases when using the briquette, and with an increase of more than 96% it is impossible to obtain a briquette with the required mechanical strength (briquettes crumble after stamping), which ensures required gas-dynamic properties of the furnace shaft.

Cement is used as a binder, and when using less than 4%, it is not possible to obtain the required mechanical strength of the briquette, and with an increase of more than 18%, the strength of the briquette decreases due to cracking during drying, the non-production costs of briquette production increase, and the total content of the iron-zinc component in briquettes.

The inventive briquettes were made of materials with the following chemical composition:

Blast furnace slurry: 10-43% Fe _total ; 10-41% C; 3.0-10.0% CaO; 0.5-3.0% MgO; 2.0-8.0% Al ₂ O ₃ ; 6.2-8.2% SiO ₂ ; 0.50-10.0% Zn.

Cement (M - 500): 6.0-6.6% Al ₂ O ₃ ; 3.0-3.08% Fe ₂ O ₃ ; 0.20-0.39% FeO; 56.0-57.8% CaO; 30-34% MgO; up to 0.05% P ₂ O ₅ .

The above components were mixed, moistened, underwent a pressing process and drying in natural conditions.

Briquettes were used in the smelting of cast iron to produce zinc-containing dust in a cupola. Trapped high-zinc off-gas dust was produced in a bag filter.

The chemical composition of the captured dust: 35-62% Zn; 5.0-23% Fe _total ; 5.0-13.5% C; 3.0-12.0% CaO; 0.5-3.8% MgO; 2.0-8.6% Al ₂ O ₃ ; 6.2-9.2% SiO ₂ .

The achievement of these results is based on the recycling of blast furnace slurry. The blast furnace slurry was sent to a briquette factory, where materials were mixed in predetermined proportions, followed by briquetting. Further, the dried briquettes were shipped for use. The newly caught dust was again shipped to the briquette factory. The described technological operations were carried out until the necessary accumulation of Zn in the captured dust. Below are the compositions of samples of briquettes with obtaining the final result during 40 cycles (heats).

Table 1 The number of cycles The content of ZnO in dust,% one 7.43 2 7.81 3 8.22 four 8.64 5 9.08 6 9.55 7 10.04 8 10.56 9 11.11 10 11.68 eleven 12.28 12 12.91 13 13.58 fourteen 14.28 fifteen 15.01 16 15.79 17 16.60 eighteen 17.45 19 18.35 twenty 19.30 21 20.29 22 21.34 23 22.44 24 23.59 25 24.81 26 26.09 27 27.43 28 28.84 29th 30.33 thirty 31.89 31 33.53 32 35.26 33 37.08 34 38,99 35 41.00 36 43.11 37 45.33 38 47.67 39 50.12 40 52.70

The inventive briquette for the production of zinc intermediate in the smelting of cast iron has made it possible to efficiently utilize production waste to obtain an intermediate for the zinc industry in the form of trapped dust with a high zinc content.

Information sources

1. AS of the USSR No. 1546506, class С22В 1/24.

2. Tarasov A.V., Utkin N.I. General metallurgy. - M.: Metallurgy, 1997 - 592 p.

Claims (1)

A briquette for producing a zinc intermediate in the smelting of pig iron, including carbon-containing, iron-containing and zinc-containing materials, as well as a binder, characterized in that blast furnace slurries are used as carbon-containing, iron-containing and zinc-containing materials, and cement is used as a binder in the following ratio of components, wt .%:
blast furnace slurry 82-96 cement 4-18