RU2376342C1 - Briquetting method of semi-coke - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: briquetting method of semi-coke, mainly lignite, includes stages of preparation of initial components, blending, compressing, drying and impregnation provides grinding of initial components on stage of preparation up to granulometric compound 0-7 mm, and addition of slaked lime with water-calcareous ratio 3/1-5/1 with content CaO from 5 up to 15%, and after blending of components, compressing and drying, and also impregnation of briquettes by solution of liquid glass.

EFFECT: hardening of briquettes, leading to ability of multiple implementation of loading processes with briquettes, allowing water-resisting property.

2 cl, 5 ex

Description

The invention relates to the production of briquettes used as a reducing agent for metallurgical processes, and also as smokeless fuel for domestic and industrial furnaces.

A well-known coal briquette having increased strength, as well as a method for its manufacture (RU 2224007 according to class C10L 5/02 of 12/12/2001). A briquette with increased initial strength and consisting of 100 parts by weight coal fines, 1-5 parts by weight quicklime and 7-15 parts by weight molasses. The briquette has a crushing resistance of not less than 70% and a dust generation rate of not more than 20% and is suitable for use in the smelting reduction process of producing iron. The coal fines in the briquette contain from 6 to 15 wt.% Moisture. In the briquette, quicklime contains particles with a size of not more than 1 mm, and the proportion of particles with a size of not more than 0.3 mm is at least 50% by weight. A method of manufacturing such briquettes includes operations: mixing 1-5 parts by weight quicklime with 100 parts by weight coal fines and aging the mixture; mixing 7-15 parts by weight molasses with a seasoned mixture and their mixing and direct formation of a mixed mixture in order to obtain briquettes. The method in which coal fines contains from 6 to 15 wt.% Moisture. The method in which quicklime contains particles with a size of not more than 1 mm, and the proportion of particles with a size of not more than 0.3 mm is not less than 50% by weight. A method in which aging is carried out from 2 minutes to 2 hours to convert quicklime to slaked lime. A method in which stirring is carried out for 2-50 minutes to increase the curing rate. A method in which, after direct formation, the heating and drying operation is not carried out.

The disadvantage of this invention is that to achieve increased strength, the bonding ability of calcium sugar, which is formed as a result of a chemical reaction between quicklime and molasses, is used. However, the chemical reaction between quicklime and molasses is limited by the short residence time in the system. Quicklime quickly reacts with moisture and molasses, helps to harden the ingredients, which prevents the uniform distribution of quicklime throughout the mixture, this reduces mechanical strength and makes storage and transportation difficult.

The closest technical solution and the achieved result is a method for producing carbon-containing briquettes, including mixing coke or coal fines with crushed waste from metallurgical production, sulfonic acid or molasses derivatives and lime, briquetting the mixture and subsequent heat treatment and cooling of the briquettes. The lime powder is introduced into the mixture or applied to the briquette in the form of a layer of a saturated aqueous solution of lime with the addition of 5-30 wt.% Derivative of sulfonic acid or molasses (RU 2123029 according to CL 10/5).

The disadvantage of the invention is the complexity of the technological process for the production of briquettes and the use of burnable components in the composition of briquettes.

The invention solves the problem of increasing the strength of briquettes.

The technical result when using the invention is the ability to repeatedly perform loading and unloading operations with briquettes having water resistance.

The specified technical result is achieved by the fact that at the stage of preparation of the starting components, the semi-coke is crushed to a particle size distribution of 0-7 mm and slaked lime is added with a water-lime ratio of 3 / 1-5 / 1 with a CaO content of 5 to 15%, and the resulting briquettes are impregnated with a liquid solution glass with a density of 1.12-1.2 g / cm ³ for, for example, 30 s.

To obtain briquettes from brown coal semi-coke, semi-coke of initial particle size distribution of 70-30% and crushed 30-70% was used, slaked lime with a water-lime ratio of 3 / 1-5 / 1 with a CaO content of 5 to 15% was used as a binder.

The initial semi-coke is a dispersed material with an average grain size of 0.5-3 mm. The crushed semi-coke was obtained by grinding in a ball mill (residue on a sieve of 0.63 no more than 5%). Lump quicklime was shut with water in a ratio of 1 kg of lime to 2.5 liters of water until a lime dough is obtained. For faster and more uniform slaking and obtaining a homogeneous lime test, lime was periodically mixed during the slaking process. The resulting lime dough was stored in a closed container. To obtain a different water-lime ratio, the obtained lime dough was diluted with water in the required ratio; for better mixing, a vertical type propeller mixer was used.

The press powder was prepared as follows: the dry components were weighed in accordance with the recipe, averaged by stirring, and then the required amount of lime binder was added. The mixture was vigorously stirred until a homogeneous composition was obtained.

In the manufacture of samples, the pressing pressure varied from 30 to 80 MPa. The obtained samples were dried at a temperature of 100-250 ° C, to a moisture content of not more than 3%.

In order to increase water resistance, semi-coke briquettes were impregnated with a solution of liquid glass with a density of 1.12-1.2 g / cm ³ . The briquette was immersed in a solution of water glass for 30 seconds, removed and dried at a temperature of 100-250 ° C, to a moisture content of not more than 5%.

Example 1. Use the following components: 100 parts by weight semi-coke mixture (50 parts by weight of the initial semi-coke, 50 parts by weight of crushed semi-coke) as a binder - 10 parts by weight in terms of CaO slaked lime with a water-lime ratio of 5/1.

The starting components were prepared as follows: the semi-coke was ground in a ball mill to a sieve residue of 0.63 no more than 5%. Lump quicklime was shut with water in a ratio of 1 kg of lime to 2.5 liters of water until a lime dough is obtained. For faster and more uniform slaking and obtaining a homogeneous lime test, lime was periodically mixed during the slaking process. To obtain a water-lime ratio of 5/1, the lime dough was diluted in an appropriate proportion with water.

The press powder was prepared as follows: dry components, initial and ground semicoke, were weighed in accordance with the recipe, averaged by stirring, and then a lime binder was introduced. The mixture was vigorously stirred until a homogeneous composition was obtained. The resulting press powder is briquetted at a pressure of 50 MPa, followed by drying at 100-250 ° C, to a moisture content of not more than 3%, hot briquettes are cooled at ambient temperature.

Further, to increase the water resistance, the briquettes are immersed in a liquid glass solution with a density of 1.12-1.2 g / cm ³ for 30 s, then they are removed and dried at a temperature of 100-250 ° C. The obtained briquettes from brown coal semicoke according to this invention have a compressive strength of 12.3 MPa, when saturated with water, retain their shape and practically restore their strength to the original after drying 200 ° C.

Example 2. Obtaining briquettes from brown coal semicoke according to example 1, but per 100 parts by weight semicoke mixture take 6 weight.h. in terms of CaO slaked lime. The resulting briquettes have a strength of 8.1 MPa.

Example 3. Obtaining briquettes from brown coal semicoke according to example 1, but per 100 parts by weight semicoke mixture take 14 wt.h. in terms of CaO slaked lime. The resulting briquettes have a strength of 13.9 MPa.

Example 4. Obtaining briquettes from brown coal semicoke according to example 1, but with a ratio of semicoke mixture of 70 parts by weight source and 30 parts by weight crushed semi-coke. In this case, briquettes with a compressive strength of 10.2 MPa were obtained.

Example 5. Obtaining briquettes from brown coal semicoke according to example 1, but with a ratio of semicoke mixture of 30 parts by weight source and 70 parts by weight crushed semi-coke. In this case, briquettes with a compressive strength of 9.7 MPa were obtained.

Claims (2)

1. A method for briquetting a semi-coke, mainly brown coal, comprising the steps of preparing the starting components, mixing, pressing, drying and impregnating, characterized in that at the stage of preparing the starting components, the semi-coke is crushed to a particle size distribution of 0-7 mm and slaked lime with a water-lime ratio of 3 / is added. 1-5 / 1 with a CaO content of 5 to 15%, dried briquettes, for example, are impregnated with a layer of water glass and dried. 2. The method according to claim 1, characterized in that after mixing the components, pressing under a pressure of 30-80 MPa and drying at a temperature of 100-250 ° C, the briquettes are impregnated with a solution of water glass with a density of 1.12-1.2 g / cm ³ in flow, for example, 30 s.