RU1531398C - Method of manufacturing magnesia-carbonic refractory - Google Patents

Abstract

The invention relates to the refractory industry, mainly to methods for the manufacture of refractories. The aim of the invention is to increase the operational stability of the refractory by reducing the degree of carbon burnout. To produce a periclase-carbon refractory, coarse-grained periclase powder is loaded into a centrifugal mixer and mixed with organic carbon dioxide. holding component, ferrophosphoric and dispersed periclase powders and all components are mixed again until granules are formed, from which, without drying them, a refractory is formed by pressing, ramming or vibration. The degree of carbon burnout in the resulting refractory is 1.9-30.7 °; 1 tab. Joint venture

Description

The invention relates to the refractory industry, mainly to methods for the manufacture of refractories

The aim of the invention is to increase the service life of the refractory by reducing the degree of burnout of carbon with

The method is carried out as follows.

Coarse-grained periclase powder is loaded into a centrifugal mixer, moistened with organic binder and mixed, then the carbon-containing component powder, ferrophosphoric and dispersed periclase powders are added and all components are mixed again until granules are formed, from which, without drying, they form a refractory by pressing , tampering or vibration Products without drying or after drying at a temperature of no more than 200 C ship the consumer m.

As periclase powder, you can use fused periclase, its underfusion (crust), sintered periclase and periclase-lime powders; as a carbon-containing component - graphite, anthracite, graphite spel, electrode breakdown, coke and core, as an organic binder - lignosulfonates, phenol-formaldehyde, coal, furan, petroleum and other resins, a binder of phenol-formaldehyde powder (TFP), paraffin, drying oil and others

Joint venture

with

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Used as antiok

Sidant ferrophosphoric powder, having a low melting point (t 9 ° C), sinter periclase-carbon refractories at lower temperatures, compacts the structure and thereby reduces the degree of carbon burnout

The greatest effect from the use of ferrophosphorus powder is achieved when creating a dense granular structure of refractory materials. Consistent pelletizing of grains of coarse-grained periclase powder, first with organic bonding, then with a carbon-containing component, ferrophosphoric and dispersed pericles: granular powders leads to the formation of granules with the following structure: grains of periclase, the shell on the grains is cermet, consisting of dispersed powders of graphite, ferrophosphorus and periclase, impregnated with organic Coy

This leads to a decrease in the coefficient of internal friction at the same time for all grains, which leads to an increase in the plasticity and homogeneity of the mass,

The mechanism for forming the cermet structure of periclase-carbon refractory consists in wetting the grains of coarse-grained periclase and ferrophosphorus powders with an organic binder, polymerizing it at low temperatures, and thereby forming a strong frame between the grains of periclase powder, graphite, and antioxidant. With increasing temperature under refractory service conditions up to 55 ° C, volatiles are removed from the organic binder. A further increase in temperature leads to the oxidation of graphite, ferrophosphorus powder, and binding to carbon oxides, iron phosphates, and iron oxides. Carbon oxides form a reducing medium in refractory, iron phosphates melt, sinter the granule shell with the formation of a strong and dense ceramic structure, and iron oxides interact with periclase with the formation of high-temperature compounds - magnesiuustite

0

5

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5

5

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5

0

5

(t GGD 210P ° C) and magnesioferrite (t 1750 ° C).

The reactions of the formation of magnesiuustite and magnesioferrite are accompanied by an increase in volume of about 7, which leads to a densification of the structure of periclase-carbon products, thereby preventing the diffusion of oxygen in them. At high temperatures, a reducing medium exists in the products, periclase grains are bonded with highly refractory magnesia-iron-containing compounds that prevent carbon burnout. The conservation of carbon at the service temperature of periclase-carbon refractory due to the densification of its structure is the basis for increasing its resistance in the linings of thermal units with

Examples of the implementation of the method and the properties obtained in the specified method of refractory are given in the table,

As can be seen from the table, in the refractory obtained by this method, the degree of carbon burnout is on average 3-8 times less than in the prototype

Claims (1)

The claims A method of manufacturing a periclase-carbon refractory comprising mixing coarse and particulate periclase filler, an organic binder, a carbon-containing component and an antioxidant and forming a mixture, characterized in that, in order to increase the operational stability of the refractory by reducing the degree of carbon burnout, a ferrophoric is used as an antioxidant powder and the formation of the mixture is carried out from granules obtained by mixing the coarse filler first with organic bonding d, and then with the rest of the components of the mixture in the following ratio of components, wtD: Periclase S-E powder Organic Bond 2-15 Carbon containing component2-25 Ferrophosphoric powder 2-15 thirteen Coal Tar-6 Prototype