Ceramic mass

FIELD: building industry and materials.

SUBSTANCE: invention relates to the composition of ceramic mass. Ceramic mass comprises light-melting clay raw, ground blast furnace ferromanganese granulated slag as a waste after cast iron smelting with the maximal size of particles 1.25 mm of the following composition, wt.-%: SiO₂, 33-39; CaO, 39-42; MgO, 7-10; Al₂O₃, 7-10; MnO, 4-8; FeO, 0.2-0.3; S, 2.4-2.7, and the ground depleted iron-containing catalyst as a waste in manufacturing ammonia, being these components are taken in the following ratio, wt.-%: light-melting clay raw, 80-90; indicated blast furnace ferromanganese slag, 9.85-19.9, and indicated depleted iron-containing catalyst, 0.1-0.15. Invention can be used in manufacturing wall ceramics (slotted stones, among them building bricks). The proposed invention provides enhancing the compression strength, crack-resistance values in drying and improving the architecture image due to elimination of granules (tubercles) of granulated slag projecting on their surface and elimination of gray-green-like tint on color surface of articles.

EFFECT: improved preparing method, improved and valuable properties of ceramic mass.

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The invention relates to the field of construction, namely, the composition of the ceramic material, and may find application in the production of ceramic wall (slab stones, including wall and brick).

The known composition of the ceramic material contained in autospid. The USSR №1189848, MCL⁵04 In 33/00, published in 1987, and includes wt.%:

The disadvantages are the counterpart:

Thneed water absorption of the finished products ceramics and increases frost resistance and disposed in the form of slag.

2. Low architectural views, as metallurgical slags give greyish shades on the surface of red or light red shushica clay.

3. Toxins, especially in the form of containing high amount of Mn, give a greenish shade.

The closest composition to the weight given in autospid. The USSR №1276637, MCL⁵04 In 33/00, published 15.12.1986,, bull. No. 46 and includes components when following their ratio, wt.%:

from gas cleaning CO₂ethanolamine solution

The main disadvantages of complicating the issue facing bricks are:

1. The lack of cracking during drying, because you do not use the potential of hydraulic activity of slag.

2. Not high enough the architectural appearance of brick, which limits its use as a face. The negative effect give larger particles of slag larger than 1.25 mm (up to 5 mm), exposed on the surface in the form of irregular inclusions. Negatively on the color of the brick effect and greenish bearing ferromanganese from slag.

3. Insufficient compressive strength (10-15 MPa)that delimits the receiving face brick with the brand M100-M.

4. Violated environmental cleanliness in the sphere of production, as ferrovanadium slag contains an oxide of a heavy metal V₂O₅(of 0.18 to 0.19 wt.%);

5. The complexity of the composition of the mass.

The objective of the proposed invention is to increase the compressive strength, crack resistance during drying and architectural views, by eliminating protruding on the surface of the granules (bumps) of slag and exceptions gray-greenish tint is and the color of the surface of products.

To solve the problem in the composition of the ceramic material that includes fusible clay raw materials, crushed-bearing ferromanganese slag and waste ammonia as crushed-bearing ferromanganese granulated slag injected crushed blast-bearing ferromanganese slag-a waste of smelting iron with a maximum particle size of 1.25 mm composition (wt.%): SiO₂- 33-39%, CaO - 39-42; MgO - 7-10; Al₂About₃- 7-10; MnO - 4-8; FeO - 0,2-0,3; S - 2,4-2,7, and the waste product ammonia - ground exhaust iron-containing catalyst, in the following ratio of all components, wt. %:

Characteristic components of the mass 1.

Clay raw materials.

As a clay quarry raw materials adopted by a mixture of local clay loam (85%) and local fusible clay (15 wt.%). The latter are more durable than loam and more flexible, but more expensive. The accepted ratio is explained by the following factors:

a) Maintaining strength in the required manner, including, and adding (in which surate in manufacturing) scrap bricks up to 2 wt.% the same composition;

b) Economic feasibility.

1.1. Loam. After firing are the color of red light. The resistance - 1250°i.e. fusible clay raw materials. Air linear shrinkage - 7-8% (highly sensitive to drying). The limit of compressive strength after firing at temperatures of 950° - 17,31 MPa, and at 1050°-23,0 MPa, at 980° - 20,6 MPa. Moderately plastic (C.P. - of 12.6 and 12.7). Sour, with a content of Al₂About₃- 11,64 and 11.8%. Refers to the number of non-caking up to 1250°clay raw materials.

1.2. Fusible clay. Color after firing (950-980°S) - cream. The limit of compressive strength - 42-46 MPa. The resistance - 1250-1270°, stiff. Air shrinkage (linear) - 6,5-7%. Refractory, non-caking, which is insensitive to drying.

Clay raw material is adopted in the experiment is a mixture of loam - 85 percent and fusible clay - 15%. Properties after firing 980°S: terracotta color, without vysokoobrazovannyj, ultimate compressive strength of 34 MPa.

2. Bearing ferromanganese slag. This is a departure from the bearing ferromanganese smelting iron. Color light green. Meets the requirements of THE 14-128-D-2-03.

Chemical composition, wt.%: SiO₂- 33-39%, CaO - 39-42; MgO - 7-10; Al₂About₃- 7-10; MnO - 4-8; FeO - 0,2-0,3; S - 2,4-2,7.

After granulation has a bulk density of 400-700 kg/m³. The maximum particle size after grinding -1,25 mm

Particle size distribution is left to grinding (private residues on the sieves), wt.%: fraction >5 mm - 0; fraction of 2.5-5 mm 29,5%; fraction of 1.25-2.5 mm - 12.5 mm; fraction to 0.63-1.25 mm - 32; fraction 0,315-0,63 - 21; fraction of 0.14-0,315 - 4; fraction less 0.14-1.

Refers to organic waste.

After grinding prevails fraction (>50%) smaller than 0,315 to 0.63.

3. Exhaust (not regenerated) catalyst for the production of ammonia.

Color - dark claret. Is granules of cylindrical shape, a length of 30-35 mm and a diameter of 2.5-3 mm, Not solid, i.e. easily ground to a fine powder.

In the experiments adopted with a specific surface area of 250-300 m²/kg. Used as a Supplement to the ore in the smelting of iron.

The chemical composition of the spent catalyst, wt.%:

Implementation of the proposed structure

Oldservername specified clayey raw materials (85 wt.% loam and 15 wt.% fusible clay) after the rough grinding mixed with occasioanly crushed-bearing ferromanganese slag (waste from bearing ferromanganese smelting of cast iron and it is ferrous waste ammonia production. The mixture governale to the molding material, missed twice through a laboratory is attornye rollers with a gap of 2 mm The mass was placed in plastic bags (to maintain humidity) and after daily aging used for forming samples of size 5×5×5 see Dried samples 48 hours with a maximum temperature of 70°and then annealed at a maximum temperature of 980°C. the ratio of the components (dry ingredients) in the table.

Thus, the proposed composition of the mass and, accordingly, the finished samples of wall ceramics on the basis of them received the traditional way. After drying, the samples were visually examined for cracks and set the degree of fracture toughness, and after firing on the compressive strength, as well as architectural views.

The fracture strength was determined as follows.

a) was Determined by the total surface (before drying) of five samples, which was

S₁=(6×S_o)×5=6×25×5=750 cm²,

where S₁- the total surface of five samples,

S_o- the surface of one face, i.e. the 25 cm².

b) After drying was determined by the total surface of all sides from five samples, no cracks - S₂cm². Hence, the fracture toughness was %

Data fracture toughness, tensile strength at compression and architectural appearance (color, presence of inclusions, mildew) are shown in table 1.

And the Alize properties of ceramic samples made on the basis of mass No. 2, 3, 4, shows:

1. The strength of ceramics under compression has increased about 2 times that gives a background to obtain hollow brick (voidness not less than 21%); with a mark not less than M100-M.

2. Increased degree of fracture toughness by 20%.

3. Improved architectural appearance by eliminating dark red color grayish-green and granular inclusions on the surface that gives the prerequisite of obtaining the brick.

The goal is explained by the following physical and technological processes during drying and firing.

The crack resistance can be justified as follows.

a) you Know that all of granulated blast-furnace slag have poorly hydraulic properties inherent astringent substances, such as cement clinker, and gidravlicheskiy increases in humid environments and at elevated temperatures (up to 100°). In the production of ceramics such conditions are provided in the drying process, especially during heating (high relative humidity and high temperature).

b) it is Also known that with the increase of the specific surface binding materials including slag, hydraulic activity, i.e. strength (after curing of specimens pressed from 100% slag and under normal conditions of hardening sharply in the melt, so: before grinding activity-bearing ferromanganese slag is 3-4 MPa, and after fine grinding becomes equal to 10-12 MPa.

In this case, i.e. with a maximum particle size of 1.25 mm and the prevailing faction less 0,63 mm, the activity of the slag was within 6-8 MPa (6 MPa after preparation, and 8 MPa after 28 days normal curing).

Therefore, molded semi-finished ceramics can be considered as formed concrete, because the minerals, slag type nCaO×mSiO₂(calcium silicate), nCaO×mAl₂O₃(calcium aluminate) in the initial period of drying to chemically attach the molding water, turning into hydrosilicate and hydroalumination calcium slag (see Volzhenskiy AV" Mineral binders", Destroyest), which entails a reduction of the amount of evaporated moisture in the raw weight at a critical moment of cracking.

Chemically attached water, as it is known, from minerals (hydrosilicates and hydroalumination calcium) are removed at temperatures above 400°i.e. when firing ceramics, and non-hazardous period for cracks firing ceramic crock.

However, to create a molded mass of capillary-conducting ability of the evaporation of water during drying slag was subjected to a moderate degree of grinding.

C) Increasing the strength.

is using hydraulic capacity of the slag in the drying process has a positive effect on increasing strength, for two reasons, specifically:

1. No cracks that can occur during drying and firing;

2. Due to the grinding of the slag increases the specific surface of the glass rim of the slag, which is involved (as a flux) in the formation of ceramic crock. Wetlands are known to increase the strength.

g) Increasing architectural type.

1. Ground iron-treated catalyst acts as a flux, and on the other hand, acts as intense pigment, which compensates (excludes) gray-greenish-bearing ferromanganese brick.

2. With the increase of the specific surface of the slag is a higher degree of homogeneity in the mixing process, which has a positive effect on strength and architectural appearance of ceramics.

3. Slag, with a maximum particle size of 1.25 mm, gives formations "bumps" on the smooth surface of brick, which is positive for the brick. Crushed slag allows you to produce hollow brick. The application of the proposed structure will allow you to get a large economic effect in the manufacture of bricks due to the following:

- Recycled waste - bearing ferromanganese blast slag and exhaust catalyst.

- Increased profits from the sale of the front hollow brick is and 25-30% in comparison with ordinary brick wall (prototype).

Ceramic material that includes fusible clay raw materials, crushed-bearing ferromanganese slag and waste production of ammonia, characterized in that the crushed-bearing ferromanganese granuloma the aqueous slag injected crushed blast-bearing ferromanganese slag - waste of smelting iron with a maximum particle size of 1.25 mm composition (wt.%): SiO₂- 33-39, CaO - 39-42; MgO - 7-10; Al₂About₃- 7-10; MnO - 4-8; FeO - 0,2-0,3; S - 2,4-2,7, and the waste product ammonia - ground exhaust iron-containing catalyst, in the following ratio of all components, wt.%:

Clay fusible raw 80-90

The specified domain-bearing ferromanganese slag 9,85-19,9

Specified exhaust iron-containing catalyst of 0.1-0.15