LU81808A1 - REFRACTORY ELEMENT AND MANUFACTURING METHOD THEREOF - Google Patents

Description

L-2447

Q GRAND-DUCHY OF LUXEMBOURG Patent No .............................. Y ....... V V

du ........- 1.9..r.J Q .1979 ................ Minister

Title issued · ^^ conom'e Nationale et des Classes Moyen _ Industrial Property Service

5¾¾ LUXEMBOURG

Patent Application I. Application

General Gunning S.A., 37, rue Notre-Dame, Luxembourg, m

Luxembourg, represented by Jean Waxweiler, 21-25 Allee '"ScÏÏeîfër,

Luxembourg, acting as agent ____________ (2) ·· - * · ............ * .......... ........... ... ....— .......................................... ........................— ........... * ............. ........

deposits ........ this nineteen october one thousand nine hundred and seventy <3) at ..... hours, at the Ministry of National Economy and the Middle Classes, in Luxembourg: 1. this request for obtaining a patent for an invention concerning:

Refractory element and method of manufacturing this element.

declares, assuming responsibility for this declaration, that the inventor (s) is (are): 2. the delegation of power, dated ---------------- ---------------------------------------------------------- ----- the ”IIÜ .___________________________________________________ 3. the description in French language _________________________________ of the invention in two copies; 4 .............. / ................ drawing boards, in two copies; 5, the receipt of the taxes paid to the Luxembourg Registration Office,. nineteen october nineteen hundred and seventy nineteen the ...................................... .................................................. .................................................. .................................................. .................................................. ..............................

claims for the above patent application the priority of one (s) application (s) of '(6) .................... 1 ..... .................................................. ................. filed in (7) ......................... Z ................................................. .................................................. ..

the ------------------------------- L ____________________________________________________________________________________________—---------------- -------------------------------- (8> ..... ~ ......... .... .............. take up residence for him / her and, if appointed, for their representative, in Luxembourg ............. .......................

..Jean Waxweiler .., .. 2.1-.25 Alley δ £ Κβ. ££ .βχ ..> 1.υχ © ιΐώ.Ω.Μβ ................ .................................................. uo) requests the issuance of a patent for the subject described and represented in the abovementioned appendices, - with postponement of this grant to ............ / ...... ..........................month.

Lq ................ authorized representative ..........................

.............he- ...............

Π. Deposit Minutes

The above application for a patent for invention has been filed with the Ministry of National Economy and the Middle Classes, Industrial Property Service in Luxembourg, dated: 19.10.1979 ^ 1? Γ · the Minister at 15 QO. hours f of the National Economy and the Middle Classes,

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M 13 MOIRE D E S G R I P T I F FILING IN SUPPORT OF A PATENT DEFENSE IN THE GRAND DUCHY OF LUXEMBOURG

• \ '' 'Γ ·' ~ Γ-— I - "^ 111 REFRACTORY ELEMENT AND MANUFACTURING METHOD THEREOF.

GENERAL GUNNING S.A.

- 1 -

The present invention relates generally to mixed compositions for the manufacture of pressed bricks of very high density.

5 The refractory bricks currently used are composed of granulated refractory products mixed with raw clay, tar, or other chemicals, liquids or solids, and water.

These mixtures are kneaded, deaerated and pressed or compressed to form monolithic pieces, the latter then being dried and then baked.

These prefabricated parts all have various drawbacks such as: - High cost price because their cooking at high temperature in order to obtain a material which will no longer have significant volumetric variations, requires a great debauchery of energy during cooking.

- This same firing also results in a deformation of the block which then no longer has a flat surface state laughed at the rigorous dimensions.

The object of the invention is to remedy these drawbacks because: - On the one hand, it recommends the use of noble materials, already stabilized and in selected particle sizes, which results in the addition of an appropriate binder, reacting cold to suppress the baking phase while safeguarding the physical characteristics of the material.

- On the other hand, the fact of eliminating the cooking phase 30 makes it possible to keep the surface condition and the dimensions of the block intact.

- Finally, the pressure of very high density bricks provides maximum compactness, minimum porosity and high density.

35 In addition, the invention makes it possible to remedy certain drawbacks presented by uncooked bricks, based on sand, containing 7 to 8% of alumina, currently commonly produced but whose major drawback is the brittleness despite all the aggregates of coagulation existing on the 40 market.

- 2 - The invention and the manufacturing process therefore relate essentially to: - the choice of aggregates, the geological and physical nature of the products composing their particle size as well as their homogeneity - the incorporation of suitable binders allowing cold bonding - The use of pressing equipment with an adequate density.

1.- THE CHOICE OF AGGREGATES AND THEIR GRANULOMETRY AS WELL AS

THEIR HOMOGENEITY__

The aggregates which can be either aluminous or basic must all be calcined at a temperature close to their temperature of use.

Their particle size must be as close as possible to the curve according to the following formulation: Y = A + (100 - A) \ / d ~ 7 20 V * in which y =% of grains of the mixture passing through the mesh of of sieve of dimension d A = Bolomey coefficient for a fluid mass taken equal to .25 14 in the present case.

d * dimension of the mesh considered (valid) D = dimension of the maximum grain of the mixture.

(d and D expressed in the same units)

Such a formulation has the advantage of producing materials having good plastic behavior during their use, either in the press or in the press, while having sufficient rigidity as soon as this stress ceases, regardless of any consideration on the binder. As for homogeneity, it will be a determining factor in the quality of the finished product since it will condition the good distribution of the aggregates on the one hand, but above all the optimum dispersion of the binder in the mass.

This can be obtained using a mixer fitted with the following accessories or working tools: 40 - Mixer tank fitted with a rotating floor - 3 - - Internal tooling of the tank composed of a vortex whose speed of rotation can vary from 300 to 1000 rpm and a scraper agitator.

5 The scraper agitator grooves and constantly pushes the material towards the vortex.

These two accessories rotate in the same direction while the rotary sole rotates in the opposite direction.

2.- INCORPORATION OF A SUITABLE BINDER ALLOWING A

10 COLD CONNECTION_

The binders we use are chemical binders from the phosphate family.

These products, known for many years, are commonly used as binders in many refractory masses. However, when used as is, they do not allow cold bonding of aggregates.

In fact at 180 ° C, the primary aluminum phosphate transforms aluminum magnetophosphate by dehydration, and the metaphosphate remains stable up to 800 ° C. Beyond 20 ° C, aluminum metaphosphate releases P20, - t and we witness the reverse process of phosphate formation which gives orthophosphate from poly- and pyrophosphate. As the temperature increases and after all the P205 has disappeared / A1203 remains.

'25A1203. 3P205. 6H20 ^ 2A1 (H2P04) 3 ORTHOPHOSPHATE PRI-

3H ^ 0 180oc MAYOR OF ALUMINUM

Al203. 3P205 - ^ 2A1 (P03) 3 ALUMI METAPHOSPHATE.

820 ° C

30 A1203. 2P205 —A12 (P4013) ALUMI POLYPHOSPHATE.

850 ° C

2A1203. 3P205 -> A14 (P207) 3 ALUMI PYROPHOSPHATE.

35,880 ° C

Al203 .P205 _2A1 P04

1000 ° C

Al ~ O,

40 Z J

T

- 4 -

The table above illustrates the stages of metaphosphate formation as the temperature increases.

The invention consists in adding to it a product causing a cold bond.

To do this, a basic addition should be made which makes it possible to neutralize the phosphates in the form of micronized colloidal products such as alumina or magnesia.

The reaction will be completed by the incorporation of carbo-methylcellulose intended to retain and then release the necessary humidity during the chemical setting. In addition, this agent, by its lubricating power will facilitate subsequent pressing and will make the extrusion of the blocks easier.

Finally, this agent will disappear when the refractory is put into service and will leave only a minimum of deposit after combustion.

It should be noted that the compositions thus prepared and after incorporation of the binders must in any case be rapidly formed within a period which may not exceed 8 to 12 hours.

3. - THE USE OF HIGH DENSITY PRESSING EQUIPMENT;

A brick of optimum quality is only obtained after * 25 compliance with the recommendations in paragraphs 1 and 2 above, only after pressing under at least 400 atmospheres.

To do this, the selected material must meet the following characteristics: 30 - Pressing force greater than 400 atmospheres - Double compression effect - Deaeration of the pressed block during tightening.

The shaped refractory elements will then be stored in a ventilated place and cannot be put into service until after 48 hours. This period is indeed necessary to reach the end of the chemical reaction as described in paragraph 2 above.

We give below as an indication some examples of the composition of bricks prepared according to the 40 characteristics of the invention.

* - 5 - a) Bri2ue_à_base_de_sablei_

Raw silico-aluminous substance titrating 6 to 8% of slightly dehydrated alumina to contain only 7% of water 5 with a particle size between 0.5 and 1.5 mm. The pyroscopic resistance of use of the brick could be improved by additions of quartz, flint, disthene, zirconium silicate, zircon oxide for example, additions which will also bring an increase in volume intended to compensate for the shrinkage of the raw clay laws of temperature rise.

The invention will consist in supplementing this preparation with the agents described above in the following proportions: 15 - Phosphates from 0.5 to 3.5% of the mixture - Colloidal micronized products from 2 to 6% of the mixture - CarbomethylceQlulose of 5 loà 1% of the mixture.

b) Brick with 60% of A ^ O ^ 20 Aluminous substance titrating more or less 60% of alumina with a particle size as close as possible to the curve described above composed of: - 80 to 90% of andalusite , kerphalite and others - 5 to 7.5% of a colloidal clay.

The invention will consist in supplementing this preparation with the additions described above in the following proportions: - Phosphates from 0.5 to 3.5% of the mixture - Micronized colloidal products from 2 to 6% of the mixture 30 - Carbomethylcellulose of 5 at 1% of the mixture.

c) Brick with 80% of A ^ O-ji

Highly aluminous substance titrating more or less 80% of alumina with a grain size as close as possible 35 to the curve described above composed of: - 80 to 90% of bauxite, gypsum and others ...

- 5 to 7.5% of a colloidal clay.

The invention will consist in supplementing this preparation with the additions described above in the following proportions: 40 - 6 - - Phosphates from 0.5 to 3.5% of the mixture - Colloidal micronized products from 2 to 6% of the mixture - Carbomethylcellulose from 5 ° / o to 1% of the mixture.

5 d) Brig_to_80 ^ 85 _% _ de_MgO

Magnesium substance titrating more or less 85% of MgO, with a particle size as close as possible to the curve described above composed of: - 85 to 95% of magnesia, chromium and others ...

10 - 2.5 to 5% of a colloidal clay.

The invention will consist in supplementing this preparation with the additions described above in the following proportions: - Phosphates of 0.5 to 3.5% of the mixture - Colloidal micronized products of 2 to 6% of the mixture - Carbomethylcellulose of 0, 5d £ at 1% of the mixture e) Brigue_de_çhrome_magnesésie £

Substance based on magnesia and chromium ore with a particle size as close as possible to the curve described above composed of: 20-85 to 95% of chromium magnesia - 2.5 to 5% of a colloidal clay.

The invention will consist in supplementing this preparation with the additions described above in the following proportions: 25 - Phosphates from 0.5 to 3.5% of the mixture - Micronized coüoidal products from 2 to 6% of the mixture - Carbomethylcellulose of 0, 5 ^ to 1% of the mixture.

f) Brigue_de_carbure_de_siliçiunu

Substances based on silicon carbide of a ganulome-30 sorts as close as possible to the curve described above composed of: '- 85 to 95% of silicon carbide - 2.5 to 5% of a colloidal clay or other colloï-cfcux products.

The invention will consist in supplementing this preparation with the additions described above in the following proportions: - Phosphates from 0.5 to 3.5% of the mixture - Micronized colloidal products from 2 to 6% of the mixture - Carbomethylcellulose of 0, 5 ^ to 1% of the mixture.

40

Claims (10)

1. Refractory element such as a brick, characterized in that it is essentially composed of 75 to 90% 5 of refractory aggregates with high mechanical resistance, of a chemical binder of the alumina monophosphate type and of reagents such as products micronized colloidals and carbomethyl cellulose. '2. Refractory element according to claim 1. 10 characterized in that the aggregates must approach in their particle size of the formulation: Y = A + (100 - A) [fzn Vd 15 in which: Y =% grains of the mixture passing through the sieve mesh of dimension d- A = Bolomey coefficient for a fluid mass taken equal to 14 in the present case. 20 d = dimension of the considered mesh (variable) D = dimension of the maximum grain of the mixture. (d and D expressed in the same units) 3. Refractory element according to any one of claims 1 and 2, characterized by a very great »25 homogeneity of the mass to be pressed using a material as described above. 4. Refractory element according to any one of claims 1 to 3, characterized by a chemical bond using an agent of the phosphatic type chosen for its refractory qualities, its gel stability and its safe handling. from a medical point of view. 5. Refractory element according to any one of claims 1 to 4, characterized by the versatile aspect of the phosphate chemical binders which can be indifferently used for the bonding of aluminous masses and basic masses. 6. Refractory element according to any one of claims 1 to 5, characterized by the addition of alumina 40 or micronized colloidal magnesia intended to cause the cold reaction of the chemical binder described in claim 4. 7. Refractory element according to any one of claims 1 to 5, and 6 characterized by the addition of carbomethoxycellulose intended to release the necessary humidity during the chemical setting. 8. Refractory element according to any one of claims 1 to 7, characterized by a shaping delay 10 which cannot exceed 8 to 12 hours. 9. Refractory element according to any one of claims 1 to 8, characterized by a pressing, suitable for the circumstance in order to obtain the maximum compactness. 10. Refractory element according to any one of claims 1 to 9, requiring storage of at least 48 hours in a ventüi place eliminating any drying. 20 * 1