RU2524364C2 - Method of producing heat-insulating structural material - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to production of heat-insulating structural materials. The method of producing heat-insulating structural materials includes crushing silicate lumps to specific surface area of 2500 cm²/g, mixed with a modifier, a reinforcement additive in form of portland cement, a foaming agent in form of hydrogen peroxide and hardening water, pouring into an article mould and carrying out heat treatment of the article with microwave currents for 15 minutes at temperature of 300°C, wherein the modifier used is superplasticiser S-3, and an additional reinforcement additive used is basalt microfibre with the following ratio of components, wt %: said silicate lumps 62-64, superplasticiser S-3 0.01-0.012, portland cement 10-12, basalt microfibre 0.04-0.1, hydrogen peroxide 0.5-0.7, hardening water 25.

EFFECT: improved physical and mechanical properties.

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Description

The present invention relates to the production of building materials, namely the production of heat-insulating structural materials. The proposed method is intended for the manufacture of heat-insulating products with minimal energy consumption and time with acceptable thermal (strength, sound-proof, heat-insulating, etc.) characteristics, including with alternating temperature effects.

Known methods for producing raw material mixtures for the manufacture of heat-insulating material according to the USSR copyright certificate No. 272879, 1967, IPC SB 38/08 - [1] and according to the USSR copyright certificate No. 1282468, 1985, IPC SB 38/02 - [2] .

The disadvantage of analogues is that the heat-insulating materials obtained from them have low compressive strength, high fire hazard and water absorption.

Also known is the “Method of obtaining raw mixtures for the manufacture of heat-insulating material” according to the USSR author's certificate No. 1396511, 1993, IPC С04В 38/02, С04В 28/26 - [3], including mixing finely ground silicate blocks of 100 parts by weight, sodium silicofluoride 18-20 parts by weight, pore former 5-10 parts by weight, mineral filler 8-16 parts by weight and expandable polystyrene 20-30 parts by weight, loading the mixture into a mold and subsequent foaming, the granules of the expanding polystyrene being mixed first with 16-24 parts by weight an aqueous solution of sodium silicate with a density of 1.3-1.5 g / cm ³ , then a finely ground silicate block is introduced, after which the remaining components are introduced into the mixture and mixed. In other words, a method of manufacturing a heat-insulating structural material consists in grinding a silicate block, mixing it with a modifier, a strengthening additive, a foaming agent and mixing water, and subsequent heat treatment.

The method allows to increase the strength (compression) of the obtained insulating material, as well as reduce its fire hazard and water absorption. However, you can point to the following disadvantages of the analogue [3]:

firstly, the use of polystyrene significantly reduces the fire resistance of the heat-insulating material obtained from the mixture;

secondly, high energy consumption for heat treatment;

thirdly, the increased complexity of the technology of sequential mixing of the components of the mixture (mandatory is the initial mixing of polystyrene granules with an aqueous solution of sodium silicate).

These disadvantages are solved in the prototype of the claimed invention - the application: "A method of manufacturing a heat-insulating structural material" No. 2007121986 dated December 20, 2008, MPK СВВ 28/00 - [4], including grinding silicate blocks, mixing it with a modifier, hardening additive, with foaming reagent and mixing water and subsequent heat treatment, while grinding the silicate block is carried out to a specific surface of 2500 cm ² / g, lignosulfonate is used as a modifier, Portland cement is used as a hardening additive, as e foaming reagent - hydrogen peroxide, in the following ratio of the components of the mixture, wt.%: the specified silicate block 62-64, lignosulfonate 0.04-0.06, Portland cement 5-7, hydrogen peroxide 0.5-0.7, water mixing 30, the heat treatment of the product is carried out by microwave currents for 15 minutes at a temperature of 300 ° C.

The disadvantage of the prototype is that the use of lignosulfonate in it does not provide good flowability, requires more mixing water, which significantly impairs its physical and mechanical properties. In addition, the prototype has a relatively low tensile strength (bending, chipping), as well as low dynamic strength and work failure.

The indicated disadvantages of the analogues and the prototype set the task of improving the spreadability of the proposed structural and heat-insulating material and its physical and mechanical properties. In particular, a significant increase in tensile strength (bending, chipping, etc.), as well as an increase in dynamic strength and fracture work.

These problems are solved by the fact that in the method of manufacturing structural heat-insulating material, which consists in the fact that the silicate block is crushed to a specific surface of 2500 cm ² / g, mixed with a modifier, a strengthening additive in the form of Portland cement, a foaming agent in the form of hydrogen peroxide and with mixing water, it is poured into the shape of the product and then the product is heat treated with microwave currents for 15 minutes at a temperature of 300 ° C, S-3 superplasticizer is used as a modifier, and as an additional hardener General additives use basalt microfiber in the following ratio of the components of the mixture, wt.%:

indicated silicate block 62-64 superplasticizer C-3 0.01-0.012 Portland cement 10-12 basalt microfiber 0.04-0.1 hydrogen peroxide 0.5-0.7 mixing water 25

In this case, as in the prototype, the composition of the mixture includes only non-combustible materials, and the process itself occurs at relatively low temperatures and processing time of the material.

In addition, the “Restored building element” is known according to the patent for utility model of the Russian Federation No. 79579 dated 06.06.2008, IPC E02D 37/00, E02G 23/02 - [5], the building mixture of which contains S-3 superplasticizer and fiber, including steel fibers. However, the analogue [5] is intended for other purposes; it has high thermal conductivity, including due to the high thermal conductivity of steel fibers.

Well-known analogue: “Multilayer outer wall panel” according to the patent for utility model of the Russian Federation No. 81742 dated 03/27/2009, IPC E02C 2/06 - [6], the building mixture from which it is made, contains fiber reinforced polystyrene in its composition , including basalt. As a disadvantage of the analogue [6], it should be noted that the polystyrene included in its composition is combustible and at the same time, the use of such a composition in building structures is very limited.

The well-known analogue: “Mix for foam concrete” according to the patent of the Russian Federation No. 2306300 dated 09.20.2007, IPC С04В 38/10 - [7], contains basalt fiber, but otherwise has completely different components than in the claimed technical solution . Moreover, as a disadvantage of the analogue [7], its low strength can be noted.

An analogue is also known: “A method of manufacturing ceramic foam products” according to RF patent No. 2251540 dated 05/10/2005, IPC SB04/02 - [8], which contains basalt fiber, but its manufacture requires high-temperature firing at a temperature of 940 ÷ 980 ° C, and this requires high energy costs for the production of products and, as a result, leads to a sharp increase in their cost.

Thus, the implementation of the proposed method for the manufacture of structural heat-insulating material is as follows:

the silicate block is crushed in a ball mill until particles with a surface of 2500 cm ² / g are formed, mixed with a strengthening additive (Portland cement), a modifier (C-3 superplasticizer), basalt microfiber, a blowing agent (hydrogen peroxide) and mixing water and the mixture is placed in form. The mold with the mixture is subjected to heat treatment by microwave currents at t = 300 ° C and a processing time of 15 minutes.

According to the proposed method for the preparation of a new structural and heat-insulating material, a series of experiments was conducted in a pilot production. The composition of the mixture for structural heat-insulating material was taken according to the formula of the claimed invention.

One of the options for the implementation of "Structural and heat-insulating material" in the composition of the ingredients is given in the following unit ratio, wt.%:

indicated silicate block 63 superplasticizer C-3 0.01 Portland cement 11.29 basalt microfiber 0.1 hydrogen peroxide 0.6 mixing water 25

The results of the experiments in the pilot plant for the production of structural and thermal insulation material:

density: 398-417 kg / m ³ ;

ultimate compressive strength: 2.5-4.5 MPa;

thermal conductivity: 0.085-0.098 W / (m · K).

Carrying out heat treatment of the mixture by the microwave current field creates conditions for uniform heating and expansion of the mixture of components. The uniformity of the porous structure of the manufactured structural and heat-insulating material and its quality (stability of its thermophysical properties) are ensured.

Also, in the proposed method, the intermediate process of cooking liquid glass is excluded and heat treatment by microwave currents is introduced at t = 300 ° C. Known methods analogues (of non-combustible materials) include heat treatment at temperatures equal to 1000-1200 ° C, and processing time for ~ 9 hours.

Comparative energy costs for the production of well-known building structural and heat-insulating materials and the proposed method for the manufacture of structural and heat-insulating material are shown in table 1.

Table 1 Comparative energy consumption No. Name of material Energy consumption, kW / m ³ one Mineral wool 10,000 2 Foam concrete, aerated concrete 1700 3 Brick 500 four Wood 180 5 Proposed structural heat-insulating material 190

Thus, the implementation of the proposed method will achieve a significant improvement in the spreadability of the proposed structural and heat-insulating material and its physico-mechanical properties. In particular, an increase in tensile strength (bending, chipping, etc.), as well as an increase in dynamic strength and fracture work. At the same time, the energy consumption and laboriousness of the production of structurally insulating products with their acceptable thermophysical characteristics will be at a minimum level.

The use of basalt microfiber in small quantities will significantly increase the strength (including dynamic) of products and work on their destruction, that is, their physical and mechanical properties. Reducing the amount of mixing water further increases the strength of the finished product and reduces the energy consumption for removing excess moisture during heat treatment. Moreover, microwave current treatment allows to obtain a temperature inside the product higher than on the surface, which contributes to uniform heating and the release of excess moisture and gases throughout the volume of the product. This will lead to the formation of a uniform porous structure of the product. The uniform composition and porosity of the heat-insulating product provide the same strength and thermophysical and other characteristics throughout the volume of the material, and also allow it to be used both facing and as elements of supporting and self-supporting structures, as a filling of building structures.

The use of a fundamentally new initial mixture, which ensures the production of a new structural and heat-insulating material at relatively low temperatures (t = 300 ° C) and its heat treatment in the field of microwave currents, makes it possible to obtain uniform physical and mechanical characteristics over the entire mass of the product with a minimum processing time.

Elements of building structures made by the proposed method can be used for high-rise construction as enclosing and self-supporting, and for low-rise construction - as supporting and enclosing.

The manufactured elements of building structures, in which blocks from the proposed structural and heat-insulating material were used, have been in operation since 2008 without visible signs of destruction of the latter.

The implementation of the method of manufacturing structural heat-insulating material in the aggregate of the features of the claims is new to the methods of manufacturing heat-insulating materials, which meets the criterion of "novelty."

The above set of features is not currently known from the prior art and does not follow from well-known rules, methods of manufacturing structural and heat-insulating materials, and this proves compliance with the criterion of "inventive step".

The implementation of the proposed method for the manufacture of structural and heat-insulating material with the specified set of essential features does not present any structural, technical and technological difficulties, hence the compliance with the criterion of "industrial applicability" follows.

List of sources used

1. USSR author's certificate No. 272879, 1967, IPC С04В 38/08.

2. USSR author's certificate No. 1282468, 1985, IPC С04В 38/02.

3. USSR author's certificate No. 1396511, 1993, IPC С04В 38/02, С04В 28/26.

4. Prototype - application for invention No. 2007121986 dated December 20, 2008, IPC С04В 28/00.

5. Patent for utility model of the Russian Federation No. 79579 dated 06.06.2008, IPC E02D 37/00, E02G 23/02.

6. Patent for utility model of the Russian Federation No. 81742 dated 03/27/2009, IPC E02C 2/06.

7. RF patent No. 2306300 dated 09/20/2007, IPC С04В 38/10.

8. RF patent №2251540 dated 05/10/2005, IPC С04В 38/02.

Claims (1)

A method of manufacturing a structural heat-insulating material, namely, that a silicate block is crushed to a specific surface of 2500 cm ² / g, mixed with a modifier, a strengthening additive in the form of Portland cement, a foaming agent in the form of hydrogen peroxide and mixing water, is poured into the product form and then heat treatment of the product with microwave currents for 15 minutes at a temperature of 300 ° C is carried out, characterized in that C-3 superplasticizer is used as a modifier, and as an additional strengthening additive use basalt microfiber in the following ratio of the components of the mixture, wt.%:
indicated silicate block 62-64 superplasticizer C-3 0.01-0.012 Portland cement 10-12 basalt microfiber 0.04-0.1 hydrogen peroxide 0.5-0.7 mixing water 25