RU2242437C2 - Batch for production of cellular glass - Google Patents

Abstract

FIELD: building materials useful in particular as lightweight building, acoustic and ornamental materials.

SUBSTANCE: claimed batch contains (mass %) foaming agent 0.1-1.0; hemihydrate plaster as stabilizer of cellular structure 1.0-8.0; Portland cement 0.5-10.0; and balance: glass. Foam slurry of batch is hold in molds and stabilized during 4-8 h. Drying and baking of stabilized foam slurry are carried out without moldings.

EFFECT: reduced energy intensity; cellular glass with increased mechanical strength and improved ornamental properties.

3 cl, 1 ex, 2 tbl

Description

The invention relates to building materials and can be used as a light building and acoustic decorative material.

Known charges for producing cellular glass, consisting of crushed glass and foamed foaming agent in water, providing for the fixation of the cellular structure with subsequent sintering [1].

However, these charges in a foamy state are unstable in time, they are destroyed during drying, since they practically do not have mechanical strength. The resulting blocks of cellular glass from such blends after sintering have an inhomogeneous structure and density.

Closest to the proposed is a mixture for the manufacture of cellular glass, in which as a foaming agent use a soap root containing 32 ... 33% saponin in an amount of 0.5-2% of the mass of glass, and bentonite or refractory clay as a foam stabilizer 4-6% and soluble glass with a specific gravity of 1.26 3-4%, the rest is glass [2].

The disadvantage of this mixture is the lack of mechanical strength obtained by drying the foam. The transportation of dried honeycomb glass blocks for firing and the firing process itself is associated with shocks and vibrations, leading to the violation of extremely fragile structures of ground glass, which leads to a high percentage of rejected finished products and unproductive energy and material resources. The fragile structure of unfired cellular glasses does not allow to introduce decorative granular inclusions into their composition, to pre-anneal machining and calibrate block sizes. Processing sintered blocks of cellular glass is laborious, requires a large consumption of hardware and manual labor.

The present invention solves the problem of increasing mechanical strength, reducing the energy intensity of production and improving the decorative properties of cellular glass.

To achieve the task, the mixture for the manufacture of cellular glass, including glass, a foaming agent and a stabilizer of the cellular structure, according to the proposed solution, semi-aquatic gypsum is used as the stabilizer of the cellular structure and it additionally contains Portland cement grade 400-600 in the following ratio of components, wt.%:

Foaming agent 0.1-1.0

Semi-aquatic gypsum 1.0-8.0

Specified Portland cement 0.5-10.0

Glass Else

For a more complete achievement of the task, the exposure of the foam suspension of the charge in the forms and its stabilization is carried out for 4-8 hours.

For a more complete achievement of the task, the drying and firing of the stabilized foam suspension of the mixture is carried out without metal forms.

As a foaming agent, for example, “morpene” (TU 0258-001-01013393-94) is used.

Increasing the mechanical strength and reducing the energy intensity of the production of cellular glass made from a raw material charge with the addition of semi-aquatic gypsum and Portland cement is based on the peculiarities of the processes of physical and physico-chemical nature that occur during the formation and stabilization of the structure, drying, preparation for firing and firing of cellular glass.

To prepare a charge of cellular glass, one of the types of glass is used, for example, the battle of container glass; it is ground in ball mills to a specific surface of 300-600 m ² / kg. At the final stage of glass grinding, semi-aquatic gypsum and Portland cement are introduced. The last two components have a dispersion commensurate with the dispersion of the glass; therefore, at the last stage of grinding the glass, mixing of the three components of the mixture practically occurs. Mixing is carried out until a homogeneous distribution of the components by mass of the mixture is achieved (determined by accelerated chemical analysis of samples taken from different points of the mill). It is allowed to mix ground glass with semi-aquatic gypsum and cement in a separate mixer.

Technical foam is prepared in a foam generator. The amount of foaming agent is selected based on the requirements for the structure and degree of stability of the resulting foam. The blowing agent consumption is 0.1-1.0% by weight of the charge materials.

Mixing technical foam with a mixture of glass, semi-aquatic gypsum and Portland cement is carried out, for example, in a high-speed paddle mixer for 5-10 minutes. After that, the resulting mixture is poured into molds, forming blocks, plates and other products. The mixing time of the dry components of the mixture with technical foam is limited by the fact that the semi-aquatic gypsum begins to hydrate, while in the foam suspension water is bound, and crystalline hydrates of the two-gypsum are formed. These two processes occur simultaneously, while the initial structure of the cellular glass block is created and fixed. Introduction to the composition of the raw material mixture of semi-aquatic gypsum in an amount of 1.0-8.0 wt.% Allows you to fix the spatial structure that prevents settling in the form of the obtained cellular glass, however, an increase in the content of gypsum binder in the mixture over 8.0 wt.% Does not allow to obtain enough strong samples capable of withstanding form stripping and allowing subsequent sintering without molds. The function of further strengthening the structure of the obtained foam is taken over by Portland cement grade 400-600 introduced into the mixture in an amount of 0.5-10.0 wt.%.

After 1.5-2.0 hours after mixing technical foam with the dry components of the charge, an intensive increase in the strength of the obtained foam begins due to hydration of Portland cement.

After 4-10 hours, the foam reaches a strength that can be removed from the molds, dried, machined and then sintered, i.e. obtaining the final product - cellular glass.

Analysis of the strength characteristics of the obtained cellular glass samples at different technological stages shows:

- use raw materials with a foaming agent content of less than 0.1 wt.%, semi-aquatic gypsum less than 1.0 wt.%, Portland cement less than 0.5 wt.% is impractical, because the resulting semi-finished cellular glass during exposure to the mold does not gain sufficient strength to remove it from the mold without damage, and the low strength of the initially stabilized structure does not preclude the destruction of samples during transportation and drying (charge 3);

- to use the mixture with a foaming agent content of more than 1.0 wt.%, semi-aquatic gypsum more than 8.0 wt.% and Portland cement more than 10 wt.% is also impractical, since there is an unreasonable overspending of the foaming agent, cement and semi-aquatic gypsum as a result of hydration form too strong a structure in the fired block that prevents thermal shrinkage of the glass; as a result, the fired blocks of cellular glass have many shrinkage cracks that cause a sharp release of strength (charge 5).

The mixture 6, prepared according to the prototype, has extremely low initial strength characteristics, which do not allow firing blocks of cellular glass without molds. The use of expensive metal forms during firing of cellular glass leads to their rapid wear (oxidation, thermal deformation); they also require a protective coating to prevent glass from sticking. Very laborious and difficult is the process of unloading the calcined blocks from the hot molds and the direction of the blocks for annealing. The presence of forms makes it difficult to visually monitor the processes occurring at temperatures of 740-760 ° C in the furnace. Heating molds leads to additional energy consumption. These disadvantages are deprived of the claimed mixture to obtain a cellular glass. In addition, the sturdy structure of the stabilized foams allows porous and decorating additives to be introduced into the honeycomb glass mass to reduce product weight and improve the appearance of the products.

An example of a cellular glass

The raw material base for producing cellular glass is extremely wide: waste from the glass industry, container, sheet, ampoule, kinescope, electric lamp glass, glass blocks, etc. Glass cullet (in our case, sheet glass) after the jaw crusher was crushed in a hammer mill, dosed, loaded into ball mill and brought to a specific surface area of 450-500 m ² / kg At the final stage of grinding, semi-aqueous gypsum and Portland cement were introduced (in our case, Portland cement of the “500” grade manufactured by Belgorodsky Cement CJSC, Belgorod). Joint grinding was carried out until a uniform distribution of the components over the mass of the mixture was achieved. Ready dry mixture was unloaded into the hopper.

Technical foam was prepared in a foam generator. In our case, we used the “morpen” foaming agent (manufactured by LLC “SPO Shield”, Shebekino, Belgorod Region, according to TU 0258-001-01013393-94).

The technical foam was mixed with the dry components of the resulting mixture in a high-speed paddle mixer for 10 minutes. The ratio of components in the mixture are presented in table 1.

The resulting mixture was unloaded in plastic molds with removable walls. It was kept at 20-24 ° C for 8 hours. The forms were disassembled, the samples were sent for drying and dried to a moisture content of 3-5%. Firing was carried out at a temperature of 740-750 ° C for 20 minutes until complete heating, achieving uniform volumetric shrinkage of the sample to a density of 400 kg / m ³ . After firing, the samples were sent for annealing. In the process of annealing, a slow uniform cooling of the samples occurs at a rate of 0.6-0.8 ° C / min to a temperature of 50 ° C. Annealing took 10-12 hours.

Table 1 presents the specific compositions of cellular glass, in table 2 their strength properties.

As can be seen from the above tables, the use of the inventive charge for the production of cellular glass will reduce labor and energy costs and get high-strength building materials. In addition, waste of any kind of glass is disposed of.

Literature

1. Boldyrev A.S. and other building materials. Directory. M .: Stroyizdat, 1989.-S. 490-491.

2. Spirin Yu.L. Handbook for the production of heat and sound insulating materials. M .: Stroyizdat, 1975. 325-328.

Claims (3)

1. The mixture for the manufacture of cellular glass, including glass, a foaming agent and a stabilizer of the cellular structure, characterized in that as a stabilizer of the cellular structure using semi-aquatic gypsum and it additionally contains Portland cement grade 400 - 600 in the following ratio, wt.%: Foaming agent 0.1 - 1.0 Semi-aquatic gypsum 1.0 - 8.0 Specified Portland cement 0.5 - 10.0 Glass Else 2. The mixture according to claim 1, characterized in that the exposure of its foam suspension in the forms and its stabilization spend 4 to 8 hours 3. The mixture according to claim 1, characterized in that the drying and firing of its stabilized foam suspension is carried out without metal forms.