RU2734982C1 - Crude mixture for making gypsum articles - Google Patents

Abstract

FIELD: construction; chemistry.

SUBSTANCE: invention relates to production of construction materials, wall blocks, slabs, panels, 3D blocks, 3D slabs, small piece cast from gypsum. Invention contains a crude mixture for making gypsum articles. Crude mixture contains semi-aqueous gypsum, aluminium sulphate Al₂(SO₄)₃, calcium hydroxide Ca(OH)₂, water and a mineral foam filler. Ratio of components in mixture is the following, wt. %: semi-aqueous gypsum 59–59.3; mineral foam filler 3.12–3.42; calcium hydroxide 0.43–0.45; aluminium sulphate 0.0260–0.1066; water is balance.

EFFECT: technical result is reduction of density and weight of articles from gypsum, their hardening without complication of production technology.

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Description

The invention relates to the field of production of building materials, wall blocks, slabs, panels, 3D blocks, 3D slabs, small-piece gypsum casting.

Known raw mixture for the production of gypsum materials obtained by a simplified technology, containing hemihydrate gypsum, aluminum sulfate, calcium hydroxide and water (RU, p. No. 2564429, IPC C04B 28/14, 09/27/2015).

The disadvantage of this composition is its sufficiently high density, which reduces the possibility of its widespread introduction into the production of 3D products from gypsum casting.

Known gypsum mixture for finishing and masonry work, the production of building parts and structures, as well as for decorative and finishing small-piece work, containing a binder based on semi-aqueous gypsum and hollow microspheres, as well as water until a test of normal density is obtained (RU, p. No. 2476402, IPC С04В 28/14, С04В 11/00, 02/27/2013.).

The invention makes it possible to reduce the density and increase the strength of the gypsum mixture, however, due to their very high fragility, hollow microspheres, due to their very high fragility, do not allow the use of a machine method for obtaining a finished raw mixture due to their destruction.

The objective of the invention is to develop the composition of the raw mixture for the manufacture of gypsum products.

The technical result of the invention is to reduce the density and weight of gypsum products, as well as to strengthen them without complicating the production technology.

The task and the specified technical result are achieved by introducing foam fillers (granular foam ceramics, foam glass) into the raw mixture for the manufacture of gypsum products.

The raw mix for the manufacture of gypsum products includes semi-aqueous gypsum, water and a complex reinforcing additive consisting of aluminum sulfate and calcium hydroxide, with the following ratio of components, wt. %: semi-aqueous gypsum 59,000-59,300, aluminum sulfate 0.0260-0.1066, calcium hydroxide 0.43-0.45, water - the rest and additionally includes a foam filler 3.12-3.42.

The introduction of a lightweight foam filler into the composition helps to reduce the average density of gypsum materials and thereby makes it possible to obtain products with increased closed porosity and reduced weight. In this case, the strength indicators of the gypsum stone do not undergo significant changes due to the interaction of the filler with the crystals of calcium sulfate dihydrate at the interface.

Examples of implementation of the claimed invention are given below:

Example 1

Mixing the gypsum binder and foam filler in a dry state was carried out mechanically using an industrial mixer until homogeneous.

Lime was mixed with water at a temperature of 20 ° C in the following proportion - 3 liters per 1 kg of lime. The mixture was stirred for 2 hours at 15 minute intervals. The solution prepared in this way was kept for 12 hours, and then the settled part of the saturated lime solution was poured off and filtered twice.

Next, the required amount of dry homogeneous mixture was weighed, it was sealed with a complex reinforcing additive, which included a saturated solution of lime - calcium hydroxide and a solution of aluminum sulfate. The calculation of the amount of solutions that make up a complex reinforcing additive for kneading gypsum dough was carried out on the basis of their stoichiometric amounts. Stirring was carried out for 30 seconds with an industrial mixer and the prepared mixture was poured into casting molds. The plaster samples were hardened at normal temperature and normal humidity.

The mixture was prepared using the following ratio of components, mass. %:

semi-aquatic gypsum - 59,000; sulphate aluminum - 0.0260; calcium hydroxide - 0.43; foam filler - 3.12 water - the rest.

Example 2 (by composition)

The mixture was prepared analogously to example 1, but used the following ratio of components, wt. %:

semi-aquatic gypsum - 59,300; sulphate aluminum - 0.1066; calcium hydroxide - 0.45; foam filler - 3.42 water - the rest.

Example 3 (by composition)

The mixture was prepared similarly to the above example, but used the following ratio of components, wt. %:

semi-aquatic gypsum - 59.150; sulphate aluminum - 0.066; calcium hydroxide - 0.44; foam filler - 3.22 water - the rest.

During the experiment, it was found that the introduction of foamed ceramics into the composition of the raw mixture in an amount of 3.32 by weight. % does not affect the strength of the gypsum stone. The compressive strength reaches 10 MPa, which corresponds to the strength of gypsum stone with the addition of aluminum sulfate and calcium hydroxide; the density is 848 kg / m ³ . In the production of products from a raw mixture, there is an increase in the efficiency and operational properties of the resulting products due to the receipt of a compacted structure of the matrix of gypsum stone in the composition of the material lightened by the foam filler.

Claims (2)

The raw mixture for the manufacture of gypsum products, including semi-aqueous gypsum, aluminum sulfate Al ₂ (SO ₄ ) ₃ , calcium hydroxide Ca (OH) ₂ and water, additionally includes a mineral foam filler with the following ratio of components, wt. %: Semi-water gypsum 59-59.3 Mineral foam filler 3.12-3.42 Calcium hydroxide 0.43-0.45 Aluminum sulphate 0.0260-0.1066 Water rest