RU2622060C1 - Composition for porous aggregate production - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: composition for the porous aggregate production includes, wt %: liquid sodium glass with the density of 1.41 g/cm³ 50-75, sodium chloride ground to the size less than 0.3 mm, 1-3, burnt rocks ground before passing through the 0.14 mm sieve, 12-34, microsilica from the ferrosilicon and ferroalloys production with the average particle size of not more than 0.25 microns and containing oxides, wt %: SiO₂ 97.8; CaO 1.3; MgO 0.4; R₂O 0.5, 10-15.

EFFECT: increasing the compressive strength and the softening coefficient of the porous aggregate, industrial waste recycling.

3 tbl

Description

The invention relates to the production of building materials, in particular the production of porous aggregates based on liquid glass, intended for the manufacture of lightweight concrete, as well as heat-insulating fillings.

A known composition for producing expanded clay (porous aggregate) composition, wt.%: Waste coal flotation - 60, modified liquid glass - 40 / Denisov D.Yu. The use of coal flotation waste in the production of expanded clay / D.Yu. Denisov, I.V. Kovkov, V.Z. Abdrakhimov // Bashkir Chemical Journal. - 2008. - Volume 15. - No. 2. - S. 107-109 /.

The disadvantage of this composition of the ceramic mass is the relatively low strength of 1.7-1.9 MPa.

A known composition for producing a waterproof porous filler composition, wt.%: Sodium liquid glass - 50-70, sodium chloride - 1-3, burned rocks with a clay content of at least 50% and loss on ignition at least 16% - 22-49 / Patent No. 2481286 Russian Federation, IPC С04В 14/24. Composition for the production of waterproof porous aggregate / Abdrakhimov V.Z., Semenychev V.K., Abdrakhimova E.S., Vdovina E.V .; applicant and patent holder Samara Academy of State and Municipal Administration; claimed 06/29/2011; publ. 05/10/2013. Bull. 13.

The disadvantage of this composition is the relatively low compressive strength (2.0-2.12 MPa) and softening coefficient (93-94).

This technical solution is taken as a prototype.

The technical result is to increase the compressive strength and softening coefficient of the porous aggregate.

The specified technical result is achieved by the fact that in the composition for obtaining a waterproof porous aggregate, including sodium liquid glass with a density of 1.41 g / cm ³ , sodium chloride, ground to a size of less than 0.3 mm, and burned rocks, ground before passing through a sieve 0 , 14 mm, silica fume is additionally introduced from the production of ferrosilicon and ferroalloys with an average particle size of not more than 0.25 microns with an oxide content, wt.%: SiO ₂ - 97.8; CaO - 1.3; MgO - 0.4; R ₂ O - 0.5 in the following ratio of components, wt.%:

sodium liquid glass with a density of 1.41 g / cm ³ 50-75 sodium chloride, ground to a size of less than 0.3 mm 1-3 burned rocks 12-34 silica fume from the production of ferrosilicon and ferroalloys 10-15

Silica fume is a technogenic raw material from the production of ferrosilicon and ferroalloys. The specific surface of silica fume is in the range from 40,000 to 60,000 cm ² / g, and the average particle size is not more than 0.25 μm (25⋅10 ^-8 m). Silica fume has a low thermal expansion coefficient (temperature coefficient of linear expansion) - 0.5⋅10 ^-6 ° С ^-1 , which will increase the heat resistance of porous materials.

Silica fume from the production of ferrosilicon and ferroalloys is an ultrafine material consisting of spherical particles obtained in the process of gas cleaning of furnaces in the production of silicon-containing alloys. The main component of the material is silica of amorphous modification. The chemical composition of silica fume from the production of ferrosilicon and ferroalloys is presented in table 1.

Burned rocks formed after spontaneous combustion of oil shale were used as a finely ground filler to obtain a water-resistant porous filler. Burned rocks form in the shale mining areas. Slate, which could not be separated from the waste in the mining process, is sent to the dump. In heaps with joint storage of waste rock and shale due to the increased amount of organic compounds in the mixed waste masses, spontaneous combustion occurs, which leads to the formation of a large amount of waste - burnt rocks. Burned rocks are a product of low-temperature firing during spontaneous combustion of the rock (a mixture of clay and shale) in heaps in an oxidizing environment. The amount of burnt rocks in the heaps ranges from 75 to 90% of the dump volume. The chemical composition of burned rocks formed after spontaneous combustion of oil shale is presented in table 1.

Burned rocks, unlike clay components, although they contain more than 50% clay minerals, do not have plasticity and binding ability.

1) Commodity sodium liquid glass with a density of 1.41 g / cm ^{3 was} used as liquid glass (binder) (see GOST 13075-81).

2) Sodium chloride (GOST 13830-97, manufactured by Bassol OJSC), milled to a size less than 0.3 mm, was used as a coagulator additive.

3) As fine-grained components - burned rocks and silica fume from the production of ferrosilicon and ferroalloys, grinded before passing through a 0.14 mm sieve.

Information confirming the possibility of carrying out the invention. Compositions (table 2) for the production of porous aggregate was prepared by thoroughly mixing all the components similarly to the technology presented in the prototype. The mixture was produced in a forced action mixer in the following order. First, finely ground components and sodium chloride were loaded into the mixer, which were thoroughly mixed, then sodium glass was poured into the finished dry mixture with the mixer turned on. Mixing was carried out until a homogeneous mass, but not less than 5 minutes.

The resulting mixture by a system of knives was cut into individual granules, which were heat treated at 250-300 ° C in an oven granulator, swelling at the same time and forming spherical highly porous granules. The obtained granules were placed in an electric furnace, heated to a temperature of 790 ° C, and kept there for 10 minutes. After isothermal exposure, the granules were cooled at a cooling rate of 40 ° C / min. Physico-mechanical properties of the porous aggregate are presented in table 3.

As can be seen from table 3, the porous aggregates of the proposed compositions have higher compressive strength and softening coefficient than the prototype.

The technical solution when using silica fume from the production of ferrosilicon and ferroalloys in the proposed compositions allows to increase the compressive strength and softening coefficient of the porous aggregate.

The use of technogenic raw materials in the production of porous aggregate contributes to the utilization of industrial waste, environmental protection, the expansion of the raw material base for ceramic materials.

Claims (2)

Composition for the production of porous aggregate, including sodium liquid glass with a density of 1.41 g / cm ³ , sodium chloride, ground to a size of less than 0.3 mm and burned rocks, ground before passing through a sieve of 0.14 mm, additionally contains silica fume from the production of ferrosilicon and ferroalloys with an average particle size of not more than 0.25 microns, with an oxide content, wt.%: SiO ₂ - 97.8; CaO - 1.3; MgO - 0.4; R ₂ O - 0.5 in the following ratio of components, wt.%: sodium liquid glass with a density of 1.41 g / cm ³ 50-75 sodium chloride, ground to a size of less than 0.3 mm 1-3 burned rocks 12-34 silica fume from the production of ferrosilicon and ferroalloys 10-15