RU2589120C1 - Composition for making porous aggregate - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to production of construction materials, particularly to production of porous aggregates based on liquid glass, meant for making light concrete, as well as fill insulations. Composition for making porous aggregate contains, wt%: liquid sodium glass with density of 1.41 g/cm³ 50-75, sodium chloride ground to particle size less than 0.3 mm 1-3, burnt rocks, ground to passage through sieve 0.14 mm, 12-34, nepheline sludge wastes ground to passage through sieve 0.14 mm with content of oxides, wt%: SiO₂ - 31.9, Al₂O₃+TiO₂ - 5.8, Fe₂O₃ - 4.3, CaO - 55.7, MgO - 1.4, R₂O - 1.8, SO₃ - 0.5, 10-15.

EFFECT: technical result is increased compression strength and softening coefficient of porous aggregate, recycling industrial wastes.

1 cl, 4 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. 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 during calcination of at least 16% - 22-49 (Patent No. 2481286 of the Russian Federation, IPC С04В 14/24. Composition for the production of water-resistant porous aggregate / Abdrakhimov V.Z., Semenychev V.K., Abdrakhimova E.S., Vdovina E.V .; applicant and patent holder Samara State Academy and municipal government; announced June 29, 2011; publ. May 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, an additional nepheline dump slurry is added, milled before passing through a sieve of 0.14 mm with an oxide content, wt.%: SiO ₂ - 31.9; A1 ₂ O ₃ + TiO ₂ - 5.8; Fe ₂ O ₃ - 4.3; CaO - 55.7; MgO - 1.4; R ₂ O - 1.8 and SO ₃ - 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 burnt rocks, ground before passing through a sieve of 0.14 mm 12-34 nepheline waste slurry, ground prior to passage through a 0.14 mm sieve 10-15

Nepheline sludge (belitic) is a sandy mixture with pronounced astringent properties. The nepheline sludge of the Achinsk Alumina Refinery (Rusal Achinsk OJSC, Krasnoyarsk Territory) is the tail product of the Kiya-Shaltyr nepheline and limestone of the Mazul mine, obtained after the extraction of alumina and soda products.

The raw material base of the Achinsk alumina refinery (AGK) is made up of the Kiya-Shaltyrsky nepheline mine (Kemerovo region), where ore is mined by open pit mining, and the Mazulsky limestone mine (Achinsk). AGK works on a unique technology developed by the All-Russian (All-Union) Aluminum-Magnesium Institute (VAMI). It is based on the use of the method of sintering nepheline ore with limestone and subsequent hydrochemical processing of cake. AGK is the only enterprise in the world engaged in the industrial processing of nepheline ore. The chemical composition of nepheline dump slurry is shown in table 1.

Phase-mineralogical composition of nepheline dump slurry, wt.%: 85 - belite (β-2СаО · SiO ₂ ); the total content of impurity phases is 15%, including: 4 - Ca (OH), 3 - CaCO ₃ , 2 - hydrocarboaluminate (3CaO · A1 ₂ O ₃ · CaCO ₃ · 11H ₂ O), 2 - sodium hydroaluminosilicate (Na ₂ O · A1 ₂ O ₃ · 2SiO ₂ · 2H ₂ O), 2 - nepheline, 2 - glass.

The presence in the sludge of minerals with the hydraulic activity of belite (C ₂ S), and their hydrates, determines the possibility of obtaining binders together with liquid glass.

The particle size distribution of nepheline sludge is presented in table 2.

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 of 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 finely ground components - burnt rocks and nepheline dump slurry, ground before passing through a sieve of 0.14 mm

Information confirming the possibility of carrying out the invention. Compositions (table 3) for the production of porous aggregate was prepared by thoroughly mixing all the components, similar 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 with 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 4.

As can be seen from table 4, the porous aggregates of the proposed compositions have higher compressive strength and softening coefficient than the prototype.

The technical solution when using nepheline dump slurry in the proposed compositions allows to increase the compressive strength and softening coefficient of the porous aggregate.

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

Claims (1)

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, characterized in that it further contains nepheline waste slurry, ground before passing through a sieve of 0.14 mm with an oxide content, wt.%: SiO ₂ - 31.9, Al ₂ O ₃ + TiO ₂ - 5.8, Fe ₂ O ₃ - 4.3, CaO - 55.7, MgO - 1.4, R ₂ O - 1.8 and SO ₃ - 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 burnt rocks, ground before passing through a sieve of 0.14 mm 12-34 nepheline waste slurry, ground prior to passage through a 0.14 mm sieve 10-15