RU2439022C1 - Crude mixture for producing silicate articles using overburden rocks from mining industry - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of construction materials, specifically to production of silicate articles using incidentally extracted overburden rocks from mining industry. The crude mixture contains lime, a finely dispersed silica component and aggregate. The finely ground silica component used is ground sandy pelite-silt rock and the aggregate used is initial sandy pelite-silt rock, with the following ratio of components in wt %: unslaked lime 6-12, ground sandy pelite-silt rock 12-24 and the initial sandy pelite-silt rock 64-82.

EFFECT: low autoclaving pressure, low power consumption on autoclave treatment, low power consumption and high efficiency of the process of making bricks, recycling overburden rocks from mining companies.

3 tbl, 8 ex

Description

The invention relates to the construction materials industry, in particular to the manufacture of silicate products, using incidentally mined overburden of the mining industry.

Known raw mix for the manufacture of silicate brick, containing, wt.%: Lime 4.8-5.2, finely ground perlite 11-12, feldspar sand 77.5-78.5 and expanded perlite sand the rest (AS USSR No. 618355, С04В 15 / 06.05.08.1978).

The disadvantage of this mixture is the low strength of raw and finished products, and autoclaving of products with high pressure steam.

Closest to the technical solution adopted for the prototype is a raw material mixture for the manufacture of silicate brick, including lime, a finely divided silica component and aggregate, contains ground granodiorite as a finely ground silica component and granodiorite screening as a filler in the following ratio of components, wt.% : ground granodiorite 15-30, granodiorite screening 60-80, lime - the rest (AS USSR No. 817001, С04В 15/06, 03/30/1981).

The disadvantage of this technical solution is that it includes autoclaving products with high pressure steam.

The purpose of the invention is the reduction of pressure autoclaving.

This goal is achieved in that the raw material mixture for the manufacture of silicate products, including lime, a finely divided silica component and a filler, contains ground sand pelitic-aleurite rock as a finely ground siliceous component, and the initial sand pelitic-aleurite rock as a filler in the following ratio of components , wt.%:

quicklime 6-12

ground sand pelit-silt rock 12-24

initial sand pelitic-silt rock 64-82

This rock in large quantities falls into the mining zone during the open development of KMA iron ore deposits.

Table 1 shows the chemical composition of the sand pelitic-aleurite rock, and in Table 2, the particle size distribution.

Table 1
The chemical composition of the rock, wt.% SiO ₂ Al ₂ O ₃ Fe ₂ O ₃ Cao MgO TiO ₂ SO ₃ K ₂ O Na ₂ O p.p.p. Amount 79,4 10.26 2,57 0.05 0.02 - - 1.28 1.15 4.19 98.92

table 2
Granulometric composition of the rock The content of fractions, wt.%, The size of the sieves, mm More than 1.25 1.25-0.63 0.63-0.315 0.315-0.10 0.10-0.04 0.04-0.01 0.01-0.005 Less than 0.005 - - 1.3 14,4 18.72 42.95 5.7 16.93

The size is dominated by silt and pelitic particles. The content of psammitic particles is 15.7 wt.%. The rock contains mainly quartz. Secondary minerals (up to 10 wt.%) Contain field wheat, kaolinite, montmorillonite, hydromica and mixed layer formations.

Comparative analysis with the prototype allows us to conclude that the inventive raw material mixture differs from the known introduction of ground sand pelitic-aleurite rock with a specific surface area of 8000 cm ² / g as a finely ground silica component, and as a filler, the initial sandy pelitic-aleurite rock, and how the consequence is a decrease in pressure autoclaving due to the high reactivity of the proposed raw materials.

Thus, the claimed technical solution meets the criterion of "novelty."

The proposed raw mix is distinguished by a new qualitative and quantitative composition, and a significantly simplified brick manufacturing technology, namely, a decrease in the pressure of autoclaving from 0.8 to 0 MPa or even replacing the autoclave treatment by steaming at atmospheric pressure.

A significant decrease in pressure of autoclaving indicates the possibility of reducing energy costs for production and increasing the level of safety of the production itself, which is associated with the peculiarities of the mineralogical composition of the rock, namely the presence of minerals of aluminum silicate composition, providing synthesis of cementitious compounds at low autoclave pressures. In addition, due to the high dispersion of the proposed raw materials, in comparison with the known (granodiorite screening), it is possible to reduce the grinding time of the siliceous component. This confirms that the claimed solution meets the criterion of "inventive step".

For the preparation of the proposed raw material mixture, quicklime is used (CaO + MgO activity = 75%) and sand pelitic-aleuritic rock with the addition of finely ground sand pelitic-silt rock, with a specific surface area of 8000 cm ² / g.

Example 1

The mixture is prepared by mixing the starting components in the following ratio of components, wt.%

quicklime - 6

ground sand pelit-silt rock - 12

initial sand pelitic-silt rock - 82

Mixed components moisturize with water up to 10% by weight of dry materials. Next, the mixture is kept in a sealed chamber until the mixture is completely extinguished within 2-3 hours. Raw brick is formed from this mixture at a pressure of 20 MPa, then steamed in a steaming chamber according to the regime of 1.5 + 9 + 1.5 at atmospheric pressure and a steam temperature of 95 + 5 ° C.

Example 2

The raw material mixture with a moisture content of 12% is prepared as in example 1, in the following ratio of components, wt.%:

quicklime - 10

ground sand pelit-silt rock - 20

initial sand pelit-silt rock - 70

Raw brick is molded as in example 1, then steamed in a steaming chamber according to the regime of 1.5 + 9 + 1.5 at atmospheric pressure and a steam temperature of 95 ± 5 ° C.

Example 3

A raw mixture with a moisture content of 10% is prepared as in example 1, in the following ratio of components, wt.%:

quicklime - 6

ground sand pelit-silt rock - 12

initial sand pelitic-silt rock - 82

Raw brick is molded as in example 1, then steamed in an autoclave according to the regime of 1.5 + 8 + 1.5 at an excess steam pressure of 2 atm.

Example 4

The raw material mixture with a moisture content of 12% is prepared as in example 1, in the following ratio of components, wt.%:

quicklime - 10

ground sand pelit-silt rock - 20

initial sand pelit-silt rock - 70

Raw brick is molded as in example 1, then steamed in an autoclave according to the regime of 1.5 + 8 + 1.5 at an excess steam pressure of 2 atm.

Example 5

The raw material mixture with a moisture content of 12% is prepared as in example 1, in the following ratio of components, wt.%

quicklime - 12

ground sand pelit-silt rock - 24

initial sandy pelitic-silty rock - 64

Raw Cypriot is molded as in example 1, then steamed in an autoclave according to the regime of 1.5 + 8 + 1.5 at an excess steam pressure of 2 atm.

Example 6

The raw material mixture with a moisture content of 12% is prepared as in example 1, in the following ratio of components, wt.%:

quicklime - 10

ground sand pelit-silt rock - 20

initial sand pelit-silt rock - 70

Raw brick is molded as in example 1, then steamed in an autoclave according to the regime of 1.5 + 8 + 1.5 at an excess steam pressure of 4 atm.

Example 7

A raw mixture with a moisture content of 10% is prepared as in example 1, in the following ratio of components, wt.%:

quicklime - 6

ground sand pelit-silt rock - 12

initial sand pelitic-silt rock - 82

Raw brick is molded as in example 1, then steamed in an autoclave according to the regime of 1.5 + 8 + 1.5 at an excess steam pressure of 8 atm.

Example 8

The raw material mixture with a moisture content of 12% is prepared as in example 1, in the following ratio of components, wt.%:

quicklime - 10

ground sand pelit-silt rock - 20

initial sand pelit-silt rock - 70

Raw brick is molded as in example 1, then steamed in an autoclave according to the regime of 1.5 + 8 + 1.5 at an excess steam pressure of 8 atm.

After seven days of exposure under natural conditions, the bricks are tested for compressive and bending strength according to GOST 8462-85. The results of physical and mechanical tests are presented in table.3.

Table 3
Physico-mechanical characteristics of silicate products Indicator Example Prototype one 2 3 four 5 6 7 8 The limit of compressive strength, MPa 23,2 19.2 28,4 28.9 23.8 28.5 27 30,4 22.6-28.8 Bending Strength, MPa 6.9 5 6.9 7.2 6.3 7.8 8.4 9,4 7.5-9.1 The average density, kg / m ³ 1960 1870 1960 1920 1850 1930 1980 1900 2140-2190 Water absorption,% 11.72 14.18 11.84 13.1 13.30 11.92 12.18 14.35 - Softening coefficient 0.85 0.78 0.74 0.87 0.92 0.95 0.73 0.77 - Frost resistance, in cycles, not less fifteen fifteen 25 35 35 35 fifty fifty - The compressive strength of raw, MPa 1.92 2.1 1.92 2.1 2.1 2.1 1.92 2.1 -

From table 3 it is seen that this raw material provides a high raw strength of 1.92-2.1 MPa, the strength of the finished products is comparable with the strength of the products of the prototype, water absorption is 11.72-13.30%, frost resistance depending on the pressure of the autoclaving is within 25-50 cycles, which meets the requirements for facing silicate brick. Products obtained by hydrothermal treatment at atmospheric pressure have a frost resistance of 15 cycles, which meets the requirements for ordinary silicate brick. High values of the softening coefficient of 0.74-0.95 for all modes of hydrothermal treatment indicate high water resistance of the material. The resulting products have an average density of 1870-1980 kg / m ³ , which is lower than that of the prototype 2140-2190 kg / m ³ .

Silicate brick with the use of sand pelitic-aleurite rock has a brown color and does not require the introduction of pigments for coloring, can be used as a facing material. The high strength of the raw material will reduce marriage during the molding process and facilitate the production of high-hollow products.

The inventive compositions of the raw mixture have a high reactivity, which allows to obtain products at a reduced pressure autoclaving (from 0.8 to 0 MPa), which in turn will reduce energy costs for autoclaving, thereby reducing energy consumption and increasing the productivity of the production process. Using the proposed compositions of raw mixtures will solve the problem of disposal of overburden rocks of mining enterprises and at the same time get a variety of silicate building products for housing, civil and rural construction.

Claims (1)

The raw material mixture for the manufacture of silicate brick, including lime, a finely divided silica component and aggregate, characterized in that, in order to reduce the pressure of the autoclaving, it contains ground sand pelitic-aleuritic rock as a finely ground siliceous component and the source sand pelitic aleri as a filler breed in the following ratio of components, wt.%:
quicklime 6-12 fine sandy pelitic-aleuritic rock 12-24 initial sand pelit-silt rock 64-82