RU2024460C1 - Raw mix for autoclave-free silicate material - Google Patents

Abstract

FIELD: manufacture of autoclave-free wall and free silicate material. SUBSTANCE: in order to prepare a raw mix, the following components are used (wt % ): 5-20 iron are beneficiation waste; and 10-30 ferrosilicium production dust, to reduce the raw mix preparation time, 0.5-20% blast furnace granular slag may be additionally added, and to reduce the duration of the technological cycle for manufacturing an autoclave-free silicate material, the time-containing component may be the dust resulting from the aspiration of lime kilns retain portions of the previously prepared dry components of the raw mix are stirred, moistened to a molding moisture content of 10 wt %, once again stirred and kept in desiccators for 2 hours. The resulting mixture is additionally made moistened to prepared nonstratifying solid raw material and cylindrical specimens are stirred and pressed. They are subjected to heat moisture treatment in a steam curing chamber for 1-1.5+2+6+2 hr and maintained at an isothermal temperature of 90± 2^°C. EFFECT: improved mechanical strength by 3-6 times, water resistance by 25-70% and frost resistance for at least 25 cycles. 3 cl, 3 tbl

Description

 The invention relates to building materials and can be used in the manufacture of wall and facing autoclave-free silicate material.

 Known raw material mixture using dust fly ash of metallurgical industries in the manufacture of autoclaved silicate materials, consisting, by weight. %: lime 6-8; fly ash 0.4-2, foundry dust 10-20; sand 70-83.6 [1].

 The disadvantage of this technical solution is that it includes autoclaving products with high pressure and temperature steam and cannot be used in the production of silicate autoclave-free materials.

 The closest technical solution, selected as a prototype, is a mortar, USSR author's certificate N 637359, MKI3 04 04 13/06, including, wt.%: Lime 20-20,4; iron ore dressing waste 56.7-64.8; dust-fly production of ferrosilicon 2.4-7.0; PRS 0.03; water the rest.

 The disadvantages of this technical solution are low mechanical strength, water resistance and frost resistance of the material.

 The aim of the invention is to increase the mechanical strength, water resistance and frost resistance of autoclave-free silicate material.

This goal is achieved in that the raw material mixture for obtaining autoclave-free silicate material contains these components in the following ratios, wt.%:
Lime-containing
component (in terms of active CaO and MgO) 5-20
Iron ore dressing waste 50-80
Dust-fly production of ferrosilicon 10-30
In order to reduce the duration of the preparation of the raw mix for autoclave-free silicate material, it additionally contains blast furnace granulated slag in the following ratios of components, wt.%:
Lime-containing
component (in terms of active CaO and MgO) 5-20
Iron ore dressing waste 50-80
Dust-fly production of ferrosilicon 10-30
Granulated blast furnace slag 0.5-20
In order to reduce energy consumption and reduce the duration of the technological cycle for the manufacture of autoclave-free silicate material, it contains a dust-containing component of the dust-extraction of aspiration of lime kilns as a lime-containing component in the following ratios of components, wt.%:
Lime-containing
component (in terms of active CaO and MgO) 5-20
Iron ore dressing waste 50-80
Dust-fly production of ferrosilicon 10-30
The advantage of the claimed technical solution is that the amount of lime and silica-containing (dust-fly-off production of ferrosilicon) components is selected in such a way that after heat-moisture treatment it allows them to almost completely react with the formation of calcium hydrosilicates of medium basicity. This provides both high mechanical strength and water resistance, as well as increased frost resistance of autoclave-free silicate material.

 In the prototype, an excess of lime is accepted, which remains in a free form to a greater extent after heat-moisture treatment, thereby reducing the mechanical strength, water resistance and frost resistance of the stone.

 In the case of additional introduction of blast furnace granulated slag into the composition of the raw material mixture, the aggregation of particles of the lime-containing component during grinding is reduced, favorable working conditions of the mills are created, the grinding time of the lime-containing component is reduced to the required fineness, and the time for preparing the raw material mixture is reduced.

 The use of a lime-containing component of a raw material mixture of dust-entrainment of suction of lime kilns allows to completely eliminate the grinding operation of the lime-containing component, which reduces energy consumption for grinding, and reduce the time of the technological cycle of manufacturing autoclave-free silicate material by eliminating the grinding operation.

 To obtain the mixture, the following components were prepared (for characteristics, see Table 1): lump lime, iron ore dressing waste, dust removal of ferrosilicon production, blast furnace granulated slag, dust removal of aspiration of lime kilns.

 Lump lime and blast furnace granulated slag were previously crushed in a jaw crusher to a maximum size of 10 mm.

PRI me R 1. Lump lime is ground in a ball mill to a specific surface of 250-300 m ² / kg The dosed dry components are mixed, moistened to a molding moisture content of 10 wt.%, Mixed and kept in desiccators for 2 hours. The resulting mixture is additionally moistened to a molding moisture, which is necessary to obtain a strong, immiscible raw material, cylinder samples with a diameter and a height of 50 mm are mixed and pressed. The samples are subjected to heat and humidity treatment in a steaming chamber according to the regime of 1-1.5 + 2 + 6 + 2 h and an isothermal exposure temperature of 90 ± 2 ^o C.

 The compositions of the raw mixes and the physicomechanical characteristics of the samples are given in Table 2.

PRI me R 2. In order to reduce the duration of the preparation of the raw material mixture, the lime-containing component (lump lime) is milled together with blast furnace granulated slag to a specific surface of 250-300 m ² / kg. At the same time, the cooking time of the raw mix is reduced by 25-30 minutes (see table. 3). Further operations for the manufacture of autoclave-free silicate material are carried out analogously to example 1.

 The compositions of the raw mixes and the physicomechanical characteristics of the samples are given in Table 2 (compositions 1-3 - known).

 PRI me R 3. In order to reduce energy consumption and reduce the duration of the technological cycle of manufacturing a silicate, non-autoclave material, dust-carrying-off of the aspiration of lime kilns is used as a lime-containing component. In this case, grinding of the lime-containing component is completely excluded, which reduces the duration of the technological cycle by 150 min, necessary for grinding the lime-containing component (see example 1) and reduces energy consumption by 7.0 kWh / t of lime-containing component (see table 3) . Further execution of the example is carried out analogously to example 1.

 As can be seen from table 2, the best from the point of view of achieving the goal are compositions 4-9, 15-19, 26-31.

 When using in the composition of the raw material mixture 3 wt.% Lime-containing component (10,11,23-25,32-33) the strength of the obtained products is 10-50% higher compared to the prototype, but a low softening coefficient (0.23-0, 35) and the products do not withstand 25 cycles of frost resistance due to the low content of lime-containing component.

 With an increase in the lime-containing component in excess of 20 wt.% (12-14,21,22,23,34-36), the mechanical strength does not exceed that for the prototype (12,21,34) due to the large amount of highly basic calcium hydrosilicates formed and the presence of incompletely bound lime . This leads to low water resistance (12,14,21,22,34-36) and frost resistance.

 An increase in the content of iron ore dressing wastes over 80 wt.% (10,23,32) leads to a decrease in mechanical strength, water resistance and frost resistance due to the low concentration of binder.

 A decrease in the consumption of iron ore dressing waste below 50 wt.% (13,22,35) leads to a sharp decrease in water resistance and insufficient frost resistance (not lower than 0.75), despite the high mechanical strength in the dry state.

 With the introduction of less than 10 wt.% Dust-fly ash from the production of ferrosilicon (10,21,23,32,34) into the raw material mixture, lime is incompletely bonded to the heat-moisture treatment process and, as a result, the physical and mechanical properties of the autoclave-free silicate material decrease (strength , water resistance, frost resistance).

 The introduction of more than 30 wt.% Dust-fly ash from the production of ferrosilicon (11,13,22,33,35) into the raw material mixture leads to a decrease in water resistance and frost resistance of products due to incompletely reacted dust-fly ash from the production of ferrosilicon.

 The dosage optimality of blast furnace granulated slag in the composition of the raw material mixture is determined from the data in Table 3.

 When adding 5 wt.% Blast furnace slag to lump lime, grinding time and specific energy consumption are slightly reduced. An increase in the input of blast-furnace slag more than 50 wt.% To lump lime worsens the grinding ability of the binder and increases the specific energy consumption. The mechanical strength is also slightly different from the prototype at low water resistance and frost resistance of products.

Thus, the optimal compositions in order to increase the mechanical strength, water resistance and frost resistance of autoclave-free silicate material are selected on the basis of experimental data and are in the range, wt.%:
Lime-containing
component (in terms of active CaO and MgO) 5-20
Iron ore dressing waste 50-80
Dust-fly production of ferrosilicon 10-30
Blast furnace slag (granular) 0.5-20
The proposed composition of the raw material mixture for autoclave-free silicate material exceeds mechanical strength in comparison with the prototype by 3-6.6 times, water resistance by 25-70%, and has frost resistance of at least 25 cycles.

 In the case of using blast furnace granulated slag in the composition of the raw material mixture, the mixture preparation time is reduced by 25-30 minutes compared to the prototype.

 When used as a lime-containing component of dust-entrainment of aspiration of lime-kilns, the duration of the technological cycle is reduced by 2-2.5 hours and energy costs are reduced by at least 7.0 kWh / t of lime-containing component.

Claims (2)

1. RAW MATERIAL MIXTURE FOR AN INDEAVY CLAVICOUS SILICATE MATERIAL, comprising a lime-containing component, iron ore dressing waste and dust-fly of ferrosilicon production, characterized in that, in order to increase strength, water resistance and frost resistance, it contains these components in the following ratio, wt.%:
lime-containing component (in terms of active CaO + MgO) 5 - 20
Iron ore dressing waste 50 - 80
Ferrosilicon dust fly ash 10 - 30
2. The mixture according to claim 1, characterized in that, in order to reduce the duration of the preparation of the mixture, it additionally contains 0.5 to 20% of blast furnace granulated slag.  3. The mixture according to claim 1, characterized in that, in order to reduce energy consumption and reduce the duration of the technological cycle for the manufacture of autoclave-free silicate material, it contains lime-containing component of dust-extraction of aspiration of lime kilns.

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