RU2184652C2 - Method for production of lime-and-sand brick and production line for its realization - Google Patents

Abstract

FIELD: production of building materials. SUBSTANCE: the production line has tanks and proportioners for intermediate storage and production of source material components and semi-finished products, conveying systems, silo towers, ball mill which is additionally provided with a pipe-line with a proportioner for feeding of steam through a neck to the first chamber, a rod mill is installed behind the ball mill. The process consists in dosage of the binder, aggregate and water, and simultaneous feed of them to the rod mill. In the mill the components get mixed, lime is hydrated, aggregate is activated and the mix is humidified to a mounting humidity of 4 to 10%. The mix is processed in the rod mill with specific energy expenditures within 7 to 16 kJ per kilogram of dry mix. Then molding of the green brick and its autoclave processing are carried out. EFFECT: simplified production process and reduced consumption of lime. 2 cl, 1 dwg, 1 tbl

Description

 The invention relates to the production of building materials autoclaved, for example, silicate brick.

 A known method of producing silicate brick by grinding lime together with sand in a ball mill, dosing and mixing the obtained lime-silica binder with sand-aggregate, moistening the mixture in a paddle mixer, extinguishing it in a silo reactor for 1-3 hours, re-mixing with additional wetting in paddle or rod mixers. The mixture is then pressed and the raw brick is autoclaved (1).

 The disadvantage of this method is the multi-operation technology, high capital costs and increased consumption of lime, the most expensive component of the raw mix.

 There is also a method of producing silicate brick (2), which consists in the fact that the supply of water to the raw material mixture is carried out only once during the first mixing of all its components. This allows you to reduce the time of extinguishing the mixture from 2-3 hours to 10-15 minutes and to avoid the use of silos. After quenching, it is necessary to re-mix the mixture to eliminate the clods formed. This method according to the technical nature and the task is closest to the claimed and adopted as a prototype.

 The application of the method for producing silicate brick according to the prototype revealed a number of its disadvantages, namely, the degree of lime hydration is unstable and this leads to a decrease in the quality of the brick. In addition, the use of this method does not significantly simplify the technology and reduce the number of devices in the production line.

 The objective of the present invention is to significantly improve the quality of bricks, reduce lime consumption, simplify the production flowchart. The problem is solved by new technological processes that represent the essence of the proposed method for producing silicate brick.

The essence of the method for producing silicate brick according to this invention is that it includes the processes of dosing and grinding the components of the binder, mixing it with aggregate sand, moistening and extinguishing the mixture, pressing the raw material and autoclaving the brick, which differs in that the lime grinding process -silica binder in a ball mill serves water with a temperature of up to 120 ^o C or at the same time water and water vapor in an amount sufficient to hydrate calcium oxide in lime by 70-100%. Then the binder and aggregate sand, as well as additional water, are dosed and fed continuously and simultaneously to the core mill, in which the components are mixed, lime is slaked out, the aggregate is activated and the mixture is moistened to a molding moisture of 4-10%, while the raw material mixture is processed in a core mill with specific energy consumption from 7 to 16 kJ per 1 kg of dry mix.

 To implement the above-described method for producing silicate brick, a technological line has been developed consisting of containers for intermediate storage of raw materials and semi-finished products, sand, lime and binder dispensers, a ball mill, presses, autoclaves and transport systems, which differs from the known ones in that the ball mill is equipped with two pipelines with dispensers for supplying water and steam, and the production line instead of mixers contains a core mill, the productivity of which provides processing heel entire mixture with specific power consumption of 7 to 16 kJ per 1 kg of dry mix.

 The flow line diagram is shown in the drawing. The line consists of a hopper of crushed lime 1, a hopper of a kvarpeseska - a component of binder 2, batchers of lime, sand and a binder 3, a pipeline with a batcher for water 4, a pipeline with a batcher for steam 5, a ball mill 6, a container for a binder 7, a container for sand - aggregate 8, a rod mill 9, a buffer tank for the finished mixture 10, presses 11, autoclaves 12. All units and apparatuses are connected by transport systems in the form of conveyor belts, screws, elevators, trolleys, which are not shown in the diagram.

 The technological line for implementing the method of producing silicate brick works as follows. Crushed lime fraction 0-30 mm from the hopper 1 with the help of the batcher 3 is fed into a ball mill 6. At the same time from the hopper 2 to the mill 6 serves sand, as well as water or water with water vapor through pipelines with batchers 4 and 5. Water and steam are fed in an amount sufficient to extinguish lime by 70-100%.

 In a ball mill 6, fine grinding of lime is carried out and sand is coarser coarser, while the effect of chemical dispersion of lime during its hydration is used, which significantly accelerates the entire grinding process. The binder is transported to the tank 7, from where it is supplied by the dispenser 3 to the rod mill 9. Simultaneously with the binder, sand aggregate from the tank 8, as well as water, are supplied through the pipeline with the dispenser 4 to the rod mill 9.

 In the core mill 9, the binder is intensively mixed with aggregate, lime is extinguished and the raw material mixture is moistened to the desired molding moisture, which is in the range of 4-10%.

 The core mill 9 operates at a capacity that allows the processing of the raw mix with specific energy consumption in the range of 7-16 kJ per 1 kg of dry mix. Such processing allows us to additionally provide mechanochemical activation of the aggregate sand, which is coarsely crushed, and its surface is peeled from foreign minerals, which significantly increases the reactivity of quartz sand during hydrothermal synthesis of calcium silicates in an autoclave.

 The finished mixture from the core mill 9 is fed into the buffer tank 10, then distributed through the presses 11, and the formed raw material is subjected to hydrothermal treatment in autoclaves 12. where the brick acquires the necessary strength.

An example implementation of the method. Use quenching lime with an activity of 75%, which, together with sand in a ratio of 1: 1, is ground in a ball mill to a residue on sieve 008 of 5-7%, while 86 kg of water with a temperature of 90 ^o C per one is fed into the ball mill a ton of binder. The extinguishing of lime in a ball mill is carried out by 90%. The resulting binder, sand with a moisture content of 4% and water in a predetermined ratio (17% binder, 83% sand and 7% water) are continuously fed to a core mill, the productivity of which is set such that the energy consumption is 12 kJ / kg of dry mix.

 Disposable mechanochemical treatment of the mixture in a core mill provides complete slaking of lime, obtaining an additional amount of fine sand fractions (0.14 mm), grinding of clay or flock lumps in the sand and good homogenization of the mixture with a moisture content of 5.5%. The resulting brick has high physical and mechanical properties (brand "200-250"). Lime consumption is 315 kg per thousand pieces of conventional brick, which is 25% lower in comparison with the technology of the prototype.

 Distinctive features of the method and its advantages are partially reflected in the table. The technical and economic efficiency of the proposed method and the technological line for producing silicate brick consists in the possibility of increasing the physicomechanical properties of products (strength, frost resistance, durability), reducing lime consumption by 20-25%, and also simplifying production by eliminating one mixing stage and silos reactors. The technology for the production of silicate bricks and stones is becoming more manageable and stable. Depending on the magnitude of the specific energy consumption during the processing of the raw material mixture, a predetermined grade in terms of strength or a reduction in the consumption of expensive lime is stably achieved.

 The strength of the raw material, which characterizes the molding properties of the mixture, sharply increases, the appearance and preservation of the geometry of the brick are improved. Capital costs are significantly reduced due to a decrease in the volume of industrial buildings and a reduction in technological transport.

Sources of information
1. L.M. Khavkin. Silicate brick technology. M., Stroyizdat, 1982

 2. S. D. Mamontov, M. S. Schwartzzeid. Autosvid. USSR 311880 "Method for the production of silicate brick." Bulletin 08.25.1971

Claims (3)

 1. A method of producing silicate brick, including the processes of dosing and grinding the components of the binder, mixing it with aggregate, moistening and extinguishing the mixture, pressing raw material and autoclaving, characterized in that the binder, aggregate and water are dosed and fed simultaneously to a core mill, in which the components are mixed, hydrated lime, activate the aggregate and moisten the mixture to a molding moisture content of 4-10%, while the silicate mixture is processed in a core mill with specific energy consumption from 7 to 16 kJ and 1 kg of dry mix. 2. A method of producing silicate brick according to claim 1, characterized in that in the process of grinding a lime-silica binder, water is supplied to a ball mill with a temperature of up to 120 ^o C or at the same time water and water vapor in an amount sufficient for lime hydration for 70-100 %  3. A production line for implementing the method according to claim 1 or 2, consisting of containers for intermediate storage of raw materials and semi-finished products, dispensers of components and semi-finished products, a ball mill, transport systems, silos, a rod mill, presses and autoclaves, characterized in that a core mill, the productivity of which ensures the processing of the entire raw mix with specific energy consumption from 7 to 16 kJ per 1 kg of dry mix, is installed behind the ball mill, which is additionally equipped with a pipeline with ozatorom feed through the neck into the first chamber of steam.

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