RU2845039C1 - Glass dolomite sheets production process line - Google Patents

Abstract

FIELD: construction materials.

SUBSTANCE: invention relates to the field of the construction materials industry and serves for the manufacturing of sheet materials from low-fired magnesia raw materials, mainly of caustic dolomite. Invention comprises process line for production of glass dolomite sheets intended for making partitions, inner lining of premises (walls, ceilings) of residential and public purposes. Process line contains four sections: the first section for receiving and supplying raw materials with perlite, metakaolin, fibre, superplasticizer and caustic dolomite, magnesium chloride salt solution with bischofite, second section for proportioning and mixing of components, third section for mechanical activation of caustic dolomite with super plasticizer, fourth section for moulding glass dolomite sheet.

EFFECT: high strength of glass dolomite sheets, simple process of making said sheets.

1 cl, 1 dwg

Description

The invention relates to the field of the building materials industry, namely to a method for producing sheet materials using a low-fire magnesia binder.

A method is known for producing glass-magnesite sheets (RU 2008145190 A) by mixing the components of a raw material mixture: magnesium oxide MgO with magnesium chloride MgCl ₂ , fillers, wood waste and oxidizers for the purpose of further molding.

The disadvantage of the proposed method of sheet production is the cost of introducing additional components of the mixture - oxidizers, sensitive reagents. The large variability of the raw materials used as filler (perlite, sand, dolomite flour, fly ash, slag, foaming agent) can lead to an uncontrolled decrease in the quality of finished products.

A method for producing reinforced building material from magnesite binder is known (RU 2100190 C1). The process line consists of the following sections: raw material warehouse, molding mixture preparation, molding, preliminary curing, subsequent processing, finished product warehouse and curing. Sheet molding is performed by feeding the molding mixture through a tray with simultaneous pulling of the reinforcing material through a layer of magnesite binder.

A significant disadvantage of this method is the use of a thin material in the form of a film to limit the formed sheet on both sides, which entails additional costs for tooling consumables due to increased wear rate and limited service life.

The invention (RU 2772474 C1) "Technological line for the production of glass dolomite sheets" is accepted as a prototype, which proposes a technological line for the production of composite sheet material based on magnesia binder from caustic dolomite, with a smooth face layer, additional reinforcement from a glass mesh. The technological line contains a firing section, preparation of raw components, a reactor section, and a section for the production of glass dolomite sheets, etc.

The disadvantage of this method is the complication of the technological line for sheet production. The presence of dolomite firing departments, preparation of raw materials significantly increases the number of operations, necessary equipment, area for deployment of the technological line and complicates the sheet production process.

The objective of the present invention is to develop a technological line for the production of glass dolomite sheets, obtaining a fire-resistant material with improved physical and mechanical characteristics.

The technical result is an increase in the strength of glass dolomite sheets and a simplification of the technological process of their production.

In the present technological line, the raw materials are supplied already crushed, dried, as a suspension of magnesium oxide solution prepared for further work. The claimed invention differs from the prototype in that the caustic dolomite is fed into the mixer after its joint activation in the vortex layer apparatus with the superplasticizer. The superplasticizer and non-activated caustic dolomite powder are mixed in the deagglomerator, after which they are fed via a screw conveyor for further processing into the vortex layer apparatus, which allows for the formation of a denser structure of the resulting composite and an increase in the compressive strength of sheets at 28 days of age by 1.4 times.

The sequence of technological operations for the production of glass dolomite sheet from caustic dolomite is shown in the drawing.

The proposed technological line for the production of glass dolomite sheets consists of four main sections: 1 - receiving and feeding raw materials; 2 - dosing and mixing of mixture components; 3 - mechanical activation; 4 - forming of glass dolomite sheet.

According to the proposed method, in section 1, pre-prepared bulk raw materials such as perlite (5), metakaolin (6), fiber (7), caustic dolomite (9) are fed into intermediate bins/silos through loading hatches to a specified level. During storage of the initial raw materials, an optimal temperature and humidity regime is maintained in the bin: the mass fraction of moisture in the caustic dolomite powder is no more than 2%, the air temperature is not lower than +5°C. The salt solution (8) of magnesium chloride (bischofite) is delivered pre-prepared and kept in a settling tank for 12 to 24 hours while maintaining the activity of the sealant and is poured into the dispensing bin. The bins are installed either above the dispensers, in the case of a vertical arrangement of the raw material supply unit, or to the side of them - in the case of a horizontal arrangement. Dry components from the bin are fed by a rotary feeder (11) via a screw conveyor to a weigh batcher (12). Superplasticizing additives (10) from big bags are fed separately to the batchers using unloaders.

In section 2, dry components are fed into the mixer (15) via a screw conveyor: fiber, metakaolin, activated caustic dolomite and mixed for 3-5 minutes, then bischofite is loaded by a pump and the mixture is additionally mixed for 2-3 minutes. For timely quality control of the resulting magnesite raw material, a sampler is installed in the mixer.

Before feeding the caustic dolomite to section 2, the dry mixture of caustic dolomite and superplasticizer additionally passes through mechanical activation section 3. At the first stage, caustic dolomite (9) and additives (10) are fed from the dispensers via a screw conveyor to the mixer (13), then at the second stage the mixture is mixed for 2-3 minutes until a homogeneous mass without dry lumps is obtained. The additives are plasticizers based on a mixture of polymers of sodium-based lignosulfonic acid salts. At the third stage, the resulting raw mixture is processed in a vortex layer apparatus (14) at the specified activation parameters: time 3-5 min., rotation frequency of the electromagnetic field 50-70 Hz, ratio of the mass of ferrimagnetic bodies to the mass of the crushed material 0.3-0.4. Afterwards, the activated mixture enters the common deagglomerator (15) together with other components and is mixed with all the contents of the deagglomerator until a homogeneous mass is obtained.

In section 4, the finished product is directly formed - a glass dolomite sheet. Depending on the requirements for the finished product (class of material, its physical and mechanical, operational characteristics), it is possible to exclude or, on the contrary, introduce additional operations: coloring the raw mix, feeding one / two reinforcing layers of fiberglass, feeding a glaze layer.

The substrates (16) are brought to the conveyor belt by a loader and cassettes (17) with an adjustable thickness of future products from 3-14 mm are fed. The "glaze" (19) is fed to the cassettes located on the feed table (18). The glaze is a concentrated aqueous solution of MgO and bischofite, which is prepared separately. Then, fiberglass (20) is spread on the resulting face layer, rolled out with a roller, leveled and pressed into it. The mixture is continuously fed from the mixer from section 2 to the cassettes, then moved for compaction and uniform distribution of the original mass to the vibrating table (21) and the molder (22) with a forming roller. If it is necessary to install the 2nd layer of fiberglass mesh (23), an additional feed table (24) is installed on the conveyor before moving the cassettes to the molding zone, where the reinforcing layer is laid. In the strength gain section (25), the glass dolomite sheets are pre-dried at a temperature of +24 to +26°C for 6-8 hours. The sheets are trimmed (26) by an automatic knife along the line between the cassettes. The calibrated finished glass dolomite sheets are removed from the substrate (27) and moved to pallets for further storage and packaging, while the substrate (28) is collected.

Claims (1)

A process line for the production of glass dolomite sheets comprising 4 sections, wherein the first section for receiving and feeding raw materials contains bins with pre-prepared bulk raw components - perlite, metakaolin, fiber, superplasticizer and caustic dolomite, a bin with a saline solution of magnesium chloride - bischofite; the second section for dosing and mixing components contains dispensers and screw conveyors for feeding components to a deagglomerator; the third section for mechanical activation contains a mixer and a vortex layer apparatus for joint activation of caustic dolomite with superplasticizer for 3-5 min, at a rotation frequency of the electromagnetic field of the apparatus of 50-70 Hz, at a ratio of the mass of ferrimagnetic bodies to the mass of the material being crushed of 0.3-0.4 and subsequent feeding to the deagglomerator; the fourth section for forming the glass dolomite sheet contains a feed table with cassettes located on it, onto which the glaze and glass fabric are fed, a conveyor belt for moving the cassettes to the zone for feeding the mixture from the deagglomerator, a zone for compaction and distribution on a vibrating table and a former with a forming roller, a zone for drying and cutting sheets.