SU1717560A1 - Process for making frit - Google Patents

Abstract

The invention relates to the building materials industry and can be used in the production of enamels. The purpose of the invention is to improve working conditions, reduce the preparation of volatile and toxic components and increase the yield of frit. The method includes natural moistening of hygroscopic components to a moisture content of 5-10%, mixing them with the rest of the charge components to a total moisture content of 2.5-7%, compacting on a roller press and obtaining tiles with a moisture content of 4-8% and a density of 1300-1800 kg / m3 , obtaining from it granules with a size of 3-10 mm. The yield of the product up to 76%. Dust in the workplace 19.4-30 mg / m3. 1 tab.

Description

The invention relates to the building materials industry, namely the production of vitreous enamels.

The purpose of the invention is to improve working conditions, reduce the loss of volatile and toxic components, increase the yield of frit and improve its quality.

The essence of obtaining Frits according to the proposed method consists in the following. Before mixing, the hygroscopic components of the mixture are kept indoors in an atmosphere at an air temperature of 15–30 ° C and a relative air humidity of 50–70%. At the same time, the hygroscopic components (for example, nitrate, borax, boric acid) absorb moisture from the air for a certain time to a moisture content of 5.0–10.0%. Then hygroscopic and plastic components (cryolite, titanium oxide) are loaded into the mixer, mixed, and then introduced

dry sand and mix. The ratio of the humidity of sand and other components and mixing modes provides the mixture with a total humidity of 2.5-7.0%. Then the mixture is subjected to compaction on a roller press. The charge is fed to the loading hopper of the press and subjected to rolling at a pressing pressure of 120-300 MPa. Due to the high specific pressures, the surface of the rolls and the mixture is heated to a temperature of 60-80 ° C, at which the release of chemically bound water occurs, for example, in boron-containing components (borax, boric acid). These pressing parameters provide tiles with a moisture content of 4.0–8.0%, a density of 1300–1800 kg / m2, and a strength of 1.0–3.0 MPa. Then, granules with a size of 3–10 mm are obtained from the tile.

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The obtained granules are loaded into the furnace, providing in the process of loading the bulk mass of the granules is 1100-1500 kg / mch, and due to the higher flowability of the granules compared to the powder, they are evenly distributed in the working volume of the furnace.

Then, the charge is boiled by 10–20% faster than the standard time, after which the glass-enamel is drained and its thermal granulation into water.

Comparative tests were carried out on the known and proposed methods for boiling the mixture of the composition of titanium enamel T-5K, which is used in the manufacture of sanitary ware.

The test results are shown in the table.

As a result of the tests, it was established that when using powder batch, there is a high dust content at the place of loading the batch into the furnace and during its transportation. The powder mixture in the cubicles is compacted and after storage its unloading requires great physical effort.

During the cooking process, especially in the initial stage, volatility and toxic components are carried away from the furnace, which are partially deposited in the flue ducts and released into the atmosphere. Conducted tests of the proposed method showed that when the hygroscopic components were aged at 15-30 ° C and relative air humidity of 50-70% (examples 2-5), their humidity reaches 5-10%, and after mixing in a predetermined order with other components 2 , 5-7.0%. When the parameter values are less than the claimed range (example 1), the charge is then obtained dry and it is not possible to carry out the compaction process to obtain a quality tile (high density, strength, small amount of spillage).

At high values of the regime parameters (Example 6), the hygroscopic components are over-humidified and difficult to mix.

When compacting on roller presses with a pressure of 120-300 MPa to obtain a tile with a moisture content of 4.0-8.0%, a density of 1300-1800 kg / m, and a splitting strength of 1.0-3.0 MPa, granules of size 3-10 are obtained from the tile mm (example 2-5). At the same time, the amount of spillage (uncompacted fines) is minimal and equal to 10-23%.

With smaller values of the extrusion parameters and the characteristics of the tile (there is no direct dependence between them, and it is determined only experimentally) it turns out not strong and of low density.

tile (example 1), from which it is impossible to obtain granules with given sizes and humidity.

At high values of operating parameters (example 6), a thin tile with a thickness of 1.0-2.0 mm is obtained, the rolls are heated to 90 ° C with increased humidity, leading to undesirable solid-phase reactions. The strength of such

the compacts fall, and the tile in the cubicle begins to caking. Cooking of such tiles and granules occurs with large energy consumption.

3-10 mm tile granules

quickly pour out from the tube into the furnace and are evenly placed throughout the furnace. They boil faster, providing a higher yield and lower dust content (Example 2-4). With

smaller granules do not provide high thermophysical properties of the packed mixture and strong dusting is observed. Granules with large sizes are unevenly distributed throughout the working volume of the furnace, mainly in the form of a conical heap. They narrow the cross section of the furnace for the passage of flue gas. The cooking mode becomes not optimal and the cooking time cannot be shortened in this case. results

mixing, compaction and cooking at the ratios (examples 2-5) showed that the loading into the furnace occurs in conditions of low dustiness, with less labor, the cooking time is reduced compared to the powder mixture by 10-20%. The yield of the product is increased by 2-5%. The mode parameters that provide maximum results for the goal are given in Example 4.

Claims (1)

The invention of the method of obtaining the Frit, including the preparation of the powder mixture by mixing 5 sand, hygroscopic and plastic components, its compaction, loading into the oven, cooking and thermal melt granulation, characterized in that, in order to improve working conditions, reduce losses 0 volatile and toxic components, increasing the output of the Frit, hygroscopic components of the mixture are pre-incubated at a temperature of 15-30 ° C and relative humidity of 50-70% to humidity 5 5-10%, then they are mixed with plastic components, sand is introduced, the mixture with humidity 2.5-7.0% is compacted by compaction on roller presses with a specific pressing pressure of 120-300 MPa to obtain a tile with humidity 4 -8%, density 1300–1800 kg / m, strength 13–3–10 mm, and loading into the furnace is carried out at MPa, granules with a bulk grain size of 1100–1500 kg / m are formed from a tile. Humidity source by