SU1717581A1 - Method of making construction products - Google Patents

Abstract

The invention relates to the building materials industry and can be used in the manufacture of wall materials. The purpose of the invention is to reduce thermal conductivity. The method of obtaining building products involves grinding (wt.%) Lime 80-90 and clay 10-20 in a jet mill at a particle collision speed of 300-500 m / s to a particle size of 7-15 microns, pressing and hydrothermal treatment. The method provides a density of 1960–2010 kg / m3, compressive strength 28.4–34.8 MPa, bending 3.0–3.5 MPa, water absorption 16.2–17.8%, frost resistance 100 cycles, thermal conductivity 0.56-0.64 W / m-deg. 2 tab.

Description

The invention relates to the production of building materials and can be used in the manufacture of wall materials.

The purpose of the invention is to reduce thermal conductivity.

The method is carried out as follows. Known as stone sawing waste (Alminskoye field) is mixed with clay (Kurtsovskoye field), the chemical composition is given in Table 1, in the ratios indicated in Table 2, to obtain a mixture of 10 kg each. . 5 kg of each mixture are ground in an ICP-0.5 steam jet counter mill at particle collision rates to a particle size respectively listed in Table 2.

The size of the initial particles of limestone and clay before feeding them into the mill does not exceed 10 mm.

The grinding of the mixture is carried out in a steam mill ICP-0.05, with a capacity of 5 kg / h. The temperature of the heat carrier is 100-110 ° C, the pressure is 0.5-0.7 MPa. The rate of collision of the particles is controlled by the pressure of the coolant supplied to the ejector. The velocity of the coolant is 150–250 m / s, the velocity of collision of particles is 300–500 m / s.

Autoclaving mode: time, pressure rise up to 0.8 MPa 2 hours, holding time at a pressure of 0.8 MPa 8 hours, pressure descent time 2 hours. Raw strength after pressing 0.4-0.5 MPa.

Examples of the mean value of the impact velocity due to the specified limits and other indicators of the main properties are given in Table 2.

The crushed mixtures are moistened to a moisture content of 7% and of these samples are pressed on a hydraulic press PMM-150 — beams 4x4x16 cm in size according to a two-stage mode — at the first stage, the pressing pressure is 10 MPa, at the second stage — 40 MPa. The pressed samples are subjected to guides.

with

rotated in an autoclave AL-0.5 in the mode of 2-8-2 hours at a pressure of 0.8 MPa. After pressing, the physicomechanical parameters of the samples are determined by standard methods. The parameters of the method and the physico-mechanical parameters of the samples for each example are given in table 2. The strength of raw material after pressing is 0.4-0.5 MPa.

Grinding a mixture of these components at a rate of collision of particles of 300-500 m / s leads to decarbonization of limestone with the formation of CaO and the activation of S102, MaO3, Fe203 HI of other substances contained in the clay. Grinding components to a particle size of 8–15 µm significantly increases the number of contacts between particles and ensures the most complete participation of all activated substances in reactions during stone formation during the pressing process and subsequent hydrothermal processing.

In addition, the clay content in the mixture has a plasticizing effect during the formation of products by pressing, which leads to stress relaxation, significantly reduces the number of pressing defects and improves the quality of products.

The upper and lower limit values of the method are justified as follows. The lower boundary value of the clay additive is 10%. A decrease in clay addition of less than 10% leads to a decrease in the strength and frost resistance of the products due to the insufficient amount of substances (HUA, RV203, etc.) necessary for the complete chemical reactions during hydrothermal processing.

The upper boundary value of the clay additive, equal to 20%, is justified by the cessation of the growth of strength and the decrease in the frost resistance of products with an increase in the amount of clay.

The optimal ratio of the number of starting components is the following,%: known to 85, clay 15.

The lower boundary value of the particle collision velocity is 300 m / s. Decreasing this rate decreases the amount of CaO in the mixture, which leads to

reduce the strength of products.

The upper boundary product, which is also optimal, the velocity of collision of particles of 500 m / s is due to the technical capabilities and energy and energy of the grinding equipment.

The lower particle size limit is 8 μm. Reducing the particle size of less than 8 microns is limited by the increase in energy costs for their production.

An increase in the particle size of 15 μm of Bepee leads to a decrease in the number of particle contacts during pressing, which reduces the strength of the products.

It is possible to use cheap

raw materials, such as limestone sawmill waste.

The use of the proposed method for the production of construction products reduces the energy consumption of production by 20-25%, makes it possible to utilize significant amounts of limestone waste and reduce production costs by up to 20%. In addition, the addition of clay improves molding properties.

mixture during pressing, which improves the quality of products. The application of the method in the construction industry will significantly expand the resource base of local building materials.

Claims (1)

The invention The method of obtaining construction products by grinding lime to a particle size of 7-15 microns in a jet mill at a particle collision speed of 300-500 m / s, pressing and hydrothermal treatment, characterized in that, in order to reduce thermal conductivity, clay is additionally introduced into the mill in an amount 10-20% by weight of the mixture. Table g Spreadsheets