SU635063A1 - Raw mix for making asbestos-cement articles - Google Patents

Description

one

The invention relates to the field of building materials, in particular to the production of asbestos-cement products. The proposed raw mix can be used at asbestos-cement plants, especially those that are part of alumina enterprises.

The known raw material mixture for the manufacture of asbestos-cement products, containing, by weight. %: Portland cement 45-50, asbestos 5-15, kaolinite clay burned 35-50.1.

Also known mixture containing weight. %: Portland cement 75-97, reinforcing asbestos fiber 1 -15; CAC 2-10 2.

The closest in composition to the proposed raw mix, containing Portland cement, asbestos and dihydrate gypsum in the amount of 1-5i% by weight of Portland cement, 3.

However, products from known mixtures have strength properties. In addition, their synthesis requires a lot of time due to the reduced rate of hardening of the cement.

The purpose of the invention is to increase the strength and speed of hardening of products.

This goal is achieved by the fact that the proposed raw mixture for the manufacture of asbestos-cement products, including Portland cement, asbestos and a two-water giis, additionally contains calcium hydrogranates of composition

ZSaO (A1, D)., OZX8Y., (6-2X),

where, 01-0.5, where, 01-0.5, with the following ratio of components, weight. %: Portland Cement55-93

Asbestos 5-25

Two-water gypsum1-10

Calcium hydrogranates 1-10

The described raw material mixture can be prepared by any known method. In the wet process, the addition of calcium hydrogranates is most expediently carried out in the process of preparing asbestos-cement mass at the stage of displacement of dissolved asbestos, portland cement and water. With the dry method add-. Calcium hydrogen garnetting in the form of a dry powder is advisable to carry out at the last stage of the components displacement. The theoretical basis for the achievement of this goal is the formation in the process of hydrothermal synthesis. calcium hydrosulfuruminates and calcium hydrosulfoferrites, which provide not only acceleration of the product synthesis process, but also chemical self-stressing of asbestos fibers, which makes it possible to improve the strength properties of the products and shorten the duration of the technological cycle.

Example. Raw mixes are made of Portland cement for asbestos-cement products of the brand 400 Pikalevsky Cement Plant and asbestos of Balsenovsky and Dzhetygara deposits of grades P-5-65 and M-6240 in a 1: 1 ratio. As additives, two-water gins of the Novomoskovsk plant are used with a content of sulfuric anhydride of 65% and a number of hydrongates corresponding to the general formula

WAAA. A1, O, XSiO, (6-2X) H, O,

where, 01-0,5. As an additive, instead of synthetic hydrogrenates, the down-flowing products of the alumina production of the Tikhvin and Achinsk alumina plants will be tested.

Since the properties of asbestos-cement products with the addition of synthetic hydrogrones and white (hydrogranate) alumina production slots do not differ significantly (assuming identical composition of the raw mixture), the composition and properties of asbestos-cement samples obtained only with the addition of white schlum Tikhvin alumina are given as an example plant, as the most typical representative of the proposed gidroganat.

Asbestos cement samples are prepared according to the following procedure.

Asbestos is preliminarily milled in a mortar 3 mnn, and then subjected to fluffing in a propeller bed for 7 minutes. Portland cement, ground gypsum and white sludge are added to the resulting asbestos slurry at a predetermined ratio. Averaging is performed in the same blender with a liquid to solid ratio of 5 for 5 minutes. On the vacuum unit, the prepared suspension is filtered, and from the resulting pitch under a pressure of 60 kgf / cm, sample samples of 1X1X3 cm are formed. The setting of the glasses is carried out according to the combined mode: diving at 60 ° C for 4 hours and subsequent storage in wet conditions x at 20 ° C for 7 days.

The test results for the extreme and average values of the components in the proposed raw mix are shown in the table.

As follows from the experimental data given in the table, the use of white schlama (hydrogarnet) additives for the preparation of asbestos-cement products makes it possible to significantly increase the duster of the samples and reduce or completely abandon the second stage of hardening — holding the samples under proper conditions, since immediately after steaming the strength of the samples corresponds to the brand (more than 160 kgf / cm). Petrographic analysis of solidified samples with and without added white sludge shows that in samples containing white sludge, the number of tobermorite-type neoplasms is 10-15% more, i.e., the samples are cemented more intensively and deeply, the amount of etringitta is 3-10 %

Thus, the use of the proposed raw material mixture for the production of asbestos-cement products does not allow to obtain a significant economic effect due to an increase in the quality of asbestos-cement products, a reduction in the time and cost of their synthesis.

Claims (3)

Invention Formula Raw mix for the manufacture of asbestos-cement products, including Portland cement, asbestos and two-water gypsum, characterized in that, in order to increase the strength and speed of hardening of the products, it additionally contains calcium hydrogranates of the composition ZSaO (A1, D) 2OZH8 {O ,, (6-2x) H2O, where., 01-0.5, with the following ratio of components, weight. %: 5 Portland cement 55-93 Asbestos 5-25 Two-water gypsum 1 -10 Calcium hydrogarnet 1 - 10 Sources of information taken into account during the examination 635063 6 1. USSR Author's Certificate No. 301317, cl. C 04B 15/16, 1968. 2. USSR author's certificate N ° 412161, cl. C 04B 15/16, 1972. 5 3. USSR author's certificate. V9 338505, cl. C 04B 15/16, 1969.