SU1379266A1 - Method of producing anhydrite binder - Google Patents

Abstract

The invention relates to the procurement of construction materials and can be used in the manufacture of anhydrite in the living. The purpose of the invention is to increase the mechanical strength. The method of obtaining anhydrite in the slurry involves mixing citrogypsy calcined at 400–420 ° C with a volcanic slag previously treated for 1.5–2.0 hours with a 3-5% aqueous solution of sulfuric acid at a liquid-solid ratio of 1: 1 to 3: 1 and a temperature of 55 to 75 ° C, with volcanic slag being introduced in an amount of 3.0 to 9.1 wt.%. Anhydrite in the shear has a strength of 14.2-16.2 MPa. 2 tab. (Oh (L

Description

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The invention relates to the building materials industry and can be used in the manufacture of anhydrite burners,

The purpose of the invention is to increase the mechanical strength.

. According to the proposed method, citrogips-waste production of citric acid containing 95–96 wt.% Calcium sulfate dihydrate is used. The calcination product at 400-420 C has the following chemical composition, wt,%: CaO 38.4; S04 57.45; SiO 0.70; , 1.75; MgO 0.62, ppt 1.08, as well as volcanic shpak - porous and loose rock consisting of volcanic glass of basic composition.

The chemical composition of the volcanic slag treated with acid and calcined at 400–420 ° C is as follows, wt%: SiOi 53.63; , 17.20; 6.70; TiOi 1.25; CaO 4.40; MgO 2.65; SO, 1.80; 4.13; KzO 2.25; ppt 5.99.

In addition, technical sulfuric acid is used.

The method of preparation of raw materials is as follows.

The initial citrogips are preliminarily dried in an oven at 55–60 ° C for 6–7 h, crushed, and then fired at 400–420 C for 3–3.5 h. The resulting product is crushed, passed through a sieve. No. 02 and vylazhivayut to stabilize

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properties. The true density of calcined citrogens is 2.75-2.85 g / cm, the bulk density is 0.55-0.60 g / cm. Crushed shpak is passed through a sieve No. 014 and subjected to processing 3-5% sulfuric acid solution according to GOST. In this respect, W: T (1.0: 3.0): 1. The resulting mixture was incubated for 1.5-2 hours at 55-70 ° C, after removing the liquid phase. The resulting product is calcined for 3-3.5 hours at 400-420 C.

The method proceeds as follows.

Annealed cytogypsum is mixed with a volcanic millstone activator prepared by the described method with a component ratio of 10: 1–32.3: 1.

Samples of 4–4–16 cm in size are prepared from the prepared mixture to determine the brand of the batter (of normal density). The capacity of the perpetrator is determined according to the standard for portland cement according to GOST. The prepared beams are stored for 28 days in a desiccator at 18–20 ° C and a relative humidity of 60%. Then the samples were dried at 55-60 ° C in a drying cabinet to a constant weight and tested.

The properties of the obtained material are given in Table. one.

Table 1

The amount of calcined cytogypsum, wt.%

Volcanic slag processing conc. acid,%

W: T

Processing temperature, Processing time, h Firing, C Firing time, h

90.1 97.0 92.6

Technological parameters

Amount of acid treated and calcined volcanic slag

Strength, MPa

In tab. 2 shows the comparative indicators of the properties in the recipient obtained by the known and proposed methods.

table 2

Way

Compressive strength, MPa

Suggested Famous

14.2-16.2 7.2-8.5

As follows from the table. 2 data, obtained by the proposed method, is characterized by twice the mechanical strength compared with 13792664

Continuation of table 1

Indicators for an example

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9.1 3.0 7.4 U, 2 15.0 16.2

obtained in accordance with a known method.

Claims (1)

Invention Formula The method of obtaining anhydrite to a stranger by burning cytogypsum at 400-420 ° C and mixing with a curing activator, characterized in that, in order to increase mechanical strength, volcanic slag is used as an activator, which is pretreated for 1.5-2 hours 3-5% aqueous solution of sulfuric acid at a liquid-solid ratio of 1: 1 to 3: 1 and a temperature of 55-75 s, and then burned at 400-420 s, and the hardening agent is introduced in the amount 3-9.1 wt.%.