SU1640133A1 - Method of producing cast stone - Google Patents

Abstract

The invention relates to the manufacture of stone products. The purpose of the invention is to improve the quality of products by reducing deformation, increasing crack resistance and increasing flexural strength, as well as reducing energy consumption for their production. The method of obtaining stone casting involves melting the charge, introducing a finely dispersed modifier into the melt, pouring the melt into molds and crystallization. As a fine modifier, a crushed stone casting of identical phase composition with a specific surface area of 1000–3000 cm2 / g is used, with an amount of 0.8–1.5% of the mass of the melt. The fluidity of the melt is 26–30 mm (according to the Hernt viscometer), the strength of the products obtained for bending is 75–85 MPa, the number of scrap by deformation is 1–2%, and the cod is 3–4%. 1 tab. e to

Description

The invention relates to the manufacture of stone products.

The aim of the invention is to improve the quality of products by reducing the deformation, increasing the crack resistance and increasing the flexural strength, as well as reducing the energy consumption for their production.

The method is carried out as follows.

The rock crushed to the size of pieces of 50–250 mm — pyroxene porphyrite with the addition of 1.5–2% chromite melts at 1400– 1420 ° C. Melt

poured into the ladle, at a melt temperature of 1250-1280 ° C, a modifier is introduced into the ladle manually or with a stream of compressed air — crushed stone casting with a specific surface of 1000-3000 cm2 / g in an amount of 0.8-1.5% of the mass of the spread. Then the melt is poured into metal frames and held in them until it solidifies. The castings are removed from the framework, placed in a furnace for crystallization and annealing. The crystallization of castings occurs within 8-9 minutes at.

r

920 Gs cooling of castings is carried out at 20 ° C for 20-22 hours.

The melt has the following chemical composition, wt.%: 8 South 48-52J TiOa, 1.3-5.7 1.7f 12.1-15; FeO 6.3-9.7, Reg03 ZITb.O; CaO 7-12; MgO 7-10J 1-3; CgO 0.5-1.5 / 0.4-1.0.

The stone casting powder introduced into the melt is similar in phase and chemical composition with crystallizing stone casting, consists of glass, pyroxene, magnetite (not more than 5%). When introduced into the ladle, the powder is melted at 1250-1280 ° C, however, in the future, the nuclei of the future crystalline stone casting phases (pyroxene, magnetite) remain, which ensures the formation of crystallization centers uniformly distributed throughout the volume.

The introduction of a modifier, similar in chemical and phase compositions to stone casting, does not cause the development of stresses during crystallization during the solidification of the casting and subsequent heat treatment, as well as during the cooling of products, which leads to an increase in crack resistance,) reduction in deformation and scrap and increase in - 30 st.

The parameters of the implementation of the method are shown in the table

The method allows to significantly reduce the energy consumption for the production of Ј $ of products from stone casting due to the fact that the marriage of stone casting contains a significant amount of glass having a low hardness and easy

grinding. In addition, the use of a more low-melting modifier does not require fine grinding of the modifier, which reduces the energy consumption for grinding.

The phase composition of the modifier is similar to the phase composition of the resulting stone cast, which does not cause additional stresses during crystallization and, as a result, allows to increase the bending strength to 75-85 MPa.

The time of forming the slabs 180x250x30 mm in size without the addition of a modifier is 3 minutes 28 seconds, and with the addition of a 0.8% stone casting rejection - 2 minutes 45 seconds At the same time, the number of defective products having deformation and cracks is reduced.

Claims (1)

Invention Formula The method of obtaining stone casting, including melting the mixture, introducing a finely dispersed modifier into the melt, pouring the melt into molds and crystallization, in order to improve the quality of the products by reducing the deformation, increasing the fracture toughness and increasing the flexural strength, as well as reducing energy consumption for their production, as a finely dispersed modifier, a ground stone casting of identical phase composition with a specific surface area of 1000–3000 cm2 / g in an amount of 0.8–1.5% of the mass p is used alloy.