SU1689353A1 - Mixture for producing refractories - Google Patents

Abstract

This invention relates to refractory technology that can be used to cast metal, for example steel. In order to increase the strength and resistance to the first thermal shock while maintaining metal cladding resistance, the mixture contains. wt.%: refractory filler - base, graphite 15-35, antioxidant additive 4-15, synthetic material 2-10, binding 2-10. At the same time, the synthetic material contains CaO and in a ratio from 1: 2 to 2: 1 with a total content of ResO3 and TI02 from 4.2 to 9.6% by weight and SIO2 not more than 4.0% by weight. 3 tabl

Description

WITH

with

The invention relates to the manufacture of refractories and can be used in the manufacture of products for casting metal, such as steel.

The aim of the invention is to increase the strength and resistance to the first thermal shock while maintaining metal slag resistance.

Corundum, high-alumina material, zirconium oxide and zircon are used as a refractory filler, graphite of GT or GE grades is used as graphite, and crystalline silicon, silicon carbide, refractory clay or mixtures thereof are used as antioxidant additives.

The binder may be a technical lignosulfonate or an organic binder based on phenol-formaldehyde

resin liquid and / or solid (LBS, LST, TFP).

The compositions of the charge are given in table. one.

The materials used are electrocorundum, high-alumina chamotte and fused CaO stabilized zirconium oxide with a fraction of 1-0 mm, graphite grade GT-2 and GE-2, silicon carbide, crystalline silicon. 0.063 mm, ground refractory clay, ground fr. 0.5 mm, technical lignosulfonate, bakelite lacquer, powdered phenolic binder, as a synthetic material containing CaO and AlaOa, is synthetic slag produced in electric furnaces of a converter shop or a sintered material of the appropriate composition - fine ground fractions 0.1 mm,

CX 00 Yu SO (L 00

The compositions of samples of synthetic material are given in table 2.

At the same time make samples of the mixture composition, wt.%: Corundum fraction 1-0 mm 61,7; Sintered MDO fraction О.088 mm 0.3: graphite 25; silicon carbide 6: bakelite lacquer 7.

Samples were prepared from the blend of the blending compound, wt%: corundum 57; graphite 25; silicon carbide 10; calcium aluminate 3; Phenol-formaldehyde resin 5 Bakelite lacquer is used as a resin, and high-alumina cement is used as calcium aluminate.

Samples to determine the strength and resistance to the first thermal shock are molded at a specific pressure of 80 MPa, calcined in a reducing atmosphere at 1380PS. Sample size: diameter 36 mm, height 40 mm.

The antioxidant additive and the synthetic material are injected into the pre-mixed refractory filler and graphite, the rest after the introduction of the finely ground components.

The resistance to the first thermal shock is determined by the following method: heating the sample in a Tamman furnace in argon (nitrogen) to 1500 ° C - dropping into water. In this case, the sounding of the sample is carried out before heating and, after extraction from water, the thermal stability is calculated by the formula

Vi T -, 7-. where Vrj and Vi - the speed of Vro

ultrasonic waves cannot travel through the sample

. / t i - lb °. ha

five

0

five

30 o5

five

0

before testing (Vo) and after testing (Vi). Heat resistance is higher than T closer to 1.

Metal slag resistance is determined by the crucible method. Crucibles are molded from the corresponding mixture, 10 g of steel is placed into the well, and 10 g of slag are poured on top. The composition is then melted, held for 0.5 h and the wear of the crucible on the original cross-section area is measured. (diametral) section.

The results of determining the ultimate strength in compression, thermal resistance to the first thermal shock and metal and slag resistance are given in Table 3.

The tests were carried out according to the same methodology, the number of definitions for each experiment is three.

Claims (1)

Invention Formula The mixture for the manufacture of refractories, including refractory filler from the group of corundum, high alumina chamotte, zirconia, zircon, graphite, an antioxidant additive and a temporary binder, characterized in that, in order to increase the strength and resistance to the first thermal shock, it additionally contains a fine synthetic material containing, wt.%: A120z 30-58; CaO 29-60; S102 1.5-4; TiO2 0.8-2.2; Fe203 2 0-8.5 and others 0.4-4.3, with CaO being in the ratio from 1: 2 to 2: 1, with the following ratio of blend components, wt%: graphite 15-35; antioxidant flax additive 4-15; synthetic material 2-10: said temporary binding 2-10; specified refractory filler rest -Table 1 Compressive strength, PPa Heat resistance Metalloyl resistance,% 24 30 24 25 25 29 22 0.94 0.96 0.95 0.95 0.94 0.95 0.92 0.16 0.16 0.16 C 14 0.16 0.18 0.16 Table 2 Table 3