SU1261737A1 - Composition of cold-hardening sand for making moulds and cores - Google Patents

Abstract

COMPOSITION OF A COOLING MIXTURE FOR THE MANUFACTURE OF CASTING FORMS AND STEM, including a refractory filler based on silicon dioxide, an aluminum-chromophosphate binder, a curing agent, characterized in that, in order to reduce the hygroscopicity of the mixture, the body also contains a set of halogen hardener containing hardener containing hardener, in order to reduce the hygroscopicity of the mixture; the ratio of ingredients, wt. Alumochromophosphate binder 3,0-6,0 Fly ash (waste I thermal power plant (L)) 1.0-4.0 Refractory filler based on the rest of silica

Description

one

The invention relates to foundry and can be used to make molds and cores from cold-hardening phosphate mixtures.

The purpose of the invention is to reduce the hygroscopicity of the mixture.

The composition of the proposed mixture includes a refractory filler, aluminum-chromophosphate binder, and zolaunos of thermal power plants.

Quartz sand is used as a refractory filler, aluminum-chromophosphate binder is used in accordance with Specification 6-18-166-78, fly ash is taken from Zmiyiv State District Power Plant of Donetsk Region.

Fly ash is a waste of thermal power plants that use coal. It is a fine powder and has the following chemical composition, May.%:

Sio

40-50

g 15-20

A1.0, 10-15 Fe, 0, 3-7

Cao

With its introduction into the core or molding mixture, the formation of one and a half or two-substituted occurs. aluminum phosphates of iron and calcium, which are deposited in the pores of the structures of the molds and cores, thereby reducing the capillary energy of the pores. Sorption of lags Reduced from air.

The compositions of the known and proposed mixtures are given in table 1, their technological properties - in table 12.

As an example, below is the optimal composition of the proposed rod mixture, wt.%:

Quartz sand 93.5

AHFSA

Fly ash 2.5 Her compressive strength after 24 hours is 22jl kgf / cm, life61737J

Vuchet more than 60 minutes, precipitation of 0.07%, gas permeability 200 units, hygroscopicity 0.23.

The proposed blend is prepared 5 as follows.

The quartz sand is mixed with fly ash for 2 minutes, after which AHFS is introduced and stirring is continued for another 30 seconds. ten

Known mixing equipment from foundries can be used to mix the components. The manufacture of molds and cores from this mixture is carried out by compacting them in flasks and core boxes by any of the known methods (manually, by vibration, etc.). Shapes and rods harden at room temperature.

When using the proposed CTS, it is possible to obtain molds and rods with reduced hygroscopicity, good embossing bridges under normal sanitation and hygienic working conditions.

When the content of fly ash in the mixture is less than 1%, the mixture does not harden sufficiently quickly at room temperature, and if it contains more than 4%, it does not survive enough.

The use of the proposed mixture for the preparation of rods provides, in comparison with the known mixture, a decrease in the hygroscopicity of the forms and rods on the AHFS. Reducing the hygroscopicity prevents the mixture from softening when they are laid before pouring, which often leads to the destruction of molds and rods during casting. In addition to airborne saturation with moisture, the forms and rods have additional gassing when

pouring metal, which negatively affects the quality of the casting. The reduction in hygroscopicity reduces the waste of castings in gas shells.

Table 1

Alumochromophosphate binder (AHFS) 4.03.0.0 Iron ore concentrate or pyrol, 5, 0: zit, fly ash 91,096.5 Quartz sand 0.5

Table 2 3.04.06.06 -. 1, 02.54.05.05 96, Ju 93.5 90.0 89.0

Claims (1)

COMPOSITION OF A COLD HARDENING MIXTURE FOR THE PRODUCTION OF CASTING FORMS AND RODS, including a refractory filler based on silicon dioxide, an aluminochromophosphate binder, hardener, characterized in that, in order to reduce the hygroscopicity of the mixture, it contains heat ash (hardener) the following ratio of ingredients, wt. YAG: Alumochromophosphate Binder 3.0-6.0 Fly ash (waste from thermal power plants) 1.0-4.0 Silica Refractory Filler Else ’261737