CN104525832A - High-air-permeability molding sand for casting of large pieces and preparation method thereof - Google Patents

Abstract

Through adopting clay for sintering granulation, molding sand has good air permeability and good dispersion and can be recycled; through use of quartz sand particles, the molding sand is good in heat resistance and good in dispersion, and clay particles are prevented from being bonded; and through use of colloidal graphite, the molding sand is good in plasticity, good in heat dissipation and applicable to casting of large pieces, and the surface of the casting pieces does not easily produce pores.

Description

Large part highly-breathable molding sand of a kind of casting and preparation method thereof

Technical field

The present invention relates to casting field, particularly relate to large part highly-breathable molding sand of a kind of casting and preparation method thereof.

Background technology

There is particle size problem rambunctious in current molding sand, affects yield rate and the Modeling precision of foundry goods.Further, lack special molding sand for different types of foundry goods, make casting accuracy not high, yield rate is low.

Conventional clay molding sand has many good qualities, but exists not easy to be recycled, and poor air permeability, mobility are bad, dispersiveness is bad, collapsibility is poor, it is bad to dispel the heat, environmental pollution is serious shortcoming.

Above shortcoming needs to improve.

Summary of the invention

The object of the present invention is to provide large part highly-breathable molding sand of a kind of casting and preparation method thereof, this sand permeability is good, good heat resistance, good dispersion, and plasticity is good, and thermal diffusivity is good, and be applicable to cast large part, cast(ing) surface not easily produces pore.

Technical scheme of the present invention is as follows:

The large part highly-breathable molding sand of a kind of casting, is characterized in that being made up of the raw material of following weight portion that butadiene rubber powder 2-3, powdered whiting 14-19, aluminium isopropoxide 1-1.4, aquadag 10-14, volcanic ash 30-40, aluminium ground-slag 40-50, quartz sand 20-25, ten trifluoro octyl group trimethoxy silane 5-7, clay 150-170, water are appropriate, auxiliary agent 20-30;

Described auxiliary agent is made up of the raw material of following weight portion: chromite sand 6-8, ceramic sand 4-5, walnut sand 2-3, aluminium oxide 3-4, silica 4-5, nice foundry sand 5-7, clay 2-3, silane coupler kh-550 0.5-1, magnesia 0.4-0.7; Preparation method is: carry out ball milling by after aluminium oxide, magnesia, silica mixing, cross 200 mesh sieves, 2-2.5 hour is calcined at 1400-1500 DEG C, add Quench in cold water, then be ground into the particle that particle diameter is less than 2mm, add chromite sand, walnut sand, grinding 30-40 minute, add other residual components, grinding 20-30 minute, to obtain final product.

The preparation method of described casting large part highly-breathable molding sand, is characterized in that comprising the following steps:

(1) by clay, slag powders mixing, pulverize, cross 50 mesh sieves, the water adding 7-9% weight portion stirs, granulation, particle diameter, at 0.05-2.5mm, is sent in calcining furnace, pre-burning 20-25 minute at 300-400 DEG C, then sinter at 940-980 DEG C, take out, polish to surface roughness≤0.1mm, obtain clay particle;

(2) quartz sand is heated to melt, adds powdered whiting, volcanic ash mixes, add Quench in cold water, be ground into the quartz sand particle of 0.05-1.5mm;

(3) described clay particle, quartz sand particle are mixed with other residual components, then add the water mixing 8-13 minute of 5.4-5.8% weight portion, to obtain final product.

Beneficial effect of the present invention

Molding sand of the present invention is by using vitrified bond granulation, and good permeability, good dispersion, can recycle; By using quartz sand particle, molding sand good heat resistance, good dispersion, prevents clay particle from boning, and by using aquadag, molding sand plasticity is good, and thermal diffusivity is good, and molding sand of the present invention is applicable to cast large part, and cast(ing) surface not easily produces pore.Auxiliary agent of the present invention is high temperature resistant, good dispersion, and lubricity is good, good with the affinity of clay particle, can increase the plasticity of molding sand, gas permeability, mobility, heat resistance, prevent clay particle from boning, and improves the yield rate of foundry goods.

Detailed description of the invention

The large part highly-breathable molding sand of a kind of casting, is made up of the raw material of following weight portion (kilogram) that butadiene rubber powder 2.5, powdered whiting 16, aluminium isopropoxide 1.2, aquadag 12, volcanic ash 35, aluminium ground-slag 45, quartz sand 23, ten trifluoro octyl group trimethoxy silane 6, clay 160, water are appropriate, auxiliary agent 25;

Described auxiliary agent is made up of the raw material of following weight portion (kilogram): chromite sand 7, ceramic sand 4.5, walnut sand 2.5, aluminium oxide 3.5, silica 4.5, nice foundry sand 6, clay 2.5, silane coupler kh-550 0.7, magnesia 0.6; Preparation method is: carry out ball milling by after aluminium oxide, magnesia, silica mixing, cross 200 mesh sieves, calcine 2.3 hours at 1450 DEG C, add Quench in cold water, then be ground into the particle that particle diameter is less than 2mm, add chromite sand, walnut sand, grind 35 minutes, add other residual components, grind 25 minutes, to obtain final product.

The preparation method of described casting large part highly-breathable molding sand, comprises the following steps:

(1) by clay, slag powders mixing, pulverize, cross 50 mesh sieves, the water adding 8% weight portion stirs, granulation, particle diameter, at 0.05-2.5mm, is sent in calcining furnace, pre-burning 23 minutes at 350 DEG C, then sinter at 960 DEG C, take out, polish to surface roughness≤0.1mm, obtain clay particle;

(2) quartz sand is heated to melt, adds powdered whiting, volcanic ash mixes, add Quench in cold water, be ground into the quartz sand particle of 0.05-1.5mm;

(3) described clay particle, quartz sand particle are mixed with other residual components, then the water adding 5.6% weight portion mixes 11 minutes, to obtain final product.

The sand test data that the present embodiment obtains are as follows: green compression strength is 150KPa, gas permeability 95, and green tensile strength is 2.3KPa, compact rate of molding 42%.

Claims (2)

1. cast a large part highly-breathable molding sand, it is characterized in that being made up of the raw material of following weight portion that butadiene rubber powder 2-3, powdered whiting 14-19, aluminium isopropoxide 1-1.4, aquadag 10-14, volcanic ash 30-40, aluminium ground-slag 40-50, quartz sand 20-25, ten trifluoro octyl group trimethoxy silane 5-7, clay 150-170, water are appropriate, auxiliary agent 20-30;

Described auxiliary agent is made up of the raw material of following weight portion: chromite sand 6-8, ceramic sand 4-5, walnut sand 2-3, aluminium oxide 3-4, silica 4-5, nice foundry sand 5-7, clay 2-3, silane coupler kh-550 0.5-1, magnesia 0.4-0.7; Preparation method is: carry out ball milling by after aluminium oxide, magnesia, silica mixing, cross 200 mesh sieves, 2-2.5 hour is calcined at 1400-1500 DEG C, add Quench in cold water, then be ground into the particle that particle diameter is less than 2mm, add chromite sand, walnut sand, grinding 30-40 minute, add other residual components, grinding 20-30 minute, to obtain final product.

2. cast the preparation method of large part highly-breathable molding sand according to claim 1, it is characterized in that comprising the following steps:

(1) by clay, slag powders mixing, pulverize, cross 50 mesh sieves, the water adding 7-9% weight portion stirs, granulation, particle diameter, at 0.05-2.5mm, is sent in calcining furnace, pre-burning 20-25 minute at 300-400 DEG C, then sinter at 940-980 DEG C, take out, polish to surface roughness≤0.1mm, obtain clay particle;

(2) quartz sand is heated to melt, adds powdered whiting, volcanic ash mixes, add Quench in cold water, be ground into the quartz sand particle of 0.05-1.5mm;

(3) described clay particle, quartz sand particle are mixed with other residual components, then add the water mixing 8-13 minute of 5.4-5.8% weight portion, to obtain final product.