CN104841869A - Foundry clay molding sand and preparation method thereof - Google Patents

Abstract

The invention relates to a foundry clay molding sand, which is prepared from the following raw materials by weight part: 8-12 of zirconium dioxide, 2-3 of acetylene black, 6-8 of bentonite, 2-3 of citric acid waste residue, 2-3 of papermaking waste residue, 5-7 of an aqueous acrylic emulsion, 8-12 of eucryptite, 1-2 of lithium carbonate, 8-12 of a 2-3% sodium hydroxide solution, 200-220 of clay, a proper amount of water, and 20-30 of an assistant. The molding sand provided by the invention uses citric acid waste residue and papermaking waste residue, by means of treatment, the plasticity and strength of molding sand are increased, the high temperature cracking phenomenon can be prevented, the collapsibility is good, and the molding sand is non-sticky to castings. By using acetylene black, the dispersibility of molding sand is increased. Through use of clay, the molding sand has suitable particle size, good air permeability, good fluidity and good dispersion, the casting surface is smooth, and the molding sand also can be recycled. By using the assistant involved in the invention, the plasticity and fluidity of the molding sand are increased.

Description

A kind of foundry clay molding sand and preparation method thereof

Technical field

The present invention relates to casting field, particularly relate to a kind of foundry clay molding sand and preparation method thereof.

Background technology

The subject matter that current molding sand exists has: 1, particle size difficulty controls, if molding sand particle diameter is too large, although gas permeability is better, cast(ing) surface is more coarse, and fineness is bad; If molding sand material footpath is too little, cause mo ld void bad, foundry goods has pore to produce.2, dispel the heat bad, chill effect is poor, and shrinkage porosite, shrinkage cavity phenomenon easily appear in intricate casting inside.3, dispersed, mobility is bad, easily caking, dusting beans.4, easily foundry goods is stain.5, release property is poor.6, molding sand is targetedly lacked for different types of alloy.

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.

Therefore, the above shortcoming that molding sand exists needs to overcome.

Summary of the invention

The object of the present invention is to provide a kind of foundry clay molding sand and preparation method thereof, this molding sand plasticity is good, and intensity is high, can prevent high temperature cracking phenomena, and collapsibility is good, not sticky foundry goods, and good permeability, good fluidity, can also recycling.

Technical scheme of the present invention is as follows:

A kind of foundry clay molding sand, is characterized in that being made up of the raw material of following weight portion: zirconium dioxide 8-12, acetylene carbon black 2-3, bentonite 6-8, citric acid waste residues 2-3, waste sludge from paper mill 2-3, aqueous acrylic emulsion 5-7, eucryptite 8-12, lithium carbonate 1-2,2-3% sodium hydroxide solution 8-12, clay 200-220, water are appropriate, auxiliary agent 20-30;

Described auxiliary agent is made up of the raw material of following weight portion: useless porcelain 18-22, cullet 2-3, sodium carbonate 2-3, bentonite 3-4, carboxymethyl cellulose 0.5-1, clay 3-4, calgon 1-1.4, PP wax 1-1.4, dextrin 1-1.4, water are appropriate; Preparation method is: carry out ball milling by after useless porcelain, cullet, sodium carbonate, bentonite mixing, cross 200 mesh sieves, calcine 5-6 hour, be ground into the particle that particle diameter is less than 2mm at 1200-1220 DEG C; Add in 4-5 weight parts water by clay, carboxymethyl cellulose, dextrin, add described particle, stir after stirring, dry, pulverize, particle diameter at 0.05-2mm, then mixes with other residual components, stirs, to obtain final product.

The preparation method of described foundry clay molding sand, is characterized in that comprising the following steps:

(1) by clay, zirconium dioxide, eucryptite 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 900-1000 DEG C, take out, polish to surface roughness≤0.1mm, obtain clay particle;

(2) by citric acid waste residues, waste sludge from paper mill, the mixing of 2-3% sodium hydroxide solution, be heated to 70-80 DEG C, stir 20-25 minute, be adjusted to neutrality, dry, obtain mixed material;

(3) material that described clay particle, (2) step obtain is mixed with other residual components, then add the water mixing 7-10 minute of 2-3% weight portion, to obtain final product.

Beneficial effect of the present invention

Molding sand of the present invention employs citric acid waste residues, waste sludge from paper mill, and through process, add plasticity and the intensity of molding sand, can prevent high temperature cracking phenomena, collapsibility is good, not sticky foundry goods; By using acetylene carbon black, add the dispersiveness of molding sand; By using clay, particle size is suitable, not only good permeability, good fluidity, good dispersion, and cast(ing) surface is smooth, all right recycling; The application of the invention auxiliary agent, adds plasticity and the mobility of molding sand.Auxiliary agent of the present invention employs useless porcelain, cullet, good heat resistance, and Surface coating has clay, has good compatibility with clay particle, can increase mobility, the dispersiveness of molding sand simultaneously, prevent from boning during clay particle high temperature, be beneficial to recycling.

Detailed description of the invention

A kind of foundry clay molding sand, is made up of the raw material of following weight portion (kilogram): zirconium dioxide 10, acetylene carbon black 2.5, bentonite 7, citric acid waste residues 2.5, waste sludge from paper mill 2.5, aqueous acrylic emulsion 6, eucryptite 10, lithium carbonate 1.5,2.5% sodium hydroxide solution 10, clay 210, water are appropriate, auxiliary agent 25;

Described auxiliary agent is made up of the raw material of following weight portion (kilogram): useless porcelain 20, cullet 2.5, sodium carbonate 2.5, bentonite 3.5, carboxymethyl cellulose 0.7, clay 3.5, calgon 1.2, PP wax 1.2, dextrin 1.2, water are appropriate; Preparation method is: carry out ball milling by after useless porcelain, cullet, sodium carbonate, bentonite mixing, cross 200 mesh sieves, calcine 5.5 hours, be ground into the particle that particle diameter is less than 2mm at 1210 DEG C; Add in 4.5 weight parts waters by clay, carboxymethyl cellulose, dextrin, add described particle, stir after stirring, dry, pulverize, particle diameter at 0.05-2mm, then mixes with other residual components, stirs, to obtain final product.

The preparation method of described foundry clay molding sand, comprises the following steps:

(1) by clay, zirconium dioxide, eucryptite 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 950 DEG C, take out, polish to surface roughness≤0.1mm, obtain clay particle;

(2) by citric acid waste residues, waste sludge from paper mill, 2.5% sodium hydroxide solution mixing, be heated to 75 DEG C, stir 23 minutes, be adjusted to neutrality, dry, obtain mixed material;

(3) material that described clay particle, (2) step obtain is mixed with other residual components, then the water adding 2.5% weight portion mixes 9 minutes, to obtain final product.

The sand test data that the present embodiment obtains are as follows: green compression strength is 85KPa, gas permeability 102, and hot green tensile strength is 3KPa, and normal temperature green tensile strength is 27KPa.

Claims (2)

1. a foundry clay molding sand, is characterized in that being made up of the raw material of following weight portion: zirconium dioxide 8-12, acetylene carbon black 2-3, bentonite 6-8, citric acid waste residues 2-3, waste sludge from paper mill 2-3, aqueous acrylic emulsion 5-7, eucryptite 8-12, lithium carbonate 1-2,2-3% sodium hydroxide solution 8-12, clay 200-220, water are appropriate, auxiliary agent 20-30;

Described auxiliary agent is made up of the raw material of following weight portion: useless porcelain 18-22, cullet 2-3, sodium carbonate 2-3, bentonite 3-4, carboxymethyl cellulose 0.5-1, clay 3-4, calgon 1-1.4, PP wax 1-1.4, dextrin 1-1.4, water are appropriate; Preparation method is: carry out ball milling by after useless porcelain, cullet, sodium carbonate, bentonite mixing, cross 200 mesh sieves, calcine 5-6 hour, be ground into the particle that particle diameter is less than 2mm at 1200-1220 DEG C; Add in 4-5 weight parts water by clay, carboxymethyl cellulose, dextrin, add described particle, stir after stirring, dry, pulverize, particle diameter at 0.05-2mm, then mixes with other residual components, stirs, to obtain final product.

2. the preparation method of foundry clay molding sand according to claim 1, is characterized in that comprising the following steps:

(1) by clay, zirconium dioxide, eucryptite 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 900-1000 DEG C, take out, polish to surface roughness≤0.1mm, obtain clay particle;

(2) by citric acid waste residues, waste sludge from paper mill, the mixing of 2-3% sodium hydroxide solution, be heated to 70-80 DEG C, stir 20-25 minute, be adjusted to neutrality, dry, obtain mixed material;

(3) material that described clay particle, (2) step obtain is mixed with other residual components, then add the water mixing 7-10 minute of 2-3% weight portion, to obtain final product.