CN103521687A

CN103521687A - Molding sand for large cast steel roll and preparation method of molding sand

Info

Publication number: CN103521687A
Application number: CN201310481203.2A
Authority: CN
Inventors: 孙爱琴
Original assignee: Hefei Tenver Precision Casting Co Ltd
Current assignee: Hefei Tenver Precision Casting Co Ltd
Priority date: 2013-10-16
Filing date: 2013-10-16
Publication date: 2014-01-22

Abstract

The invention discloses molding sand for a large cast steel roll. The molding sand is prepared from the following raw materials in parts by weight: 200-240 parts of quartz sand, 20-25 parts of calcium carbonate, 90-100 parts of zirconite, 20-25 parts of diatomite, 5-8 parts of aluminum oxide, 3-4 parts of active carbon, 2-3 parts of sodium nitrate, 2-4 parts of sodium carbonate, 10-14 parts of magnesium carbonate, 3-4 parts of chlorinated paraffin, 1-2 parts of chromic oxide, 10-15 parts of kaolin, 3-5 parts of mica, 2-3 parts of rapeseed oil, 4-6 parts of sodium metasilicate and an appropriate amount of water. According to the molding sand disclosed by the invention, the quartz sand, the calcium carbonate, the zirconite, the diatomite and the like are used, and roasted at a high temperature, and dispersing and grinding of added active carbon, chlorinated paraffin, and the like are combined, so that the molding sand not only has excellent smoothness, plasticity, gas permeability, cohesiveness and toughness, but also has high strength. The molding sand disclosed by the invention is used for casting the large cast steel roll, the roll surface can be prevented from generating casting defects of sand burning, sand inclusion and the like better, the roll surface is smooth, and quality and qualified rate of the large cast steel roll are improved.

Description

A kind of molding sand for large cast steel roll and preparation method thereof

Technical field

The present invention relates to a kind of casting field, relate in particular to a kind of molding sand for large cast steel roll and preparation method thereof.

Background technology

Molding sand is in casting, to be used for the material of moulding.Molding sand is generally mixed according to a certain percentage by Modeling Materials such as Foundry sand, moulding sand binder and additional things, also available natural silica sand argillaceous, the sand formulation Sand particle diameter that common cast aluminium is used is too large or too little, molding sand material footpath is too large, although gas permeability is better, aloxite part surface ratio is more coarse, fineness is bad, molding sand material footpath is too little, causes sand mold gas permeability bad, and aluminium casting has pore to produce.Domestic and international widely used coal dust clay green-sand, generally by the mixed system of roughing sand, binding agent, coal dust additive etc. and water, formed, there is certain anti-scab effect and the cost of material is low, production efficiency is high, but its consumption is large, discharge is serious, at casting process coal dust firing, decompose and produce toxic gas and pollute.

Molding sand is different by binding agent used, can be divided into clay-bonded sand, water-glass sand, cement bonded sand, quartz sand etc., and that with clay-bonded sand, water-glass sand and quartz sand, uses is maximum.The effect of molding sand in Foundry Production is very important, and the casting wasted product causing because of the poor quality of molding sand accounts for 30～50% of the total waste product of foundry goods.Conventionally to the requirement of molding sand, be: 1, there is higher intensity and heat endurance, to bear the effect of various external force and high temperature.2, good mobility, the ability that molding sand mutually moves between sand grains under external force or Action of Gravity Field own.3, certain plasticity, molding sand is out of shape under external force, can keep the ability of the shape that gives after external force is removed.4, good gas permeability, molding sand hole sees through the ability of gas.5, high collapsibility, weighs up again grittiness, and after casting solidification, whether molding sand easily destroys, the performance of whether easily removing from foundry goods.

Current casting field development rapidly, higher for the performance requirement of steel-casting and ironcasting, thereby require further to promote the performance of molding sand.

Summary of the invention

The object of the present invention is to provide a kind of molding sand for large cast steel roll and preparation method thereof, this molding sand has high gas permeability, high strength, feature that collapsibility is good.

Technical scheme of the present invention is as follows:

For a molding sand for large cast steel roll, it is characterized in that being made by the raw material of following weight portion: quartz sand 200-240, calcium carbonate 20-25, zircon 90-100, diatomite 20-25, aluminium oxide 5-8, active carbon 3-4, sodium nitrate 2-3, sodium carbonate 2-4, magnesium carbonate 10-14, chlorinated paraffin wax 3-4, chrome green 1-2, kaolin 10-15, mica 3-5, rapeseed oil 2-3, sodium metasilicate 4-6, water are appropriate

The preparation method of the described molding sand for large cast steel roll, it is characterized in that comprising the following steps: quartz sand, calcium carbonate, zircon, diatomite mixed powder are broken into 100-200 order powder, then add active carbon, sodium nitrate, sodium carbonate, chlorinated paraffin wax, suitable quantity of water, dispersed with stirring, pugging, send in 1440-1460 ℃ of calcining furnace and calcine 4-5 hour, take out and be crushed to 50-100 order, obtain calcining material; Kaolin, mica, sodium metasilicate, rapeseed oil are mixed, grind 20-30 minute, then mix with other residual components, add and be equivalent to water wet mixing 10-15 minute of compound weight 3-5% and get final product.

Beneficial effect of the present invention

The present invention has used quartz sand, calcium carbonate, zircon, diatomite etc., through high-temperature calcination, in conjunction with adding the dispersion grinding such as active carbon, chlorinated paraffin wax, make molding sand not only there is excellent smoothness, plasticity, gas permeability, caking property, toughness, also there is high intensity; Use kaolin, mica, sodium metasilicate, rapeseed oil simultaneously, after grinding, mixed the caking property that has increased molding sand; Used rapeseed oil as binding agent, collapsibility is good; Use molding sand casting large-scale cast steel roll of the present invention, can better prevent that the casting flaws such as scab, burning into sand from appearring in roller surface, make roller surface bright and clean, the castability and the casting qualification rate that improve large cast steel roll, meet the Integrated using performances such as heavy merchant mill, strip mill roll roll working lining wearability, hot-cracking resistance, anti-accident performance.

The specific embodiment

For a molding sand for large cast steel roll, by following weight portion (kilogram) raw material make: quartz sand 220, calcium carbonate 23, zircon 95, diatomite 23, aluminium oxide 7, active carbon 3.5, sodium nitrate 2.5, sodium carbonate 3, magnesium carbonate 13, chlorinated paraffin wax 3.6, chrome green 1.5, kaolin 13, mica 4, rapeseed oil 2.5, sodium metasilicate 5, water are appropriate

The preparation method of the described molding sand for large cast steel roll, comprise the following steps: quartz sand, calcium carbonate, zircon, diatomite mixed powder are broken into 150 order powder, then add active carbon, sodium nitrate, sodium carbonate, chlorinated paraffin wax, suitable quantity of water, dispersed with stirring, pugging, send in 1450 ℃ of calcining furnaces and calcine 4.5 hours, take out and be crushed to 70 orders, obtain calcining material; Kaolin, mica, sodium metasilicate, rapeseed oil are mixed, grind 25 minutes, then mix with other residual components, add and be equivalent to the water wet mixing 13 minutes of compound weight 4% and get final product.

The processing performance of the molding sand that the present invention makes:

Green compression strength: 0.151Mpa, air penetrability: 123%, hot green tensile strength: 408Kpa, shatter index: 87%.

Claims

1. for a molding sand for large cast steel roll, it is characterized in that being made by the raw material of following weight portion: quartz sand 200-240, calcium carbonate 20-25, zircon 90-100, diatomite 20-25, aluminium oxide 5-8, active carbon 3-4, sodium nitrate 2-3, sodium carbonate 2-4, magnesium carbonate 10-14, chlorinated paraffin wax 3-4, chrome green 1-2, kaolin 10-15, mica 3-5, rapeseed oil 2-3, sodium metasilicate 4-6, water are appropriate.

2. according to claim 1 for the preparation method of the molding sand of large cast steel roll, it is characterized in that comprising the following steps: quartz sand, calcium carbonate, zircon, diatomite mixed powder are broken into 100-200 order powder, then add active carbon, sodium nitrate, sodium carbonate, chlorinated paraffin wax, suitable quantity of water, dispersed with stirring, pugging, send in 1440-1460 ℃ of calcining furnace and calcine 4-5 hour, take out and be crushed to 50-100 order, obtain calcining material; Kaolin, mica, sodium metasilicate, rapeseed oil are mixed, grind 20-30 minute, then mix with other residual components, add and be equivalent to water wet mixing 10-15 minute of compound weight 3-5% and get final product.