CN104646602A - Anti-staining foundry molding sand and preparation method thereof - Google Patents

Abstract

The invention discloses anti-staining foundry molding sand, which is prepared from the following raw materials in parts by weight: 2-3 parts of magnesium phosphate, 3-5 parts of zirconium silicate, 3.5-4 parts of montmorillonite, 25-30 parts of new sand, 60-70 parts of old sand, 1.2-1.5 parts of brewer grains, 0.04-0.06 part of a beta-naphthalenesulfonate formaldehyde condensate, 0.2-0.4 part of polyester polyol, 0.1-0.2 part of castor oil, 4-5 parts of modified pulverized coal, 0.3-0.5 part of tartaric acid and 4-5 parts of water. The zirconium silicate is added, so that the anti-staining foundry molding sand disclosed by the invention is good in chemical stability, and poor in metal compatibility, is capable of preventing sand staining, improving the plasticity. The modified pulverized coal disclosed by the invention is multiple in volatile components, little in ash, uniform in particles, good in mobility; the brightness of a casting is improved; the defects such as 10%-13% of air pores and sand staining are reduced; and the collapsibility is improved.

Description

A kind of releasing sand casting sand and preparation method thereof

Technical field

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

Background technology

So-called foundry clay green-sand, refers to by roughing sand, binding agent and conforms to thing and coordinate by a certain percentage, through overmulling system, meeting the compound of modeling requirement.Because clay green-sand casting material therefor is cheap and easy to get, casting mold is simple and convenient, and all can adapt to the single-piece production of foundry goods, in batch a large amount of production, for a long time, be the basic technology of Foundry Production always.

Molding sand will have following characteristic: 1, good permeability, and after high-temperature metal liquid cast-iron pours into casting mold, producing gas must discharge smoothly in casting mold; 2, good intensity, ensures that molding sand must possess sufficiently high intensity and deformability; 3, there is good fire resistance, the integrality 4 of thermal effect at high temperature sand mold, safe and reliable, simple to operate, easy construction can be resisted, the reduction of erection time; 5, heat endurance, mobility, plasticity, compact rate of molding are good.

Existing foundry goods also exists a lot of problem, the such as phenomenon such as buckle, sand washing, drop, sweat, pore, pin hole, shrinkage cavity and porosity, loose, crackle, scab, scab, rough surface, elephant skin, shrinkage depression, this all has very large relation with molding sand, need the performance constantly improving molding sand, can improve from raw material and sand mulling craft.

In addition, coal dust is added in foundry goods green-sand, scab defect can be prevented, improve the surface smoothness of foundry goods, and burning into sand defect can be reduced, improve the defeated and dispersed function of molding sand, for wet type G. Iron Castings, effectively can also prevent subcutaneous blowhole, available circular vortex burner, air is without preheating.The size of pulverized coal particle, shape, mobility, phosphorus content, volatile matter number, ash content content determine the performance quality of foundry goods, the quality of foundry goods can be improved by the performance improving coal dust.

Summary of the invention

The object of the present invention is to provide a kind of releasing sand casting sand and preparation method thereof, this molding sand can prevent from being stained with sand, and plasticity is good.

Technical scheme of the present invention is as follows:

A kind of releasing sand casting sand, is characterized in that being made up of the raw material of following weight portion: magnesium phosphate 2-3, zirconium silicate 3-5, montmorillonite 3.5-4, fresh sand 25-30, old sand 60-70, brewex's grains 1.2-1.5, beta-naphthalenesulfonic-acid salt formaldehyde condensation products 0.04-0.06, PEPA 0.2-0.4, castor oil 0.1-0.2, modification coal dust 4-5, tartaric acid 0.3-0.5, water 4-5;

Described modification coal dust is made up of the raw material of following weight portion: brown coal powder 3-3.5, ferrocene 0.05-0.08, lignosulfonate 0.02-0.04, ethanol 4-6, sodium chloride 0.1-0.2, potassium permanganate 0.2-0.3, lanthana 0.01-0.02, manganese dioxide 0.02-0.03, magnesia 0.1-0.2, nano-sized carbon 0.2-0.3; Preparation method is: add in ethanol by nano-sized carbon, lanthana, stir, add brown coal powder, and being ground to grain diameter is 10-40 μm, spraying dry in atmosphere of hydrogen, then mixes with other residual components, and sealing, to obtain final product.

The preparation method of described releasing sand casting sand, is characterized in that comprising the following steps:

(1) by fresh sand and old sand mixing, sieve, obtain the sand of particle diameter at 0.3-1.2mm, add in simpson mill together with magnesium phosphate, zirconium silicate, mixing 4-5 minute, then add the water of 40%, mixing 3-4 minute, obtains mixed sand;

(2) pulverized by montmorillonite, mix, add the water of 30%, be heated to 60-70 DEG C with PEPA, tartaric acid, stir 10-15 minute, then send into three-roll grinder, grinding 20-30 minute, obtains modified montmorillonoid;

(3) modified montmorillonoid (2) step obtained and other residual components join in the puddle mixer in (1) step, and evenly do not add remaining water to spray shape under halt condition, wet mixing 6-8 minute, to obtain final product.

Beneficial effect of the present invention

Molding sand of the present invention with the addition of zirconium silicate, and chemical stability is good, with the poor compatibility of metal, can prevent from being stained with sand, can also improve the plasticity of molding sand; Modification coal dust of the present invention, volatile matter is many, and ash content is few, uniform particles, good fluidity, adds the bright property of foundry goods, decreases the pore of 10-13%, burning into sand defect, improves collapsibility.

Detailed description of the invention

A kind of releasing sand casting sand, is made up of the raw material of following weight portion (kilogram): magnesium phosphate 2.5, zirconium silicate 4, montmorillonite 3.8, fresh sand 28, old sand 65, brewex's grains 1.3, beta-naphthalenesulfonic-acid salt formaldehyde condensation products 0.05, PEPA 0.3, castor oil 0.1, modification coal dust 4.5, tartaric acid 0.4, water 4.5;

Described modification coal dust is made up of the raw material of following weight portion (kilogram): brown coal powder 3.3, ferrocene 0.06, lignosulfonate 0.03, ethanol 5, sodium chloride 0.1, potassium permanganate 0.2, lanthana 0.02, manganese dioxide 0.03, magnesia 0.2, nano-sized carbon 0.3; Preparation method is: add in ethanol by nano-sized carbon, lanthana, stir, add brown coal powder, and being ground to grain diameter is 10-40 μm, spraying dry in atmosphere of hydrogen, then mixes with other residual components, and sealing, to obtain final product.

The preparation method of described releasing sand casting sand, comprises the following steps:

(1) by fresh sand and old sand mixing, sieve, obtain the sand of particle diameter at 0.3-1.2mm, add together with magnesium phosphate, zirconium silicate in simpson mill, mix 4 minutes, then add the water of 40%, mix 3 minutes, obtain mixed sand;

(2) montmorillonite is pulverized, mix with PEPA, tartaric acid, add the water of 30%, be heated to 65 DEG C, stir 13 minutes, then send into three-roll grinder, grind 25 minutes, obtain modified montmorillonoid;

(3) modified montmorillonoid (2) step obtained and other residual components join in the puddle mixer in (1) step, and evenly do not add remaining water to spray shape under halt condition, wet mixing 7 minutes, to obtain final product.

Experimental data

The testing result of the present embodiment molding sand is as follows: green compression strength 0.16MPa, normal temperature green tensile strength 22Kpa, hot green tensile strength 3.9KPa, gas forming amount 10.5ml/g, gas permeability 150, clay content 9.8%.

Claims (2)

1. a releasing sand casting sand, is characterized in that being made up of the raw material of following weight portion: magnesium phosphate 2-3, zirconium silicate 3-5, montmorillonite 3.5-4, fresh sand 25-30, old sand 60-70, brewex's grains 1.2-1.5, beta-naphthalenesulfonic-acid salt formaldehyde condensation products 0.04-0.06, PEPA 0.2-0.4, castor oil 0.1-0.2, modification coal dust 4-5, tartaric acid 0.3-0.5, water 4-5;

Described modification coal dust is made up of the raw material of following weight portion: brown coal powder 3-3.5, ferrocene 0.05-0.08, lignosulfonate 0.02-0.04, ethanol 4-6, sodium chloride 0.1-0.2, potassium permanganate 0.2-0.3, lanthana 0.01-0.02, manganese dioxide 0.02-0.03, magnesia 0.1-0.2, nano-sized carbon 0.2-0.3; Preparation method is: add in ethanol by nano-sized carbon, lanthana, stir, add brown coal powder, and being ground to grain diameter is 10-40 μm, spraying dry in atmosphere of hydrogen, then mixes with other residual components, and sealing, to obtain final product.

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

(1) by fresh sand and old sand mixing, sieve, obtain the sand of particle diameter at 0.3-1.2mm, add in simpson mill together with magnesium phosphate, zirconium silicate, mixing 4-5 minute, then add the water of 40%, mixing 3-4 minute, obtains mixed sand;

(2) pulverized by montmorillonite, mix, add the water of 30%, be heated to 60-70 DEG C with PEPA, tartaric acid, stir 10-15 minute, then send into three-roll grinder, grinding 20-30 minute, obtains modified montmorillonoid;

(3) modified montmorillonoid (2) step obtained and other residual components join in the puddle mixer in (1) step, and evenly do not add remaining water to spray shape under halt condition, wet mixing 6-8 minute, to obtain final product.