CN104057014A

CN104057014A - Gray iron casting moulding sand and preparation method thereof

Info

Publication number: CN104057014A
Application number: CN201410229460.1A
Authority: CN
Inventors: 朱安会; 马洪章
Original assignee: Anhui Xin Run Type Material Co Ltd
Priority date: 2014-05-28
Filing date: 2014-05-28
Publication date: 2014-09-24
Anticipated expiration: 2034-05-28
Also published as: CN104057014B

Abstract

The invention discloses gray iron casting moulding sand which is prepared from the following raw materials in parts by weight: 250-280 parts by weight of quartz sand, 40-45 parts by weight of sepiolite, 160-170 parts by weight of loess, 30-35 parts by weight of shell powder, 20-25 parts by weight of titanium dioxide, 40-45 parts by weight of grass meal, 2-3 parts by weight of acrylic emulsion, 30-40 parts by weight of silicon carbide, 10-15 parts by weight of pulverized coal, 50-60 parts by weight of gypsum, 3-4 parts by weight of zinc stearate, 10-15 parts by weight of bentonite, 3-4 parts by weight of ammonium dihydrogen phosphate, 4-5 parts by weight of sodium bicarbonate, 2-3 parts by weight of sodium dodecyl benzene sulfonate, 4-6 parts by weight of urea, 10-12 parts by weight of flour, 40-45 parts by weight of wood-bamboo powder and a proper amount of water. The sepiolite, the loess, the bentonite and the like are calcined, thus the gray iron casting moulding sand has excellent plasticity and caking property; by using the shell powder, the grass meal, the wood-bamboo powder and the like, the air permeability is increased; by using the titanium dioxide, the dispersity is increased and the high-temperature collapsibility is good; by using the pulverized coal, the surface of a casting is bright. The yield of the casting is increased.

Description

A kind of molding sand for casting gray iron and preparation method thereof

Technical field

The present invention relates to casting field, relate in particular to a kind of molding sand for casting gray iron 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 can be with 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 formed by the mixed system of roughing sand, binding agent, coal dust additive etc. and water, 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, decompose and produce toxic gas and pollute at casting process coal dust firing.

Molding sand, by binding agent difference used, can be divided into clay-bonded sand, water-glass sand, cement bonded sand, quartz sand etc., and that uses with clay-bonded sand, water-glass sand and quartz sand 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 giving 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 casting gray iron and preparation method thereof, this molding sand has that plasticity is good, good permeability, high temperature collapsibility are good, the feature of non-caked foundry goods.

Technical scheme of the present invention is as follows:

A kind of molding sand for casting gray iron, is characterized in that being made up of the raw material of following weight portion: quartz sand 250-280, sepiolite 40-45, loess 160-170, oyster shell whiting 30-35, titanium dioxide 20-25, grass meal 40-45, acrylic emulsion 2-3, carborundum 30-40, coal dust 10-15, gypsum 50-60, zinc stearate 3-4, bentonite 10-15, ammonium dihydrogen phosphate (ADP) 3-4, sodium acid carbonate 4-5, neopelex 2-3, urea 4-6, flour 10-12, wooden bamboo powder 40-45, water are appropriate.

The preparation method of described molding sand for casting gray iron, it is characterized in that comprising the following steps: quartz sand, sepiolite, loess, oyster shell whiting, bentonite, gypsum are put into 520-540 DEG C of calcining furnace and calcine 4-5 hour, then take out, be ground into 250-350 order powder, then add grass meal, titanium dioxide, carborundum suitable quantity of water, dispersed with stirring, pugging, send in 1420-1450 DEG C of calcining furnace and calcine 3-5 hour, take out and be crushed to 50-100 order, obtain calcining material; Zinc stearate, ammonium dihydrogen phosphate (ADP), sodium acid carbonate, neopelex, urea, flour, acrylic emulsion are mixed, grind 30-40 minute, mix 15-20 minute with calcining material, other residual components, to obtain final product.

Beneficial effect of the present invention

The present invention has used sepiolite, loess, bentonite etc. through calcining, has excellent plasticity, caking property, by using oyster shell whiting, grass meal, wooden bamboo powder etc., has increased gas permeability, by using titanium dioxide, has increased dispersiveness, and high temperature collapsibility is good; By using coal dust, make cast(ing) surface light, the present invention is easy to moulding, coremaking, and shrinkage factor is little, and casting dimension is accurate, solves foundry goods shrinkage cavity and porosity effect and reaches more than 90%, improves casting yield.

Detailed description of the invention

A kind of molding sand for casting gray iron, by following weight portion (kilogram) raw material make: quartz sand 260, sepiolite 43, loess 165, oyster shell whiting 33, titanium dioxide 23, grass meal 43, acrylic emulsion 2.5, carborundum 35, coal dust 13, gypsum 55, zinc stearate 3.5, bentonite 13, ammonium dihydrogen phosphate (ADP) 3.5, sodium acid carbonate 4.5, neopelex 2.5, urea 5, flour 11, wooden bamboo powder 43, water are appropriate.

The preparation method of described molding sand for casting gray iron, comprise the following steps: quartz sand, sepiolite, loess, oyster shell whiting, bentonite, gypsum are put into 530 DEG C of calcining furnaces and calcine 4.5 hours, then take out, be ground into 300 order powder, then add grass meal, titanium dioxide, carborundum suitable quantity of water, dispersed with stirring, pugging, send in 1430 DEG C of calcining furnaces and calcine 4 hours, take out and be crushed to 80 orders, obtain calcining material; Zinc stearate, ammonium dihydrogen phosphate (ADP), sodium acid carbonate, neopelex, urea, flour, acrylic emulsion are mixed, grind 35 minutes, mix 18 minutes with calcining material, other residual components, to obtain final product.

The sand test data that the present embodiment obtains are as follows: high temperature compression strength is more than 0.91Mpa, and gas forming amount is lower than below 13.9ml/g, heat-resistant time 170 seconds, and room temperature tensile strength is greater than 0.01Mpa, and hot-drawn intensity is greater than 0.015Mpa.

Claims

1. a molding sand for casting gray iron, is characterized in that being made up of the raw material of following weight portion: quartz sand 250-280, sepiolite 40-45, loess 160-170, oyster shell whiting 30-35, titanium dioxide 20-25, grass meal 40-45, acrylic emulsion 2-3, carborundum 30-40, coal dust 10-15, gypsum 50-60, zinc stearate 3-4, bentonite 10-15, ammonium dihydrogen phosphate (ADP) 3-4, sodium acid carbonate 4-5, neopelex 2-3, urea 4-6, flour 10-12, wooden bamboo powder 40-45, water are appropriate.

2. the preparation method of molding sand for casting gray iron according to claim 1, it is characterized in that comprising the following steps: quartz sand, sepiolite, loess, oyster shell whiting, bentonite, gypsum are put into 520-540 DEG C of calcining furnace and calcine 4-5 hour, then take out, be ground into 250-350 order powder, then add grass meal, titanium dioxide, carborundum suitable quantity of water, dispersed with stirring, pugging, send in 1420-1450 DEG C of calcining furnace and calcine 3-5 hour, take out and be crushed to 50-100 order, obtain calcining material; Zinc stearate, ammonium dihydrogen phosphate (ADP), sodium acid carbonate, neopelex, urea, flour, acrylic emulsion are mixed, grind 30-40 minute, mix 15-20 minute with calcining material, other residual components, to obtain final product.