CN1020370C

CN1020370C - Disperser for water-glass sand

Info

Publication number: CN1020370C
Application number: CN 90102788
Authority: CN
Inventors: 沈家骅
Original assignee: TIANJIN SODA FACTORY
Current assignee: TIANJIN SODA FACTORY
Priority date: 1990-05-11
Filing date: 1990-05-11
Publication date: 1993-04-28
Anticipated expiration: 2005-05-11
Also published as: CN1048341A

Abstract

The present invention relates to a breakdown agent for water glass sand. Forest sand is added with water glass accounting for 7% of the forest sand, and waste slag in resin industry is used as a breakdown agent. The breakdown agent for water glass sand is prepared from 0.5 to 2% of resin slag, 0 to 1% of graphite powder and 5 to 6% of water. When being added to the breakdown agent for water glass sand, the breakdown agent of the present invention can sufficiently improve the breakdown agent for water glass sand; the retained strength of sand moulds(cores) is from 0.56 to 3.7 Kg/cm, and both the hardening instantaneous strength of CO2 and the drying strength of CO2 can meet the requirements for manufacturing grade-two sand cores, grade-three sand cores, grade-four sand cores and grade-five sand cores. The present invention provides an effective way for popularizing water glass sand in casting industry.

Description

Disperser for water-glass sand

The invention belongs to casting sand modification field, be specially adapted to improve the sodium silicate sand collapsibility energy.

Water-glass sand is as casting binder, it is wide that it has the source, price is low, the intensity height, gas forming amount is few, smokelessly nontoxic after the cast, harmless, free from environmental pollution, energy savings, certain plasticity is arranged during high temperature, can prevent the crackle of thin-section casting, its hardening process is simple simultaneously, can alleviate moulding (core) labour intensity, shorten advantages such as production cycle significantly, but because its collapsibility performance is poor, cause the sand removal difficulty, old sand is difficult for reuse, therefore it can not extensive use on Foundry Production, domestic in recent decades in the application and development of synthetic resin, partly replaced water-glass sand, but organic resin costs an arm and a leg, harmful to human body (lung and skin), China's production of resins can't be satisfied the demand for the moment in addition, in the case, although water-glass sand cast cleaning difficulty, those can not mainly use water-glass sand with the big-and-middle-sized foundry goods of wet type.Various countries have carried out improving the research of sodium silicate sand collapsibility in recent years, many achievements have been obtained, the product of Britain Fu Saike company for example, DeXil-60 modifier under the strict process control condition of advanced person's sand blender, has some improvement to the collapsibility of water-glass sand, but the roughing sand that domestic most of producer uses is of low quality, advanced sand blender is seldom arranged, lack the Special Equipment of control air blowing technology again, so the defeated and dispersed DeGrain of DeXil-60 type modifier.This country's on September 17th, 1986, disclosed application number was 85102900 disperser for water-glass sand technology, W84-I and the defeated and dispersed agent prescription of W84-II type are disclosed, its main component is phosphate, machine oil, glycerine, potassium permanganate, with regard to its prescription, these four kinds of compositions are inorganic or organic chemical industry's product, need increase certain cost during use.

The object of the invention provides a kind of new defeated and dispersed agent material and prescription that is different from above-mentioned defeated and dispersed agent prescription, and this material is the other industry waste material, so low price, and the source is abundant, and through the production practices of our unit, easy to operate, effect is remarkable.

Disperser for water-glass sand of the present invention is basic sand to produce with Da Lin normal sand 100%, adding modulus is the waterglass 7% composition water-glass sand of 2.2-2.4, and adopting solvent is the plain 18-25% of fibre-bearing, lignin 16-20%, the resin slag 0.5-2% of alcohols 1-3% controls moisture content 5-6% as defeated and dispersed dose.The graphite powder that also can add 0-1% is as defeated and dispersed dose selection component.

Above-mentioned defeated and dispersed dose adding, water-glass sand is had in the technical process of moulding (core) satisfy CO2 sclerosis real-time intensity and the CO2 sclerosis baked strength of producing needs, and has extremely low high-temperature residual strength, in the experimentation, CO2 sclerosis real-time intensity, the CO2 baked strength that hardens, the comparison of high-temperature residual strength have been carried out to adding 1.5% resin pulp water glass sand (Da Lin sand) and light water glass sand.

Accompanying drawing is that the sclerosis of two kinds of water-glass sands is instant, oven dry, high-temperature residual strength curve.

1 is 1.5% resin pulp water glass sand curve in the accompanying drawing

2 is light water glass sand curve

The CO2 of curve 1 sclerosis real-time intensity (about 20 ℃) is higher than curve 2 as can be seen from Figure, though 120 ℃ of baked strength curves 1 are lower than curve 2, still has 15Kg/Cm²Above intensity can satisfy the needs that II in the Foundry Production, III, IV, V level core are made fully, can find out also that from Fig. 1 the high-temperature residual strength of curve 1 is very low, according to this characteristic, in the experiment with the light water glass sand, 1.5% resin pulp water glass sand, the dried 1.3Kg/Cm that draws²The white clay fired mold sand is made respectively test block and is carried out hammering sand removal test, measures its knockout amount, calculates sand production rate, and correction data sees Table 1

Table 1

Compile and hit one by one accumulative total sand production rate %

The test portion title

Numbers 123456789 10

1 light water glass sand 8 13 15 15 19 26 30 30 30 30

2 1.5% resin slags 24 39 78 100

Water-glass sand

The 3 dried 1.3Kg/Cm that draw ²14 15 22 27 32 34 38 44 50

The white clay fired mold sand

As seen from Table 1, No. 2 sample only hits four times, No. 2 core is just all gone out clearly, mass color is clean in the sample, No. 3 samples only went out 22%, No. 2 sample clearly and hit to the 10th time since the 6th time this moment, and a sand grains does not all drop, illustrated add defeated and dispersed dose after, sodium silicate sand collapsibility can obtain substantially improving.

The adding of disperser for water-glass sand of the present invention, when making water-glass sand after the modification on foundry goods, replace fired mold sand, can be less on the consolidation operation with or without arbor, simplify the structure of skeleton, reduce the colligation time, the work efficiency of moulding (core) is improved, reduce labor intensity on shakeout operation, improve the sand removal work efficiency, it is few to have given full play to the water-glass sand gas forming amount simultaneously, be difficult for to produce pore, scab, scab, superiority such as sand washing, its economic benefit is fairly obvious.Calculate relatively according to fired mold sand and 1.5% resin pulp water glass sand expense, the former is 20.9 yuan/ton for its core sand cost, and the latter is the core of 72.55 yuan of these two kinds of same specifications of sand system of usefulness, and computational costs is listed in table 2.

The typical core cost of table 2

Use fired mold sand

Molding sand title sand unit/subtotal coremaking unit/subtotal aggregate net benefit

Amount Kg ton (1) worker in man-hour (2) (1) (2) unit

Caustic soda pot bed load core 600 20.9 12.54 4 50 200 212.54

Little cap core 400 20.9 8.36 6 50 300 308.36

With resin pulp water glass sand

Caustic soda pot bed load core 600 72.55 43.53 0.5 50 25 68.53 144.01

Little cap core 400 72.55 29.02 2 50 100 129.02 179.34

As seen from Table 2, though core cost per ton exceeds three times more than than fired mold sand during with the coremaking of resin pulp water glass sand, but it is short during owing to the coremaker, improved work efficiency, add up expense at last and still saved greatly, also do not comprise here because of simplifying roughing sand that technology saves and the percent defective resulting benefit that descends.

Use disperser for water-glass sand technology of the present invention among our unit produces, the foundry goods of the big or small all kinds of specifications of successfully having cast, its maximum foundry goods weighs 13.8 tons, 75 millimeters of maximum casting section thicknesses, 3100 * 1200 millimeters of foundry goods largest contours sizes, 4000 * 1700 millimeters of maximum core sizes, 4 tons of core maximum weights, intricate casting has 33 cores.

Embodiment 1

The 1 roughing sand waterglass resin slag graphite powder of filling a prescription control moisture content

100% 7% 0.5% 1% 5-6%

Make the test block of " ∞ " word by prescription, be blown into the CO2 gas hardening, insert in 120 ℃ of baking ovens and dry, be put into after one hour in the high temperature furnace again, be incubated 15 minutes, be chilled to room temperature and survey retained strength, three kinds of strength test data are as follows:

CO2 sclerosis real-time intensity 1.36Kg/cm ²

CO2 sclerosis baked strength 19.8Kg/cm ²

High-temperature residual strength 3.7Kg/cm ²

Embodiment 2

The 2 roughing sand waterglass resin slag graphite powders of filling a prescription control moisture content

100% 7% 1% 0 5-6%

CO2 sclerosis real-time intensity 2.05Kg/cm ²

CO2 sclerosis baked strength 17.5Kg/cm ²

High-temperature residual strength 1.5Kg/cm ²

Embodiment 3

The 3 roughing sand waterglass resin slag graphite powders of filling a prescription control moisture content

100% 7% 1.5% 0.5% 5-6%

CO2 sclerosis real-time intensity 2.26Kg/cm ²

CO2 sclerosis baked strength 15.66Kg/cm ²

High-temperature residual strength 0.91Kg/cm ²

Embodiment 4

The 4 roughing sand waterglass resin slag graphite powders of filling a prescription control moisture content

100% 7% 2% 1 5-6%

CO2 sclerosis real-time intensity 1.86Kg/cm ²

CO2 sclerosis baked strength 7.10Kg/cm ²

High-temperature residual strength 0.5Kg/cm ²

Disperser for water-glass sand of the present invention can make water-glass sand adapt to the needs of foundry goods II, III, IV, the manufacturing of V level core, applies water-glass sand for foundry industry effective way is provided.

Claims

1, a kind of disperser for water-glass sand, it is characterized in that with Da Lin sand 100% be basic sand, adding modulus and be 2.2～2.4 waterglass 7% and form water-glass sand, be defeated and dispersed dose with the resin slag 0.5～2% of fibre-bearing element 18～25%, lignin 16～20%, carbohydrate 1～3%, controls moisture content 5～6%.

2,, it is characterized in that described defeated and dispersed dose also can be added 0～1% graphite powder according to the described disperser for water-glass sand of claim 1.