CN1024761C - Production method of high-temp. foamed ceramic filter plate - Google Patents

Abstract

The present invention relates to a production method for high-temperature foamed ceramic filter plates. High-temperature foamed ceramic filter plates produced by the present invention can bear the emergent heat shock and the scouring of molten iron with a high flow rate, filter molten metal magnesium, and make a breakthrough to purify molten steel; the filter plates have the advantages of acid and alkali resistance, no toxicity and no odor. The filter plates can be used for filtration purification in industry, such as food, medicine, chemical industry, etc., and can also be used as a catalyst in chemical industry.

Description

Production method of high-temp. foamed ceramic filter plate

The present invention relates to a kind of making method of hot industry refractory materials, particularly a kind of production method of high temperature foam ceramic filter.

The filtration of deposite metal was in the past many to be carried out with strainers such as core pattern, net type, filter beds, developed into since the eighties have the porosity height, internal surface area is big, the cubes foamed ceramics type more than the hole count.

It is low that present existing floamed ceramics filtrating piece exists hot strength, and thermo-chemical stability is poor, emergency heat and cooling property resistance, and chilling impact and hot melts scouring capability are not enough; Foam structure takes off slag, softening, Thermochemical Decomposition in the use; Low temperature deposite metal in energy aluminum filtration, the copper etc., but thermo-chemical stability is poor, can not filter the magnesium alloy fused mass material; And softening point temperature is low, can not the filtering molten molten steel etc. problem.

For example; it is a Tai-Ace S 150 or an aluminum phosphate as the structural foam binding agent that present floamed ceramics filtrating piece is manufactured process; work the wilkinite that reduces ceramic softening temperature and play the vitreous effect; kaolin and the aluminum oxide that plays the aggregate effect; zirconium white; chromic oxide; refractory materialss such as silicon carbide ball milling respectively become the micro mist slip; add the glue blending and make ceramic mud; and then by slowly dry for a long time; oven dry and intensification very slowly; sintering and cooling slowly just can be fired and be formed; whole technological process reaches tens hours; and temperature control is very strict; for example: be raised to 500 ℃ of regulation per minutes from 125 ℃ when firing and heat up 0.5 ℃; the regulation per minute heats up 1 ℃ from 500 ℃ to 1350 ℃; will be incubated 1～2 hour in the time of 500 ℃, insulation is 5 hours in the time of 1350 ℃.

In addition, owing to contain materials such as phosphoric acid, kaolin, wilkinite in the existing foam ceramic material, its mud contains acidity, and manual contact or operation are corrosive.

And, can not satisfy the requirement of filtering high-temperature metal melt because its foam structure softening temperature is lower, more impossiblely satisfy the filtering application of molten steel.

Task of the present invention is exactly will be by adopting a kind of new prescription and making method, make and a kind ofly can bear big flow molten hot metal and wash away and anxious thermal shocking, thermo-chemical stability is good, and energy filtering molten magnesium metal and softening point temperature high energy are broken through the floamed ceramics filtrating piece of using to purification of molten steel.

Preparating mechanism of the present invention.

Foamed ceramics is by aluminum oxide; zirconium white; chromic oxide; silicon carbide etc. are aggregate; with silica glass is high-temperature agglomerant; add glue and be mixed into muddy; this mud is poured in the perforate polyurethane foam plastic of exhausted air; extrude unnecessary mud; remaining sticking to forms uniform thin film shape ceramic filter base substrate on the porous plastics filament; after this base substrate oven dry; the short time high temperature sintering; polyurethane foam is burnt; since ceramic foam under the high temperature sintering effect vitreous become porcelain, so the porous plastics shape body replica that stays just is made for the foamed ceramics of the good through hole spongy structure of intensity.

This production method is as follows:

One, preparing raw material

1. the cellular foam sponge soft plastics of opening chooses.

This material should have elasticity, have can be after extruding can restorable again ability, there is wetting ability to be beneficial to adhesion mud, softening temperature should be greater than 120 ℃, indeformable during flash baking, the burning of can volatilizing during temperature more than 500 ℃, surplus impurity, per inch length has 5～50 eyelets, the aperture is even, should thickness not mix; The foam filament is answered even thickness, with thick shape a bit for well.

The material of choosing cuts into the size that needs.

2. the preparation of glue is pressed 1: 23～25 proportioning weight ratio such as water with the polyvinyl alcohol or the first and second basic cellulose family organism, dissolves into rare glue-like after the heating, carries out filtered through gauze after placement is cooled to room temperature, removes solid sundries in the glue.

3. the preparation of aluminum oxide, zirconium white, chromic oxide, silicon carbide micro-powder.

Aluminum oxide warp let-off high temperature sintering is converted into the corundum of phase or zirconium white, chromic oxide, silicon carbide becomes micro mist through ball milling.

4. the preparation of silica glass micro mist.

Silica glass is processed into the silica glass micro mist through ball milling.

Two. the modulation of ceramic mud

With above-mentioned three kinds of raw materials by after the following formulated, stir to form and both be convenient to pour into foaming plastic body, can after extruding mud, can on the foam filament, form the ceramic mud silicon carbide that needs adhesion layer again, aluminum oxide, chromic oxide, the little material of zirconium white 25～60%, 15～45% ceramic mud Ying Suiyong of 20～40% polyvinyl alcohol glue of silica glass micro mist are with joining, and should not deposit of a specified duration.(weight ratio).

Three. the perfusion of ceramic mud

The porous plastics of choosing is immersed in the ceramic mud for preparing, fill with and extrude unnecessary ceramic mud after kneading, remaining ceramic mud sticks to and forms uniform thin film shape coating on the porous plastics filament, makes the floamed ceramics filtrating piece base substrate.

Four. fire

Base substrate is sent in the loft drier, drying changed sintering circuit over to more than two hours under 80 ℃～125 ℃ temperature condition, several minutes in temperature is 500 ℃～1200 ℃ sintering oven, after finishing, oxygenolysis enters 1520 ℃～1600 ℃ high temperature sintering, just can come out of the stove after 5～50 minutes, cooling back product is made.

The technical process of this manufacture method is as follows:

Extruding mud → oven drying at low temperature → middle temperature volatilization burning → high temperature sintering → the air cooling of coming out of the stove → inspection packing

Because characteristics such as that binding agent-silica glass that the present invention adopts possesses is high temperature resistant, anti-chillings, can directly enter 500 ℃～1200 ℃ high temperature so do the ceramic mud foams blank that high-temperature agglomerant manufactures with quartz micropowder; The sintering of foams blank can change high temperature rapidly over to, and the heating-up time is short, the high temperature sintering soaking time is short, saves the energy, reduces cost; Floamed ceramics filtrating piece can be come out of the stove under the condition of high temperature, naturally cooling in air at room temperature.

Because its thermo-chemical stability height of silica glass melts body with magnesium thermal chemical reaction does not take place, so can filter magnesium alloy under the condition of high temperature.

Because silica glass thermostability height, hot strength is good, and the softening point temperature height can bear washing away of big flow molten iron, satisfies the temperature requirement that filters molten steel.

Because the quartz glass ball that the present invention adopts is worn into micro mist and joined slurry, so technology is simple, grasp, and sintering quick heating easily, the time is short, can save the energy, reduces cost, and is softening when filtering high-temperature molten metal, do not fall slag, do not react with molten metal.

Because the present invention does not adopt acidic substance such as aluminum phosphate or Tai-Ace S 150 to make binding agent, so the nontoxic non-corrosiveness of foamed ceramics mud is convenient to manual operations, tasteless, acid and alkali-resistance is fit to do filtration, purification usefulness in the industries such as medicine, food, chemical industry, can also do catalyst and use in chemical industry.

Example:

Select softening temperature on demand greater than 120 ℃, the aperture is even, foam filament even thickness, and one of 20/ inch poly-aminomethyl acid fat vacuole foam of gross porosity cuts into the size greater than product, and as foamed ceramics product thickness 20mm, porous plastics should thick 25mm.Length and wide contraction ratio, littler than thickness, get final product so size is bigger.

With polyvinyl alcohol in 1: the 20(weight ratio) ratio adds the water post-heating and is fused into rare glue-like, places to be cooled to carry out filtered through gauze after the room temp, removes in the glue foreign material such as solid residue, makes standby glue.

Aluminum oxide through high temperature sintering, is made its corundum that becomes the α phase, and again through the ball milling operation, the micro mist that grinds into about 20 microns is standby.

Silicon oxide is generated silica glass through high-temperature fusion, and the micro mist that is processed into about 10 microns through ball milling is standby again.

It is as follows to fill a prescription: (weight ratio)

Corundum powder 42%

Silica glass micro mist 28%

Polyvinyl alcohol glue 30%

Stir after becoming ceramic mud by formulated, can glue fine strip shape with little rod clay slurry is the best.

Ready porous plastics is immersed in the ceramic mud for preparing, fill knead after, extrude unnecessary ceramic mud, need extrude 20～70%(weight approximately) remaining ceramic mud sticks to and forms uniform thin film shape coating on the porous plastics filament.

The base substrate that makes is sent in the loft drier dry more than two hours under the temperature about 110 ℃, changed over to sintering circuit.Entered 1520 ℃～1600 ℃ sintering circuits in 3 minutes after the oxygenolysis through 1000 ℃ of temperature in sintering oven, preferably 1580 ℃ of temperature are burnt after 10 minutes and are come out of the stove, naturally cooling at room temperature, and whole technological process is finished.

If ball milling processing aggregate (aluminum oxide, zirconium white, chromic oxide, silicon carbide etc.) is when becoming the micro mist shape with silica glass (binding agent), adopt Summoning ball grinder and Summoning abrading-ball, keep the product that its irony becomes the assignment system ceramic mud to make, has affinity for iron during filtering molten metal, can reduce filter pressure, convenient cast.

Keep the product that irony becomes the assignment system ceramic mud to make, the low temperature intensity height can satisfy the filtering service requirements of some industry low-temperature high-strength.

If this operation is made the mill jar with ceramic pot, done abrading-ball by bulk material in the abrasive material, self ball milling grinds out the micro mist that does not contain the irony composition, with such micro mist preparation ceramic mud, pure white, nontoxic, tasteless, have a better chemical stability, acid and alkali-resistance can be made into the foamed ceramic body of high chemical stability, is suitable for aspects such as food, medicine, chemistry and uses.

Claims (3)

1, a kind of production method of high temperature foam ceramic filter, it is as follows to it is characterized in that pressing column weight amount proportioning: aluminum oxide, zirconium white, chromic oxide or silicon carbide micro-powder 25-60%, silica glass micro mist 20-40%, polyvinyl alcohol glue 15-45%, make base substrate and be warmed up to 1520-1600 ℃, after 5～50 minutes, come out of the stove, make product after the cooling.

2, according to the production method of the described high temperature foam ceramic filter of claim 1, it is characterized in that polyvinyl alcohol glue by weight proportion 1: the 13-25 proportioning adds water and makes.

3,, it is characterized in that silica glass grinds into 10 microns micro mist through the ball milling operation according to the production method of the described high temperature foam ceramic filter of claim 1.