CN1067665C - Gelatinization formation technology for silicate ceramic mud - Google Patents

Abstract

The present invention provides a gelatinization forming technology for silicate slurry, which relates to a new technology in slurry casting forming. A traditional slurry casing forming process uses porous materials for making molds in order that water in the slurry can be removed to form solid blanks. When the porous materials are used for making the molds, a series of inconvenience are caused, and the production cost and the plant establishment investment are increased. The technology provided by the present invention does not use the porous materials for making the molds. Inorganic compounds are added into high solid phase slurry, so the slurry is slowly solidified in the molds, and the blanks are formed. Thus, the forming molds can be made of ordinary materials, various disadvantages caused by mode manufacture by the porous materials are avoided, and simultaneously, the present invention reserves the advantages that products with complex shapes can be formed, forming equipment is simple and cheap, etc. The gelatinization forming technology can be used for producing sanitary ceramics, household ceramics, artistic ceramics, etc.

Description

The gelatinization formation technology of silicate ceramic mud

The present invention relates to a kind of moulding new technology of silicate ceramic mud.

Traditional slurry casting moulding process need be made mould with porous material, the common gypsum mould, and the characteristic of utilizing the gypsum porous water-absorbing is with moisture sucking-off in the mud, thus formation solid base substrate.Perhaps use the porous resin mould, mud makes the moisture of mud drain by the space by the slurry face is pressurizeed after injecting mould.Plaster mould damages easily, has only work-ing life tens times, and therefore the plaster mould workshop is all had in bigger ceramics factory, constantly makes the usefulness of plaster mould for moulding.The porous resin mold performance is better than plaster mould, but makes the expensive raw material price of this mould, and some raw material need be from external import.In addition, the slip casing by pressure moulding needs the expensive slip casing by pressure machine of a cover.Therefore making mould with porous material brings a series of inconvenience, increases the production cost and the investment of founding the factory.

Develop in the high-performance ceramics field closely during the last ten years gel injection method (gelcasting) (referring to: 1, M.A.Janney, O.O.Omatete; " Method formolding ceramic powders using a water-based gel castingprocess, " U.S.Patent 528362; 2, Yang Jinlong, Xie Zhipeng, yellow brave, Deng " rheological of α-Al2O3 suspensoid and gel injection molding and forming technology research ", silicate journal 26 (1) 40-46,1998) and directly cohesion injection molding (direct coagulation casting) (referring to: 1, T.J.Graule, E.H.Baarder, and L.J.Gauckler, " Shapingof Ceramic Green Compacts Direct From Suspensions by EnzymeCatalyzed Reactions; " cfi/DKC 71 (6), 317-323,1994; 2, Yang Jinlong, yellow brave waits " α-Al ₂O ₃Directly solidify the research of injection molding and forming technology ", silicate journal 25 (5), 514-519,1997) with method proposed by the invention similar part is arranged.But all at the more single lean property ceramic raw material of ratio of componentss such as aluminum oxide, silicon nitride, the scope of application is narrow for these methods, can not adapt to the silicate ceramic mud (comprising architectural and sanitary ceramics, household china, artistic porcelain etc.) that is made of the various ingredients raw mineral materials.And directly condense injection molding and only be applicable to acid mud, and silicate ceramic mud is alkaline mostly.Directly the cohesion injection molding will be made catalyzer with biological enzyme, still has suitable techno-economic question to need to solve as realizing scale operation.And gel casting need add organic monomer in mud, by monomer polymerization mud is solidified then, and this technology controlling and process more complicated not too is fit to the requirement of scale operation.

The objective of the invention is to come mfg. moulding die, to replace traditional gypsum mold with firm, impervious materials commonly used such as metal, plastics.

The present invention is modulated into solid load and reaches 50-60% by removing the method for part moisture content in the conventional silicate slurry, and viscosity is less than the mud of 1000 centipoises simultaneously.In above-mentioned mud, add a certain amount of inorganic peptizer powder, fully mix, inject the mould that the inner wall smooth densification does not absorb water then, solidify the back depanning, obtain desired ceramic body.

Mud of the present invention basic composition is clay, feldspar, quartz, wherein use chamotte (as the calcined coke jewel) to replace a part of plastic clay, and use conventional thinner (as yellow soda ash, water glass) to regulate the viscosity of mud, make conventional ceramic mud earlier.Wherein a part of mud is removed most of moisture content by methods such as press filtration or heat dryings again, then this half-dried pug is put into the mud that another part does not dewater, be modulated into solid load and reach 50-60% (volume ratio), viscosity is less than the mud of 1000 centipoises simultaneously.Inorganic peptizer with some amount before injection forming adds in the mud, after the adding, do not solidify, so that mud is injected mould at initial stage mud, added subsequently inorganic peptizer impels mud slowly to solidify with moisture generation hydration in the mud.This inorganic peptizer is made up of independent or blended sulplo-aluminate, silicate and silicon oxide, and its chemical constitution is: Al ₂O ₃: 0-55%, CaO:30-70%, SiO ₂: 0-40%, SO ₃: 0-13%.The setting rate of mud becomes with the add-on of inorganic peptizer, and the setting rate that add-on is high is fast.The add-on of inorganic peptizer is the 1-5% of mud weight.Biscuit density with moulding of the present invention is 1.50-1.60g/cm ³, the folding strength of dry back biscuit is 20.0-26.0MPa, and drying shrinkage is 2.5-3.5%, and the biscuit performance index made from traditional method are identical.

Need not make mould with porous material with the technology that the present invention proposes, but in high solid mud, add inorganic complex, mud is slowly solidified in mould, form base substrate.So just can make forming mould, thereby avoid doing the various shortcoming that mould brings, advantages such as having kept slurry casting simultaneously again can moulding complicated shape goods, molding device simple cheap with porous material with general material.The present invention can be used for saving the investment of founding the factory, and having reduced production cost in the productions such as sanitary china, household china, artistic porcelain.

Example one

Press the listed one-tenth assignment system mud of table one, add the Na of mud weight 0.15% again ₂CO ₃, 0.15% Na ₂SiO ₃NaOH with 0.08% expects: water=1: 0.38.Batching was gone into the ball mill mix grinding 8 hours.Get and ground 1/2 of slip and become mud cake, mix with second half again through press filtration.The mud solid load that so makes is 56%, pH=9, and viscosity is 545 centipoises.

Table one

Raw material	Ripe burnt precious	Feldspar	Quartzy	Camwood knag	Alkali stone	The alkali cash	Chapter village soil	The refined soil of chapter	Datong District's soil	Porcelain stone	Water (adding outward)
												w％	5	20	20	10	5	3	12	5	6	14	23

Get above-mentioned mud 100 grams and add inorganic peptizer 2 grams (chemical ingredients of inorganic peptizer as shown in Table 2) therein, stirred fast 1 minute, the two is mixed, inject punching block, open mould after 2 hours, take out 100 * 12 * 12 rectangle strips.Strip was 60 ℃ of loft drier inner dryings 3 days.Article 6, the average drying shrinkage of such strip is 3.34%, and the mean density of biscuit is 1.58g/cm ³, average folding strength is 25.2MPa.

Table two

Composition	Al 2O 3	CaO	SO 3
				w％	50.2	36.8	13.0

Example two

With the mud adding identical in the example one and the inorganic peptizer of example one same composition and same ratio, after fully stirring 1 minute, pour in the boxlike mould of making by synthetic glass, depanning after 2 hours, obtaining 90 * 70 * 5mm tabular biscuit, is 1.51g/cm in 3 days biscuit density of 60 ℃ of loft drier inner dryings ³, drying shrinkage is 3.31%, average folding strength is 21.0MPa.Example three

Mud with identical with example one adds composition inorganic peptizer as shown in Table 3 therein, and add-on is 1.5% of a mud weight.Fully stir and poured in 2 minutes in the cement mould of making ceramic soap box, cement mould internal surface is handled with the nitrocotton coating, the internal surface hole of closed die, spread butter again, make mould internal surface hydrophobic, then boron nitride is modulated into mud with alcohol, spreads upon the internal surface of mould, make the mould internal surface form one deck release layer.The demoulding in 3 hours after the slip casting.The soap box base substrate through 60 ℃ of loft drier inner dryings after 3 days biscuit density be 1.53g/cm ³, drying shrinkage is 3.41%, average folding strength is 23.2MPa.

Table three

Composition	Al 2O 3	CaO	SiO 2	SO 3
w％	48.7	35.7	2.9	12.7

Claims (1)

1. the gelatinization formation technology of a silicate ceramic mud is characterized in that:

With conventional ceramic mud separated into two parts, wherein a part of mud is removed most of moisture content by methods such as press filtration or heat dryings, then this half-dried pug is put into the mud that another part does not dewater, be modulated into solid load and reach 50-60% (volume ratio), viscosity is less than the mud of 1000 centipoises simultaneously, the inorganic peptizer of some amount is added in the mud, after the adding, do not solidify at initial stage mud, after mud injected mould, added inorganic peptizer impelled mud slowly to solidify with moisture generation hydration in the mud, this inorganic peptizer is by independent or blended sulplo-aluminate, silicate and silicon oxide are formed, and its chemical constitution is: Al ₂O ₃: 0-55%, CaO:30-70%, SiO ₂: 0-40%, SO ₃: 0-13%, the setting rate of mud becomes with the add-on of inorganic peptizer, and the setting rate that add-on is high is fast, and the add-on of inorganic peptizer is the 1-5% of mud weight.