CN1273938A - Process for preparing mixed and laminated crystal sodium silicate - Google Patents

Abstract

A process for preparing the mixed and laminated crystal sodium silicate [(delta+beta)-Na2Si2O5] includes mixing the aqueous solution of sodium silicate with sodium hydroxide, boron compound and phosphorus compound in the 1.7-2.2 of molecular ratio [(SiO2+B2O3 or P2O5)/Na2O] or 0.5-10% of weight ratio (P2O5/SiO2), stirring, reaction at 60-120 deg.C for at least 1-5 hr, spray drying at 80-400 deg.C, sintering at 550-780 deg.C for 6 hrs and breaking off to 80 meshes.

Description

The preparation method of mixed and laminated crystal sodium silicate

The present invention relates to a kind of lamina sodium silicate that mixes crystal formation [(δ+β)-Na ₂Si ₂O ₅] manufacture method, belong to the water demineralization ion-exchanger, be used for the washing assisant of washing agent and cleaning agent.

Prepare β-Na from Morey at the hydrothermal crystallization of the unbodied sodium disilicate glass of first passage in 1914 ₂Si ₂O ₅Afterwards, hydro-thermal reaction under 250-300 ℃ of temperature made β-Na in tens hours to Franke1950 by silicate starting materials and sodium hydroxide solution ₂Si ₂O ₅, the sodium silicate that Willgallis in 1964 and Range produce by sodium metasilicate and sodium carbonate fusion one dehydration, prepared α-, β-, γ-Na ₂Si ₂O ₅And determining of the degree of crystallinity of various crystal structure and X-diffracting spectrum described comprehensively.The German had synthesized δ-Na by the variation of temperature again in 1969 ₂Si ₂O ₅And given its X-diffracting spectrum.

From the nineties initial stage, people generally believe δ-Na ₂Si ₂O ₅Ion-exchange performance be better than the lamina sodium silicate of other crystal formation, therefore, Germany, the U.S. and Japan and other countries have been delivered a large amount of making pure δ-Na ₂Si ₂O ₅The process patent documentation.The process route of these methods is broadly divided into two classes, δ-Na that the first utilizes silica raw material and NaOH solution to obtain 250-300 ℃ of lower hydro-thermal reaction a few hours ₂Si ₂O ₅The Equations of The Second Kind patented method is adjusted SiO after being the unbodied sodium silicate solution that silica raw material and sodium carbonate fusion are made ₂And Na ₂Drying and dehydrating after the molecular proportion of O, and then calcining obtains δ-Na ₂Si ₂O ₅According to this research method, German Hirst company at first begins suitability for industrialized production δ-Na in nineteen ninety-five ₂Si ₂O ₅, the said firm cooperates to have built factory in Japan with the moral mountain company of Japan again subsequently, produces δ-Na ₂Si ₂O ₅Product is used as washing

Yet the J of Hirst company, the people such as Wei Kensi think β-Na ₂Si ₂O ₅Ion exchange capacity be better than δ-Na ₂Si ₂O ₅, therefore applied for respectively manufacturing β-Na in 1996 ₂Si ₂O ₅Process, this patent is with NaOH solution levelling Na with the commodity sodium silicate solution ₂O: SiO ₂Ratio be after 1: 2, place 235-300 ℃ of lower hydro-thermal reaction more than 5 hours, and cold filtration obtains the moisture sodium metasilicate product of crystallization, then product is made the β type sodium disilicate with high-exchange-capacity 450-780 ℃ of lower calcining.

As everyone knows, above-mentioned δ-Na ₂Si ₂O ₅It is a metastable crystalline sodium disilicate, has preferably ion-exchange performance, but poor at Stability in solution, the part water medium reaction takes place to 80 ℃ water, make crystalline layered structural deterioration and become amorphous state, therefore it only is applicable to the rear method of double crossing technology of washing agent, and is unsuitable for front allotment of labor's skill of washing agent, and this is undoubtedly for many years δ-Na ₂Si ₂O ₅Be in the suds and apply ineffective main cause.And β-Na ₂Si ₂O ₅Stability greatly be better than the δ type, water medium reaction does not take place in 80 ℃ of aqueous solution; Therefore people wish to produce a kind of (δ+β)-Na ₂Si ₂O ₅Mix the lamina sodium silicate of crystal formation, to improve existing properties of product, also can before washing agent production, join use.

That purpose of the present invention aims to provide is a kind of (δ+β)-Na ₂Si ₂O ₅The lamina sodium silicate that mixes crystal formation; Wherein, Si is partly replaced by B or P, forms nucleus, with the stability of accelerating to produce the reaction speed of crystallization and increasing product.More improved the compatibility with surfactant during use.The preparation method of a kind of mixed and laminated crystal sodium silicate of the present invention, prepare according to following process: with the aqueous solution of water glass, sodium hydroxide and boron compound or phosphorus compound, mix, react more than 1-5 hour at 60-120 ℃, with reaction mixture 80-400 ℃ of spraying drying, again the granular amorphous sodium silicate of moisture 5-35Wt% was calcined 0.1-6 hour at 550-780 ℃, and the bulk after will calcining is crushed into less than 80 purpose powders, just obtains mixed and laminated crystal sodium silicate of the present invention.It is any in boric acid, phosphoric acid, borate, phosphate and the oxide that the boronation that adds contains thing or phosphorus compound, and addition is B altogether ₂O ₃Or P ₂O ₅/ SiO ₂=0.5-10% (weight).Above-mentioned (SiO ₂+ B ₂O ₃Or P ₂O ₅)/Na ₂The molecular proportion of O is 1.7-2.2.Described mixed and laminated crystal sodium silicate is one to have (δ+β)-Na ₂Si ₂O ₅The crystalline layered sodium silicate of structure is described the present invention below in conjunction with accompanying drawing and preferred embodiment, and they do not limit the present invention.

Fig. 1 is preparation technology's schematic flow sheet of mixed and laminated crystal sodium silicate;

Referring to Fig. 1, with the aqueous solution, NaOH and the boron compound of sodium metasilicate or phosphorus compound three according to (SiO₂+B ₂O ₃/P ₂O ₅)∶Na ₂O=1.7-2.2 (molecular proportion) and B₂O ₃Or P₂O ₅/SiO ₂The proportioning of=0.5-10% (Wt) mixes, at 60-120 ℃ Lower reaction is more than 5 hours, and (the best is 120-in 80-400 ℃ with reaction mixture 220 ℃) spray-drying, again that the granular nothing of moisture 5-35% (best 15-25%) is fixed The shape sodium metasilicate makes 550-780 ℃ of lower calcining 0.1-6 hour and mixes crystal formation stratiform silicon Acid sodium.

Embodiment: measuring modulus is 3.3,40 degree Beaume, 5 liters of 1: 39 sodium silicate aqueous solutions of proportion, and this solution contains SiO ₂27.5%, contain Na ₂O9.5%, add 0.1 kilogram of Sodium Tetraborate or sodium phosphate, add solid NaOH0.27 kilogram (100%) again, with it 80 ℃ of following stirring reactions 5 hours, again reacted mixed solution is made the amorphous granular sodium silicates of water content 20% 180-220 ℃ of following spraying drying, then 700 ℃ of down calcinings 1 hour, and the piece material after will calcining is ground into-80 powder materials, be (δ+β)-Na ₂Si ₂O ₅Finished product.The calcium ion-exchanged capacity that uses the method for QB1767-93 to measure this product is 331mgCaCO ₃/ g product, consisting of δ type content through its crystal formation of X-ray diffraction mensuration is 30-40%, β type content is 60-70%.

Claims (4)

1, a kind of preparation method of mixed and laminated crystal sodium silicate, prepare according to following process: with the aqueous solution of water glass, sodium hydroxide and boron compound or phosphorus compound, mix,, more than 1-5 hour reaction mixture 80-400 ℃ of spraying drying, is calcined the granular amorphous sodium silicate of moisture 5-35Wt% 0.1-6 hour at 550-780 ℃ again 60-120 ℃ of reaction, and the bulk after will calcining is crushed into less than 80 purpose powders, just obtains mixed and laminated crystal sodium silicate of the present invention.

2, according to the preparation method of the mixed and laminated crystal sodium silicate of claim 1, it is characterized in that it is any in boric acid, phosphoric acid, borate, phosphate and the oxide that the boronation that adds contains thing or phosphorus compound, addition is B altogether ₂O ₃Or P ₂O ₅/ SiO ₂=0.5-10% (weight).

3, according to the preparation method of the mixed and laminated crystal sodium silicate of claim 1 or 2, it is characterized in that (SiO ₂+ B ₂O ₃Or P ₂O ₅)/Na ₂The molecular proportion of O is 1.7-2.2.

4, be characterised in that according to the mixed and laminated crystal sodium silicate of any preparation method preparation of claim 1-3 it is one and has (δ+β)-Na ₂Si ₂O ₅The crystalline layered sodium silicate of structure