CN103303940A - Method for preparing faujasite by using geopolymer by hydrothermal crystallization - Google Patents

Abstract

The invention mainly relates to a method for preparing faujasite by using a geopolymer by hydrothermal crystallization. The method comprises the following steps: by using metakaolin as a solid raw material and sodium water glass as an activator, adjusting the silica-alumina ratio of the system by use level of metakaolin; designing the silica-alumina ratio and the sodium-alumina ratio in the raw material according to theoretical composition of faujasite; mixing and stirring the solid raw material with an alkali-activator and injecting into a mould; maintaining for 12-24 hours in a constant temperature box at 40-80 DEG C; placing the maintained geopolymer in a hydrothermal kettle; and performing hydrothermal crystallization for 8-12 hours at 70-120 DEG C to prepare the faujasite material. The faujasite material can be prepared in-situ at one time by characteristic of easy moulding of the geopolymer. Compared with conventional preparation of faujasite, the method provided by the invention is simple to operate, low in cost and suitable for large-scale preparation.

Description

A kind of method of utilizing the geopolymer hydrothermal crystallizing to prepare faujusite

Technical field

The present invention relates to geology polymer material field and faujusite material field, particularly a kind of method of utilizing the geopolymer hydrothermal crystallizing to prepare faujusite.

Background technology

Geology polymer material is proposed in 1978 by French material scholar Joseph Davidovits.It is the amorphous tridimensional network that silicon-oxy tetrahedron and aluminum-oxygen tetrahedron constitute by bridging oxygen, and basic metal or alkaline earth metal cation play the effect of balance aluminum-oxygen tetrahedron negative charge.People such as Deventer infer that geology polymer material is a kind of intermediateness of zeolite molecular sieve.Usually, geology polymer material is amorphous non-crystal structure, but this seminar finds to have in the geology polymer material ordered structure of a small amount of nanoscale by high-resolution-ration transmission electric-lens (HRTEM) analysis; By further research, this geology polymer material can change into molecular sieve under corresponding hydrothermal condition.

Characteristics such as faujusite has that easy production, calcium ion exchange capacity are strong, surface adsorption power is strong, anti-soil is dirty and anti-redeposition is good, nontoxicity, pollution-free, good stability can be used for fields such as washing composition, catalyzer and fractionation by adsorption.At present, the traditional method of preparation faujusite mainly is hydrothermal synthesis method, and product all is powder particle, must could use through post forming with binding agent, causes faujusite cost height, and complicated process of preparation has limited the widespread use of faujusite.Utilize geology polymer material can prepare corresponding faujusite through hydrothermal treatment consists according to design requirements moulding different shape sample.

The patent situation relevant with the faujusite technology of preparing is as follows:

The patent No. be 200510047508 Chinese disclosure of the Invention a kind of synthetic method of faujusite, the particularly synthetic method of high silica alumina ratio faujusite.This invention faujusite building-up process is that hydrothermal crystallizing is synthetic under alkaline condition, and adopting lower molecular weight polyalcohols compound is template, does not need zeolite seed crystal, directly synthesizes the faujusite of high silica alumina ratio under hydrothermal condition.This inventive method has shortened crystallization time by selecting suitable template, has improved the combined coefficient of zeolite.But its product is particulate state, is difficult to the faujusite product according to application demand moulding different shape.

The technology that the present invention proposes is the compound system of geopolymer system preparation technology and faujusite technology, and the particularly restriction of not restricted appearance shape by retrieval, does not have the similar techniques report.

Summary of the invention

Because the faujusite of preparation was powder particle, need carry out post forming in the past, the manufacturing cost height, and also also there is the single problem of shape in faujusite.The invention provides a kind of method of utilizing the geopolymer hydrothermal crystallizing to prepare faujusite, it is extensive that this method has raw material sources, and synthetic cost is low, can design the characteristics such as shape of faujusite block materials according to application requiring.

The technical scheme that the present invention solves the problems of the technologies described above employing is as follows:

A kind of method of utilizing the geopolymer hydrothermal crystallizing to prepare faujusite, the employing metakaolin is solid material, and sodium silicate is exciting agent, and raw material is SiO according to mol ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=4～11 preparation geopolymer samples after sealed maintenance 12-24 hour, puts into water heating kettle to the geopolymer sample that maintenance is good in 40～80 ℃ of thermostat containers; Through 70～120 ℃, 8～12h hydrothermal crystallizing, can obtain relative crystallinity and surpass 90% faujusite block materials.Described metakaolin is that the above kaolin of 250 orders is calcined the powder that 2h obtains in 600～900 ℃ of air.Described modulus of water glass is 0.9～1.2 industrial sodium silicate.

The preparation method comprises the steps:

1) preparation of geopolymer sample:

1.1) the preparation metakaolin:

Be that commercially available kaolin more than 250 orders is calcined 2h and obtained metakaolin in 600～900 ℃ of air with fineness;

1.2) the preparation modulus is 0.9～1.2 industrial sodium silicate:

Industrial sodium silicate is put into plastic beaker, add an amount of NaOH and adjust modulus to 0.9～1.2, stir up to whole dissolvings, the cooling back is stand-by;

1.3) preparation geopolymer sample:

Be SiO according to mol ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=4～11 take by weighing metakaolin, add modulus again and be 0.9～1.2 industrial sodium silicate, mix and stir 30min, inject mould, and at 40～80 ℃ of maintenance 12～24h, the demoulding obtains to have certain intensity geopolymer sample;

2) preparation of faujusite:

With step 1.3) the geopolymer sample put into water heating kettle, add the deionization water cover and cross sample, the hydrothermal crystallizing temperature is 70～120 ℃, crystallization time is 8～12h, can obtain relative crystallinity at the faujusite block materials more than 90% after hydro-thermal is intact.

Compared with prior art, the present invention has the following advantages:

1. the present invention combines the advantage that the preparation geology polymer material can adopt multiple forming method, as casting, injection moulding, high-pressure molding etc.Can design the shape of zeolite like this according to application requiring, will further widen the range of application of zeolite.

2. it is simple to the invention provides a kind of technology, is fit to large-scale production, and cost is low, and starting material are the preparation method widely.

Description of drawings

Fig. 1 is the SEM figure of the embodiment of the invention 1 product.

Fig. 2 is the SEM figure of the embodiment of the invention 2 products.

Fig. 3 is the XRD figure of the embodiment of the invention 3 products.

Embodiment

The present invention is further elaborated below by embodiment.

Embodiment 1

With fineness be more than 250 orders commercially available kaolin powder through in 800 ℃ of air the calcining 2h obtain metakaolin.Industrial sodium silicate is put into plastic beaker, add an amount of NaOH and adjust modulus to 1.2, stir up to whole dissolvings, the cooling back is stand-by.SiO in molar ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=4 takes by weighing metakaolin; the sodium silicate that adds 1.2 moulds again mixes stirring 30min; inject mould; 40 ℃ of maintenance 12h; the demoulding obtains to have the test block of certain intensity geopolymer; put into water heating kettle and add deionized water, 70 ℃ of crystallization temperatures, crystallization time is that to be prepared into ultimate compression strength under the 12h hydrothermal condition be the test block of 35.7MPa faujusite.SEM collection of illustrative plates such as Fig. 1 of product.

Embodiment 2

With fineness be more than 250 orders commercially available kaolin powder through in 900 ℃ of air the calcining 2h obtain metakaolin.Industrial sodium silicate is put into plastic beaker, add an amount of NaOH and adjust modulus to 0.9, stir up to whole dissolvings, the cooling back is stand-by.SiO in molar ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=11 takes by weighing metakaolin; add 0.9 mould sodium silicate again and mix stirring 30min; inject mould; 80 ℃ of maintenance 24h; the demoulding obtains to have the test block of certain intensity geopolymer; put into water heating kettle and add deionized water, 120 ℃ of crystallization temperatures, crystallization time is that to be prepared into ultimate compression strength under the 8h hydrothermal condition be the test block of 16.8MPa faujusite.SEM collection of illustrative plates such as Fig. 2 of product.

Embodiment 3

With fineness be more than 250 orders commercially available kaolin powder through in 600 ℃ of air the calcining 2h obtain metakaolin.Industrial sodium silicate is put into plastic beaker, add an amount of NaOH and adjust modulus to 1.0, stir up to whole dissolvings, the cooling back is stand-by.SiO in molar ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=9 takes by weighing metakaolin; add 1.0 mould sodium silicates again and mix stirring 30min; inject mould; 60 ℃ of maintenance 24h; the demoulding obtains to have the test block of certain intensity geopolymer; put into water heating kettle and add deionized water, 90 ℃ of crystallization temperatures, crystallization time is that to be prepared into ultimate compression strength under the 10h hydrothermal condition be the test block of 20.4MPa faujusite.The XRD figure spectrum of product is as Fig. 3.

Claims (1)

1. a method of utilizing the geopolymer hydrothermal crystallizing to prepare faujusite is characterized in that, the employing metakaolin is solid material, and sodium silicate is exciting agent, and raw material is SiO according to mol ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=4～11 preparation geopolymer samples after sealed maintenance 12-24 hour, puts into water heating kettle to the geopolymer sample that maintenance is good in 40～80 ℃ of thermostat containers; Through 70～120 ℃, 8～12h hydrothermal crystallizing, can obtain relative crystallinity and surpass 90% faujusite block materials, described metakaolin is that the above kaolin of 250 orders is calcined the powder that 2h obtains in 600～900 ℃ of air; Described modulus of water glass is 0.9～1.2 industrial sodium silicate;

The preparation method comprises the steps:

1) preparation of geopolymer sample:

1.1) the preparation metakaolin:

Be that commercially available kaolin more than 250 orders is calcined 2h and obtained metakaolin in 600～900 ℃ of air with fineness;

1.2) the preparation modulus is 0.9～1.2 industrial sodium silicate:

Industrial sodium silicate is put into plastic beaker, add an amount of NaOH and adjust modulus to 0.9～1.2, stir up to whole dissolvings, the cooling back is stand-by;

1.3) preparation geopolymer sample:

Be SiO according to mol ratio ₂/ Al ₂O ₃=3, Na ₂O/Al ₂O ₃=1, H ₂O/Na ₂O=4～11 take by weighing metakaolin, add modulus again and be 0.9～1.2 industrial sodium silicate, mix and stir 30min, inject mould, and at 40～80 ℃ of maintenance 12～24h, the demoulding obtains to have certain intensity geopolymer sample;

2) preparation of faujusite:

With step 1.3) the geopolymer sample put into water heating kettle, add the deionization water cover and cross sample, the hydrothermal crystallizing temperature is 70～120 ℃, crystallization time is 8～12h, can obtain relative crystallinity at the faujusite block materials more than 90% after hydro-thermal is intact.

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