CN102583431A - Method for preparing 4A molecular sieves by doping bentonite with attapulgite - Google Patents

Abstract

The invention relates to a method for synthesizing 4A molecular sieves by using bentonite and attapulgite as raw materials. The method comprises the following steps of: (1) performing acid activation on the bentonite; (2) activating the attapulgite at high temperature; (3) performing alkali treatment; (4) crystallizing; and (5) washing. According to the method, the bentonite and the attapulgite are used as the raw materials, and SiO2 in the bentonite and the attapulgite is used as a silicon source to prepare the 4A molecular sieves suitable for detergent additives. Compared with the prior art, the method has the advantages that: environmental pollution and energy waste are reduced; the preparation cost of the 4A molecular sieves is reduced; process equipment is simple and is easy to control; and new ways for developing and utilizing the bentonite and the attapulgite are opened up.

Description

Wilkinite and Attapulgite mix and prepare the method for 4A molecular sieve

Technical field

The present invention relates to a kind of method of utilizing natural mineral raw to prepare the 4A molecular sieve, particularly a kind of the doping with wilkinite and Attapulgite prepares the method for 4A molecular sieve.

Background technology

The chemical formula of 4A molecular sieve is Na ₂OAl ₂O ₃2SiO ₂9/2H ₂O; Silica alumina ratio SiO ₂/ Al ₂O ₃≈ 2; The effective pore radius approximately

(0.4nm).Very easily planar water, methyl alcohol, ethanol, hydrogen sulfide, sulfurous gas, carbonic acid gas, ethene, the less molecule of propylene equal diameter; Any molecule (comprise propane) of difficult absorption diameter greater than

is that one of maximum molecular sieve kind of consumption is gone up in industry.

Each Sauerstoffatom in the 4A framework of molecular sieve all is that adjacent two tetrahedrons are common; This structure has formed and can be the big bug hole that positively charged ion and water molecules occupy; And these positively charged ions and water molecules have bigger movability, can carry out cationic exchange and reversible dehydration.The IX of 4A molecular sieve is to have Al ³⁺Carry out each Al on the ionic skeleton ³⁺Ion with a negative charge, not only can combine Na ⁺Ion also can combine other positively charged ion.Ca ²⁺, Mg ²⁺Ion can get into original Na ⁺The big bug hole that ion occupies is with the Na in the 4A molecular sieve ⁺Ion is replaced---and be the Na in the 4A molecular sieve ⁺Ion can with the Ca in the hard water ²⁺, Mg ²⁺Plasma carries out IX, thereby reaches the purpose of demineralized water.

Since the eighties; Environmental pollution receives the extensive concern of countries in the world day by day; The production of phosphorous washing powder is forbidden in the numerous and confused legislation of many countries such as Japan, the U.S., Britain; And the great market demand of detergent industry forces people to seek the substitute of STPP (tripoly phosphate sodium STPP is as the water-softening agent in the washing composition).The 4A molecular sieve combines Ca ²⁺, Mg ²⁺Ionic speed is slower than tripoly phosphate sodium STPP, and and Mg ²⁺The ionic binding ability a little less than, but the 4A molecular sieve can be with a small amount of deleterious heavy metal ion in the aqueous solution (like pb ²⁺, Cd ²⁺, Hg ²⁺) can be easy to remove fast, to the crucial meaning that purified water, use as the water-softening agent in the washing composition so can replace STPP.

4A molecular sieve preparation at present is main with the water-bath preparation method generally; Raw materials usedly be all single chemical feedstocks, cost is higher, in addition this preparing method's pre-treatment or need the acid of labor; Need higher temperature, certainly will cause environmental pollution or energy dissipation so.

Summary of the invention

In view of above-mentioned, the object of the invention aims to provide a kind of the doping with wilkinite and Attapulgite and prepares the method for 4A molecular sieve.With wilkinite and Attapulgite is raw material, and utilizes SiO wherein ₂Be suitable for the 4A molecular sieve of detergent additives as the preparation of silicon source.

The objective of the invention is to adopt following technical scheme to realize:

A kind of is the method for feedstock production 4A molecular sieve with wilkinite and Attapulgite, specifically comprises the steps:

(1) bentonitic acid activation: get 200 order wilkinites and place beaker, in beaker, add the sulfuric acid of 30%-60%, sulfuric acid and wilkinite liquid-solid ratio are 2-4; Beaker is placed on the constant temperature blender with magnetic force, acidifying 12h after-filtration under 80-100 ℃ of condition, washing in 110 ℃ of oven dry down, obtains the acidifying carclazyte to neutral, crosses 200 mesh sieves;

(2) high-temperature activation of Attapulgite: a certain amount of 200 order Attapulgite are placed retort furnace, in 800 ℃ of following roasting 1h, after the cooling, drying; In 60 ℃ of acidifying 4h, washing after the drying, places beaker to neutral with 8% sulfuric acid; Reductive agent titanous chloride and oxalic acid are added reaction certain hour under certain power ultrasonic, spinning; Obtain white recessed soil, cross 200 mesh sieves, subsequent use.

(3) alkaline purification: acidifying carclazyte and white recessed soil are mixed by a certain percentage, place reactor drum, temperature of reactor is controlled at 30-35 ℃, adds 30%NaOH solution in the reactor drum and carries out alkaline purification 2h in 60-70 ℃.

(4) crystallization: reactor drum is cooled to 30-35 ℃, under constantly stirring, adds sodium aluminate solution and water gradually, and stirring is warming up to 80-100 ℃ and carries out crystallization 6h.

(5) washing: reaction finishes after-filtration, and the filter residue water is washed till pH value 9-10, and oven dry is pulverized and promptly got 4A molecular sieve finished product.

Principle of the present invention is: through s.t. the structure of smectite in the wilkinite destroyed, formed the amorphous substance soft silica, and active with the transformation that increases reaction and structure; Replenish the required Na of preparation 4A molecular sieve structure through sodium aluminate solution ₂O, Al ₂O ₃And water, and form higher basicity; In the higher system of basicity, carrying out hydrothermal crystallizing handles; Thereby silicon-oxy tetrahedron and aluminum-oxygen tetrahedron in the alternatively mixing compound are recombinated; Be formed with tetra-atomic ring, six-membered ring structure that silicon-oxy tetrahedron and aluminum-oxygen tetrahedron are formed, and and then form α cage and β cage, thereby formation 4A molecular sieve.In the preparation process, adjust its proportioning raw materials, to reach 3Na ₂O: Al ₂O ₃: 2SiO ₂: 150H ₂The proportion of composing of O, it is required to make the ratio of each element form the composition meet the 4A molecular sieve.

Compared with prior art, remarkable advantage of the present invention is:

(1) the present invention is a raw material with wilkinite and Attapulgite, in conjunction with s.t. and two kinds of methods of roasting, and preparation 4A molecular sieve, the present invention had both reduced pollution, had also reduced the waste of the energy; Need the silicon source no longer in addition, cost is lower, provides cost savings greatly;

(2) compare with the thousands of degree activation temperatures of clay mineral such as kaolin, wilkinite need not high-temperature activation, and Attapulgite just can reach activation effect down at 800 ℃, has practiced thrift the energy to a great extent;

(3) compare with single raw material Attapulgite, wilkinite and the Attapulgite prepared 4A molecular sieve finished product calcium ion-exchanged capacity that mixes is higher.The calcium ion-exchanged capacity is 297.3-312.5mg/g, reaches the standard that is higher than 295mg/g in " detergent use 4A zeolite " (QB/T 1768-2003);

(4) preparation method of this product is simple, not high to equipment requirements, and suitable for mass production is for new way has been opened up in the development and use of wilkinite and Attapulgite resource.

Description of drawings

Fig. 1 is for being the process flow sheet of feedstock production 4A molecular sieve with wilkinite and Attapulgite.

Fig. 2 is the SEM image of 4A molecular sieve finished product.

Embodiment

Wilkinite of the present invention is taken from Jinchang, Gansu Hong Quan, and Attapulgite is taken from the Linze, Gansu; The sulfuric acid that is adopted, sodium hydroxide, the pure product of the equal operational analysis of sodium metaaluminate; Used water is the homemade zero(ppm) water in laboratory.

Below in conjunction with embodiment the present invention is further described, but protection scope of the present invention is not limited to this.

Embodiment 1:

98% vitriol oil 61.2ml is dissolved in the 38.8ml zero(ppm) water, makes 60% sulfuric acid.Get the 30g wilkinite and place beaker, in beaker, add 90ml 60% sulfuric acid, beaker is placed on the constant temperature blender with magnetic force, stir; Make it react 12h down at 90 ℃, treat to discard upper strata filtrating after its sedimentation layering, lower floor's acidifying clay wash is to neutral; Oven dry gets the acidifying carclazyte, crosses 200 mesh sieves.

98% vitriol oil 8.2ml is dissolved in the 91.8ml zero(ppm) water, makes 8% sulfuric acid; Get 108g oxalic acid and be dissolved in the 892g zero(ppm) water, make the 1.2mol/L oxalic acid solution; Get the 30g Attapulgite, place retort furnace, take by weighing 20g after the cooling, add 8% sulfuric acid 160ml in 800 ℃ of following roasting 1h; In 60 ℃ of acidifying 4h, reaction is accomplished after scouring to neutral, oven dry, and dry back adds 1.2mol/L oxalic acid 500ml; Titanous chloride 1ml places the 800W ultrasonic reactor to react 1h down at 70 ℃, spinning, and washing is to white; Drying obtains white recessed soil, crosses 200 mesh sieves.

NaOH is dissolved in 70ml zero(ppm) water with the 30g particulate state, obtains 30%NaOH solution; Get acidifying carclazyte and concavo-convex each 3g of white, in the placing response device, controlled temperature is 35 ℃, adds 30%NaOH solution 80ml and carries out alkaline purification 2h in 65 ℃.

Liquid in the alkali treatment is cooled to 35 ℃, under constantly stirring, adds 18.4g sodium aluminate solution and 250ml water gradually, to reach 3Na ₂O: Al ₂O ₃: 2SiO ₂: 150H ₂The reaction mixture proportion of composing of O.Stirring is warming up to 90 ℃ and carries out crystallization 6h.

Reaction finishes after-filtration, and filtrating is reclaimed, and the filter cake water is washed till pH value 9-10, and oven dry is pulverized and promptly got 4A molecular sieve finished product.Its form is the khaki color powder; The SEM image is hexahedron structure, and it is comparatively even to distribute; The calcium ion-exchanged capacity is 300.2mg/g.

Embodiment 2:

98% vitriol oil 61.2ml is dissolved in the 38.8ml zero(ppm) water, makes 60% sulfuric acid.Get the 30g wilkinite and place beaker, in beaker, add 90ml 60% sulfuric acid, beaker is placed on the constant temperature blender with magnetic force; Make it react 12h down at 90 ℃, treat to discard upper strata filtrating after its sedimentation layering, lower floor's acidifying clay wash is to neutral; Oven dry gets the acidifying carclazyte, crosses 200 mesh sieves.

98% vitriol oil 8.2ml is dissolved in the 91.8ml zero(ppm) water, makes 8% sulfuric acid; Get 108g oxalic acid and be dissolved in the 892g zero(ppm) water, make the 1.2mol/L oxalic acid solution; Get the 30g Attapulgite, place retort furnace, take by weighing 20g after the cooling, add 8% sulfuric acid 160ml in 800 ℃ of following roasting 1h; In 60 ℃ of acidifying 4h, reaction is accomplished after scouring to neutral, oven dry, and dry back adds 1.2mol/L oxalic acid 500ml; Titanous chloride 1ml places the 800W ultrasonic reactor to react 1h down at 70 ℃, spinning, and washing is to white; Drying obtains white recessed soil, crosses 200 mesh sieves.

NaOH is dissolved in 70ml zero(ppm) water with the 30g particulate state, obtains 30%NaOH solution; Get acidifying carclazyte 2g, the recessed native 4g of white, in the placing response device, controlled temperature is 35 ℃, adds 30%NaOH solution 80ml and carries out alkaline purification 2h in 65 ℃.

Liquid in the alkali treatment is cooled to 35 ℃, under constantly stirring, adds 18.4g sodium aluminate solution and 250ml water gradually, to reach 3Na ₂O: Al ₂O ₃: 2Si0 ₂: 150H ₂The reaction mixture proportion of composing of O.Stirring is warming up to 90 ℃ and carries out crystallization 6h.

Its calcium ion-exchanged capacity is 297.3mg/g.

Embodiment 3:

98% vitriol oil 61.2ml is dissolved in the 38.8ml zero(ppm) water, makes 60% sulfuric acid.Get the 30g wilkinite and place beaker, in beaker, add 90ml 60% sulfuric acid, beaker is placed on the constant temperature blender with magnetic force; Make it react 12h down at 90 ℃, treat to discard upper strata filtrating after its sedimentation layering, lower floor's acidifying clay wash is to neutral; Oven dry gets the acidifying carclazyte, crosses 200 mesh sieves.

98% vitriol oil 8.2ml is dissolved in the 91.8ml zero(ppm) water, makes 8% sulfuric acid; Get 108g oxalic acid and be dissolved in the 892g zero(ppm) water, make the 1.2mol/L oxalic acid solution; Get the 30g Attapulgite, place retort furnace, take by weighing 20g after the cooling, add 8% sulfuric acid 160ml in 800 ℃ of following roasting 1h; In 60 ℃ of acidifying 4h, reaction is accomplished after scouring to neutral, oven dry, and dry back adds 1.2mol/L oxalic acid 500ml; Titanous chloride 1ml places the 800W ultrasonic reactor to react 1h down at 70 ℃, spinning, and washing is to white; Drying obtains white recessed soil, crosses 200 mesh sieves.

NaOH is dissolved in 70ml zero(ppm) water with the 30g particulate state, obtains 30%NaOH solution; Get acidifying carclazyte 4g, the recessed native 2g of white, in the placing response device, controlled temperature is 35 ℃, adds 30%NaOH solution 80ml and carries out alkaline purification 2h in 65 ℃.

Liquid in the alkali treatment is cooled to 35 ℃, under constantly stirring, adds 18.4g sodium aluminate solution and 250ml water gradually, to reach 3Na ₂O: Al ₂O ₃: 2SiO ₂: 150H ₂The reaction mixture proportion of composing of O.Stirring is warming up to 90 ℃ and carries out crystallization 6h.

The products obtained therefrom form is a pale powder, and the calcium ion-exchanged capacity is 312.5mg/g.

Test Example:

Get

L/L calcium chloride solution 50mL adds quantitative 1mol/L sodium hydroxide solution in the 500mL volumetric flask, thin up is to scale; Mixing pipettes this solution 50mL again in the 300mL Erlenmeyer flask, adds water move to about 100mL; And add EDTA Disodium copper solutions 1mL, 3 of PAN indicator, ammonia property damping fluid 15mL; Use EDTA standard titration solution titration to the solution of 0.01mol/L to be glassy yellow and be terminal point, record consumes the volume (V of EDTA standard titration solution ₀).

In the 500mL volumetric flask, thin up adds certain amount of sodium hydroxide solution and regulates PH to (10.5-10.1) to scale, moves in the 1000mL there-necked flask behind the mixing with pipette, extract 0.05mol/L calcium chloride solution 50mL.There-necked flask is put into (35 ± 1) ℃ water bath with thermostatic control, the adjustment agitator speed is 600-700r/min, in flask, puts into 0.5g 4A molecular sieve sample behind the constant temperature immediately; Behind the reaction 20min, take out flask and filter with quantitative paper immediately, discard start-up portion; In the 300mL Erlenmeyer flask, adding water to volume is about 100mL, adds 0.01moL/L EDTA-Cu solution 1mL with pipette, extract clear filtrating 50mL; 3 of PAN indicator; Ammonia property damping fluid 15mL uses the EDTA standard titration solution of 0.01mol/L to drip to be glassy yellow to solution to be terminal point, and record consumes the volume (V of EDTA standard titration solution _E).

The calcium exchange capacity E of 4A molecular sieve representes with milligram carbonic acid calcium per gm anhydrous zeolite, calculates by following formula:

$E=\frac{100.08\×10\×C_E\×(V_0-V_E)}{m\×(1-X)}---\left(1\right)$

Wherein the meaning of each parameter representative is following:

C _E---the concentration of EDTA standard titration solution, unit: mol/L;

V ₀---consume the volume of EDTA standard titration solution in the blank titration, unit: mL;

V _E---consume the volume of EDTA standard titration solution in the sample titration, unit: mL;

M---sample mass, unit: g;

X---measure the 4A zeolite loss on ignition that obtains, %;

100.08---the mmole quality of lime carbonate, unit: mg/mmol.

With the C among the embodiment 1 _E, V ₀, V _E, among the m, X substitution (1), calculate the calcium ion-exchanged capacity and be:

$E_1=\frac{100.08\×10\×0.01\×(27.9-15.3)}{0.50\×(1-0.16)}=300.2\mathrm{mg}/g$

The calcium ion-exchanged capacity that in like manner, can get embodiment 2 samples is 297.3mg/g; The calcium ion-exchanged capacity of embodiment 3 samples is 312.5mg/g.

Claims (1)

1. one kind is the method for feedstock production 4A molecular sieve with wilkinite and Attapulgite, specifically comprises the steps:

(1) bentonitic acid activation: get 200 order wilkinites and place beaker, in beaker, add the sulfuric acid of 30%-60%, sulfuric acid and wilkinite liquid-solid ratio are 2-4; Beaker is placed on the constant temperature blender with magnetic force, acidifying 12h after-filtration under 80-100 ℃ of condition, washing in 110 ℃ of oven dry down, obtains the acidifying carclazyte to neutral, crosses 200 mesh sieves;

(2) high-temperature activation of Attapulgite: a certain amount of 200 order Attapulgite are placed retort furnace, in 800 ℃ of following roasting 1h, after the cooling, drying; In 60 ℃ of acidifying 4h, washing after the drying, places beaker to neutral with 8% sulfuric acid; Reductive agent titanous chloride and oxalic acid are added reaction certain hour under certain power ultrasonic, spinning; Obtain white recessed soil, cross 200 mesh sieves, subsequent use.

(3) alkaline purification: acidifying carclazyte and white recessed soil are mixed by a certain percentage, place reactor drum, temperature of reactor is controlled at 30-35 ℃, adds 30%NaOH solution in the reactor drum and carries out alkaline purification 2h in 60-70 ℃.

(4) crystallization: reactor drum is cooled to 30-35 ℃, under constantly stirring, adds sodium aluminate solution and water gradually, and stirring is warming up to 80-100 ℃ and carries out crystallization 6h.

(5) washing: reaction finishes after-filtration, and the filter residue water is washed till pH value 9-10, and oven dry is pulverized and promptly got 4A molecular sieve finished product.

Images