JPS5914273B2 - Method of using grit-free zeolite molecular sieve for water softening - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises particles having a diameter of 45 μm or less.
Zeolite 15 of type A based on crystalline aluminosilicates containing 5% by weight of hydrated water.

Zeolite-molecule i-sieves have already been known for a long time, which have special advantages for ion exchange and adsorption. Zeolite synthesis is a-Na2O x b-Ae203
x 50% of 20 aqueous synthetic mixtures containing c-SiO2 components
Based on heating to temperatures of ~300°C. Depending on the composition of the raw material mixture, reaction temperature and reaction time, the general formula N
A compound axAexSly02(xl-y)n(H2O) is obtained.

These compounds can be distinguished by their X-ray spectra. In this synthesis, sodium can be replaced by other monovalent or divalent ions. For example, the first German patent
In the specification of No. 030017, the total formula 1.0±O, 2M2
/nO, ■Al2O3■1.85±O, 5SiO2■Y
A method for producing a molecular sieve A represented by H2O (wherein M30 is a metal cation, n is its valence and Y means a value up to 6) is presented. When producing A-type, SiO2 and Ae2o3 (
A synthetic mixture is used in which water glass (for example in the form of sodium aluminic acid 35 salt) is present in a molar ratio of 2:1 and water and an alkali oxide (for example Na2O) are present in a molar ratio of 17.5:1. The known processes have in common that during the synthesis crystals with an average diameter of about 2 .mu.m or more are obtained, with a significant portion, usually 3 to 12% by weight, of critical particles of 45 .mu.m or more.

This component is displayed as a grid. This one is Mochaichi (
DIN 535 by wet sieving according to MOcker)
Confirmed by 8O. The molecular sieves are converted into shaped bodies with suitable binders for use as adsorbents, catalyst supports or ion exchangers.

The production of these moldings, due to the binder component, means a large amount of industrial consumption and at the same time a reduction in efficacy. The long diffusion path also significantly slows down the reaction rate. This makes drying the organic liquid complicated. Furthermore, ion exchange and precipitation must be separated, for example when removing metals or radioactive metals from feed water and waste water. Therefore, it is important to use powdered molecular sheep for such applications. Molecular sheep powder alone can also be used in the form of raduka. In particular, the present invention uses a powdered A-type zeolite-molecular sheet, which is configured for use as an ion exchanger, for example for the softening of water, with a grid component having a limited particle size (particles > 45 μm). The starting point is to find a way to synthesize without forming it.

The presence of a grid is essential within the scope of the present invention for the use of such molecular sheep as a phosphate substitute in cleaning and cleaning agents. This means that, especially during cleaning and purification processes in machines, the molecular sieve remains suspended in the bath (due to its low tendency to settle) to enable thorough cleaning after the process has finished. There is a need. The zeolite-molecular sieve used in the present invention contains at least 99 particles with a diameter of 45 μm or less.
．． A-type zeolite-molecular sieves based on crystalline aluminosilicate containing hydrated water containing 5% by weight, in particular 99.9% by weight, in particular 99.99J% by weight, are added to the aluminate/molecular sieve. In a method for producing a water glass-synthetic mixture by thermal crystallization, 1.9 or less: 1
The components of the synthesis mixture in a molar ratio of SiO2 to Al2O3q of , and a molar ratio of water to alkali oxide of preferably at least 30:1 are intimately mixed prior to precipitation of the amorphous pre-product. , the aluminum monosilicate suspension was subjected to a heat treatment (TOmper) under crystallization conditions after crystallization.
n) and shearing during the crystallization and/or heat treatment.

The following important measures are therefore based on the present method, which cooperatively allows a substantially quantitative synthesis of products with the desired particle limit and with a constant particle size.

Compared to known processes, a significantly higher amount of aluminum oxide component is added to the synthesis mixture.

It is therefore contemplated to carry out precipitation from the intimately mixed synthesis mixture in order to ensure uniform crystallite formation.
Furthermore, an essential measure is a heat treatment step subsequent to crystallization. At this stage, the usual conditions for crystallization are generally observed. Furthermore, shear forces must subsequently act on the aluminum monosilicate suspension during crystallization or during both process steps. Particularly low limiting particle contents can be achieved if the above measures are combined with a reduced alkali concentration in the synthesis mixture compared to the known methods. The reduction in the limiting particle fraction, which is uniformly achieved by the heat treatment and the reduced alkali concentration, is surprising.

This is because it is well known that heat treatment as well as concentration reduction leads to the formation of large crystals during crystallization, and the effects that can be achieved with the system of the present invention are contrary to this prevailing teaching. . The limiting particles constructed in accordance with the invention and the means for adjusting their proportions can be selected to obtain the desired average particle size of the crystals.

The average particle size can have a value of ≦1 μm to 15 μm and can be determined, in particular, by the shear strength acting during crystallization.

It has been found to be expedient for the purposes according to the invention to combine an average particle size of approximately 8 μm with a limiting particle size of less than 45 μm. As the critical particle size decreases, the distribution line tilted toward large particles approximates the ideal glass distribution. One important point is that the proportion of the desired limit particles can be adjusted optimally and therefore with practical advantage; the proportion can be lowered according to the invention to 0.01% by weight and even below this. It can only be achieved through the cooperation of methods and means. Examination of the settling behavior shows that the limiting particles are reduced according to the invention to a value of approximately 20 μm. The synthesis mixture is SlO2 and Ae2
O3 can be contained in a molar ratio of 0.8 to 1.6:1, particularly about 1.3:1, and water and alkali oxide can be contained in a molar ratio of 3
It can be contained in a molar ratio of 5 to 50:1.

A particularly advantageous process configuration is to precipitate the amorphous pre-product by prefilling with at least an amount of water or aluminate solution that allows for a stirring action and, under vigorous stirring, with a particularly high degree of agitation. The solution consists in simultaneously pouring into the area the I-sodium aluminate solution and the water glass solution.

The term shear O, as used in the context of the present invention, refers to any mechanical stress that reduces the size of particles present in suspension and is primarily based on a true shear action.

This shearing can be done discontinuously or continuously. Particular preference is given to recirculating processing methods in which the articles to be sheared are subjected to shearing forces several times back and forth. The standard for this is 11'1 per hour.
The so-called circulation number (Dunchsatz
A turbine stirrer, for example an EKATO turbine stirrer, is preferred as the shearing device.

However, the phase gear desolver and dispersion phone
Shearing can also be performed using a dispergat or pump, a circulation pump, or the like. The shear energy consumed in the case of processing conditions according to the invention to achieve the desired critical particle size is required to drastically reduce the average particle size. Similar shear energy (German patent application P
233O689) does not pose a practical problem.

When adjusting the limiting particles and limiting particle proportions appropriately, an average particle size of 2 μm can be achieved without impairing the important application-technical properties, namely the cleaning ability of the zeolite water softener according to the invention used in cleaning agents. It was unimaginable that anything more than that could happen. For example, when using a turbine stirrer, the stirrer is already 0.6 to 2, in particular 0.6 to 1
In particular, it can be operated with a power consumption of 0.8 kW/I. In the case of the present invention, crystallization can be carried out at, for example, 94°C;
It is advantageous to carry out at 0.05° C. and the heat treatment time is between 0.2 and 6, in particular between 0.8 and 1.8 hours, in particular between 1
Time proved to be an advantage.

The heat treatment time is determined by the fact that the maximum ion exchange capacity is achieved.
It begins at the end of crystallization, at which point the highest X-ray intensity is achieved and about 22.5% water vapor absorption is achieved. In fact, it is based on experiments that have been confirmed by optimizing the formulation. In order to optimize the process results for a given purpose, in particular the heat treatment and shear conditions must be synchronized to each other, while also regarding the molar ratio of Ae2O3/SiO2 or the alkali content in the synthesis mixture. It is practically sufficient to strictly adhere to this range.

The shear acting by the end of the crystallization stage can be so strong that the average particle size can be reduced to very small values.

In this case, the value of the limiting particles and their percentage proportion in the product likewise decreases. The influence of shear on the average particle size and on the critical particles or critical particle components nevertheless does not appear to be uniform under all process conditions. Thus, for example, in advantageous cases where the alkali concentration in the synthesis mixture is low, the average particle size increases, but the critical particle size and the critical particle proportion decrease. However, the shearing carried out during the heat treatment step primarily affects the critical particles and their proportions. The present invention provides a method having at least 99.5, in particular 99.9, in particular 99.99 (f) particles of less than 45 μm and a particle spectrum of \ ω VVv- ▼ ▼ The present invention relates to the use of zeolite monomolecular sieves of type A obtained by a method for softening water, as a phosphate substitute in cleaning and cleaning agents.

The product according to the invention has the advantage that it is already free of coarse grains during its production.

It is therefore easily suspended in baths when used as a water softener in cleaning and purifying agents, and is also used in cleaning and purifying machines and batches thereof.
chung) is particularly easily cleaned without any residue.

The invention will be explained in more detail below by way of examples.

Example 1 A commercially available wet monohydrate of 7k9, i.e. hydrated aluminum oxide with a water content of 42.5% as determined by loss on ignition, was dissolved at 100° C. in a 12% by weight caustic soda solution 50e.
dissolves under

The resulting clear solution is cooled to 80°C. Other treatments are carried out in a 60e glass vessel equipped with a stirrer. Power consumption can be measured by a connected ampere meter. The stirring speed can be adjusted non-stepwise. Stirrer EKA according to DIN28l3l with a diameter of 15 cm
It is a TO-Turbo stirrer. The stirred vessel has a diameter of 40 cm and has four flow crushing means (StrOmbre-2 Cher) at an angle of 90 volumes each. This is carried out by metering 8.8e water glass containing 26.5% by weight of SiO2 and 8% by weight of Na2O in the terminating tube.

(Before the start of the precipitation, the aluminate solution of 15e is pre-charged in a stirred vessel. The remainder is metered into the reaction mixture at the same time as the water glass.
Ends after 0 minutes. The precipitated product is roentgenically amorphous. Each component is present in the reaction mixture in the following molar ratio Δ. H2:Na2O=33 and SlO2:Ae2O3=1.3 At the end of the precipitation the stirrer consumes 0.8 kW/M3 of energy.

The reaction solution is brought to 90° C. with water vapor. , the course of crystallization initiated therein is observed by the C2a binding force. Ca-bonding strength is 19
refers to the ion exchange properties of the product.

This amount has been measured for 1e water containing CaCe2 (corresponding to 300 TrLg of CaO). It is then filtered and the CaO remaining in the water is complexometrically titrated. The difference from the original 300η is the binding capacity of the zeolite. If the Ca-binding capacity does not change further, crystallization has been completed.
After a reaction time of 80 minutes, a value of 16.4 is reached and remains unchanged.

After crystallization the temperature is increased to 95°C and
Heat treat the shear knife for 0 minutes.

The resulting crystalline product is then washed with HlO. O and then dried in a drying cabinet at 200°C. This exhibits a zeolite A<7) X-ray curve as described in German Patent No. 1,038,017. A wet sieve according to DIN 5358O is carried out to evaluate the limit particles. In this case, the sample suspended in water is placed in a MOcker.
) A swirling motion is created in the test device by means of water ejected from a rotating nozzle, with the fine components being washed through the test sieve cloth and the coarse components remaining on the sieve cloth. Dry and weigh the sieve residue. DIN4l88 as a test sieve cloth
Use a 45 μm mesh sieve according to the following. The resulting product has a particle size of 0.0 μm with a particle size of 45 μm.
It has 10%.

To further characterize the product, particle size analysis is performed on a sedimentation balance. The sample to be measured was placed in an Ultra Trax (UItra-
Turrax) followed by precipitation. The following particle distribution was found. Example 24 Wet monohydrate 5.5k9 containing 2.5% water is dissolved in a 10% by weight caustic soda solution of 50i.

The reaction vessel described in Example 1 is equipped with a propeller stirrer with a diameter of 15 (1771) according to DIN 28l3l. During precipitation and crystallization, the energy consumption of the stirring device is 0.3
It is kW/I. As in Example 1, the aluminate solution of 15e is also pre-soiled in order to ensure sufficient capacity of the stirring device at the beginning of the water glass addition. The remainder of the aluminate lye is metered in over 30 minutes. 26.5% SlO2 and 8% Na2O at the same time
・A 6.8' water glass having a diameter of 2.5 mm is placed and fed onto the propeller. The synthesis mixture thus obtained with the following molar ratio is then crystallized at 93°C: SiO2:M
2O3-1.3:1 and H2O:Na2O-39:1
, 168W after 90 minutes! A Ca binding capacity of 9Ca0/9 is achieved and the reaction is terminated. Replace the propeller with a turbo stirrer as described in Example 1 and power up to 0.8kW/
Heat treatment under shear energy at the same temperature (ie 93° C.) with an energy supply of d. After 1 hour the reaction was stopped and the product was dissolved in PHLO. Wash with O and then spray dry.

An X-line-pure zeolite of the A type is obtained which has a powder component of only 45 μm which is no longer measurable during grid measurement according to Morker (DIN 5358 O). The measurement accuracy of this method can be expressed as 0.001%. Particle analysis on a sedimentation balance shows the following particle distribution: Example 3 Approximately to Example 2, the components SiO2 and Ae2O3 are in a molar ratio of 1.3:1 and water and sodium oxide 3
A synthetic mixture containing a molar ratio of 9:1 is prepared.

After the end of the precipitation stage, a turbo stirrer with a diameter of 10 (177!) is used for shearing during the crystallization. Energy consumption is 0.
．． 6kW/M3, and the crystallization temperature is 90°C. 1
The Ca-binding capacity of the zeolite crystallized after 10 minutes was 16
1 immediately reaches the final value of CaO/9.

The stirring device is replaced by a 3-stage MIG® stirrer from the company EKATO and the synthesis mixture is heat treated at 92° C. for 4 hours (without shearing) with stirring at an energy consumption of 0.1 kW/M3. The product obtained is X-ray-graphically pure zeolite and has a concentration of 0.13 (Fb
It has a limit particle component of Example 4 A commercial wet monohydrate of 5.5k9 is dissolved in an 11% by weight caustic soda solution of 50e.

The resulting aluminate solution was placed in a 60e reaction vessel using a static mixer (StaticMixer™).
Pump by. 8.2e of water glass is metered in before mixing. After the mixing process, an aqueous clear mixture flows into the reaction vessel. At the bottom of the reaction vessel, the solution is filtered off with suction and pumped in a shearing manner at 40 h@-1 by means of a circulation pump. Pump is 1.8kW/M3
consumes energy. SiO2:Ae2O3=1,6
:1 and the synthesis mixture with a molar ratio of H2O:Na2O=37:1 is brought to 95°C. Crystallization is completed after 50 minutes.

Thereafter the temperature was increased to 105°C and under continuous shear
Heat treatment for 0 minutes. The resulting product has a grid content greater than 45 .mu.m of 0.0301) measured by Moker and the following particle spectrum measured by sedimentation balance: Example 54.5k9 commercially available wet monohydrate was converted into 50e
of 8% by weight sodium hydroxide solution.

This solution was then subjected to 4.corresponding to the method described in Example 1.
Mix vigorously with the water glass solution of 31. Crystallization is then carried out as described in Example 1 at 92° C. under the action of shear forces. The energy consumption at that time is 1kW/M3. Then, after the crystallization is complete, a heat treatment is carried out at the same shear force and temperature of 94°C.

In the resulting X-ray graph, pure zeolite A is generally 4
It does not contain the limit particles of 5 μm and has the following particle spectrum. \ωu▲νV9V All the zeolite-ion exchangers prepared according to Examples 1 to 5 can replace at least one portion of conventional phosphates in conventional detergents.

Claims (1)

[Claims] 1. An A-type zeolite containing at least 99.5% by weight of particles with a diameter of 45 μm or less and having a particle distribution of ▲a mathematical formula, a chemical formula, a table, etc.▼ and for use in water softening as a substitute for phosphates in purification agents.