GB2040900A

GB2040900A - Zeolites of small particle size

Info

Publication number: GB2040900A
Application number: GB7942151A
Authority: GB
Original assignee: JM Huber Corp
Current assignee: JM Huber Corp
Priority date: 1978-12-20
Filing date: 1979-12-06
Publication date: 1980-09-03
Also published as: DE2951192A1; AU5403079A; AU533518B2; GB2040900B

Abstract

Sodium aluminosilicate zeolites A, X, A and X are produced by the reaction of sodium aluminate and sodium silicate characterised by the steps of forming an aqueous solution of sodium aluminate; forming an aqueous solution of sodium silicate; reacting said sodium aluminate and said sodium silicate solutions at a temperature of 40 DEG and 120 DEG C.; the reaction mixture having the following molar ratios of components: (1) water to sodium 10:1 to 35:1 (2) sodium oxide to silica 1:1 to 4:1 (3) silica to alumina 1:1 to 10:1 continuing the reaction at these molar ratios to form the zeolite while controlling the molar ratios and reaction time to produce a fine particle size zeolite having an average particle size of less than 2 microns in diameter. These zeolites have magnesium and calcium exchange capacities which are superior to larger particle size zeolites and are used as fillers, extenders for TiO2 pigments, water softening agents and in detergents. Sodium silicate useful for forming zeolites is made by dissolving sand in NaOH to give solution of SiO2: Na2O molar ratio of 2.4-2.8:1 and activating by addition of 50-2000 ppm Al2O3 at 15-100 DEG C for at least 10 minutes. A method of making zeolite Y from this silicate is disclosed.

Description

SPECIFICATION Synthesis of zeolites of small and uniform size This application is a continuation-in-part of copending U.S. Application Serial No. 971,584 filed on December 1978.

The present invention relates to the production of zoelites, and more specifically to processes for the production of A, X, and mixtures of A and X, zeolites of small and uniform size having high magnesium exchange capacities, as well as a process for making zeolite Y.

Naturally occurring hydrated metal aluminum silicates are called zeolites and are well known in the art as synthetic absorbents. The most common of these zeolites are sodium alumino zeolites. Zeolites consist basically of a three-dimensional framework of SiO4 and AlO4 Tetrahedra. The tetrahedra are crosslinked by the sharing of oxygen atoms so that the ratio of oxygen atoms to the total of the aluminum and silicon atoms is equal to two or O/(AI+Si)=2. The electrovalence of each tetrahedra containing aluminum is balanced by the inclusion in the crystal of a cation, for example a sodium ion. This balance may be expressed by the formula AlJNa2= 1. The spaces between the tetrahedra are occupied by water molecules priorto dehydration. The main products of these types are known in the art as zeolite A, zeolite X, and zeolite Y.

Zeolites A, X, and Y may be distinguished from other zeolites and silicates on the basis of thei r x-ray powder diffraction patterns and certain physical characteristics. The composition and density are among the characteristics which have been found to be important in identifying these zeolites.

The basic formula for all crystalline sodium zeolites may be represented as follows: Na2O:Al2O3:xSiO2:yHO wherein the values forx andy fall in a definite range.

The value x for a particular zeolite will vary somewhat since the aluminum atoms and the silicon atoms occupy essentially equivalent positions in the lattice. Minor variations in the relative numbers of these atoms does not significantly alterthe crystal structure or physical properties of the zeolite. For zeolite A, an average value for x is about 1.85 with the x value falling within the range 1.85 + 0.5. For zeolite X, the x value falls within the range 2.5 + 0.5.

The formula for zeolite A may be written as follows: 1.0+0.2 Na20:AI203:1.85 + 0.5 SiO2:yH2O The formula for zeolite X may be written as follows: 0.9+0.2 Na2O:AI2O3:2.5SiO2:yH2O The formula for zeolite Y may be written as follows: 0.9+0.2 Na2O:Al2O3:4.51.5 SiO2:yH2O wherein y may be any value up to 6 for zeolite A, any value up to 8 for zeolite X, and any value up to 9 for zeolite Y.

Zeolite A is fully described in U.S. Patent No.

2,882,243. Zeolite X is fully described in U.S. Patent No. 2,882,244. Zeolite Y is fully described in U.S.

Patent No. 3,130,007. Processes for preparation are also disclosed in these patents. Other prior art directed to zeolite A are U.S. Patents 2,982,612, 3,058,805,3,101,251,3,119,659 and 4,041,135, which describe various procedures for zeolite A production. Other prior art directed to zeolite X are U.S.

Patents 2,979,381,3,341,284, 3,692,475,3,594,121, 3,690,823, and 4,016,246.

The present invention provides zeolites A, X, and mixtures of A and X in small and uniform particle size by a unique process using molar ratios of reactants which are different from those of the prior art.

It is an object of this invention to produce zeolites which have very high exchange capacity for both calcium and magnesium ions, and rapid calcium ion depletion rates which are superior to similar existing zeolites.

Another object of this invention is to prodice zeolites of controlled particle size which are useful as ion exchange materials in water softening compositions and detergents; as fillers in paper, rubber, and plastics; and as non-settling flatting pigments.

In one aspect the present invention provides processes for the production of zeolites of small and uniform size and having high magnesium exhange capacities characterized by the following steps: a) forming an aqueous solution of sodium aluminate; b) forming an aqueous solution of sodium silicate; c) mixing said sodium aluminate and said sodium silicate solutions at a temperature of 40 to 1200C.; d) reacting said mixed sodium silicate and sodium aluminate at a temperature slightly higher than said mixing temperature, the reaction mixture having the following molar ratios of components: (1) water to sodium oxide 10:1 to 35:1 (2) sodium oxidetosilica 1:1 to 4:1 (3) silica to alumina 1:1 to 10:1 e) continuing the reaction at these molar ratios to form the zeolite while controlling the molar ratios and reaction time to produce a fine particle size zeolite having an average particle size of less than 20 microns in diameter; and f) recovering the zeolite.

In one embodiment of the invention, zeolite A of small and uniform size having a high magnesium exchange capacity is formed when the reaction mixture has a water to sodium oxide molar ratio of between 10:1 and 35:1, preferably between 15:1 and 20:1, most preferably about 20:1, a sodium oxide to silica molar ratio of between 1:1 and 4:1, preferably between 1:1 and 2.5:1, more preferably between 1.5:1 and 2:1, most preferably about 2:1; and a silica to alumina molar ratio of between 1:1 and 10:1, preferably between 1.4:1 and 10:1, more preferably between above 2.0:1 and 4.5:1, more preferably between 3:1 and 8:1, most preferably about 3:1. In a separate embodiment, when the sodium oxide to silica molar ratio is less than 4:3, the silica to alumina molar ratio is at least 3:1. When the sodium oxide to silica molar ratio is at least 4:3, the sodium oxide to alumina molar ratio is at least 4:1. Further, when the SiO2:Al2O3 molar ratio is 2.0:1 or below, the maximum temperature of reaction is about 80"C.

Also, as this ratio decreases, the number of combinations of variables decreases.

The particle size of zeolite A may be controlled by adjusting the silica to alumina molar ratio, with the particle size decreasing as the silica to alumina molar ratio is increased and the particle size increasing as the silica to alumina molar ratio is decreased.

The particle size can also be controlled by adjusting either the sodium oxide to alumina molar ratio or the alumina concentration, with the particle size decreasing as the sodium oxide to alumina molar ratio is increased or the alumina concentration is decreased, and the particle size increasing as the sodium oxide to alumina molar ratio is decreased or the alumina concentration is increased.

This zeolite A has a calcium carbonate exchange capacity greater than 230 mg calcium carbonate per gram zeolite and a magnesium carbonate exchange capacity greater than 90, and preferably greater than 120 mg magnesium carbonate per gram zeolite. The resulting particles exhibit a narrow differential weight percent gaussian distribution with an average particle size of no more than 2.1 microns with at least 90% of the weight between 0.1 and 4.0 microns, wherein the cumulative percent population exhibits at least 35% less than one micron, with no more than 5% greater than 5 microns.

This zeolite A most preferably has a calcium carbonate exchange capacity greater than 250 mg calcium carbonate/g zeolite and a magnesium exchange capacity greater than 140 mg carbonate/g zeolite. It has 90% of the particles less than 2 microns. The resulting zeolite particles preferably exhibit a narrow differential weight percent gaussian distribution with an average particle size of no more than 1.6 microns with at least 90% of the weight between 0.1 and 4.0 microns, wherein the cumulative percent population exhibits at least 64% less than one micron, with no more than 1% greaterthan 2.0 microns. It is useful as an ion exchange material in water softening compositions and detergents; as a filler in paper, rubber and plastics; and as a nonsettling flatting pigment.

In a further embodiment, zeolite X of small and uniform size having a high magnesium exchange capacity is formed when the reaction mixture has a water to sodium oxide molar ratio of between 25:1 and 90:1, preferably between 30:1 and 60:1, most preferably about 30:1; a sodium oxide to silica molar ratio of between 1:1 and 3:1, preferably between 1.2:1 and 1.7:1, most preferably about 1.6:1; and a silica to alumina molar ratio of between 5:1 and 10:1, preferably between 6:1 and 8:1, most preferably about 7.3:1.

This zeolite X has a calcium carbonate exchange capacity greater than 205 mg calcium carbonate per gram zeolite and a magnesium exchange capacity greater than 130 mg magnesium carbonate per gram zeolite, with the resulting zeolite particles exhibiting a narrow differential weight percent gaussian distribution with an average particle size of no more than 2.2 microns with at least 90% of the weight between 0.1 and 5.0 microns, wherein the cumulative percent population exhibits at least 41% less than one micron, with no more than 5% greater than 3.2 microns.

This zeolite X preferably has 90% of the particles less than 2 microns. It preferably has a calcium carbonate exchange capacity greater than 230 mg calcium carbonate/g zeolite and a magnesium carbonate exchange capacity greater than 135 mg magnesium carbonate/g zeolite. It is useful as an ion exchange material in water softening compositions and detergents; as a filler in paper, rubber and plastics; and as a non-settling flatting pigment.

In still a further embodiment, a combination of from 20 to 80% zeolite X and from 20 to 80% zeolite A is formed when the reaction mixture has a water to sodium oxide molar ratio of between 10:1 and 60:1, preferably between 20:1 and 50:1, more preferably between 25:1 and 35:1, most preferably about 30:1; and a sodium oxide to silica molar ratio of between 0.5:1 and 3:1, preferably between 1.4:1 and 3:1, more preferably between 1.6:1 and 2:1, most preferably about 1.7:1; and a silica to alumina molar ratio of between 2:1 and 15:1, preferably between 2:1 and 10:1, more preferably between 2:1 and 8:1, most preferably about 5.3:1.

This combination of zeolite A and zeolite X has a calcium carbonate exchange capacity greater than 220 mg calcium carbonate per gram zeolite and a magnesium exchange capacity greater than 115 mg magnesium carbonate per gram zeolite, with the resulting zeolite particles exhibiting a narrow differential weight percent gaussian distribution with an average particle size of no more than 5.4 microns with at least 90% of the weight between 0.1 and 10.0 microns, wherein the cumulative percent population exhibits at least 37% less than one micron, with no more than 5% greater than 5 microns.

This combination of zeolite A and zeolite X preferably has 90% of the particles less than 2 microns. It preferably has a calcium carbonate exchange capacity greater than 230 mg calcium carbonate/g zeolite and a magnesium exchange capacity greater than 135 mg magnesium carbonate/g zeolite. It is useful as an ion exchange material in water softening compositions and detergents; as a filler in paper, rubber and plastics; and as a non-settling flatting pigment.

In a still further embodiment of the present invention, zeolite Y is produced by dissolving sand in a sodium hydroxide solution at a pressure of at least 100 psig, preferably 140 psig; heated to a temperature of at least 130"C., activating the sodium silicate thus formed with alumina, forming a sodium aluminate solution, adding sodium aluminate solution to the sodium silicate solution so that all of the sodium aluminate solution is added within 30 seconds to form a reaction mixture comprising a sodium silicate mother liquor and an amorphous sodium alumino silicate pigment having, in total, a certain composi tion, heating the mixture to a temperature of from 80 to 1200C., reacting the mixture at a temperature of from 80 to 120"C., then recovering the zeolite produced. The sodium silicate solution has a silica to sodium oxide molar ratio of between 2.4:1 and 2.8:1, preferably about 2.4:1. The sodium silicate is activated with from 50 to 2000 ppm alumina at a temperature of from 15 to 10000. for at least 10 minutes, preferably with from 400 to 600 ppm alumina at room temperature, most preferably with about 500 ppm alumina. The sodium silicate solution is heated to a temperature of between 80 and 120"C., preferably 90"C. The sodium aluminate solution is also heated to a temperature of between 80 and 120"C., preferably 90"C. The composition ofthe reaction mixture has a sodium oxide to silica molar ratio of between 0.5 and 1.0:1, preferably about 0.56:1. It has a silica to alumina molar ratio of between 7:1 and 30:1, preferably between 7:1 and 10:1, and most preferably of about 7.8:1. The reaction mixture also has a water to sodium oxide molar ratio of between 10:1 and 90:1, preferably between 20:1 and 40:1 and most preferably of about 20:1. The reaction mixture is reacted at a temperature of from 80 to 120"C. until crystalline zeolite Y is formed, preferably at a temperature of from 80 to 1000C., most preferably at a temperature of about 100 C. The sodium silicate mother liquor may be recycled as a source of sodium silicate solution.

In its broadest aspect, the present invention is based upon four different discoveries: (1) the discovery that the type of zeolite formed is determined by how long it takes for the zeolite to be formed art a given reaction temperature; (2) the discovery that the reaction time needed to crystallize a zeolite at a given reaction temperature is a function primarily of the water to sodium oxide molar ratio, with the sodium oxide to silica and silica to alumina molar ratios having a smaller effect on reaction time; (3) the discovery that the magnesium exchange capacity of zeolite A is a function of particle size of the zeolite; and (4) the discoverythatthe particle size of a zeolite is a function of silica to alumina molar ratio, sodium oxide to alumina molar ratio, and alumina concentration.

The zeolites of small and uniform particle size of this invention are produced using these four discoveries in a reaction mixture having a high silica to alumina molar ratio, with the other oxide molar ratios adjusted to produce the desired zeolite. In the known processes for forming zeolites, a reaction mixture of sodium-aluminum-silicate water is prepared having a particular composition. This mixture is maintained at a certain temperature until crystals are formed, then the crystals are separated from the reaction mixture. For silica to alumina molar ratios greater than two, the reaction mixture consists of a sodium silicate mother liquor and an amorphous sodium alumino silicate pigment. When this two phase reaction mixture is reacted at elevated temperatures, nothing visually happens for a certain period of time, but after that period of time the zeolite rapidly crystallizes and can then be separated from the reaction mixture.

The present invention is based in part upon the discovery that, for any particular source of silica, the type of zeolite formed is determined by the reaction time necessary for the beginning of crystallization to occur at a given reaction temperature. When the reaction time is short, hydroxy-sodalite is formed, but when the reaction time is longer, zeolite A is formed. When the reaction time is still longer, zeolite X is formed. When the reaction time is between that necessary for the formation of zeolite A and that necessary for the formation of zeolite X, then a combination of zeolite Aand zeolite X is formed. The reaction time is dependent upon the source of silica and whether or not the silica has been activated. The preferred reaction time can be found readily by experimentaion for any particular source of silica.

The reaction time necessary for crystallization at a given reaction temperature can be controlled in a variety of ways, but the major way of controlling reaction time is by adjusting the water to sodium oxide molar ratio of the reaction mixture. The reaction time necessary to form a zeolite is directly proportional to the water to sodium oxide molar ratio used. For instance, when the source of silica is not activated with alumina, the preferred water to sodium oxide molar ratio for making zeolite A is between 15:1 and 20:1; for making zeolite X, it is between 30:1 and 60:1 and for making a combina- tion of zeolite X and zeolite A it is between 25:1 and 35:1. One possible explanation is that a higher water to sodium oxide ratio means the solution is more dilute, which means that it takes longerforthe reaction sites to come together, which causes a longer reaction time. Therefore, to get a zeolite A in a reaction mixture having a sodium oxide to silica molar ratio and a silica to alumina molar ratio where normally a zeolite X would be formed, one would decrease the water to sodium oxide ratio. Adjusting the water to sodium oxide molar ratio is the main control for determining which type of zeolite is formed and is analogous to a course control on a proportional feedback controller.

This relationship between the water to sodium oxide molar ratio and the type of zeolite formed was not previously known. For instance, prior art U.S.

Patents 2,882,243 and 2,882,244, show a water to sodium oxide molar ratio of from 35 to 200 for the production of zeolite A and a water to sodium oxide molar ratio of from 35 to 60 for the production of zeolite X, respectively. If anything, this would imply that the reaction mixture for preparing zeolite A should have a higher water to sodium oxide molar ratio than the reaction mixture for preparing zeolite X, which is not the case. In U.S. Patent 3,119,659, the water to sodium oxide molar ratio for the production of zeolite A is from 20 to 100 while the waterto sodium oxide molar ratio for the production of zeolite X is from 30 to 60. None of the above patents show that the water to sodium oxide molar ratio should be higher for making zeolite X than for making zeolite A.

Another way of controlling the reaction time necessary for crystallization at a given reaction temperature is by adjusting the sodium oxide to silica molar ratio of the reaction mixture. The reaction time necessary to form a zeolite is inversely proportional to the sodium oxide to silica molar ratio used. The effect of sodium oxide to silica molar ratio is less pronounced than that of water to sodium oxide molar ratio.

One possible theory as to why increasing the sodium oxide to silica molar ratio would decrease the reaction time necessary to form a zeolite is that increasing the sodium oxide to silica molar ratio, for a given water to sodium oxide molar ratio reduces the viscosity of the reaction mixture.

Adjusting the silica to alumina molar ratio of the reaction mixture also affects the reaction time necessary for crystallization at a given reaction temperature, but this effect is much less than the effect of sodium oxide to silica molar ratio, which in turn is much less than the effect of water to sodium oxide molar ratio. For a given water to sodium oxide molar ratio and a given sodium oxide to silica molar ratio, the reaction time necessary to form a zeolite is directly proportional to the silica to alumina molar ratio.

The reaction time at a given temperature can be reduced by adding the sodium aluminate solution to the sodium silicate solution at a fast rate of addition, preferably so that all of the sodium aluminate solution is added within 30 seconds, and more preferably simultaneously. Thus, the reaction time necessary for crystallization at a given reaction temperature can be increased by increasing the water to sodium oxide ratio; decreasing the sodium oxide to silica molar ratio; increasing the silica to alumina molar ratio and adding the two materials at a slow rate of addition.

Using these criteria, it has been found that the preferred reaction time for forming zeolite A is about 1/2 to 8 hours, for zeolite X, about 1/2 to 8 hours, and mixtures of zeolites A and X, about 4 to 8 hours.

The present invention is also based upon the discovery that the magnesium exchange capacity of zeolite A is a function of zeolite particle size. As the particle size decreases, the magnesium exchange capacity increases. For zeolite A, when the average diameter is 2.4 microns, the magnesium capacity is only 62 mg/g, when the average diamter is 1.1 microns, the magnesium capacity is about 124 mg/g, and when the average diameter is 0.8 microns, the magnesium capacity is 159 mg/g.

Much more important than the effect of silica to alumina molar ratio on reaction time is the effect of silica to alumina molar ratio on particle size. The reason for this effect is not known but the particle size of a zeolite increases as the silica to alumina molar ratio of the reaction mixture decreases. The particle size decreases as the silica to alumina molar ratio increases in the reaction mixture. For instance, the silica to alumina molar ratio of zeolite A is 1.85 t 0.5. Therefore, a zeolite A formed in a reaction mixture having a silica to alumina molar ratio of 10.1 would have a smaller particle size than a zeolite A formed in a reaction mixture having a silica to alumina molar ratio of 2:1. This means that one can control the particle size of a zeolite bli adjusting the silica to alumina molar ratio of the reaction mixture.

In order to increase particle size one would adjust the silica to alumina molar ratio of the reaction mixture so that it approaches the silica to alumina molar ratio of the desired product. For zeolite A, that ratio is 1.85 t 0.5. For zeolite X it is 2.5 + 0.5. In order to decrease particle size one would adjust the silica to alumina molar ratio of the reaction mixture so that it departs from the silica to alumina ratio of the desired product.

For zeolite A down to SiO2:AI203 ratio of 2 or above, and for zeolite X, the silica to alumina molar ratios of the reaction mixtures used in the present invention are higher than the silica to alumina molar ratios of the desired product. Therefore, to increase the particle size of either zeolite X or zeolite A or a combination thereof, one would decrease the silica to alumina molar ratio of the reaction mixture. In order to decrease the particle size, one would increase the silica to alumina molar ratio of the reaction mixture.

Other means of controlling the particle size of the final product include adjusting either the sodium oxide to alumina molar ratio or the alumina concentration of the reaction mixture. The particle size is inversely proportional to the sodium oxide to alumina molar ratio, and directly proportional to the alumina concentration. The effects of the sodium oxide to alumina molar ratio and the effects of alumina concentration on particle size are of similar magnitude as the effect of silica to alumina molar ratio.

Since silica to alumina molar ratio, sodium oxide to alumina molar ratio, and alumina concentration are all interrelated, it is unclear, at present, which is the predominate factor, but any of the three variables or a combination thereof can be used to control particle size.

The sodium oxide to silica molar ratio of the reaction mixture also affects the particle size of the final product, but this effect is much smaller in magnitude than the effect of silica to alumina molar ratio. For a constant silica to alumina molar ratio, the particle size is inversely proportional to the sodium oxide to silica molar ratio. As the sodium oxide to silica molar ratio increases, the particle size decreases. As the sodium oxide to silica molar ratio decreases, the particle size increases. Thus, the effect of sodium oxide to silica molar ratio of the reaction mixture on particle size can be used in combination with the effect of silica to alumina molar ratio of the reaction mixture on particle size as a means of controlling particle size.

The water to sodium oxide molar ratio of the reaction mixture also affects the particle size of the final product, but this effect is smaller in magnitude than the effect of sodium oxide to silica molar ratio. The reaction temperature also affects the particle size.

Although batch composition and reaction temperature are used to control particle size, there are conditions under which agglomeration can occur.

Agglomeration will result in a product which does not exhibit the expected particle size or properties.

The processes as described in the patent examples are directed to optimum conditions under which there is no agglomeration. If the temperature of the reactants at the time of mixing is too low or the concentration of the sodium oxide or water are severely altered in the solutions being used, one can expect agglomeration. At an extreme a bimodal distribution may appear. These effects can be overcome by such techniques as longer rates of addition, reverse sequence of addition, higher agitation speeds, etc. The point is that these techniques are not really controlling the primary particle size, they are merely changing the degree of agglomeration. Only batch composition and reaction temperature control primary particle size, and the type of the product formed.

In the present invention, the zeolites of small and uniform size having high magnesium exchange capacities are produced by forming a sodium aluminate solution, forming a sodium silicate solution, and mixing the sodium aluminate solution and the sodium silicate solution to produce a reaction mixture. For SiO2:AI203 molar ratios greater than 2, this mixture comprises a sodium silicate mother liquor and an amorphous sodium alumino silicate pigment.

For such ratios of 2 or below, the mixture contains a sodium aluminate mother liquor. The reaction mixture is heated and reacted at a temperature of from 40 to 120"C, preferably 60 to 100 C until the desired zeolite is formed, and recovering the desired zeolite from the mother liquor. In the preferred procedure, the sodium silicate and sodium silicate solution are preheated to a temperature of 50 to 120"C., preferably60to 100 C., priorto mixing. After mixing an exothermic reaction occurs which raises the temperature about 10"C. at which temperature the reaction takes place. The zeolite is then recovered from the reaction mixture by conventional solids separation techniques such as filtration. The mother liquor or filtrate may be recycled to provide dissolved values of sodium and silica or sodium and alumina.

In one aspect, the sodium silicate solution used in this process can be formed by dissolving sand in a sodium hydroxide solution at a pressure of at least 100 psig and a temperature of at least 130"C. to produce a sodium silicate solution having a silica to sodium oxide molar ratio of between 2.4:1 and 2.8:1.

The word "sand" is to be given its usual meaning of "a loose material consisting of small but easily distinguishable grains, usually less than two millimeters in diameter, most commonly of quartz resulting from the disintegration of rocks, and commonly used for making mortar and glass, as an abrasive, or for molds in founding." A temperature of at least 130"C. is used to dissolve the sand because it is more difficult to dissolve sand at lower temperatures.

This sodium silicate solution is activated with from 50 to 2000 ppm alumina preferably, and heated to a temperature between 40 and 120 C. for at least 10 minutes, preferably with 400 to 600 ppm alumina at room temperature. Alumina concentrations of less than 50 ppm do not activate the silica. Alumina concentrations of more than 2000 ppm cause the alumina to precipitate out of the solution as an amorphous sodium alumino silicate. Preferably the silica to sodium oxide molar ratio of the sodium silicate solution is about 2.4:1 to 2.8:1, since this sodium silicate solution is usually less expensive to make than solutions having higher silica to sodium oxide molar ratios, such as waterglass. Activation of the sodium silicate solution is necessary in the production of zeolite Y but optional in production of zeolites A and X, and mixtures of A and X.

After a sodium silicate solution is formed, and is either activated or not activated, a sodium aluminate solution is

TABLE I BROAD RANGES FOR MAKING ZEOLITES Water Sodium Oxidel Silical Zeolite Sodium Oxide Silica Alumina A 10-35 1-4 1-10 X 25-90 1-3 5-10 X & A 10-60 0.5-3 2-15 Y 10-90 0.5-1 7-30 The preferred oxide mole ratio ranges for making each zeolite using a source of sodium silicate that has not been activated with alumina are shown in Table II.

TABLE II PREFERRED RANGES FOR MAKING ZEOLITES (Unactivated) Water Sodium Oxidel Silical Zeolite Sodium Oxide Silica Alumina A 15-20 1.4-2 2-4 X 30-60 1.2-1.7 6-8 X & A 20-50 1.6-3 2-10 The preferred oxide mole ratio ranges for making each zeolite using a source of sodium silicate that has been activated with alumina are shown in Table 111.

TABLE III PREFERRED RANGES FOR MAKING ZEOLITES (Activated) Water Sodium Oxidel Silical Zeolite Sodium Oxide Silica Alumina A 25-35 1.4-2 3-7 X 30-40 1 -1.2 5-7 X & A 15-16 0.7-1.7 5-10 Y 20-40 0.5-1 7-10 To ensure a good yield of the desired zeolite pro duct, it is necessary to react the zeolite mixture beyond a certain minimum time. If, however, the reaction is continued too long, the product starts to lose silica, that is the silica to alumina ratio starts to fall, and if the reaction is continued even further, then the product may recrystallize to an undesirable zeolitic material. There is an optimum reaction time which is, in part, determined by the ratios and con centrations of the original reaction mixture, by the size of the batch, the time required to mix the ingredients and the rate of heating. The optimum reaction time for particular molar ratios can readily be deter mined by experiment. However, in general reaction times for zeolite A production range from 0.5 to 8 hours, and for zeolite X from 2 to 8 hours.

Once the zeolite has been separated from the mother liquor, the mother liquor may be recycled.

Recycling of the mother liquor eliminates the prob lem of how to dispose of the mother liquor.

Although it is possible to use the process of the pre sent invention without recycling the mother liquor, failure to recycle the mother liquor could make the process cost prohibitive.

The silica to alumina molar ratio of zeolite X is about 2.5:1 and the silica to alumina molar ratio of zeolite A is about 1.85:1. As stated above, the particle size of the zeolite is smaller when the silica to alumina molar ratio of the reaction mixture is higher than the silica to alumina molar ratio of the desired zeolite, at silica to alumina molar ratios of greater than 2. Because of this, the zeolite X and the zeolite A of the present invention have smaller particle sizes than those of the prior art.

Because of their normal particle size, the zeolite X, the zeolite A and mixtures of the present invention are both useful in a variety of uses such as an ionexchange material in water softening compositions and detergents; as a filler in paper, rubber and plastics; and as a non-settling flattening pigment, Zeolite Y is useful as an adsorbent.

The zeolite A, having a smaller particle size, has a higher magnesium ion exchange capacity than prior art zeolite A having larger particle sizes. This increased magnesium ion exchange capacity makes this zeolite A expecially useful as an ion exchange material in water softening compositions and detergents.

Another factor that makes the zeolites especially useful as ion exchange materials is their fast calcium carbonate depletion rate. These zeolites remove calcium ions faster than zeolites having larger particle sizes. The zeolites A having the smaller particle size exchanges the calcium ions at a faster rate than the zeolite A having the larger particle size.

As can be seen in Tables I, ll and Ill, the ranges of water to sodium oxide molar ratios needed to produce zeolite X, zeolite A, a combination of zeolite X and zeolite A or zeolite Y overlap each other. The water to sodium oxide molar ratio is the major controlling factor which determines the reaction time necessary for crystallization at a given reaction temperature, which in turn determines the type of zeolite formed. But, as stated above, there are other factors that have a smaller effect on reaction time, such as sodium oxide to silica molar ratio, silica to alumina molar ratio, degree of agitation and rate of addition of the sodium aluminate solution to the sodium silicate solution. These additional factors can either add to or subtract from the effect of water to sodium oxide molar ratio.

For instance, either zeolite X or zeolite A can be formed from a reaction mixture having a water to sodium oxide molar ratio of 30:1. In that case, the additional factors would determine which type of zeolite would be produced. If the sodium oxide to silica molar ratio is 1.2:1 and the silica to alumina molar ratio is 8:1, then zeolite X will be produced.

But if the sodium oxide to silica molar ratio is 2:1 and the silica to alumina molar ratio is 3:1, then zeolite A will be produced. The type of zeolite formed depends on the total effect of the water to sodium oxide molar ratio and all of the additional factors mentioned above.

One of the results of using the principles of the present invention is the ability to make a controlled combination of zeolite X and zeolite A in the same reaction. A combination of from 20 to 80% zeolite A can be formed by adjusting the reaction time necessary for crystallization to a time between that required to make zeolite X and that required to make zeolite A. The composition of the combination depends on the reaction time. If the reaction time is close to that required to make zeolite X, much more zeolite X will be formed than zeolite A. If, on the other hand, the reaction time is close to that of zeolite A, much more zeolite A will be formed than zeolite X. By adjusting the reaction time, one can make any desired combination of zeolite X and zeolite A.

The combination of zeolite X and zeolite A has an average particle size less than 2 microns in diameter.

It is useful, because of its small particle size, as an ion exchange material in water softening compositions and detergents, as a filler in paper, rubber and plastics, and as a non-settling flatting pigment.

Any source of sodium silicate can be used in the present invention, but one particularly desirable source of sodium silicate is sand dissolved in caustic. The advantage of this source is its low cost. The sand is dissolved in a sodium hydroxide solution at a pressure of at least 100 psig and a temperature of at least 130"C. to produce a sodium silicate solution having a silica to sodium oxide molar ratio of bet ween 2.4:1 and 2.8:1. Preferably the pressure is about 140 psig, producing a sodium silicate solution having a silica to sodium oxide molar ratio of about 2.4:1. Activation of the silica is always used in production of zeolite Y.

The time required to produce a given product from batches of identical chemical composition will be dependent on the source of silicon dioxide. Each dif ferent type of silica source has its own time table specifying the reaction times needed to form each type of zeolite. One of the discoveries upon which this invention is based is the fact that this time table can be changed by activating the silica source with alumina, as described above. The alumina concentration limits of 50 to 2000 ppm alumina are critical values since alumina concentrations below 50 ppm fail to activate the sodium silicate solution.

The alumina used to activate the sodium silicate solution may suitably be provided by a soluble aluminum compound such as sodium aluminate or a water soluble aluminum salt, such as aluminum sulphate. Sodium aluminate is, however, the preferred reagent since it limits the tendency to introduce foreign ions into the zeolite lattice.

There is an important difference between the effect of activation and the effect of reaction time controlling factors such as water to sodium oxide molar ratio, sodium oxide to silica molar ratio, silica to alumina molar ratio and rate of addition. The reactio time controlling factors are used to adjust the reaction time necessary for crystallization so that it will match with the reaction time in a time table to produce a particular zeolite. Activation changes the time table. For that reason, the preferred oxide mole ratios for producing a desired zeolite are different when a source of silica is either activated or not activated (see Tables II and III above).

EXAMPLES The invention will be further illustrated by the following examples which set forth particularly advantageous method and compositions embodiments.

While the examples illustrate the present invention, they are not intended to limit it. In the examples and throughoutthe disclosure, parts are by weight unless otherwise indicated.

The following examples were carried out as described herein by forming the silicate and aluminate solutions, preheating each solution to the indicated temperature, and adding the aluminate solution to the silicate solution in the time specified. The resulting gel was broken down by agitation until the homogeneous slurry was obtained and the batch was then reacted at the indicated temperature for the reaction period. The resulting product was characterized by its calcium ion exchange capacity based on mg calcium carbonate/g zeolite, and magnesium ion exchange capacity based on mg magnesium carbonate/g zeolite. The resulting zeolite particles are characterized by differential weight percent gaussian distribution with an average particle size in microns and an indication of the weight between 0.1 and 2.5 microns. The cumulative percent population is also described. These criteria are set forth in the follow ing tables.

In the examples, calcium carbonate exchange capacity was determined by placing the zeolite in an exchange solution, agitating for fifteen minutes, filtering off the zeolite and titrating the filtrate with EDTA (ethylenediaminetetraacetic acid) solution to determine how much calcium ions had been removed. The exchange solution was made from calcium chloride to obtain a concentration equivalent to 1229 calcium carbonate per liter. The filtrate was buffered to pH 10, then Erich rome Black T indi cator(3-hydroxy-4-((1 -hydroxy-2-naph- thyl)azo) - 7 - nitrol - naphthalenesulfonic acid sodium salt) was added to the filtrate priorto EDTA titration.

Magnesium carbonate exchange capacity was determined by placing the zeolite in an exchange solution, agitating for fifteen minutes, filtering off the zeolite and titrating the filtrate with EDTA solution to determine how much magnesium ions have been removed. The exchange solution was made from magnesium chloride to obtain a concentration equivalent to 1000 ppm magnesium carbonate. The filtrate was buffered to pH 10, then Erichrome Black T indicator was added to the filtrate prior to EDTA filtration.

Particle size measurements were made by Coulter Counter (Model TAII). Particle size analysis by Coulter Counter measures both sample volume and number of particles in specific size ranges. Since volume % and weight% are synonymous when all particles have the same density, weight% is used since it is the most conventional way to express particle size data.

The following terms have been used in describing the particle size of the present invention: Gaussian distribution: The frequency curves of a gaussian distribution, also known as symmetrical or bell-shaped frequency curves, are characterized by the fact that observations equidistant from the central maximum have the same frequency.

Average particle size: The average particle size is the size at which 50% of the total weight is accounted for. Results were confirmed by Scanning Electron Microscope.

Cumulative% population: The cumulative% population is the percentage of all the counted particles.

The following are examples for the preparation of zeolite A and the characterization of the product. In these examples, the exchange rates refer to the zeolite on an anhydrous basis.

TABLE IV COMPOSITION OF REACTION MIXTURE FOR THE PREPARATION OF ZEOLITE A Water Sodium Sodium Oxidel Silical % Sodium Example Oxide Silica Alumina % Water Oxide %S lica %Alumina 1 30 3.0 2.5 95.34 3.18 1.06 0.42 2 25 2.4 3.0 94.14 3.77 1.57 0.52 3 25 2.4 3.0 94.14 3.77 1.57 0.52 4 25 2.4 2.5 94.04 3.76 1.57 0.63 5 25 2.4 2.0 93.90 3.76 1.57 0.78 6 25 2.4 2.0 93.90 3.76 1.57 0.78 7 25 2.0 2.5 93.63 3.75 1.87 0.75 8 25 2.0 2.0 93.46 3.74 1.87 0.93 9 25 2.0 2.0 93.46 3.74 1.87 0.93 10 20 3.0 2.5 93.17 4.66 1.55 0.62 11 20 3.0 2.5 93.17 4.66 1.55 0.62 12 20 3.0 2.5 93.17 4.66 1.55 0.62 13 20 2.8 2.5 93.02 4.65 1.66 0.66 14 20 2.8 2.5 93.02 4.65 1.66 0.66 15 20 2.8 2.5 93.02 4.65 1.66 0.66 16 20 2.6 2.5 92.86 4.64 1.79 0.71 17 20 2.6 2.5 92.86 4.64 1.79 0.71 18 20 2.6 2.5 92.86 4.64 1.79 0.71 19 20 2.2 5.3 92.85 4.64 2.11 0.40 20 25 1.6 2.0 92.81 3.71 2.32 1.16 21 20 2.4 3.0 92.78 4.64 1.93 0.65 22 20 2.4 3.0 92.78 4.64 1.93 0.65 23 20 2.2 4.3 92.76 4.64 2.11 0.49 24 20 2.0 7.3 92.73 4.64 2.32 0.32 25 20 2.0 7.3 92.73 4.64 2.32 0.32 26 20 2.0 6.3 92.68 4.63 2.32 0.37 27 20 2.4 2.5 92.66 4.63 1.93 0.77 28 20 2.4 2.5 92.66 4.63 1.93 0.77 29 20 2.4 2.5 92.66 4.63 1.93 0.77 30 20 2.4 2.5 92.66 4.63 1.93 0.77 31 20 2.0 5.3 92.62 4.63 2.32 0.44 32 20 1.9 7.3 92.60 4.63 2.44 0.33 33 20 2.0 4.3 92.52 4.63 2.31 0.54 34 20 2.4 2.0 92.49 4.62 1.93 0.96 35 20 2.4 2.0 92.49 4.62 1.93 0.96 36 20 1.8 7.3 92.46 4.62 2.57 0.35 37 20 2.2 2.5 92.44 4.62 2.10 0.84 38 20 2.2 2.5 92.44 4.62 2.10 0.84 39 20 2.2 2.5 92.44 4.62 2.10 0.84 40 20 1.8 6.3 92.41 4.62 2.57 0.41 41 20 2.0 3.3 92.37 4.62 2.31 0.70 42 20 2.0 3.3 92.37 4.62 2.31 0.70 43 20 1.7 7.3 92.30 4.62 2.72 0.37 44 20 1.8 4.3 92.23 4.61 2.56 ' 0.60 45 20 2.0 2.5 92.17 4.61 2.30 0.92 46 20 2.0 2.5 92.17 4.61 2.30 0.92 47 20 2.0 2.5 92.17 4.61 2.30 0.92 48 20 2.0 2.5 92.17 4.61 2.30 0.92 49 20 1.6 7.3 92.12 4.61 2.88 0.39 50 20 1.6 7.3 92.12 4.61 2.88 0.39 51 20 1.6 7.3 92.12 4.61 2.88 0.39 52 20 1.6 7.3 92.12 4.61 2.88 0.39 53 20 1.6 7.3 92.12 4.61 2.88 0.39 54 20 1.8 3.3 92.06 4.60 2.56 0.77 55 20 1.6 5.3 91.98 4.60 2.87 0.54 56 20 2.0 2.0 91.95 4.60 2.30 1.15 57 20 2.0 2.0 91.95 4.60 2.30 1.15 58 20 1.5 7.3 91.92 4.60 3.06 0.42 59 20 1.5 7.3 91.92 4.60 3.06 0.42 60 20 1.5 6.3 91.86 4.59 3.06 0.49 61 20 1.5 6.3 91.86 4.59 3.06 0.49 62 20 1.8 2.5 91.84 4.59 2.55 1.02 63 20 1.8 2.5 91.84 4.59 2.55 1.02 64 20 1.8 2.5 91.84 4.59 2.55 1.02 65 20 1.5 5.3 91.77 4.59 3.06 0.58 66 20 1.4 7.3 91.69 4.59 3.28 0.45 67 20 1.6 3.3 91.68 4.58 2.87 0.87 68 20 1.6 3.3 91.68 4.58 2.87 0.87 69 20 1.6 3.3 91.68 4.58 2.87 0.87 70 20 1.6 3.3 91.68 4.58 2.87 0.87 71 20 1.6 3.3 91.68 4.58 2.87 0.87 72 20 1.4 6.3 91.63 4.58 3.27 0.52 73 20 1.6 3.0 91.60 4.58 2.86 0.96 74 20 1.4 5.3 91.54 4.58 3.27 0.62 75 20 1.6 2.5 91.43 4.57 2.86 1.14 76 20 1.6 2.5 91.43 4.57 2.86 1.14 77 20 1.4 3.3 91.20 4.56 3.26 0.99 78 20 1.6 2.0 91.17 4.56 2.85 1.42 79 20 1.6 2.0 91.17 4.56 2.85 1.42 80 20 1.2 7.3 91.13 5.56 3.80 0.52 81 20 1.2 6.3 91.05 4.55 3.79 0.60 82 20 1.4 2.5 90.91 4.55 3.25 1.30 83 20 1.4 2.5 90.91 4.55 3.25 1.30 84 20 1.2 4.3 90.80 4.54 3.78 0.88 85 20 1.2 3.3 90.56 4.53 3.77 1.14 86 15 2.4 2.5 90.45 6.03 2.51 1.01 87 15 2.4 2.0 90.23 6.02 2.51 1.25 88 20 1.2 2.5 90.23 4.51 3.76 1.50 89 15 2.0 2.0 89.55 5.97 2.99 1.49 90 15 1.6 2.5 88.89 5.93 3.70 1.48 91 15 1.6 2.0 88.56 5.90 3.69 1.85 92 15 1.6 2.0 88.56 5.90 3.69 1.85 TABLE V ZEOLITE A- REACTION CONDITIONS Temps. "C. Time of Reaction Reaction Example Silicate Aluminate Addition (sec.) Temp. "C. Time (hers.) 1 90 90 30 100 4.0 2 50 50 30 60 8.0 3 70 70 30 80 2.0 4 50 50 30 60 7.5 5 50 50 30 60 6.0 6 70 70 30 80 2.5 7 50 50 30 60 6.5 8 50 50 30 60 6.5 9 70 70 30 80 2.5 10 50 50 30 60 4.0 11 70 70 30 80 1.5 12 90 90 30 100 0.5 13 50 50 30 60 4.0 14 70 70 30 80 2.0 15 90 90 30 100 0.5 16 50 50 30 60 3.0 17 70 70 30 80 2.0 18 90 90 30 100 0.5 19 90 90 30 100 0.5 20 50 50 30 60 8.0 21 50 50 30 60 3.5 22 70 70 30 80 2.0 23 90 90 30 100 1.0 24 90 90 30 100 2.0 25 90 90 30 100 1.0 26 90 90 30 100 1.0 27 50 50 30 60 4.0 28 70 70 30 80 1.5 29 90 90 30 100 2.5 30 90 90 30 100 0.5 31 90 90 30 100 1.0 32 90 90 30 100 1.0 33 90 90 30 100 1.0 34 50 50 30 60 3.5 35 70 70 30 80 1.0 36 90 90 30 100 1.0 37 70 70 30 80 1.5 38 50 50 30 60 4.0 39 90 90 30 100 0.5 40 90 90 30 100 2.0 41 90 90 30 100 2.0 42 90 90 600 100 2.0 43 90 90 30 100 1.0 44 90 90 30 100 2.0 45 50 50 30 60 4.0 46 70 70 30 80 3.0 47 50 50 30 60 3.5 48 90 90 30 100 0.5 49 90 90 30 100 2.0 50 90 90 300 100 1.5 51 90 90 600 100 2.0 52 90 90 1200 100 2.0 53 90 90 30 100 2.0 54 90 90 30 100 1.0 55 90 90 30 100 2.0 56 50 50 30 60 4.5 57 70 70 30 80 1.5 58 90 90 30 100 2.0 59 90 90 30 100 2.0 60 90 90 30 100 8.0 61 90 90 30 100 2.0 62 70 70 30 80 1.5 63 50 50 30 60 4.0 64 90 90 30 100 0.5 65 90 90 30 100 2.0 66 90 90 30 100 4.0 67 90 90 30 100 1.5 68 90 90 30 100 1.5 69 90 90 300 100 1.5 70 90 90 600 100 1.5 71 90 90 1200 100 1.5 72 90 90 30 100 3.0 73 70 70 30 80 3.0 74 90 90 30 100 3.0 75 70 70 30 80 3.0 76 90 90 30 100 1.0 77 90 90 30 100 1.0 78 50 50 30 60 4.0 79 70 70 30 80 2.3 80 90 90 30 100 3.0 81 90 90 30 100 3.0 82 70 70 30 80 3.0 83 90 90 30 100 2.0 84 90 90 30 100 2.0 85 90 90 30 100 2.0 86 50 50 30 60 3.5 87 50 50 30 60 3.5 88 70 70 30 80 3.0 89 50 50 30 60 2.0 90 70 70 30 80 1.0 91 50 50 30 60 3.5 92 70 70 30 80 1.0 TABLE VI EXCHANGE CAPACITY FOR ZEOLITE A Sodium Silical Oxidel Average Calcium Magnesium Example Alumina Alumina %Alumina Diameter Capacity Capacity 1 2.5 7.5 0.42 2.4 292 62 2 3.0 7.2 0.52 0.9 300 134 3 3.0 7.2 0.52 1.25 274 136 4 2.5 6.0 0.63 0.86 283 145 5 2.0 4.8 0.78 1.4 300 141 6 2.0 4.8 0.78 2.1 273 124 7 2.5 5.0 0.75 1.1 322 133 8 2.0 4.0 0.93 1.5 304 136 9 2.0 4.0 0.93 2.4 278 105 10 2.5 7.5 0.62 0.90 295 162 11 2.5 7.5 0.62 1.3 293 163 12 2.5 7.5 0.62 1.4 295 107 13 2.5 7.0 0.66 0.93 291 158 14 2.5 7.0 0.66 1.2 293 156 15 2.5 7.0 0.66 1.5 287 117 16 2.5 6.5 0.71 0.90 288 154 17 2.5 6.5 0.71 1.4 300 154 18 2.5 6.5 0.71 1.5 278 118 19 5.3 11.7 0.40 0.7 270 163 20 2.0 3.2 1.16 2.0 283 127 21 3.0 7.2 0.65 1.1 280 137 22 3.0 7.2 0.65 0.83 335 131 23 4.3 9.5 0.49 0.84 249 159 24 7.3 14.6 0.32 0.95 273 148 25 7.3 14.6 0.32 1.0 262 147 26 6.3 12.6 0.37 0.7 252 147 27 2.5 6.0 0.77 0.80 282 153 28 2.5 6.0 0.77 1.3 295 150 29 2.5 6.0 0.77 1.0 299 145 30 2.5 6.0 0.77 1.5 284 123 31 5.3 10.6 0.44 0.75 249 145 32 7.3 13.9 0.33 0.86 260 149 33 4.3 8.6 0.54 0.93 290 142 34 2.0 4.8 0.96 1.1 327 155 35 2.0 4.8 0.96 1.7 293 125 36 7.3 13.1 0.35 0.88 261 146 37 2.5 5.5 0.84 1.4 289 152 38 2.5 5.5 0.84 0.85 285 149 39 2.5 5.5 0.84 1.7 300 109 40 6.3 11.3 0.41 0.95 297 123 41 3.3 6.6 0.70 0.94 292 136 42 3.3 6.6 0.70 1.1 251 126 43 7.3 12.4 0.37 0.80 264 147 44 4.3 7.7 0.60 1.90 286 99 45 2.5 5.0 0.92 1.1 281 157 46 2.5 5.0 0.92 1.3 290 149 47 2.5 5.0 0.92 0.87 296 134 48 2.5 5.0 0.92 1.7 283 124 49 7.3 11.7 0.39 1.0 255 135 50 7.3 11.7 0.39 1.0 245 144 51 7.3 11.7 0.39 0.90 259 149 52 7.3 11.7 0.39 0.84 257 151 53 7.3 11.7 0.39 1.1 272 144 54 3.3 5.9 0.77 1.1 290 103 55 5.3 8.5 0.54 0.92 255 150 56 2.0 4.0 1.15 1.3 297 140 57 2.0 4.0 1.15 2.0 293 115 58 7.3 11.0 0.42 0.9 256 145 59 7.3 11.0 0.42 1.1 249 127 60 6.3 9.5 0.49 0.95 273 127 61 6.3 9.5 0.49 1.1 234 123 62 2.5 4.5 1.02 1.2 287 157 63 2.5 4.5 1.02 1.0 281 149 64 2.5 4.5 1.02 1.7 281 113 65 5.3 8.0 0.58 1.1 250 118 66 7.3 10.2 0.45 1.5 254 143 67 3.3 5.3 0.87 1.2 265 145 68 3.3 5.3 0.87 1.5 248 136 69 3.3 5.3 0.87 1.4 264 128 70 3.3 5.3 0.87 1.4 254 127 71 3.3 5.3 0.87 1.7 239 92 72 6.3 8.8 0.52 1.6 307 145 73 3.0 4.8 0.96 1.95 292 135 74 5.3 7.4 0.62 1.4 278 148 75 2.5 4.0 1.14 1.2 288 160 76 2.5 4.0 1.14 2.0 278 86 77 3.3 4.6 0.99 1.3 272 121 78 2.0 3.2 1.42 1.2 311 118 79 2.0 3.2 1.42 2.2 300 119 80 7.3 8.8 0.52 1.6 241 144 81 6.3 7.6 0.60 1.4 300 144 82 2.5 3.5 1.30 1.3 286 145 83 2.5 3.5 1.30 1.9 288 112 84 4.3 5.2 0.88 1.2 290 148 85 3.3 4.0 1.14 1.6 274 153 86 2.5 6.0 1.01 0.92 315 157 87 2.0 4.8 1.25 1.4 289 140 88 2.5 3.0 1.50 1.6 273 134 89 2.0 4.0 1.49 0.97 275 145 90 2.5 4.0 1.48 1.2 274 129 91 1.6 3.2 1.85 1.4 312 143 92 1.6 3.2 1.85 1.8 279 155 A linear regression analysis was performed upon the above data, with correlation coefficients (r) calculated for certain variables. This analysis showed a definite correlation between magnesium exchange capacity and average particle size (r = -0.581).

Based on this sample, there is less than a 1% probability that no correlation exists between these two variables. There is less than a 1% probability that there is no correlation between silica to alumina molar ratio and average particle size (r = -0.405); between sodium oxide to alumina molar ratio and average particle size (r = -0.469); and between alumina concentration and average particle size (r = +0.465). Thus, the average particle size and the magnesium exchange capacity can be controlled by adjusting either the silica to alumina molar ratio or the sodium oxide to alumina molar ratio orthe sodium oxide to alumina molar ratio or the alumina concentration.

TABLE VII ZEOLITE A- PARTICLE CHARACTERISTICS Average Micron Range Cumulative Particle Size ofatleast %LessThan Example Microns 90% of Weight One Micron Other 1 2.4 1.0-4.0 19 Max 5% > 3.2 2 0.9 0.1-2.0 96 Max 5% > 1.25 3 1.25 0.1 - 2.5 67 Max 1% > 2.0 4 0.86 0.1 -1.6 92 Max 1% > 2.0 5 1.4 0.1 - 2.5 58 Max 2% > 2.5 6 2.1 0.1 - 4.0 35 Max 5% > 2.5 7 1.1 0.1-2.5 86 Max 1% > 1.6 8 1.5 0.1 - 2.5 58 Max 1% > 2.5 9 2.4 0.1 - 5.0 61 Max 1% > 10 0.9 0.1 - 2.0 92 Max 1% > 1.6 11 1.3 0.1-3.2 68 Max 1% > 2.0 12 1.4 0.1 - 2.5 56 Max 1% > 2.5 13 0.93 0.1-2.5 92 Max1% > 1.6,a 14 1.2 0.1 - 2.5 73 Max 1% > 2.0 15 1.5 0.1-3.2 55 Max1% > 2.5,a 16 0.9 0.1 - 2.5 93 Max 1% > 1.6 17 1.4 0.1-3.2 64 Max1% > 2.0,a 18 1.5 0.1-3.2 53 Max 1% > 2.5 19 0.7 0.1 -1.6 98 Max 1% > 1.3 20 2.0 0.1 - 4.0 39 Max 1% > 3.2 21 1.1 0.1-2.5 97 Max 1% > 1.6 22 0.8 0.1-1.6 95 Max 1% > 1.6 23 0.84 0.1 - 2.0 94 Max 1% > 1.3 24 0.95 0.1-2.0 96 Max 1% > 1.3 25 1.0 0.1-2.0 96 Max 1% > 1.3 26 0.7 0.1-2.0 98 Max 1% > 1.3 27 0.8 0.1-2.0 96 Max 1% > 1.25 28 1.3 0.1 - 2.5 71 Max 1% > 2.0 29 1.0 0.1-2.5 88 Max 1% > 1.6 30 1.5 0.1 - 3.2 55 Max 1% > 2.5 31 0.75 0.1 - 2.0 97 Max 1% > 1.3 32 0.86 0.1 - 2.0 96 Max 1% > 1.3 33 0.93 0.1 - 2.0 97 Max 1% > 1.25 34 1.1 0.1-2.0 83 Max1% > 2.0,u 35 1.7 0.1 - 4.0 46 Max 1% > 2.5 36 0.88 0.1-2.0 96 Max 1% > 1.3 37 1.4 0.1 - 3.2 73 Max 1% > 2.0 38 0.85 0.1-2.5 94 Max 1% > 1.6 39 1.7 0.1-4.0 50 Max1% > 2.5,u 40 0.95 0.1 - 2.0 97 Max 1% > 1.3 41 0.94 0.1 - 2.0 94 Max 1% > 1.6 42 1.1 0.1-2.0 82 Max 1% > 1.6 43 0.8 0.1 - 2.0 96 Max 1% > 1.3 44 0.9 0.1 - 2.0 97 Max 1% > 1.6 45 1.1 0.1 - 3.2 94 Max 1% > 1.6 46 1.3 0.1 - 3.2 77 Max 1% > 2.0 47 0.87 0.1 - 2.0 96 Max 1% > 1.3 48 1.7 0.1 -4.0 54 1% > 2.5 49 1.0 0.1 - 2.0 86 Max 1% > 1.6 50 1.0 0.1-1.6 80 Max 1% > 1.6 51 0.9 0.1 - 1.6 90 Max 1% > 1.6 52 0.84 0.1 - 1.6 95 Max 1% > 1.6 53 1.1 0.1-2.0 97 Max 1% > 1.6 54 1.1 0.1-2.5 86 Max 1% > 2.0 55 0.92 0.1 - 2.0 95 Max 1% > 1.6 56 1.3 0.1 - 3.2 71 Max 1% > 2.0 57 2.0 0.1 - 5.0 40 Max 1% > 58 0.9 0.1-2.0 96 Max 1% > 1.6 59 1.1 0.1 - 2.0 96 Max 1% > 1.6 60 0.95 0.1 - 2.5 95 Max 1% > 1.6 61 1.1 0.1-2.0 95 Max 1% > 1.6 62 1.2 0.1-3.2 80 Max 1% > 2.0 63 1.0 0.1 - 2.5 92 Max 1% > 1.6 64 1.7 0.1 - 4.0 56 Max 1% > 2.5 65 1.1 0.1 - 2.0 95 Max 1% > 1.6 66 0.9 0.1-2.0 97 Max 1% > 1.6 67 1.2 0.1 - 2.0 85 Max 1% > 1.6 68 1.5 0.1 -3.2 53 Max 1% > 2.5 69 1.4 0.1 - 3.2 51 Max 5% > 2.0 70 1.4 0.1 - 3.2 54 Max 4% > 2.0 71 1.7 0.1-4.0 62 Max2% > 2.5,u 72 1.1 0.1-3.2 91 Max 1% > 2.0 73 0.95 0.1 - 2.0 95 Max 1% > 1.6 74 1.4 0.1-3.2 95 Max 1% > 1.6 75 1.2 0.1 - 3.2 80 Max 1% > 2.0 76 2.0 0.1 - 5.0 48 Max 1% > 3.2 77 1.3 0.1 - 3.2 76 Max 1% > 2.0 78 1.2 0.1 - 3.2 76 Max 1% > 3.2 79 2.2 0.1 - 5.0 34 Max 1% > 3.2 80 1.6 0.1 - 4.0 80 Max 5% > 1.6 81 1.4 0.1 - 4.0 95 Max 1% > 2.0 82 1.3 0.1-3.2 79 Max1% > 2.0,u 83 1.0 0.1 - 5.0 57 Max 1% > 3.2 84 1.2 0.1 - 3.2 86 Max 1% > 2.0 85 1.6 0.1 - 4.0 80 Max 1% 2.0 86 0.92 0.1 - 2.0 98 Max 1% > 1.25 87 1.4 0.1 - 3.2 77 Max 1% > 2.0 88 1.6 0.1 - 4.0 71 Max 1% > 2.5 89 1.97 0.1 - 2.5 91 Max 1% > 1.6 90 1.2 0.1-3.2 95 Max 1% > 1.6 91 1.4 0.1 - 3.2 67 Max 1% > 2.5 92 1.8 0.1 - 4.0 53 Max 1% > 2.5 The following examples for preparation of small particle size zeolite A were carried out to illustrate the use of molar ratios of SiO2:AI203 in the range of 1:1 to 1.5:1.

TABLE VIII composition of reaction mixture for preparation of zeolite a Waterl Sodium Sodium Oxide! Silica Silicate Solution Aluminate Solution Example Oxide Silica Alumina %Na2O %SiO2 %Na2O %Al2O3 93 15 1.6 1.5 10.6 25.8 17.4 15.9 94 25 1.6 1.5 5.5 13.4 14.9 13.6 95 15 2.4 1.5 8.3 20.2 19.8 10.8 96 25 2.4 1.5 3.3 8.2 19.8 10.8 97 20 2.4 1.0 6.2 15.3 15.9 13.0 98 20 2.0 1.0 8.5 20.8 13.9 14.2 99 25 2.4 1.0 4.0 9.8 15.9 13.0 100 25 2.0 1.0 5.2 12.8 13.9 14.2 TABLE IX REACTION CONDITIONS -ZEOLITE A Preaheating Temp C. Time of Reaction Reaction Example Silicate Aluminate Addition Sec Temp. C. Time - Hrs 93 70 70 30 80 1.5 94 50 50 30 60 6.0 95 50 50 30 60 3.5 96 50 50 30 60 4.0 97 50 50 30 60 5.0 98 50 50 30 60 6.5 99 50 50 30 60 5.0 100 50 50 30 60 7.0 TABLE X PARTICLE CHARACTERIZATION - ZEOLITE A Average Micron Range Cumulative Particle Size ofatleast %Less than Example Microns 90% of Weight One Micron Other 93 2.2 0.1 - 5.0 58 Max 1% > 3.2 94 1.8 0.1 -4.0 33 Max 1% > 3.2 95 1.7 0.1 -4.0 44 Max 1% > 2.5 96 1.5 0.1-2.5 56 Max 1% > 2.5,u 97 1.2 0.1 - 2.5 74 Max 1% > 2.0ju 98 1.3 0.1 -3.2 73 Max 1% > 2.0y 99 1.1 0.1 - 2.5 82 Max 1% > 2.0,u 100 1.4 0.1 -3.2 69 Max 1% > 2.0,u TABLE XI EXCHANGE CAPACITY FOR ZEOLITE A Example Average Diameter Calcium Capacity Magnesium Capacity 93 2.2 298 93 94 1.8 296 111 95 1.7 294 100 96 1.5 311 134 97 1.2 291 93 98 1.3 270 96 99 1.1 289 121 100 1.4 270 114 As may be seen from Examples 1 to 92, the following are preferred molar ratios for production of zeolite A at reaction temperatures of 60 to 100 C.: WatertoSodiumOxide 15.0to30.0 Sodium Oxide to Silica 1.2 to 3.0 Silica to Alumina 2.0 to 7.3 In addition, Examples 93-100 illustrate a further preferred combination of conditions for production of small particle size zeolite A: using reaction temperatures of 60 to 800C., reaction times of 1.5 to 7.0 hours, and the following molar ratios: Water to Sodium Oxide 15.0 to 25.0 Sodium Oxide to Silica 1.6 to 2.4 Silica to Alumina 1.0 to 1.5 In Tables, Xll, Xlil, XIV and XV, the following are examples for production of zeolite X and characterization ofthe products.

Thereafter, in Tables XVI, XVII, XVIII and XIX, are examples for preparation of mixtures of zeolite A and zeolite X and characterization of the products.

These tables also set forth the exchange capacities of the products.

TABLE XII COMPOSITION OF REACTION MIXTURE FOR THE PREPARATION OF ZEOLITE X Waterl Sodium Sodium Oxide! Silical % Sodium Example Oxide Silica Alumina % Water Oxide %Silica %Alumina 101 30 1.7 7.3 94.73 3.16 1.86 0.25 102 30 1.6 7.3 94.61 3.15 1.97 0.27 103 30 1.5 7.3 94.46 3.15 2.10 0.29 104 30 1.5 7.3 94.46 3.15 2.10 0.29 105 30 1.5 5.3 94.36 3.15 2.10 0.40 106 30 1.4 7.3 94.30 3.14 2.25 0.31 TABLE XIII REACTION CONDITIONS -ZEOLITE X Temperature "C.

Silicate Aluminate Time of Reaction Reaction Example Solution Solution Addition <RTI TABLE XV EXCHANGE CAPACITY FOR ZEOLITE X Sodium Silical Oxidel Average Calcium Magnesium Example Alumina Alumina %Alumina Diameter Capacity Capacity 101 7.3 12.4 0.25 2.0 244 135 102 7.3 11.7 0.27 1.7 227 140 103 7.3 11.0 0.29 2.2 228 139 104 7.3 11.0 0.29 2.8 209 136 105 5.3 8.0 0.40 2.2 -225 140 106 7.3 10.2 0.31 1.5 235 155 TABLE XVI COMPOSITION OF REACTION MIXTURE FOR THE PREPARATION OF ZEOLITE A AND ZEOLITE X Waterl Sodium Sodium Oxide! Silica! % Sodium Example Oxide Silica Alumina % Water Oxide % Silica %Alumina 107 30 2.0 7.3 95.03 3.17 1.58 0.22 108 30 1.9 7.3 94.94 3.17 1.67 0.23 109 30 1.8 7.3 94.84 3.16 1.76 0.24 110 30 1.7 6.3 94.69 3.16 1.86 0.30 111 30 1.7 5.3 94.64 3.16 1.86 0.35 112 30 1.6 6.3 94.57 3.15 1.97 0.31 113 30 1.7 5.3 94.51 3.15 1.97 0.37 114 30 1.5 5.3 94.36 3.15 2.10 0.40 115 30 1.5 3.3 94.14 3.14 2.09 0.63 116 30 1.5 2.5 93.95 3.13 2.09 0.84 117 30 1.5 2.5 93.95 3.13 2.09 0.84 TABLE XVII REACTION CONDITIONS- ZEOLITES A & X Temps. C. Time of Reaction Reaction Example Silicate Aluminate Addition (sea) Temp. "C. Time (Hrs.) 107 90 90 30 100 4.0 108 90 90 30 100 4.0 109 90 90 30 100 4.0 110 90 90 30 100 6.0 111 90 90 30 100 4.0 112 90 90 30 100 6.0 113 90 90 30 100 8.0 114 95 95 300* 100 5.0 115 90 90 30 100 4.0 116 90 90 30 100 4.0 117 90 90 300 100 6.0 * Silicate and Aluminate Solutions Combined Simultaneously.

TABLE XVIII ZEOLITES A & X - PARTICLE CHARACTERIZATION Average Particle Micron Range ofat Cumulative % Less Example Size - Micron Least 90% of Weight Than One Micron 107 2.0 0.1-4.0 45 108 1.7 0.1-3.2 48 109 1.8 0.1-4.0 40 110 1.9 0.1-3.2 38 111 1.9 0.1-4,0 41 112 2.7 0.1-5.0 41 113 2.7 0.1-4.0 42 114 3.3 0.1-6.4 42 115 2.9 0.1-5.0 42 116 4.0 0.1-8.0 37 117 5.4 0.1-10.0 44 TABLE XIX EXCHANGE CAPACITY FOR A COMBINATION OF ZEOLITE A AND ZEOLITE X Sodium Silical Oxide! Average Calcium Magnesium Example Alumina Alumina %Alumina Diameter Capacity Capacity 107 7.3 14.6 0.22 2.0 255 130 108 7.3 13.9 0.23 1.7 240 135 109 7.3 13.1 0.24 1.8 228 139 110 6.3 10.7 0.34 1.9 224 141 111 5.3 9.0 0.35 1.9 229 138 112 6.3 10.1 0.31 2.7 221 130 113 5.3 8.5 0.37 2.7 304 130 114 5.3 8.0 0.40 3.3 235 143 115 3.3 5.0 0.63 2.9 257 150 116 2.5 3.8 0.84 4.0 256 118 117 2.5 3.8 0.84 5.4 303 129 The following examples illustrate activation of the silicate solution with alumina.

EXAMPLE 118 A sodium silicate solution of composition 3.4% sodium oxide and 8.5% silica was activated with 600 ppm alumina from a sodium aluminate solution. At a temperature of 70"C., a sodium aluminate solution, also at 70 C., of composition 24.2% sodium oxide and 8.3% alumina, was added to the sodium silicate within thirty seconds. The resulting gel was broken down by agitation until a homogeneous slurry was obtained. The batch was then reacted at 80 C. for 2.5 hours. The total batch composition had a water to sodium oxide molar ratio of 25:1, a sodium oxide to silica molar ratio of 2:1 and a silica to alumina molar ratio of 3:1. The resulting product was zeolite A which exhibited a calcium ion exchange capacity of 277 and magnesium ion exchange capacity of 175.

The resulting zeolite particles exhibited a narrow differential weight percent gaussian distribution with an average particle size of 1.1 microns with at least 90% of the weight between 0.1 and 2.0 microns. The cumulative percent population exhibited 78% less than one micron, with no more than 2% greater than 1.6 mcrons.

EXAMPLE 119 A sodium silicate solution of composition 4.0% sodium oxide and 10.0% silica was activated with 600 ppm alumina from a sodium aluminate solution.

At a temperature of 70"C., a sodium aluminate solution, also at 70 C., of composition 25.6% sodium oxide and 7.5% alumina, was added to the sodium silicate within thirty seconds. The resulting gel was broken down by agitation until a homogeneous slurry was obtained. The batch was then reacted at 80"C. for 22 hours. The total batch composition had a water to sodium oxide molar ratio of 30:1, a sodium oxide to silica molar ratio of 1:2 and a silica to alumina molar ratio of 7:1. The resulting product was zeolite X which exhibited both a calcium ion exchange capacity at 252 and magnesium ion exchange capcacity of 147. The resulting zeolite particles exhibited a narrow differential weight percent gaussian distribution with an average particle size of 2.0 microns with at least 90% of the weight between 0.1 and 3.2 microns. The cumulative percent population exhibited 52% less than one micron, with no more than 1% greater than 4.0 microns.

EXAMPLE 120 A sodium silicate solution of composition 3.6% sodium oxide and 9.0 /O silica was activated with 600 ppm alumina from a sodium aluminate solution. The sodium silicate was then heated to 70 C. for thirty minutes. At that time a sodium aluminate solution, also at 70"C., of composition 29.5% sodium oxide and 5.3% alumina, was added to the sodium silicate within thirty seconds. The resulting gel was broken down by agitation until a homogeneous slurry was obtained. The batch was then reacted at 80"C. for six hours. The total batch composition had a waterto sodium oxide molar ratio of 25:1, a sodium oxide to silica molar ratio of 1.7:1 and a silica to alumina molar ratio of 7:1. The resulting product was a combination of 40% zeolite X and 60% zeolite A. This product exhibited a calcium ion exchange capacity of 284 and magnesium ion exchange capacity of 139.

The resulting zeolite particles exhibited a narrow differential weight percent gaussian distribution with an average particle size of 0.8 microns with at least 90% of the weight between 0.1 and 3.2 microns. The cumulative precent population exhibited 90% less than one micron, with no more than 1% greater than 1.3 microns.

EXAMPLE 121 A sodium silicate solution of composition 11.2% sodium oxide and 27.15% silica was activated with 500 ppm alumina from a sodium aluminate solution.

The sodium silicate was then heated to 90"C. for thirty minutes. At that time a sodium aluminate solution, also at 90 C., of composition 10.4% sodium oxide and 14.6% alumina was added to the sodium silicate within thirty seconds. The resulting gel was broken down by agitation until a homogeneous slurry was obtained. The batch was then reacted at 100"C. for 24 hours. The total batch composition had a sodium oxide to silica molar ratio of about 0.56:1, a silica to alumina molar ratio of about 7.8:; and a water to sodium oxide molar ratio of about 20:1. The resulting product was zeolite Y with a silica to alumina molar ratio of 5.2:1.

Thus, in operation, either zeolite X, zeolite A, a combination of the two, or zeolite Y can be formed by dissolving sand in a sodium hydroxide solution to form a sodium silicate solution, activating it with alumina, forming a sodium aluminate solution and quickly adding the sodium aluminate solution to the activated sodium silicate solution.

WA TER SOFTENING COMPOSITIONS As indicated above, the small particle size zeolites of the invention are useful in several areas. Thus, a water soluble softening composition can be formed containing a binding agent, a solubilizing agent, water and the zeolites of the present invention. Zeolite A, zeolite X or a combination of the two can be used. In these compositons, sodium silicate may be used as the binding agent, with the silica to sodium oxide ratio being between 1:1 and 3.3:1, preferably about 2.5:1 since that is the most common molar ratio found in detergent formulations. At least 1% sodium silicate is required to bind the bead, but more than 20% sodium silicate limits the amount of sodium silicate than can be added to the system without enough improvement in bead strength to justify the lower aluminosilicate levels. The most preferred binding agent would bea sodium polysilicate having a silica to sodium oxide ratio of 2.5:1.

About 1% to 20% of a suitable solubilizing agent should be present including soluble sodium phosphates, carbonates, bicarbonates, tetraborates and sodium sulfate. The preferred solubilizing agent is sodium sulfate.

Some water is needed in the water softening bead.

Otherwise the ion exchange capacity of the sodium silicate is reduced. In a preferred embodiment of the present invention, at least 66% by weight of an anhydrous basis of zeolite of this invention is added to 1 to 20% by weight of sodium sulfate and the remainder is water. This slurry is then dried with nozzle atomization in a spray dryer at inlet temperatures of below 540"C. to produce beads. If the beads are dried at a temperature of above 540"C., some ion exchange capacity can be lost.

DETERGENT COMPOSITIONS A detergent composition can be formed containing a high magnesium exchange capacity. Zeolite A, zeolite X, or a combination of these zeolites of the invention are used in a preferred aspect by spraying a liquid surfactant onto the zeolite to form a freeflowing powder or pellets. Care must be taken not to exceed the absorbency limits of the pigment. The powder or pellets are then added to detergent formulations without further drying. The powder or pellets are dry blended into a dry detergent formulation.

The surfactant can be anionic, non-ionic or amphoteric although the surfactants include the higher alkyl aryl sulfonic acids and their alkali metal and alkaline earth metal salts such as, for example, sodium dodecyl benzene sulfonate, sodium tridecyl sulfonate, magnesium dodecyl benzene su Ifonate, potassium tetradecyl benzene sulfonate, ammonium dodecyl toluene sulfonate, lithium pentadecyl benzene sulfonate, sodium dioctyl benzene sulfonate, disodium dodecyl benzene disulfonate, disodium diisopropyl naphthalene disulfonate and the like, as well as the alkali metal salts of fatty alcohol esters of sulfuric and sulfonic acids, the alkali metal salts of alkyl aryl (sulfothioic acid) esters and the alkyl thiosulfuric acid.

Non-ionic surface active compounds, such as those products produced by condensing one or more relatively lower alkyl alcohol amines, such as methanolamine, ethanolamine, propanolamine, with a fatty acid such as lauric acid, cetyl acid, tall oil fatty acid, abietic acid, to produce the corresponding amide may also be used. In addition, amphoteric surface active compounds such as sodium N-coco beta amino propionate, sodium N-tallow beta amino dipropionate, sodium N-lauryl beta iminodipropionate and the like may also be used.

The use of small particle size zeolite A was evaluated by substituting it for phosphate in basic detergent formulations. Washing tests were conducted in a terg-otometer, Model 7243, machine.

Tests were run at 0.15% detergent concentration in 120 and 240 ppm hard water (Ca:Mg=2:1) at 120 F.

A wash time of fifteen minutes at 125 rpm with two five-minute rinses was used. Detergency was determined on soiled test cloths of cotton, spun dacron, cotton/dacron with permanent press, and cotton shirting wash and wear. The detergency value was determined by using a Gardner Model XL-10 reflectometerto measure reflectance before and after washing. The results on Table XX indicate that small particle size zeolite A can replace phosphates in detergent formulations and may even improve overall detergency. This is particularly evident in the 240 ppm hardness test. It is believed that the favorable results obtained in these tests can be attributed to the ability of small particle size zeolite A to remove both calcium and magnesium ions from solution at extremely rapid rates.

TABLEXX USE OF SMALL PARTICLE SIZE ZEOLITE A IN DETERGENTS 120 ppm Hardwater 240 ppm Hardwater &num;1 &num;2 &num;3 &num;4 FORMULA TION wt% gms wt% gms 'wit% gms 'wit% gms Sodium Tripolyphosphate 25 .375 - - 25 .375 - Small particle size Zeolite A (Example 35) - - 25 *.469 - - 25 *.469 Richonate45B 12 .18 12 .18 12 .18 12 .18 Richonal A 5 .075 5 .075 5 .075 5 .075 Condensate Co 3 .045 3 .045 3 .045 3 .045 Carboxymethylcellulose 1 .015 1 .015 1 .015 1 .015 Sodium Silicate 15 .225 15 .225 15 .225 15 .225 Sodium Sulfate 39 .585 39 .585 39 .585 39 .585 *Active Basis 120 ppm Hardwater 240 ppm Hardwater RESULTS &num;1 &num;2 &num;3 &num;4 Test Cloth % Improvement % Improvement % Improvement /Olmprovement Cotton 32.8 39.0 33.4 34.1 Spun Dacron 3.0 15.8 10.7 42.4 Cotton/Dacron permanent press 17.8 17.2 18.8 20.2 Cotton shirting wash and wear 22.8 19.9 19.7 24.8 %Total Detergency 76.4 91.9 82.6 121.5 PAPER COMPOSITIONS Paper compositions can also be formed containing zeolites of small and uniform size of this invention including zeolite A, zeolite X, or a combination of the two. The use of small particle size zeolite A as a filler in fine paper was evaluated by adding itto various types of furnishes. These furnishes included both bleached and unbleached pulps. Handsheets of various basis weights and different types of pulp were made using a Nobel and Wood Sheet machine. Tests on these handsheets were done according to the following TAPPI (The American Pulp and Paper Institute) standards: T425m - Opacity of Paper T452m - Brightness of Paper and Paperboard T41 Om - Basis Weight of Paper and Paperboard.

Table XXI indicates that single pass retention of zeolite A is not dependent on size and that its retention is significantly higher than Hydrex, a registered trademark of the J. M. Huber Corporation, for an amorphous sodium magnesium aluminosilicate.

This suggests that the mechanism of zeolite A retention is different and that it is functional to species rather than size. It is reasonable to suspect that the retention mechanism is due to a charge effect between the crystalline material and the pulp rather than mechanical effect. Surprisingly, the small particle size zeolite A of the present invention showd markedly better optical effects in both brightness and opacity than commercial zeolite A and was equal to the best known synthetic (Hydrex) used for this application.

TABLEXXI USE OF SMALL PARTICLE SIZE ZEOLITE A AS A FILLER IN FINE PAPER BASIS WT. % TAPPI TAPPI 25 x 38 x 500 PIGMENT BRIGHT PIGMENT %FILLER &num;!REAM gisqm RETAINED NESS OPACITY Unfilled 50.9 75.3 85.0 82.8 Small Particle Size 3 52.1 77.1 58 86.7 86.5 Zeolite A 6 50.2 74.3 55 88.2 89.0 (Example 10) 9 51.3 75.9 53 89.3 90.6 Commercial 3 50.8 75.2 56 85.6 84.6 Zeolite A 6 52.2 77.3 55 86.1 86.1 9 53.5 79.2 56 86.5 ' 87.2 Unfilled 48.9 72.4 85.5 82.2 Small Particle Size 3 51.5 76.2 41 87.4 86.1 Zeolite A 6 51.3 75.9 38 88.8 88.5 (Example 10) 9 51.4 76.1 34 89.9 90.1 Hydrex* 3 50.1 74.1 28 87.4 86.1 6 50.2 74.3 30 88.7 88.2 9 49.8 73.3 31 89.6 89.4 * Registered Trademark of J. M. Huber Corporation The use of small particle size zeolite A of this invention as an extenderfortitanium dioxide in paper was evaluated by adding it to a bleached pulp paper furnish. The paper furnish was 50% bleached hardwood and 50% bleached softwood Kraft. Handsheets were made and the properties were tested following the previously described procedures.

Table XXII shows the single pass retention of zeolite A in combination with titanium dioxide. This data also suggests a different mechanism of retention and confirms the results obtained in a single filler system. Optical properties obtained using small particle size zeolite A were significantly better than larger size material (commercial zeolite A) and equal to Hydrex.

TABLE XXII USE OF SMALL PARTICLE SIZE ZEOLITE A AS AN EXTENDER FOR TITANIUM DIOXIDE IN FINE PAPER BASIS WT.

85 x 38x 500 BRIGHT PIGMENT FILLER &num;REAM gisq m RETAINED NESS OPACITY Unfilled 50.9 75.3 85.0 82.8 50% Small Particle Size 3 50.6 74.9 61 87.8 88.4 Zeolite A (Example 10) 6 51.0 75.5 58 89.6 91.9 and 50% Titanium Dioxide 9 50.7 75.0 55 90.8 93.8 50% Commercial 3 50.5 74.7 59 87.2 87.7 Zeolite A and 6 51.3 75.9 60 88.7 91.0 50 /O Titanium Dioxide 9 51.4 76.1 60 89.7 92.9 Unfilled 48.9 72.4 85.5 82.2 50% Small Particle Size 3 51.5 76.2 47 88.3 88.2 Zeolite A (Example 10) 6 51.0 75.5 42 89.8 91.4 and50% Titanium Dioxide 9 50.3 74.4 40 90.9 93.4 50 /O Hydrex and 3 50.3 74.4 24 88.3 88.5 50% Titanium Dioxide 6 49.9 73.9 36 89.8 91.7 9 49.5 73.3 39 90.9 93.5 The use of small particle size zeolite A as a filler in newsprint was evaluated by adding it to a standard newsprint furnish. Newsprint handsheets consisting of 65% groundwood and 35% semi-bleached Kraft paper were made using the Noble and Wood Sheet machine. The sheets were printed at a pick-up of 1.7 and 2.59 ink/sq. m using a Vandercook Proofing Press with a solid block and a 4 mil impression pressure. After 24 hours, brightness readings on the reverse side of printed and unprinted sheets were made. These were then plotted and results reported as strike-through values at 209 ink/sq. m (modified version of the Larocque strike-through test).

The data on Table XXIII also indicates that the retention mechanism of zeolite A is different than other specialty fillers commonly used for newsprint applications. The results also confirm that small particle size zeolite A is superior to commercial zeolite A and compares favorably with Zeolex 23, a registered trademark of the J. M. Huber Corporation, for an amorphous sodium aluminosilicate.

TABLE XXIII USE OF SMALL PARTICLE SIZE ZEOLITE A IN NEWSPRINT Basis Wt TAPPI TAPPI SIT &commat; 24 x 36 x 500 Caliper 2gl2m SIT PIGMENT RETENTION FILLER &num;REAM glsqm MILS MM BRIGHTNESS OPACITY INK REDUCTION Unfilled 28.8 46.9 3.0 0.76 59.3 83.7 17.1 Small Particle 37 2 30.1 49.0 3.1 .079 61.0 86.5 13.4 22 Size ZeoliteA 35 4 30.4 49.5 3.1 .079 62.3 88.0 10.4 39 Zeolex23 29 2 28.8 46.9 3.0 .076 60.2 84.8 13.1 23 35 4 29.5 48.0 3.0 .076 61.1 85.7 9.8 43 Unfilled 29.6 48.2 3.3 .084 58.6 86.4 12.3 Commercial 38 2 30.6 49.8 3.2 .081 59.2 87.7 11.4 7 ZeoliteA 43 4 31.3 50.9 3.2 .081 59.6 88.8 10.6 14 The use of small particle size zeolite A in paper coatings was tested in various coating formulas.

Two of these were as follows: 1. 87% Hydrasperse Clay 5% Titanium dioxide 8% Pigment 2. 92% Hydrasperse Clay 8% Pigment.

These formulations were prepared at 58% solids using 16 parts per hundred binder level (75% starch 25% Latex) and were ground using a Cowles Dissolver. Paper used was a 32&num; base stock which was coated 133300 sq. ft. using a Keegan Laboratory Trailing Blade Coater. All sheets were supercalendered 3 nips at 150 degrees Fahrenheit and 100 psig.

Sheets were then checked for gloss, opacity and brightness using the following TAPPI standards: T-480m Gloss of Paper T-425m Opacity of Paper T-452, Brightness of Paper and Paperboard.

The results of Table XXIV show small particle size zeolite A to be superior to commercial zeolite A. This is most obvious in better gloss development, but there is also significant improvement in both brightness and opacity when used as either an extender for titanium or as a filler. Similar effects were seen in tests on coated board.

TABLE XXIV USE OF SMALL PARTICLE SIZE ZEOLITE A AS ATITANIUM DIOXIDE EXTENDER IN PAPER COATINGS (87% Hydrasperse Clay - 5% TiO2 8% Pigment) 75 degree TAPPI TAPPI Pigment Gloss, % Brightness Opacity Small Particle 64.9 71.1 90.9 Size Zeolite A (Example 10) Commercial 55.0 70A 90.3 Zeolite A USE OF SMALL PARTICLE SIZE ZEOLITE A AS A PIGMENT IN PAPER COATINGS (92% Hydrasperse Clay - 8% Pigment) 75 degree TAPPI TAPPI Pigment Gloss, % Brightness Opacity Small Particle 64.0 69.3 89.0 Size Zeolite A (Example 10) Commercial 55.9 68.1 88.5 Zeolite A RUBBER COMPOSITIONS A rubber composition can be formed containing zeolite A, zeolite X, or a combination of the two, of this invention.

The rubbers (alternatively referred to herein as elastomers, which materials are unvulcanized) which can be employed in the invention include both natural and synthetic rubbers. Exemplary of suitable synthetic rubbers are styrene-butadiene, butyl rubber, nitril rubber, polybutadiene, polyisoprene, ethylene propylene, acrylic, fluorocarbon rubbers, polysulfide rubbers and silicone rubbers. Mixtures of copolymers of the above synthetic rubbers can be employed alone or in combination with natural rubber. The preferred rubbers are nitrile rubber, styrene-butadiene rubber, natural rubber, polyisoprene, and mixtures thereof because they are most compatible with polyester fibers, although minor amounts of other rubbers can be included without adverse effects. U.S. Patent 3,036,908 is incorpo rated by reference to show the formation of rubber compositions containing zeolites.

PLASTIC COMPOSITIONS A plastic composition can be formed containing zeolites of small and uniform size. Either zeolite A, zeolite X, or a combination of the two, can be used.

NON-SETTLING FLATTING PIGMENT The zeolite of this invention can also be used as non-settling flatting pgiments. Either zeolite A, zeol ite X, or a combination of the two, can be used.

Small particle size zeolite A was evaluated as a non-settling, flatting pigment in nitrocellulose lac quer and as a prime pigment extender in flat latex paint systems. Tests in the nitrocellulose lacquer system were conducted by adding the zeolite to a lacquer. The amount of zeolite used was equivalent to 10% by weight of vehicle solids. The lacquer and zeolite were blended together using a Hamilton Beach Model 936 Blender at 16,000 rpm for four minutes and the resulting mixture was then strained through a fine mesh paint strainer. Hegman grind was determined in the usual manner and the mixture was then drawn down on Leneta Sc paper panels using a &num;34 wire wound coatings application rod.

The panels were dried at room temperature for 45 minutes under dust-free conditions in a vertical position. A Gardner multi-angle gloss meter was used to determine gloss (60 degree head) and sheen (85 degree head) of the panels. Settling was evaluated using an accelerated test with an arbitrary scale ofO (fail) to 10 (none) after 7 days at 120OF.

The results on Table XXV show that small particle size zeolite A was superior to commercial zeolite A in all categories, and the exceptional clarity of the lacquer containing small particle size zeolite A would be of significant value in specialty applications.

TABLE XXV USE OF SMALL PARTICLE SIZE ZEOLITE A AS A NON-SETTLING, FLATTING PIGMENT IN NITROCELLULOSE LACQUER Sample Hegman 60 Gloss 85 Sheen Settling Small Particle Size ZeoliteA(Example10) 6.25 15 27 8 Commercial Zeolite A 6.00 33 71 1 The use of small particle size zeolite A as a prime pigment extender in flat latex paint systems was evaluated as follows: Part I of the formulation was mixed, Part II of the formulation was then added and the entire mixture was blended for 10 minutes on a Cowles high speed mixer. The zeolite A was added at this time and dispersed for 5 minutes. The letdown (Part lil) was then added to complete the formulation and mixed for an additional 5 minutes. The resulting paint was drawn down on Leneta 1 B paper panels using a &num;34 wire wound coatings application rod. The panels were dried at room temperature under dust-free conditions in a vertical position. A Gardner multi-angle gloss meter was used to determine the gloss and sheen of the panels.

TABLE XXVI Weight, gms Weight, gms Formulation &num;1 &num;2 Part I Water 200 200 Cellosize OP-15000 0.5 0.5 AMP-95 2 2 Daxad 30 8 8 Ethylene Glycol 17 17 SuperAd 1 1 Napco 1 1 Partll R-901 150 150 Huber70C 100 100 G-White 150 150 Small particle size Zeolite A (Example 10) 60 Commercial Zeolite A A 60 Part III Water 183 183 QP-15000 3 3 AMP-95 3 3 Texanol 8 8 Napco NDW 2 2 Amsco 3011 264 264 TABLE XXVII USE OF SMALL PARTICLE SIZE ZEOLITE A AS A PRIME PIGMENT EXTENDER IN FLAT LATEX SYSTEMS Brightness, Contrast 60 85 Sample YB Ratio Gloss Sheen Small Particle Size Zeolite A (Example 10) 89.6 0.968 3 7 Commercial Zeolite A 87.6 0.958 3 4 The results on Table XXVII indicate that small particle size zeolite A performs better than commercial zeolite A as a prime pigment spacer in this paint system. This is evident by the brightness and contrast ratios which indicate that the small particle size zeolite A is significantly more efficient and better performing in optical properties.

Zeolite Y of this invention has been found to have particularly good absorption characteristics as is Semonstrated by the representative adsorption data n Table XXVIII.

TABLE XXVIII ADSORBATE DATA FOR ZEOLITE Y Adsorbate Pressure Temperature Weight % (mm.Hg) ('C.) Adsorbed HzO 25 25 35.2 CO2 700 25 26.0 n-pentane 200 25 14.9 (C4F9)3N 0.07 25 1.1 (C4F9)3N 1.5 50 21.4 Krypton 20 -183 70.0 Oxygen 700 -183 35.7 The foregoing data were obtained in the following manner: Samples of zeolite Y which had been activated by dehydration at a temperature of approximately 350"C., under vacuum, were tested to determine their adsorptive properties. The adsorption properties were measured in a McBain-Bakeradsorption system. The zeolite samples were placed in light aluminium buckets suspended from quartz springs.

They were activated in situ, and the gas or vapor under test was then admitted to the system. The gain in weight of the adsorbent was measured by the spring extensions as read by a cathetometer. In Table XXVIII the pressure given for each adsorption is the pressure of the adsorbate. The term "weight % adsorbed" in the table refers to the percentage increase in the weight of the activated adsorbent.

As may be seen from the adsorption data in the table, activated zeolite Y can be employed to separate molecules having a critical dimension greater than that of heptocosafluorotributylamine from molecules having smaller critical dimensions. The critical dimension of a molecule is defined as the diameter of the smallest cylinder which will accommodate a model of the molecule constructed using the best available van der Waals radii, bond angles, and bond lengths.

A unique property of zeolite Y is its strong preference for polar, polarizable and unsaturated molecules, providing, of course, that these molecules are of a size and shape which permit them to enterthe pore system. This is in contrast to charcoal and silica gel which show a primary preference based on the volatility of the adsorbate.

Zeolite Y is distinguished from other molecular sieve types, for example, zeolite X described in U.S.

Patent 2,882,244, by its exceptiona

Claims

**WARNING** start of CLMS field may overlap end of DESC **. TABLE XXVII USE OF SMALL PARTICLE SIZE ZEOLITE A AS A PRIME PIGMENT EXTENDER IN FLAT LATEX SYSTEMS Brightness, Contrast 60 85 Sample YB Ratio Gloss Sheen Small Particle Size Zeolite A (Example 10) 89.6 0.968 3 7 Commercial Zeolite A 87.6 0.958 3 4 The results on Table XXVII indicate that small particle size zeolite A performs better than commercial zeolite A as a prime pigment spacer in this paint system. This is evident by the brightness and contrast ratios which indicate that the small particle size zeolite A is significantly more efficient and better performing in optical properties. Zeolite Y of this invention has been found to have particularly good absorption characteristics as is Semonstrated by the representative adsorption data n Table XXVIII. TABLE XXVIII ADSORBATE DATA FOR ZEOLITE Y Adsorbate Pressure Temperature Weight % (mm.Hg) ('C.) Adsorbed HzO 25 25 35.2 CO2 700 25 26.0 n-pentane 200 25 14.9 (C4F9)3N 0.07 25 1.1 (C4F9)3N 1.5 50 21.4 Krypton 20 -183 70.0 Oxygen 700 -183 35.7 The foregoing data were obtained in the following manner: Samples of zeolite Y which had been activated by dehydration at a temperature of approximately 350"C., under vacuum, were tested to determine their adsorptive properties. The adsorption properties were measured in a McBain-Bakeradsorption system. The zeolite samples were placed in light aluminium buckets suspended from quartz springs. They were activated in situ, and the gas or vapor under test was then admitted to the system. The gain in weight of the adsorbent was measured by the spring extensions as read by a cathetometer. In Table XXVIII the pressure given for each adsorption is the pressure of the adsorbate. The term "weight % adsorbed" in the table refers to the percentage increase in the weight of the activated adsorbent. As may be seen from the adsorption data in the table, activated zeolite Y can be employed to separate molecules having a critical dimension greater than that of heptocosafluorotributylamine from molecules having smaller critical dimensions. The critical dimension of a molecule is defined as the diameter of the smallest cylinder which will accommodate a model of the molecule constructed using the best available van der Waals radii, bond angles, and bond lengths. A unique property of zeolite Y is its strong preference for polar, polarizable and unsaturated molecules, providing, of course, that these molecules are of a size and shape which permit them to enterthe pore system. This is in contrast to charcoal and silica gel which show a primary preference based on the volatility of the adsorbate. Zeolite Y is distinguished from other molecular sieve types, for example, zeolite X described in U.S. Patent 2,882,244, by its exceptional stability toward steam at elevated temperatures. This is a property which makes zeolite Y particularly suitable for such processes as gas drying. CLAIMS

1. A method for the production of sodium aluminosilicate zeolites by the reaction of sodium aluminate and sodium silicate characterized by the following steps: a) forming an aqueous solution of sodium aluminate; b) forming an aqueous solution of sodium silicate; c) mixing said sodium aluminate and said sodium silicate solutions at a temperature of 40 to 1 20'C.; d) reacting said mixed sodium aluminate and sodium silicate at a temperature slightly higher than said mixing temperature, the reaction mixture having the following molar ratios of components: (1) waterto sodium oxide 10:1 to 35:1 (2) sodiumoxidetosilica 1:1to4:1 (3) silica to alumina 1:1 to 10:1 e) continuing the reaction at these molar ratios to form the zeolite while controlling the molar ratios and reaction time to produce a fine particle size zeolite having an average particle size of less than 2 microns in diameter; and f) recovering the zeolite; wherein, when the silica to alumina molar ratio is 2.0:1 or below, the maximum temperature of the reaction does not exceed 80"C.; and wherein the molar ratios selected for reaction within the ranges given are such that the particle size of the zeolite product increases as the silica to alumina molar ratio decreases, and decreases as the silica to alumina molar ratio increases, and wherein the particle size of the zeolite product is inversely proportional to the sodium oxide to alumina molar ratio, and directly proportional to the alumina con centration; and further provided that the variables of molar ratios and reaction temperature are selected from within the ranges given to provide a fine particle size zeolite having an average particle size of less than 2 microns in diameter and having a high magnesium exchange capacity.

2. A method according to Claim 1 for producing zeolite A of small and uniform size having a high magnesium exchange capacity characterized by the steps of: a) mixing together said sodium aluminate solution and said sodium silicate solution to produce a reaction mixture having in total a water to sodium oxide molar ratio of between 10:1 and 35:1; a sodium oxide to silica molar ratio of between 1:1 and 4:1; and a silica to alumina molar ratio of between 1:1 and 10:1; wherein, when the sodium oxide to silica molar ratio is less than 4:3, the silica to alumina molar ratio is between 3:1 and 10:1, and when the sodium oxide to silica molar ratio is more than 4:3, the sodium oxide to alumina molar ratio is greater than 4:1; b) heating said mixture; c) reacting said mixture until zeolite A is formed; and d) recovering said zeolite A.

3. A method of producing zeolite A of small and uniform size having a high magnesium exchange capacity according to Claim 2 characterized in that the mixture has a water to sodium oxide molar ratio of between 10:1 and 35:1; a sodium oxide to silica molar ratio of between 1:1 and 2.5:1; and a silica to alumina molar ratio of between 3:1 and 10:1 and wherein said reaction mixture is heated to, and reacted at, a temperature of from 50 to 100 C..

4. A method of producing zeolite A of small and uniform size having a high magnesium exchange capacity according to Claim 2 characterized in that the mixture has a water to sodium oxide molar ratio offrom 15:1 to 30:1; a sodium oxide to silica molar ratio offrom 1.2:1 to3:1; and a silica to alumina molar ratio of from 2:1 to 7.3:1.

5. A method of producing zeolite A of small and uniform size having a high magnesium exchange capacity according to Claim 2 characterized in that said sodium silicate solution is formed by: a) dissolving sand in a sodium hydroxide solution at a pressure of at least 100 psig, heated to a temperature of at least 130 C. to produce a sodium silicate having a silica to sodium oxide molar ratio of between 2.4:1 and 2.8:1; b) activating said sodium silicate solution by treating with from 50 to 2000 ppm alumina; and c) heating said sodium silicate solution to between 40"C and 1200C..

6. A method of producing zeolite A of small and uniform size having a high magnesium exchange capacity according to Claim 2 characterized in heating said sodium aluminate solution and the sodium silicate solution to a temperature of 50into 80"C.; said sodium aluminate solution is added to said sodium silicate solution within a period of time less than 30 seconds to form a mixture having a water to sodium oxide molar ratio of about 20:1; a sodium oxide to silica molar ratio of about 1.5:1; a silica to alumina molar ratio of about 7.3: 1; heating said mixture at a temperature of about 60 to 90"C.; and recovering said zeolite A.

7. Zeolite A produced by the method of Claim 2 characterized in that the resulting zeolite particles exhibit a narrow differential weight percent gaussian distribution with an average particle size of no more than 2.1 microns with at least 90% of the weight between 0.1 and 4.0 microns, wherein the cumulative percent population exhibits at least 35% less than one micron, with no more than 5% greater than 5 microns, with a calcium carbonate exchange capac ity greater than 230 mg calcium carbonate per gram zeolite and a magnesium carbonate exchange capac ity greater than 90 mg magnesium carbonate per gram zeolite.

8. A method of producing zeolite X of small and uniform size having a high magnesium exchange capacity in accordance with Claim 1 characterized by the steps of mixing the sodium aluminate solution and the sodium silicate solution to produce a reaction mixture comprising a sodium silicate mother liquor and an amorphous sodium alumina silicate, in total having a water to sodium oxide molar ratio of between 25:1 and 90:1; a sodium oxide to silica molar ratio of between 1:1 and 3:1; and a silica to alumina molar ratio of between 5:1 and 10:1; heat ing said mixture and reacting until zeolite X is formed; and recovering said zeolite X.

9. A method of producing zeolite X of small and uniform size having a high magnesium exchange capacity according to Claim 8 characterized in that the mixture has a water to sodium oxide molar ratio of between 30:1 and 60:1; a sodium oxide to silica molar ratio of between 1.2:1 and 1.7:1; and a silica to alumina molar ratio of between 6:1 and 8:1.

10. A method of producing zeolite X of small and uniform size having a high magnesium exchange capacity according to Claim 8 characterized in that said sodium silicate solution is formed by: a) dissolving sand in a sodium hydroxide solution at a pressure of at least 100 psig heated to a temperature of at least 130"C. to produce a sodium silicate solution having a silica to sodium oxide molar ratio of between 2.4:1 and 2.8:1 b) activating said sodium silicate solution bytreating with from 50 to 2000 ppm alumina; and c) heating said sodium silicate solution to between 40"C and 120"C.

11. A zeolite X produced by the process of Claim 8 characterized in that the resulting zeolite particles exhibit a narrow differential weight percent gaussian distribution with an average particle size of no more than 2.2 microns with at least 90% of the weight between 0.1 and 5.0 microns, wherein the cumulative percent population exhibits at least 41% less than one micron, with no more than 5% greater than 3.2 microns, said zeolite X having a calcium carbonate exchange capacity greater than 205 mg calcium-carbonate per gram zeolite and a magnesium exchange capacity greater than 130 mg magnesium carbonate per gram zeolite.

12. A method according to Claim 1 for producing a combination of zeolite A and zeolite X character ized by the steps of mixing together the sodium aluminate solution and said sodium silicate solution to produce a reaction mixture comprising a sodium silicate mother liquor and an amorphous sodium alumina silicate, in total having a water to sodium oxide molar ratio of between 10:1 and 60:1; a sodium oxide to silica molar ratio of between 0.5:1 and 3:1; and a silica to alumina molar ratio of between 2:1 and 15:1; heating said mixture and react ing said mixture until a combination of zeolite A and zeolite X is formed; and recovering said combination of zeolite A and zeolite X.

13. A method of producing a combination of zeolite A and zeolite X according to Claim 12 characterized in that the mixture has a water to sodium oxide molar ratio of between 20:1 and 50:1; a sodium oxide to silica molar ratio of between 1.4:1 and 3:1; and a silica to alumina molar ratio of between 2:1 and 10:1.

14. A method of producing a combination of zeolite A and zeolite X according to Claim 12 characterized in that said sodium silicate solution is formed by: a) dissolving sand in a sodium hydroxide solution art a pressure of at least 100 psig heated to atemper- ature of at least 1300C. to produce a sodium silicate solution having a silica to sodium oxide molar ratio of between 2.4:1 and 2.8:1; b) activating said sodium silicate solution by treating with from 50 to 2000 ppm alumina; and c) heating said sodium silicate solution to between 40 and 120"C.

15. Awatersoftening composition containing a zeolite of Claim 1.

16. A detergent containing, as an ion exchange material, a zeolite of Claim 1.

17. A paper containing, as a filler, a zeolite of Claim 1.

18. A rubber containing, as a filler, a zeolite of Claim 1.

19. A plastic containing, as a filler, a zeolite of Claim 1.

20. A non-settling flatting pigment comprising a zeolite of Claim 1.

21. A method for preparation of a sodium silicate solution useful for forming zeolites by the process of Claim 1 characterized by the steps of: a) dissolving sand in a sodium hydroxide solution at a pressure of at least 100 psig heated to a temperature of at least 130 C. to produce a sodium silicate solution having a silica to sodium oxide molar ratio of between 2.4:1 and 2.8:1; b) activating said sodium silicate solution with from 50 to 2000 ppm alumina at a temperature of between 15 and 100"C. for at least 10 minutes; and c) heating said sodium silicate solution to a temperature of between 80 and 120"C.

22. A method for producing a small particles size crystalline zeolite Y, said method being characterized by the steps of: a) dissolving sand in sodium hydroxide solution at a pressure of at least 100 psig and a temperature of at least 130"C. to produce a sodium silicate solution having a silica to sodium oxide molar oxide ratio of between 2.4:1 and 2.8:1; b) activating said sodium silicate solution with from 50 to 2000 ppm alumina at a temperature of from 15'to 100 C. for at least 10 minutes; c) forming a sodium aluminate solution; d) adding said sodium aluminate solution rapidly to said activated sodium silicate solution to produce a reaction mixture comprising a sodium silicate mother liquor and an amorphous sodium alumino silicate pigment, in total having a sodium oxide to silica molar ratio of between 0.5:1 and 1:1; a silica to alumina molar ratio of between 7:1 and 30:1; and a water to sodium oxide molar ratio of between 10:1 and 90:1; e) heating said mixture to a temperature of from 80 to 120 C.; f) reacting said mixture at a temperature of from 80 to 120"C. until crystalline zeolite Y is formed; and g) recovering said zeolite Y.