Note: Descriptions are shown in the official language in which they were submitted.
~ WO96/18577 ~ g 2 5 PCTIAU9Sl00699
TITLE
"PROCESS FOR FORMING ALUMINO-SILICATE DERIVATIVES"
FIELD OF THE INVENTION
THIS INVENTION relates to the formation of
new materials in the form of alumino-silicate
derivatives and processes to form these new materials
which are obtained by the chemical modification of
clay minerals and other aluminium-bearing minerals.
The derivatives of these clays or aluminium-
bearing minerals, are characterised by a predominanceof tetrahedrally-coordinated Al~ 3 which has resulted
from the chemical modification of octahedrally-
coordinated Al~ in the parent mineral. This
transformation of the atomic-scale structure makes
available a higher number of exchangeable sites than
would be normally available in the original clay
structure.
BACKGROUND OF THE INVENTION
Two features of the new materials which may
result from the modification of these clays or of
aluminium-bearing minerals are an enhanced capacity to
exchange cations from solution (i.e. a cation exchange
capacity) and/or an increase in the available surface
area when compared with the properties of the initial
starting mineral (e.g. clay or zeolite). These two
features are of considerable significance to the cost-
effective use of these derivative materials in a wide
range of applications for cation-exchange (e.g. for
removal of toxic metal ions from aqueous and non-
aqueous solutions; removal of NH~ from aqueous andnon-aqueous solutions, as detergent builders and as
water softeners), absorption (e.g. for the removal of
gases from the environment, for absorption of cations
from solutions), as agents for the controlled release
of desired cations into an environment and as
substrates for catalysis reactions in the modification
of hydrocarbons and other chemicals.
WO96/18577 , ~ 5 PCT/AU95/00699 -
Clay minerals are part of the larger family
of minerals called phyllosilicates - or "layer"
silicates. These clay mlnerals are typically
characterised by two-dlmenslonal arrangements of
tetrahedral and octahedral sheets, each with speclfic
elemental compositlons and crystallographic
relationshlps which deflne the mineral group.
Thus,the tetrahedral sheet may have the composition
T2Os (where T, the tetrahedral cation, ls Sl, Al and/or
Fe) and the octahedral sheet may commonly contain
cations such as Mg, Al and Fe, but may also contain
other elements such as Li, Tl, V, Cr, Mn, Co, Ni, Cu
and Zn (Brlndley and Brown, 1980, Crystal structures
of clay mlnerals and their X-ray ldentlflcation,
Mineralogy Soc., London). Each of these clay mineral
groups can be further classified lnto trloctahedral
and dioctahedral varieties, dependlng on the occupancy
of the octahedra in the respective sheet
arrangement(s). Some speciflc mlneral specles may
show catlon occupancles which are intermediate between
the two varleties. Nevertheless, the relatlve
arrangement of these tetrahedral and octahedral sheets
also defines the baslc mineral groups ln that an
assemblage which links one tetrahedral sheet wlth an
octahedral sheet is known as a 1:1 layer type mlneral.
An assemblage which llnks two tetrahedral sheets wlth
one octahedral sheet ls known as a 2:1 layer mineral.
Thls baslc classlflcatlon of mlneral specles, based
upon the crystallographlc relatlonshlps of speclfic
sub-units, is well-known by those skilled in the art
of clay mineralogy and forms a basis for description
of this invention.
Notwlthstandlng the crystallography of these
sub-units within clay minerals, thë alumino-silicate
derivatives of this invention also include minerals
which contaln a tetrahedral framework of oxygen atoms
surroundlng elther slllcon or alumlnium ln an extended
~ WO96/18577 2 2 0 1 9 2 5 PCT/~U7~J69~
three-dimensional network. For example, various
zeolites contain different combinations of linked
tetrahedral rings, double rings or polyhedral units,
but they are also amenable to provide an alumino-
silicate derivative (hereinafter referred to as "ASD")of the invention.
The production of an amorphous derivative,
termed "kaolin amorphous derivative" (KAD) from kaolin
clays which are 1:1 alumino-silicates, has been
10described in an earlier disclosure ~WO95/00441). This
specification describes the production of KADs from
the kaolin clay staring material by reaction of the
kaolin clay with an alkali metal halide MX where M is
alkali metal and X is halide.
15In this specification, the reference to MX
was the only example of a suitable reagent which could
convert the majority of the octahedrally co-ordinated
aluminium in the kaolin group mineral to tetrahedrally
co-ordinated aluminium. However, no reference was
made to any possible mechanism by which this
phenomenon occurred.
However, surprisingly it has now been
discovered that an alternative reagent such as a
highly basic solution in the form of MOH where M is an
alkali metal cation can provide a similar result
wherein the majority of the octahedrally co-ordinated
aluminium can be converted to tetrahedrally co-
ordinated aluminium.
Without wishing to be bound by theory, it is
hypothesised that a reagent which can achieve this
particular result may comprise a compound that
disassociates into cationic species and anionic
species such that hydroxyl ions are present in a
concentration which is in excess compared to the
concentration of hydrogen ions. In addition to this
feature or in the alternative, the compound causes to
be formed in the resulting solution due to interaction
WO96/18577 ~ 2 5 PCT/A~g~J~C69~ ~
with the alumino-silicate mineral, hydroxyl ions in
excess concentrations compared with the concentration
of hydrogen ions.
With the formation of excess hydroxyl ions,
it would seem that such excess hydroxyl ions result in
reconstruction of cation-oxygen bonding within the
starting material such that a stable, amorphous
material with the abovementioned desirable properties
may be formed.
Again, while not wishing to be bound by
theory, this chemical transformation or conversion may
be represented by the following example in which
kaolinite, with Al and Si in octahedral and
tetrahedral sites in the kaolinite structure,
respectively, is reacted with an alkali metal halide
where the cation is K~ or an ammonium ion in an aqueous
solution such that excess halide (e.g. X~) is readily
exchangeable with the available hydroxyl groups (OH)
in the kaolinite structure. This exchange results in
the formation of a highly basic solution with an
excess of OH- ions which can cause rearrangement of
octahedrally co-ordinated aluminiu=m through the action
of these OH- ions on hydrogen-bonded oxygen atoms. This
rearrangement of aluminium co-ordination results in
primarily tetrahedrally co-ordinated aluminium in this
resultant stable material. This therefore provides a
suitable explanation why MX was a suitable reagent in
the case of WO95/00441.
Alternatively, a highly basic solution can
be generated by the use of a reagent such as a
compound which disassociates into cationic and anionic
species. The anions, present in excess, may also
cause the rearrangement of octahedrally co-ordinated
aluminium to tetrahedrally co-ordinated aluminium
through their action on hydrogen-bonded oxygen atoms.
Other examples of this type of chemical transformation
of clays include the reaction of kaolinite or
~ WO96/1~577 2 ~ ~ ~ g 2 5 PCT/AU95/00699
montmorlllonite with a caustic reagent (e.g. MOH;
where M is a cation such as K+, or Nat or Li~) such
that rearrangement of octahedrally co-ordinated
aluminium to tetrahedrally co-ordinated aluminium
through their action on hydrogen-bonded oxygen atoms
occurs.
SUMMARY OF THE INVENTION
It therefore follows that the present
invention provides a process for the preparation of an
alumino-silicate derivative which involves reacting a
solid corresponding starting material with MOH where M
is alkali metal to provide an amorphous alumino-
silicate derivative (ASD).
The realisation that MOH may be utilised in
addition to MX to provide an ASD iS advantageous
because it has now been appreciated that MOH can be
utilised to provide an ASD from any corresponding
starting material. This is surprising because an
amorphous derivative can now be manufactured, for
example, from 2:1 clays which include montmorillonites
and other members of the smectite group. The
production of an amorphous derivative from these 2:1
clays is surprising insofar as the structure and
chemistry of these minerals is markedly different to
that of the 1:1 kaolin group minerals. A unit layer of
the clays in the kaolin group consists of one
octahedral sheet and one tetrahedral sheet so that
both sheets are exposed to the interlayer space, a
region which is accessible to reacting species.
However, a 2:1 clay mineral comprises one octahedral
sheet and two tetrahedral sheets. The octahedral
sheet, which contains octahedrally co-ordinated
aluminium, is sandwiched between the tetrahedral
sheets. The transformation of this octahedral sheet is
not readily predictable using metal halides to similar
reacting species since the interlayer space is
surrounded by tetrahedral sheets. It is also relevant
WO96/18577 r 2 2 ~ ~ ~ 2 ~ PCT/AU95/00699
to point out that the octahedral sheet in 2:1 clay
minerals would not be readily accessible to metal
halide. It would be assumed by those skilled in the
art that reacting species wlth 2:1 clay minerals would
provide different products to reaction products
described in W095/00441 for these reasons.
The reaction rate and preferred forms of
these alumino-silicate derivatives with desirable
properties will be dependent on the precise
temperature of reaction for a gIven period of time. In
general, a reaction temperature may be utilised which
is less than 200C for a period of time of one minute
to 100 hours. More preferably, the temperature is
between 50-200C and the reaction time is less than 24
hours. In concert with this rearrangement of co-
ordination of the aluminium atom(s), the presence of
an additional cation (from the reagent) causes the
disordered structure to be stabilised through
"attachment" of the cation to an exchange site so
formed by this rearrangement. During the overall
chemical transformation, loss of aluminium (as well as
minor amounts of silicon) from the alumino-silicate
structure to the highly basic solution may occur. The
preferred pH of this highly basic solution, during and
near the end of the reaction, is generally > 12,
although reaction to form the preferred ASD may occur
for solutions with pH > 7Ø
Examples of alumino-silicates which may be
modified by the process(es) of the invention include
montmorilIonite, kaolin, natural zeolite (e.g.
clinoliptolite/heulandite) as well as illite,
palygorskite and saponite. ASDs of the invention are
characterised by predominant tetrahedral Al+3 which has
been transformed from an initial octahedrally co-
ordinated state within the parent mineral (e.g. clay).In the case of e.g. montmorillonite clays, the
tetrahedral Al~3 has been transformed from a
wog6/l8sn 2 2 G 1 9 ~ 5 PcT/Augs/on699
octahedrally-coordinated Al+~ withln the parent mineral
(e.g. clay). Further elucidation of this ASD,
henceforth designated M-ASD, where M is the exchanged
cation obtained by the speciflc formation process, can
be obtained by conventional mineral characterisatlon
techniques which demonstrate the following
properties:-
(1) an "amorphous" nature (to X-ray
diffraction), i.e. without any apparent
long range order of the repeat units;
(2) an enhanced capacity to exchange
cations (compared with the original
starting mineral) from a solution;
(3) an increase in the available surface
area of the material (compared with the
original starting mineral) as measured
by the conventional BET isotherm;
(4) an enhanced capacity (compared with the
original starting mineral) to adsorb
anionic species or complex polyanions
from solution; and/or
(5) an enhanced capacity (compared with
original starting mineral) to absorb
oil and/or organic molecules.
In relation to propérty (2), this may be
exemplified by the ASDs of the invention having a
cation exchange capacity of 20-900 milli-equivalents
per 100 g as measured by exchange of ammonium or metal
cations from an aqueous solution. Most preferably the
cation exchange capacity as measured by exchange of
ammonium is between about 300-450 milli-equivalents
per 100 g.
In relation to property (3), this may be
exemplified by the ASDs of the invention having a
surface area less than 400 m'/g~' as measured by the BET
isotherm which is higher than the clay mineral
starting material. Most preferably the BET surface
WO96/18577 2 2 ~ 1 9 2 5 PCTIAU95/00699 ~
area is between 25 m-/g~l and 200 m~/g~~.
Properties (4) and (5) are demonstrated
hereinafter in Examples 15 and 16. In these Examples,
adorption of phosphate ions on the M-ASD may be
increased by factors of greater 2.5 times that in
solution. This property may be applied to adsorption
of many other significant anionic species.
Additionally, absorption of oil by an M-ASD so formed
may be at least a factor of two highr than that of the
starting alumino-silicate mineral.
One form of the ASD of the invention has the
chemical composition:-
MpAl~lSi~O~(OH)sXI-uH,O
where M is an ammonium cation or exchangeable metal
cation, X is a halide, 0.5 < p c 2.0, 1.0 < q ~ 2.2,
4.5 < r < 8.0, 1.0 < s < 3.0, 0.0 < t < 1.0 and 0.0 <
u < 3Ø In one specific form, the ASD may contain
the element potassium, such that M=K.
ASDs having the abovementioned chemical
composition may be prepared by the reaction of the
alumino-silicate starting material, such as clay
mineral or zeolite, with MOH and MX in combination.
In an especially preferred form of the
invention, ASDS have the chemical composition:-
MpAlqSi~Or(OH)s-uH~O
wherein M is an ammonium cation or exchangeable metal
cation, 0.5 < p < 2.0, 1.0 < q < 2.2, 4.5 < r < 8.0,
1.0 < s < 3.0 and 0.0 < u < 3.0
ASDs having the above described chemical
composition may be prepared by a process wherein the
initial starting alumino-silicate, such as a clay
mineral, is reacted with MOH alone.
In the ASD referred to above, it is possible
to exchange, at least partly, the alkali metal cation
with any cation which is stable in aqueous solution.
Such exchange cations include other alkali metal
cations, alkaline earth cations, transition metal
~ WO96/18577 2 2 G ~ g ~ 5 PCT/AU95i`~63~
cations, lanthanlde and actinide cations, heavy metal
cations and ammonium. While exchange does not proceed
to completion for all cations, there are many
transition metal cations (e.g. Mn2~, Cr'+, Co't, Ni2t,
Cu2~, Zn2+, Ag~), lanthanide cations (e.g. La~+, Nd~)
and heavy metal cations (e.g. Pb2', Cd2+, Hg2~) which
do. For some cations exchange is complete after three
hours at room temperature (e.g. Pb'~, Cu-t, NH~+, Na t ~
Cat2, K~, Mg~2, L1 t ), while others require longer times
and higher temperatures.
Such cation exchange essentially preserves
the XRD-amorphous character of the unexchanged ASD.
However, the specific surface of the exchanged
materials, while still higher than that of kaolin,
does increase or decrease depending on the exchange
cation.
For example, in the case of exchange of Cut'
from an aqueous solution, a new mat:erial, termed Cu-
ASD, is formed and which, for example, shows a high
surface area as measured by the conventional BET
isotherm. To differentiate, in generic formulae,
between new ASD materials formed directly via the
transformation of a clay or other alumino-silicate (as
in Examples 1 to 8 below) and those ASD materials
formed by direct cation exchange with the directly
derived ASD, the following terminology is utilised ln
this document:
M-ASD denotes material directly formed
via the general processes described in
Examples 1 to 8.
MC-ASD denotes material subsequently
formed via a cation exchange with M-ASD
material. Descriptions of this type of
- material, and the methods used to
obtain same, are given in Examples 8,
12 and 13.
Clearly partially formed ASDs in which two
WO96/18577 ; ~ 2 ~ ~ ~ 2 ~ PCT/AU95/00699 -
1 0
cations occupy sites or in which multiple cations are
exchanged via a series of partial reactions are
possible forms of this new material.
The term "ASD" as used hereinafter only
includes within its scope alumino-silicate
derivatives.
In the process, ratios of reactants that may
be employed vary widely, as described hereinafter.
The primary crystallographic methods to
define ASD material are powder X-ray diffraction (XRD)
and solid-state MAS (magic angle spinnlng) NMR
(nuclear magnetic resonance) spectroscopy. In the
case of powder XRD, the formation of M-ASD as a
primary component of the reaction is denoted by a loss
of sharp diffraction peaks corresponding to the
original starting mineral (e.g. Ca-montmorillonite)
and a corresponding increase in intensity of a broad
"hump" between 22 and 32 2~ using CuK~ radiation
(see, for example, FIG. 2c). With certain processing
conditions, byproducts such as sodalite or
kaliophillite may form (e.g. as in FIGS. 1b or 2b),
although the predominant phase present is an alumino-
silicate derivative. An example of typical XRD
patterns, for the starting montmorillonite (STx-1) and
for the respective M-ASD materials formed by two
different processes (Examples 1 and 3 given below),
are given in FIGS. 1a to 1c and FIGS. 2a to 2c,
respectively. In the case of solid-state NMR
spectroscopy, the MAS NMR signal for -'Al nuclei in M-
ASD material gives a dominant peak at ~58 ppm (FWHM ~16 ppm) which is due to tetrahedral coordination of
aluminium (as shown in FIG. 3). As is known by those
skilled in the art, montmorillonites such as STx-1 and
SWy-1 contain octahedrally-coordinated aluminium ions.
This crystallographic feature can be demonstrated by a
number of methods including recalculation of chemical
analyses as mineral formulae and assignment of
~ WO96/18577 ~ 2 ~ ~ 9 2 ~ PCTIA~9~1?~C9~
, 1
aluminium atoms to the octahedral sites in the
montmorillonite structure.
The above two primary crystallographic
techniques define the atomic arrangements of the
critical elements in this new material termed alumino-
silicate derivative and form the basis of a family of
mineral derivatives which have been obtained by the
chemical reaction of aluminium-bearing minerals such
as clays and zeolites. The essential crystallographic
features are:-
the transformation of long-range order
to an "amorphous" structure showing a
broad X-ray diffraction "hump", or
peak, between 22 and 32 2~ using CuK~
radiation; and
the presence of primarily tetrahedrally
co-ordinated aluminium.
Chemical analysis can be effected by a
number of means, but in this disclosure, the use of an
electron microprobe to quantify the amounts of
elements with atomic number greater than 11 (i.e. Na
or higher) is illustrated. The presence of oxygen is
determined according to general principles for
microanalysis of minerals known to those skilled in
the art. Depending on the nature of the reactant, an
exchangeable cation, such as Na or K, will be present
in the alumino-silicate derivative. Typical examples
of the chemical compositions of alumino-silicate
derivatives formed by reaction of caustic potassium
hydroxide with montmorillonite (formed by the method
given in Examples 1 & 2) are given in Table 1. These
chemical analyses show low total values which implies
the presence of water of hydration - an expectation
for material formed by these processes. In addition,
typical examples of the chemical compositlons of
alumino-silicate derivatives formed by reaction of
caustic potassium hydroxide or sodium hydroxide with
WO96/18577 2 ~ ~ ~ 9 2 5 PCT/AU95/00699 ~
12
kaolin (Examples 5 and 6) are given in Table 2.
A preferred formula for this type of
derivative is:-
MrAlqSi,Or(OH)sX~-uH,O
where M is a cation exchanged from the reactant (e.g.
Nat, Li r or Kr), X is an anion derived from the
reactant (e.g. OH or F- or Cl, etc.). The abundance
of these elements in M-ASD with respect to each other
include, but are not limited to, the following values
for the atomic proportions:-
0.2 < p < 2.0, 0.5 < q < 2.5, 4.0
< r < 12, 0.5 < s < 4.0, 0.0 < t <
1.0 and 0.0 < u < 6Ø
Bulk physical properties for these alumino-
silicate derivatives, such as BET surface area, cationexchange capacity (CEC), oil absorption, degree of
basicity etc., are influenced by the nature of the
processing used to form the ASD. In another aspect of
the invention, this relationship shows that specific
ASDs may be more suited to one application (e.g.
removal of trace amounts of divalent cation) than
another (e.g. absorption of gases or oils) but that in
relative comparison to the clay mineral used to form
the ASDs, each ASD has properties more suited to the
application than the clay.
For example, it is possible to develop a
wide range of CEC values and surface area values for
ASDs formed from kaolinite depending on the conditions
used for processing. As described hereinafter, a high
concentration of hydroxyl ions present during the
reaction to form an ASD can be obtained by a variety
of reactants and reaction conditions. Accordingly,
FIG. 5 shows a plot of CEC values obtained by the
method give for NH~ exchange in Example 10 versus
. 35 surface area values for over 150 separate reactions
involving clay minerals and a reactant such as a metal
hydroxide which may be in combination with metal
~ WO96/18577 2 2 ~ ~ 9 2 5 PCT/AU95/00699
13
halide. Data for conditions under which the
reaction(s) do not go to completion (i.e. primarily
clay mineral in the product) or under which other
phases may be formed as secondary components (e.g.
kaliophillite or zeolite K-F) are also included in
FIG. 5. This plot designates approximately the extent
of the preferred properties which provide for a
predominance of M-ASD in the final product.
In W095/00441, the preferred form of the ASD
is termed kaolin amorphous derivative. However, other
kaolin amorphous derivatives can be formed by the use
of reactants such as alkali hydroxides or combinations
of alkali halides and alkali hydroxides. In these
instances, the preferred features may extend across a
broad range of values. The final product may include
different by-products to that disclosed in WO95/00441.
These by-products, such as kaliophilite and zeolite K-
F, occur in relatively low proportions with the ASD
and do not significantly affect the preferred features
of the ASD so formed.
The as-formed ASD, for example, via reaction
with KOH, will contain a high percentage of K+ ions on
the exchangeable sites of this new material. For
example, Table 1 indicates ~10 wt% K70 in the case of
montmorillonite-derived M-ASD. In Table 2, the amount
of K2O ranges between ~13 wt% and ~20 wt% for kaolin-
derived M-ASD using the method outlined in Example 6.
As shown in Examples 9 and 10, cations such as Cu+7,
Li+ or NH~+ will readily exchange wlth the Kt or Na~ of
these exchangeable sites in an M-ASD to form a Cu-
rich, Li-rich or NH~+ -rich derivative, respectively.
In this instance, the Cu-ASD shows a high value for
available surface area (see Table 3) which, with
- suitable pre-treatment, enables use of this material,
for example, as a catalyst for dehydrogenation
reactions of organic compounds. Similarly, ammonium-
exchanged ASD, or NH~-ASD, has significant potential
WO 96/18S77 2 ~ ~ ~ 9 ~ 5 PCrlAU9~ C9~ ~
1 4
for use as a fertiliser or nutrient-provider in the
agricultural, horticultural and feedstock industries.
Alternatively, M-ASD (where M=K or Na) may also be
used in the agricultural or horticultural industries
to exchange ammonium ion onto a stable substrate (e.g.
to form NH~-ASD) for later easy removal, or subsequent
use.
Other uses of the ammonium-exchange capacity
of ASDs such as extraction of ammonium ion from
industrial effluent or from waste products are readily
envisaged by those skilled in the art.
A general schematic showing the conditions
of OH- concentration (obtained by a preferred method
noted above) and temperature for the reaction is given
in FIG. 6. In this schematic, the transition from one
form of product (e.g. ASD) to another (e.g. zeolite K-
F) may not be marked by sharp boundaries but the
transition area implies a change in the relative
proportions of product present. As noted in the
schematic, there ls a broad region of processing
conditions in which predominantly ASDs form.
The invention therefore in a further aspect
includes ASDs falling within the shaded area of FIG.
6.
Within this broad formation region, ASDs
with specific combinations of the preferred properties
may be formed (refer FIG. 5).
As noted above, M-ASD may be produced by a
number of similar processes which involve the
following generic modifications to the parent mineral
structure:-
attack by the reactant anion or cation
(e.g. OH-, F-, Cl- or K', Na+ or Li~) so
that a proportion of the Al-O and/or
Si-O bonds within the mineral structure
are weakened or broken;
loss of long-range periodicity
~ WO96118577 2 2 ~ ~ 9 ~ 5 PCT/A~-951~99
(sometimes referred to as
"crystallinity") in the mineral
structure so that the derivative
material resembles the original
structure only as a disordered (short-
range ordered) array of sub-units (e.g.
SiO~ tetrahedra; AlO, tetrahedra and
newly-formed exchange sites' which may
or may not contain a cation);
loss of a proportion of aluminium atoms
(and/or a lesser amount of silicon
atoms) from the original parent
mineral(s)
addition of the reactant cation (e.g.
Nar, Kt or Li') as well as a smaller
proportion of the reactant anion to the
derivative material structure.
The followlng generic modifications to bulk
physical properties also occur with progress of any of
these processes for the formation of an M-ASD:-
the reaction proceeds with an increase
in the viscosity of the reaction
mixture to a certain maximum level -
determined by the relative proportions
and nature of the initial reactants;
an increase in the "dispersability" of
individual particles formed during the
reaction process - this is assumed due,
in part, to a reduction in size of the
individual alumino-silicate particles -
compared with the dispersability and/or
- size of the original starting mineral
(e.g. clay or zeolite);
an increase in the bulk volume occupied
by a dried powder (i.e. a fluffy-' or
less-compact powder) compared with the
volume occupied by the original
W096/l8577 2 2 ~ 1 ~ 2 ~ PCT/AU95/00699 ~
16
starting mineral (e.g. clay or
zeolite).
Given the above generic modifications to the
original mineral species, and not wishing to be bound
by theory, the following classes of reaction
conditions are shown to for~ this alumino-silicate
derivative (M-ASD):-
1. Clay plus caustic reaction (e.g. kaolin+ KOH or montmorillonlte + NaOH);
2. Clay plus metal halide plus caustic
(e.g. kaolin ~ KCl + KOH or
montmorillonite + KCl + KOH);
3. Zeolite plus caustic (e.g. heulandite/
clinoptilolite + NaOH).
A summary of these classes of reactions,
using various combinations of reactant concentrations,
along with some product properties, are given in Table
4. In all these classes of reactions, water is added
to the reaction mix in various amounts. These
classes of reactions are listed in order to
demonstrate the variety of methods which can be used
to arrive at the formation of alumino-silicate
derivatives with the basic properties noted above.
Specific examples of the formation of
alumlno-silicate derivatives are given below.
EXAMPLES
Exam~le 1: Forma t i on o f M-ASD f rom Ca -
mon tmori l l oni te cl ay
20 g of Source Clay montmorillonite from
Texas (Sample No. STx-1; van Olphen and Fripiat, 1979,
Data handbook for clay materials and other non-
metallic minerals, Pergamon Press, Oxford, 342pp.) is
thoroughly mixed with 30 g of potassium hydroxide
(KOH) and 40 mls of distilled water in a beaker and
then heated at 80C for three hours. The resulting
slurry is washed with water until any excess potassium
hydroxide is removed. The powder is then dried and
~ 2 0 ~ 9 2 5
WO 96/18577 PCT/AU9~ C9
1 7
subjected to a series of characterisatlon tests which
include powder X-ray diffraction (FIGS. 1c and 2c),
solid-state MAS NMR ( FIG. 3), electron microprobe
analysis (Table 1, column 1), ammonium exchange
capacity, Cu+- exchange (Table 4), and BET surface area
measurements (Table 4). Data from these
characterisation technlques indicate that the material
has an atomic arrangement (i.e. crystallographic
features) as defined above). In general, XRD analysis
indicates that with this type of reaction the amount
of byproducts formed is minimal (sometimes negligible)
and that ~ 90% of the product is comprised of M-ASD
material.
ExamPle 2: Formation of M-ASD via caustic reaction
wi th Na -mon tmori l l on i t e cl ay
g of Source Clay montmorillonite from
Wyoming (Sample No. SWy-1; van Olphen and Fripiat,
1979, Data handbook for clay materials and other non-
metallic minerals, Pergamon Press, Oxford, 342pp.) is
thoroughly mixed with 30 g of potassium hydroxide
(KOH) and 40 mls of distilled water in a beaker and
heated at 80C for three hours. The resulting slurry
is washed with water until any excess potassium
hydroxide is removed. The powder is then dried and
subjected to a series of characterisation tests which
include powder X-ray diffraction, solid-state MAS NMR
(FIG. 4), electron microprobe analysis (Table 1,
column 2), ammonium cation exchange capacity (Table
4), Cu+2 exchange (Table 4), and BET surface area
measurements (Table 4). Data from these
characterisation techniques indicate that the material
has an atomic arrangement (i.e. crystallographi
features) as defined above. In general, XRD analysis
indicates that, with this type of reaction, the amount
of byproducts formed is minimal (sometimes negligible)
and that ~ 90% of the product is comprised of M-ASD
material.
WO96118577 ~ 2 ~ 2 ~ PCT/AU95100699
18
In both samples of montmorillonite clay
noted above, impurity minerals such as quartz,
carbonates and poorly-defined silica minerals are
present. ~In all cases, the presence of minor amounts
5 of impurity minerals does not significantly affect the
nature of these reactions and/or the formation of
alumino-sillcate derivatives.
ExamPle 3: Formation of M--ASD from Ca-
montmorillonite using caustic NaOH
20 g of Source Clay montmorillonite from
Texas (Sample No. STx-1; van Olphen and Fripiat, 1979,
Data handbook for clay materials and other non-
metallic minerals, Pergamon Press, Oxford, 342pp.) is
thoroughly mixed with 60 g of sodium hydroxide (NaOH)
and 60 mls of distilled water in a beaker and heated
at 80C for three hours. The resulting slurry is
washed with water until any excess sodium hydroxide is
removed. The powder is then dried and subjected to a
series of characterisation tests which include powder
X-ray diffraction (FIGS. lb and 2b), ammonium exchange
capacity (Table 4), and sET surface area measurements
(Table 4). Data from these characterisation
techniques indicate that the material has an atomic
arrangement (i.e. crystallographi features) as defined
above. In general, XRD analysis shows that with this
type of reaction the amount of byproducts formed is
somewhat higher than in Examples 1 and 2 and that a
significant proportion of the byproduct is the mineral
sodalite. As shown below in Example 10, the removal
of impurity phases formed by this reaction, or similar
reactions, can be effected by washing the products
with an acid.
ExamPle 4: Formation of M-ASD via reaction of a
natural zeolite with caustic NaOH
A sample of natural zeolite which contains
two specific mineral species, clinoptilolite and
heulandite, has been obtained from an operating mine
22~ ~925
WO96/18577 PCT/AU95/00699
19
in Eastern Australia. Both clinoptilolite and
heulandite are Ca-Na-based alumino-silicates (e.g.
with chemical composition (Ca,Na2)[Al2Si7O~8]- 6H~O). In
this case, 5 g of natural zeolite (powdered to < 1 mm
size fraction), 5 g of NaOH and 20 mls of distilled
water are thoroughly mixed in a beaker and then heated
at 80C for three hours. The resulting slurry is
washed with water until any excess sodium hydroxide is
removed. The powder is then dried and subjected to a
series of characterisation tests which include powder
X-ray diffraction (FIG. 7), ammonium exchange capacity
(Table 4), Cu~2 exchange (Table 4) and BET surface area
measurements. Data from these characterisation
techniques indicate that the material has an atomlc
arrangement (i.e. crystallographic features) as
defined above.
ExamPle S: Formation of M-ASD via reaction of
kaol in wi th NaOH
g of kaolin supplied by Commercial
Minerals ("Micro-white kaolin") is thoroughly mixed
with 10 g of sodium hydroxide (NaOH) and 20 mls of
distilled water in a beaker and heated at 80C for
three hours. The resulting slurry is washed with
water until any excess sodium hydroxide is removed.
The powder is then dried and sub~ected to a series of
characterisation tests which include powder X ray
diffraction (FIG. 8b), ammonium exchange capacity, Cu~2
exchange (Table 4), and BET surface area measurements
(Table 4). Data from these characterisation
techniques indicate that the material has an atomic
arrangement (i.e. crystallographic features) as
defined above. In general, XRD analysis shows that
with this type of reaction the amount of byproducts
formed is somewhat higher than in Examples 1 and 2 and
that a significant proportion of the byproduct is the
mineral sodalite. As shown below in Example 12 (and
FIG. 14), the removal of impurity phases formed by
WO96/18577 ~ 2 ~ 1 ~ 2 ~ PCT/AU9S/0069~ -
this reaction, or similar reactions, can be effected
by washing the products with a dilute acid.
ExamPle 6: Formation of M-ASD via reaction of
kaol in wi th KOH
5 g of kaolin supplied by Commercial
Minerals ("Micro-white kaolin") is thoroughly mixed
with 26.88 g of potassium hydroxide (KOH) and 20 mls
of distilled water in a beaker and heated at 80C for
four hours. The resulting slurry is washed with water
until any excess potassium hydroxide is removed. The
powder is then dried and subjected to a series of
characterisation tests which include powder X-ray
diffraction (FIG. 8c), ammonium exchange capacity
(Table 4) and BET surface area measurements (Table 4).
FIG. 9 shows an -'Al solid state NMR signal for the M-
ASD so formed. Data from these characterisation
techniques indicate that the material has an atomic
arrangement (i.e. crystallographic features) as
defined above. In general, XRD analysis indicates
that, with this type of reaction, the amount of
byproducts formed is minimal (sometimes negligible)
and that ~ 90~ of the product is comprised of M-ASD
material.
As noted above, the formation of M-ASD via
reaction with KOH may occur over a range of
temperatures and/or concentrations of hydroxide. FIG.
10 plots the variation in desired properties of these
M-ASDs for reactions with kaolin at different
concentrations of KOH at different temperatures of
reaction. In FIG. 1OB, BET surface area values show a
gradual decrease with temperature of reaction (for
temperatures above and below the preferred temperature
of 80C) and with increased concentration of KOH.
Correspondingly, FIG. 10A shows that the relative CEC
values (for exchange of ammonium) for various M-ASDs
also gradually decreases with temperature of reaction
for temperatures above and below the preferred
~ WO96/18577 2 ~ 0 1 9 2 5 PCT/AU95100699
21
temperature of 80C. The change in CEC value for
increased KOH concentration is less marked under these
reaction conditlons. In addition, the relative
amounts of water used in the reaction process can be
varied depending on the concentration(s) of hydroxide.
Table 5 shows the attainment of similar CEC and SA
values for an M-ASD using two different ratios of
kaolin to KOH for two different "consistencies" of
solution (i.e. determined by the amount of water
added) under identical temperature and reaction time
conditions.
Example 7: Formation of M-ASD via reaction of
kaol in wi th KOH and KCl
g of kaolin supplied by Commercial
Minerals ("Micro-white kaolin") is thoroughly mixed
with 4.48 g of KOH, 11.92 g of KCl and 20 mls of water
in a beaker and heated to 80C in a beaker for 16
hours. The resulting slurry is washed with water
until any excess potassium hydroxide and potassium
chloride is removed. The powder is then dried and
sub~ected to a series of characteri,sation tests which
include powder XRD (FIG. 8D), solid-state "Al NMR
(FIG. 11), ammonium exchange capacity and BET surface
area measurements (Table 4). Data from the
measurements indicate that the material has an atomic
arrangement (i.e. crystallographic features) as
defined above. In general, XRD analysis indicates
that, with thls type of reaction, the amount of by-
products formed is minimal and that > 90% of the
product is comprised of M-ASD material. In this case,
the BET surface area and CEC (NH~t) values for the M-
ASD so formed are 28 m-/g and 356 meq/100 g,
respectively. An indication of the means by which
- specific desired properties can be achieved with these
M-ASDs is given in FIG. 12 which plots both CEC and
BET surface area values for a range of M-ASDs produced
by this general reaction class for a limited set of
WO96118577 2 2 0 ~ ~ ~ g PCT/AUg5/00699 ~
22
KOH/KCl concentrations. In FIG. 12A, the CEC values
lncrease with increase in KCl concentration under the
same reaction conditions (time and temperature) and in
FIG. 12B, there is a minor but measurable decrease in
surface area with increased KCl concentration under
the same reaction conditions.
ExamPle 8: ~ormation of M-ASD via reaction of
kaolin with LiOH
5 g of kaolin supplied by Commercial
Minerals ("Micro-white kaolin") is thoroughly mixed
with 20 g of LiOH and 20 mls of water in a beaker and
heated at 80C for 16 hours. The resulting slurry is
washed with water until excess LiOH is removed. The
powder is then dried and subjected to a series of
characterisation tests which include powder XRD (FIG.
8E), ammonium exchange capacity and BET surface area
measurements (Table 4). Data from the measurements
indicate that the material has an atomic arrangement
(i.e. crystallographic features) as defined above. In
this case, the BET surface area and CEC (NH~t) values
for the M-ASD so formed are 31 m-/g and 79 meq/100 g,
respectively.
ExamPle 9: Uptake of Cu~- from an aqueous solution
using M-ASD and formation of M-ASD
75 mg of M-ASD, obtained by the general
process defined in Example 2, is placed in a 0.1 M
NaNO3 solution containing 200 ppm Cu+' at pH ~5.6 and
shaken overnight for a period of approximately 16
hours and held at room temperature (~25C) during this
time. The sample was centri~uged and an aliquot of
the supernatant solution was analysed for remaining
Cu~-. In this experiment, the concentration of Cut-
remaining in the aqueous solution is 52.8 ~g/ml (or
52.8 ppm). This result indicates that, in this
specific case, the M-ASD produced by the process
described in Example 2 will remove 74% of the Cu~'
cations in a 200 ppm Cul' solution in a period of
~ 2 0 1 9 2 5
WO96/18577 PCT/AU95/00699
23
approximately 16 hours at room temperature. This
example presents one method used for assessing the
relative capacity of these new materials for exchange
of Cu+2 cations.
Table 4 lists, for various classes of
processing conditions used in these reactlons, the
proportion of Cut' removed from a standard solution by
a defined amount of M-ASD under the above standard
conditions. Data on preferred properties for a range
of starting clays or zeolites are given in Table 6.
This Table provides data on CEC (NH,'), surface area,
Cu~2 exchange and other properties for comparison with
slmilar data on ASDs in other Tables. Values for
remaining Cut- which are less than 100 ~g/ml are
reasonably considered commercially-viable materials
for the exchange of divalent cations. In general,
this tabulation of Cut' exchange capacity is considered
a guide to the relative exchange capacity for each M-
ASD for a wide range of cations including Al+;, Mgt-,
Ca+2, Fe+2, Cr+3, Mnt', Ni+', Co~', Ag+, Zn'2, Srt', Nd'-;,
Hg+2, Cd+2, Pbt' and UO t ~
The material formed upon exchange with Cu+2,
designated Cu-ASD, is itself a new material which has
similar structural properties to the generically-
designated M-ASD except for the replacement of, for
example, K (and/or Li and/or Na) on the exchange site
with Cu. This material has high surface area values,
in some cases, considerably higher than that recorded
for the original M-ASD material before Cu+2 exchange.
A summary of BET surface area values for selected
copper-exchanged ASD materials is given in Table 3.
- Example 10: Exchange of N~J+ from an aqueous
solution using M-ASD and formation of
- M,-ASD. Determination of CEC for
various cations (e.g. Nat and LII).
0.5 g of M-ASD formed by modification of
clay minerals using the methods noted above is placed
WO96/18S77 2 2 0 ~ 9 2 5 PCT/AU9~/00635 ~
24
in a centrifuge bottle and 30 ml of 1 M NH~Cl ls added
and allowed to equilibrate overnight. The sample is
centrifuged and the supernatant is removed. A fresh
amount of~30 ml 1 M NH.Cl is added and the sample is
shaken for 2 hours. This procedure of centrifuging,
removal of supernatant and addition of 30 ml 1 M NH,Cl
is repeated three times. Any entrained NH~Cl is
removed by washing with ethanol. At this point, the
remaining material is an exchanged ASD, such as NH~ASD.
To determine a CEC value for the specific M-ASD
material, a further 30 ml of 1 M NH~Cl is added to the
washed sample and allowed to equilibrate overnight.
The supernatant is then collected after centrifugation
and a further 30 ml of 1 M KCl solution is~ added and
shaken for two hours. This procedure of centrifuging,
removal of supernatant and addition of KCl is repeated
three times. Finally, distilled water ls added to
make up 100 ml of solution and the amount of NH~t
present is measured by ion-selective electrode. This
procedure follows that given by Miller et al., 1975,
Soil Sci. Amer. Proc. 39 372-373, for the
determination of cation exchange capacity and similar
procedures are used for CEC determination for other
cations such as Na and Li+. All CEC values tabulated
for a range of M-ASDs have been determined by this
basic procedure. Table 7 gives the CEC values for
exchange of NH~, Na+ and Li~ for a range of M-ASDs
made by the methods outlined above.
ExamPle 11: Improvement in the CUt- exchange
capacity for M-ASD by pre-treatment
Samples of 2 g of M-ASD formed by the
generic process (clay + reactant) using kaolin are
placed in alumina crucibles, heated to different
temperatures (from 105C up to 600C in 50C
intervals) for periods of two hours. Each sample is
cooled to room temperature and then subjected to a Cur'
exchange experiment as described in Example 9 above.
~ WO96/18577 2 2 0 1 9 2 5 PCT/AU9~lC~69~
The relative exchange of Cu~' compared with untreated
M-ASD (25C) is given in FIG. 13. In this figure, the
amount of Cu+- exchanged from solution is presented for
a number of different temperature treatments between
50C and 250C. As is evident from FIG. 13, an
increase in the Cu t_ exchange capacity has occurred for
those samples of M-ASD heated to temperatures between
100C and 200C. In the specific cases shown in FIG.
13, increases in the exchange capacity by about 10%
relatlve occur through this pre-treatment.
ExamPle 12: Removal of impurity byproducts by final
t rea tmen t wi th d i 1 u t e a ci d
As noted previously, in cases where clay or
zeolite is reacted with NaOH or, alternatively, when
clay is reacted with a high concentration o~ KOH,
significant levels (> 5% relative) of impurity phases
occur in the product. In this example, samples
prepared by reacting kaolin with a caustic agent
(Examples 3 and 5 above) have been subsequently
treated to remove the impurity phases such as
sodalite. 5 g of reaction product are mixed with 50
ml of 0.25 M HCl in centrifuge tubes, shaken for a
period of approximately two hours and then washed with
distilled water. XRD of the dried powders after this
treatment show that the impurity phases have been
removed and, if present, constitute < 5% relative of
the total product phases. FIG. 14 shows XRD traces
for an M-ASD prepared by the method given in Example 5
above before and after treatment with acid,
respectively. XRD peaks corresponding to impurity
phases present in the M-ASD sample are designated by
an asterisk (*) in FIG. 14.
Example 13: Conversion of KAD to Na-ASD via
exchange reaction
Two samples of KAD and derived from two
different kaolins (Commercial Minerals "Micro-white"
KCM4, Table 4; and Comalco Minerals kaolin from Weipa:
WO96/18577 ~ 9 ~ 5 PCT/AU95/00699 -
26
KWSD1) and produced by the method outlined in
WO98/00441 were selected for this experiment. In the
former case, sample number KCM4, 2 g of material were
equilibrated with 50 ml of 1 M NaOH solutlon. In the
latter case, sample number KWSD1, 10 g of material
were equilibrated with 50 ml of 1 M NaOH solution. In
each case, the supernatant was discarded and
additional amounts of fresh 1 M NaOH were added three
times to ensure complete equilibrium exchange at the
appropriate concentration. The samples were finally
washed with deionised water, dried to a powder and
analysed for bulk chemical composition (electron
microprobe analysis), Cu+' cation exchange (via method
outlined in Example 9, above) and crystal structure
(via XRD).
Table 8 summarises the data collected on
both the original KAD materials (KCM4 and KSWD1) and
the Me-ASD materials -designated as KCM4-Na and KSWD1-
Na, respectively. Electron microprobe analyses allow
the calculation of cation exchange capacities (CEC's)
using the K~O and Na~O contents and assuming that all
the available alkali ion occupies exchangeable sites.
Comparison of the values shown in Table 8 for the Na-
ASD with respect to the KAD suggests that a small
percentage of the analysed potassium may be present as
an impurity phase. Nevertheless, the high values
calculated for CEC are indicative of materials which
have great significance for commercial use as cation
exchangers. Experimentally-determined values for CEC
(using the method of Example 10 above) are also given
for these samples in Table 8. In addition, the amount
of Cut' removed from solution is higher in the case of
the Na-ASD material - by approximately 10-12% relative
to the K-ASD material. This improvement in Cut2
exchange is presumably due to the lower affinity of Na
for the exchange site in the alumino-silicate
derivative. Powder XRD patterns of the KAD and the
~ WO96/18577 2 2 0 1 9 2 S PCT/AU951W699
Na-ASD (FIG. 15) show that the essential short-range
ordered structure remains in the alumino-silicate
derivative and, colncidentally, that minor levels of
impurity phases (e.g. containing F- and/or Kt; see
electron microprobe analyses in Table 8) are also
removed from the material.
ExamPle 14: Uptake of metal cations in low
concentrations from solutions
30 mls of 0.005 N solution of a given
element (typical examples are given in Table 9) is
mixed with 0.075 g of M-ASD in a centrifuge tube. The
suspension is allowed to equilibrate for 16 hours on a
rotary shaker after which the suspension is
centrifuged and the supernatant is analysed for
remaining concentration of metal cation. The amount
of element taken up by the M-ASD is calculated from
the difference in concentrations of the given element
before and after equilibrium. In Table 9 this uptake
is expressed as milli-equivalents per 100 g of
material. Table 9 gives data for the following
elements at 0.005 N: Cu, Ni, Zn, Ag, Co, La, Cd, V,
Hg, Fe, and Mn. Data for 0.01 N Ca and Li are also
given in this Table.
ExamPle 15: Uptahe of phosphate ions from solution
1.5 g of M-ASD was shaken with 30 ml of 0.01
M CaCl2 solution containing Ca (H,PO~), at an initial P
concentration of 200 ppm. The samples were allowed to
equilibrate on a shaker for 17 hours. After
equilibration, the samples were centrifuged and
supernatant was analysed for residual P by ICP. The
amount of P adsorbed was calculated by subtracting the
residual concentration from initial concentration.
This procedure of P adsorption was also used for Ca
(HPO~) at 10 ppm concentration in 0.01M CaCl,. The
amount of P adsorbed for selected samples is given in
Table 10. Similar experiments on P uptake from
solutions with lower initial concentrations on P are
WO96/18577 2 2 ~ ~ g 2 ~ PCT/AU95/00699 ~
28
shown in FIG. 16. The amount of P~ adsorbed by M-ASD
depends on the initial starting concentrations.
Example 16: Absorption of oil
4 drops of boiled linseed oil from a burette
were added onto 5 g of sample ln the centre of a glass
plate. While adding the oil, four drops at a time,
the sample was kneaded using a pallet knife. Addition
of oil and kneading procedure was carried out until
the sample turned into a hard, putty-like lump. After
this point, oil was added drop by drop. After each
addition of oil, the mass was kneaded and the point at
which one drop created a sample capable of being wound
around the pallet knife in a spiral was noted down.
If this was not possible, the point just before the
sample became soft with one additional drop of boiled
linseed oil was considered as the end point. The oil
added to the sample until end point was considered as
absorbed. The data expressed as amount absorbed per
100 g of sample is given in Table 11.
~ WO96tl8577 2 2 ~ ~ 9 2 -5 PCT/AU95/00699
29
TABLES
TABLE 1 Averaged microprobe analyses for derivatives
of montmorillonites.
Element wt ~ STx-1 Derivative SWy-1 Derivative
oxide
Na.O 0.03 0.26
K~O 10.47 7.69
MgO 5.07 3.15
CaO 2.47 1.26
Al,03 20.37 21.43
SiO, 49.72 49.15
Fe,O~ 0.84 3.75
Total 88.94 86.43
TABLE 2 Averaged microprobe analyses for derivatives
of kaolinite
Element wt KCM-16 SC3-7 SC0.5-9 KCM-17
% oxide
Na.O 13.06 0.11 0.13 0.58
K~O 0.51 18.54 19.78 13.49
Al,O~ 32.90 33.13 29.78 32.09
SiO~ 42.25 44.87 39.86 42.86
Fe~O3 0.89 0.85 0.75 0.97
Total 89.61 97.5 90.28 89.99
TABLE 3 Surface area for Cu-ASD materials
Sample No. Surface area m~/g
Cu-KCM-3C 114
Cu-KCM-17 130
Cu-KCM-18 155
Cu-KCM-19 146
Cu-KCM-21 211
WO96/18577 2 2 O ~ ~ 2 ~ PCT/AU95100699 --
~n
E ~ ~ N ~C ~ CO C,~ N OD C')
C~
*
:~'~I`~CCCCCC
O z cr ~ o c~ o ~ ID (S~ N r` O
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V LL~ --
~)
O ~ YY~ZZyy_y
U~
-, E s
~ ..
~, F ~oo ~ ~ oo
+ I + + +
O ~ ~_ z ~ y Y o ~ Y o o o
Y Y Y Y
u~
u~
O ; O X ~ X O ~ ~ ~ L~ ~ ' '
~- ~ " o F C`~
~ ~ Z LU LU LU LU LU LU LU LU
E- L
SUBSTITUTE SH EET (RULE 26)
~ WO96/18577 2 ~ ~ 1 g 2 5 PCT/AU95/00699
31
TABLE 5 Properties of M-ASD obtained by varying the
conditions of the process
Kaolin/ 20 mls of H2O 10 mls of H2O
KOH
ratio
CEC SA Consistency CEC SA Consistency
(NH4 ' ) (m2/g) (NH4 ~)(m2/g)
3.6 463 21 suspension 185 125 paste
5.4 184 124 paste 208 44 paste
TABLE 6 Properties of starting materials used in
various Examples
CEC SA Cu~Z * Oil
(meq/100 g (m'/g) Absorption
NHJ) (ml/100g)
KGa-l Kaolin ~10 6 ~190 32
KCM Kaolin 15 24 ~190 58
STx-1 Ca-Mont 60 84 164 60
SWy-1 Na-Mont 96 32 148 44
Zeolite l 98 ~15 140 24
TABLE 7 CEC of a range of samples for 1 molar
strength of monovalent cati.ons
CEC (meq/100 g)
Sample No. NH4 Wa Li
SC3-7 240 510 721
(Example 7)
SC0.5-9 317 571 888
(Example 6)
STXVC-1A 131 272 nd
(Example 1)
STXVC-2A 142 nd 414
(Example 1)
SUBSTITUTE SHEET (RULE 26)
WO96/18577 ~ 9 2 ~ PCT/AU95/0~699
32
TABLE 8 Averaged microprobe analyses for original K-
ASD and its exchanged derivative Na-ASD
Element wt KWSD1-K KWSD1-Na KCM4-K KCM4-Na
oxide
F 5.65 - 4.87 0.20
Na7O 0.85 7.92 0.87 10.00
K70 19.78 5.34 21.10 2.64
Al,O~ 28.33 28.634 26.47 28.15
SiO7 42.12 46.46 40.97 47.42
Fe7O~ 2.09 2.21 1.02 1.52
Total 98.47 90.57 95.3 89.93
CEC (cale) 420 369 447 378
Cu* 63 46 51 36
CEC(NH~t) 224 216 241 241
~ WO 96/18577 2 2 0 ~ 9 2 5 PCT/AI,-951~û639
~ ~ ~D C C
-
o C U~ o
~ -- ~ O ~:r
U~
v
O ~ ~ ~-- o
E C~ -- _ _ _
a
~ ~D O O U~
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h E
V~ C -- ~
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Z ~o
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c~ a t_ "
'~ o ~ X :~
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WO96/18577 2 2 ~ ~ 9 2 ~ PCT/AU95~699 ~
34
ABLE 10 The phosphate sorption capacity of selected
samples
Sample No. P adsorbed on P adsorbed on
solid from 200 solid from 10
ppm P as H~PO~- ppm P as HPOJ--
( ~lg/g ) ( llg/g )
SC3-5 1330 38
SC3-7 450 31
SC0.5-9 2796 85
ABLE 11 Oll absorptlon capacity for selected M-ASD
materials
Sample Number Oil Absorption
Capacity (ml/100 g)
SC3-7 (Kaolin + KOH + KCl) ~ 90
SC0.5-9 (Kaolin + KOH) 99
SC0.5-13 (Kaolin + KOH + KCl) 119
SC0.5-14 (Kaolin + KOH) 103
220 ~925
WO96/18577 PCT/AU95/00699
LEGENDS
TABLE 4
nd not determined
* Cu concentration in ppm remaining in solution
from an initial value of 20 ppm. See Example 9.
TABLE 7
nd not determined
TABLE 8
* Cu concentration in ppm remaining in solution
from an initial value of 20 ppm. See Example 9.
TABLE 9
nd not determined
FIG. 1
Powder XRD patterns for (a) starting material Texas
montmorillonite (STx-1) before reaction, (b) product
formed after reaction with NaOH (Example 3), and (c)
product formed after reaction with KOH (Example 1).
For FIG. 1, detailed enlargements of the region
between 20 and 35 2~ are given in FIG. 2.
FIG. 2
Higher scale enlargements of powder XRD traces shown
in FIG. 1 demonstrating the region between 20 and 35
2~. For FIGS. 2c and 2d, corresponding to sample
numbers STx-4 and STx-5 in Table 4, the presence of a
broad "hump" between 22 and 32 2~ is readily
observed.
FIG. 3
27Al MAS NMR spectrum for the product obtained by
reaction of Ca-montmorillonite with KOH (Sample No.
STx-2 in Table 4).
FIG. 4
7Al MAS NMR spectrum for the product obtained by
reaction of Na-montmorillonite with KOH (Sample No.
SWy-2 in Table 4).
FIG. 5
Plot of CEC vs surface area for a range of samples
obtained using various reactions given in Table 4.
WO96/18577 2 2 0 ~ ~ 2 5 PCT/AU95100699 ~
36
The plot shows that products with wide range
properties can be obtained by these reactions.
FIG. 6
A schematic diagram showing products that can be
formed at various temperatures and KOH concentrations.
FIG. 7
Powder XRD trace for (a) zeolite starting material
before reaction and (b) product obtained after
reaction with NaOH (Sample No. Zeo-1 in Table 4;
Example 5, in text). Xray peaks corresponding to
impurity phases such as quartz, which is present in
the starting material, are denoted in FIG. 5B. Note
that the zeolite peaks diminish considerably in the
trace for the reaction product.
FIG. 8
Powder XRD trace for (a) starting kaolin before
reaction, (b) product obtained after reaction with
NaOH (byproducts from the reaction are designated with
an *) as detailed in Example 5, (c) product obtained
after reaction with KOH as detailed in Example 6, (d)
product obtained after reaction with KOH + KCl as
deteailed in Example 7 and (e) product obtained after
reactions with Li Oh as detailed in Example 8.
FIG. 9
27Al MAS NMR spectrum for the product obtained by
reaction of kaolinite with KOH.
FIG. 10
Plots of CEC (a) and surface area (b) for products
obtained at various temperatures and KOH
concentrations. The KOH levels are expressed as
moles/20 ml of water.
FIG. 11
27Al MAS NMR spectrum for the product obtained by
reaction of kaolinite with KOH and KCl.
FIG. 12
Plots of CEC (a) surface area and (b) for products
using KOH and KCl at 80C. The KOH and KCl
f WO96/18577 PCT/AU9S/00699
37
concentrations are expressed in moles/20 ml for 5 g of
clay used in the reactions.
FIG. 13
Plot of the amount of Cu+2 exchanged from a solution
containing 200 ppm Cu+2 for a K-ASD sample after heat
treatment for two hours (Example 11). Note the
increase in Cu+2 exchange for K-ASD material heated
between 100C and 200C.
FIG. 14
Powder XRD trace for sample KCM-8 (a) before and (b)
after treatment with dilute acid (Example 12). Note
that XRD peaks for impurity phases evident in FIG. 14A
(denoted by *) are not present in FIG. 14B.
FIG. 15
Powder XRD trace for (a) K-ASD material formed by
reaction with KF (Example 4) and (b) Na-ASD material
formed by exchange in a concentrated NaOH solution
(Example 13).
FIG. 16
Histograms showing amount of phosphorous adsorbed at
various initial P concentrations in the solution. The
amount of P adsorbed increases with increase in P
concentration in the solution.
