Note: Descriptions are shown in the official language in which they were submitted.
203r~33
`HOECHST AKTIENGESELLSCHAFT HOE 90/F 084 Dr.GT/~e
Description
Process for the selective flotation of phasphorus
minerals
~his invention relates to the separation of phosphorus
minerals such as apatite, phosphorite, francolite and the
like by means of flotation from raw ores or preconcen-
trates with the aid of mixtures of anionic oxhydril
collecting agents, of which one component comes from the
group of the monoalkyl alkenylsuccinates.
According to Winnacker and KUchler: Chemische Technologie
[Chemical Technology], Volume 4 (Metalle [Metals]), 4th
edition, Carl Hanser Verlag Munich Vienna, 1986, page 66,
collecting agents are organochemical compounds which, in
addition to one or more apolar hydrocarbon radicals,
carry one or more chemically active polar groups which
are capable of being adsorbed on active centers of the
mineral and thus rendering the latter hydrophobic.
As is known, flotation (froth flotation dressing) is a
widely used sorting method for mineral raw materials, in
which one or more minerals of value are separated from
the worthless ones. The mineral raw material is prepared
for flotation by dry, but preferably wet grinding of the
precomminuted ore to a suitable grain size which depends,
on the one hand, on the degree of intergrowth, i.e. on
the size of the individual qrains in a mineral assembly,
and, on the other hand, also on the maximum grain size
which is still to be floated and which can differ very
widely depending on the mineral. The type of flotation
machine used also has an influence on the maximum grain
size which is still to be floated. Although not the rule,
it is frequently the case that the well crystallized
magmatic phosphate ores allow coarser grinding (for
example <0.25 mm) than those of marine-sedimentary origin
- 2 - ~7~83
(for example ~0.15 mm).
Further steps in the preparation of the ores for flota-
tion can comprise a preseparation of worthless material
on the one hand, for example, by gravimetric sorting or
gravity dressinq (separation of relatively coarse con-
stituents) and, on the other hand, by de-sludging
(separation of extreme fines). The removal of magnetic
minerals which, for example, are almost always present in
phosphate ores of magmatic origin, by means of magnetic
separation is a further possible pre-enrichment method.
However, the invention is not restricted to flotation
processes which have been preceded by any preconcentra-
tion.
A distinction is made between two procedures with respect
to the minerals to be obtained in the froth. In direct
flotation, the mineral or minerals of value are collected
in the froth, which is produced on the surface of the
flotation pulp, which re~uires that their surfaces have
been rendered hydrophobic beforehand by means of one or
more collecting agents. The worthless minerals are then
found in the flotation tailings. In the converse flota-
tion, the worthless minerals are rendered hydrophobic by
collecting agents, whereas the flotating tailings form
the actual concentrate of value. The present invention
relates to the direct flotation of phosphorus minerals,
but this can also follow a preceding converse flotation
stage which, for example, comprises a flotation of
silicate minerals by means of cationic collecting agents.
A large number of anionic and amphoteric chemical com-
pounds are known as collecting agents for phosphorus
minerals, and these include, for example, saturated and
unsaturated fatty acids, (stearic acid, oleic acid,
linoleic acid, linolenic acid) and sodium, potassium or
ammonium soaps thereof, monoalkyl and dialkyl phosphates,
alkanesulfocarboxylic acids, alkylarylsulfonates, acyl-
aminocarboxylic acids and alkylaminocarboxylic acids.
- 3 _ ~37g~3
Moreover, collecting agents are known which are adducts
of sulfosuccinic acid (cf., for example, US Patents
4,207,178, 4,192,739, 4,158,623 and 4,139,481 and SV
Patent 1,113,317). Many of these chemical compound
classes have, however, an inadequate selectivity which
does not allow the production of saleable concentrates or
necessitates the use of larger quantities of regulating
reagents, specifically of deadening agents for the gangue
minerals.
In USSR Inventor~s Certificate 1,084,076, collecting
agents for phosphorus minerals, specifically apatite, of
the type of monoalkyl alkyl- and alkenylsuccinates of the
general formula
R1 - CH - CO - OH
1 2
CH2- CO - OR
where R1 = R2 = C,-Cl6-alkyl or -alkenyl, are described.
~hese collecting agents are classified as particularly
selective. In the flotation tests given as examples in
this inventor's certificate with carbonate-silicate
apatite ores, monoalkyl alkenylsuccinates with R1=Ca-C1o~
alkenyl and R2=C7-C12-alkyl or R2=C10-C1~-alkyl were used.
In a further publication by W. A. Iwanowa and
I. B. Bredermann: ~Alkyl(Alkenyl)bernsteinsaure-alkyl-
monoester - effektiver Sammler fUr die Apatitflotation
[Monoalkyl alkyl(alkenyl)succinates - effective collec-
ting agents for apatite flotation3" (from the book:
A. M. Golman and I. L. Dimitrijewa (Editors): Flotations-
reagenzien [Flotation agents], published by "Nauka",
Moscow, 1986; cf also Chem. Abstr. 106 (14): 104652n), R1
in the abovement~oned formula is likewise restricted to
C~-C12-alkenyl and/or C10-C13-alkyl radicals and the primary
alcohols used for the esterification are restricted to
those with R2=C7-C12 radicals.
.
. ~- .
2~3i~3
-- 4 --
In German Patent Application 3,900,827, the use of those
monoalkyl alkenylsuccinates for the flotation of phos-
phorus minerals is described which are esterified with
short-chain alcohols (R2 = Cl-C4-alkyl).
It has now been found that a further improvement can be
achieved if the monoalkyl alkenylsuccinates described in
German Patent Application 3,900,827 are combined with one
or more, known co-collecting agents. A mutually boosting
synergistic effect of the flotation collecting agents
occurs in this case.
The invention thus relates to a process for the selective
flotation of phosphorus minerals, wherein a mixture or
combination of a compound of the formula la and/or lb
Rl - CH - COOM (la) and/or Rl - CH - COOR2 (lb)
CH2- COOR2 CH2- COOM
in which R1 is branched or unbranched C8-Ca4-alkenyl and
preferably C12-C18-alkenyl, R2 is branched or unbranched
C1-C4-alkyl and M is hydrogen, ammonium, triethanol-
ammonium, an alkali metal atom or an alkaline earth metalatom, with one or more of the following compounds (co-
collecting agents)
R - CO-N - (CH2) n ~ COOM (2)
X
RO - CH2CHCH2 - N - CH2 - COOM (3)
OH X
R - NH - CO - CH2 - CH - COOM (4)
SO3M
RO - CO - CH2 - CH - COOM (5)
SO3M
~ 5 - 2~3~
CH2 - COOM
R - N - CH - COOM t6)
CO - CH~ - CH - COOM
SO3M
R -- N -- ( CH2 ) n ~ COOM ( 7 )
X
R -- N -- ( CH2 ) n ~ COOM ( 8 )
( CH2 ) n ~ COOM
R - C - [Po(oH)2]2 (9)
OH
R - N - [CH2 ~ P(H)2]2 ( 10)
R - CO - NH - OM ( 11)
R - COOH (12)
2 0 R - SO2NH - CH2COOM ( 13 )
and
petroleumsulfonates
R'SO3M (14)
in which R is C12-C24-alkyl and preferably C12-C18-alkyl
and/or C12-C24-alkenyl and preferably C12-C1a-alkenyl, R' is
an aliphatic/alicyclic and/or aromatic radical from
petroleum fractions, X i8 hydrogen or C1-C4-alkyl, M is
hydrogen, ammonium, triethanolammonium, an alkali metal
atom or the equivalent of an alkaline earth metal atom,
and n is a number from 1 to 6, is used as the collecting
agent for the flotation.
- 6 - 2~37~
The mixture or combination which is to be used according
to the invention i8 preferably composed to the extent of
5 to 95~ by weight of the compound of the formula la
and/or lb and correspondingly to the extent of 95 to 5%
by weight of one or more of the co-collecting agent6
described above.
The preparation of the monoalkyl alkenylsuccinates of the
formulae la and/or lb is carried out in a known manner by
reacting alkenylsuccinic anhydrides with Cl-C4-alcohols in
a l:l molar ratio. For complete conversion, the mixture
is either heated for 5 hours to about 80-l20nC, or
catalytic quantities of the corresponding alcoholate are
added. In this case, the reaction is complete after one
hour. The co-collecting agents ~2) to (14) are known and
commercially available products.
The addition of the collecting agent combination of
monoalkyl alkenylsuccinate and co-collectinq agents to
the flotation is possible together or separately, un-
diluted or in the form of aqueous solutions.
The collecting agent mixtures or combinations aacording
to the invention are suitable for the flotation of all
phosphorus minerals such as apatite, phosphorite or
francolite from raw ores or preconcentrates with carbon-
ate gangue, silicate gangue and/or quartz gangue, both
from ores of magmatic genesis and sedimentary or meta-
morphic genesis.
The synergistic collecting agent mixtures or combinations
are added to the flotation pulp in quantities of pre-
ferably 20 to 2000 and especially 50 to 200 g/tonne of
raw ore or preconcentrate to be floated. The collecting
agent mixture or combination can be added stepwise in
several portions or in a single step.
As compared with the individual components, the mixtures
or combinations according to the invention show a
- 7 _ 2~3 ~ ~3
synergistic effect. A synergistic effect i8 here under-
stood as meaning that the recovery R of the collecting
agent combination of the collecting agents A, B, C ... N,
i-e- R~A ~ C ... N~ in % is, at the same applied quantity of
collecting agent (in g of collecting agent per tonne of
raw ore) greater than the total of the proportionate
individual recoveries, determined by calculation, i.e.
a RA + b R~ + c FC + n RN r R~ ~ C N being the recovery
by the individual collecting agents A, B, C ... N and a,
b, c ... n being the proportion of the individual col-
lecting agents A, B, C ... N in the overall mixture
(A, B, C ... N), and 100~ of the overall mixture being
set at 1.
R(A B C ... N~ > a RA + b RE~ + c Rc + ... + n RN
It is known to modify the flotation properties of anionic
oxhydril collecting agents in a positive direction by
means of co-adsorbents. In most cases, this relates not
80 much to the selectivity of the primary collecting
agent, but rather to the activity thereof, i.e. to the
applied quantity thereof, and to the regulation of the
froth evolution. Modification with nonionic substances,
preferably those which are water-insoluble and have a
polar character, i8 also possible for the collecting
agent mixtures or combinations to be used according to
the invention. Examples of suitable compounds are alco-
hols having n- or iso-alkyl chains, alkylene oxide
adducts of alcohols, alkylphenols and fatty acids, fatty
acid alkanolamides, sorbitan fatty acid esters, poly-
alkylene glycols, alkyl or alkenyl glycosides, saturated
and unsaturated hydrocarbons, and the like.
The activity and froth evolution of monoalkyl alkenyl-
succinates and mixtures or combinations thereof with co-
collecting agents can also be positively influenced by a
content of ~-olefins.
If ~uch co-adsorbents are used for the flotation, the
- '
.~ ,
- 8 - 2 ~ 3 ~
collecting agent mixture or combination/co-adsorbent
ratio can vary within wide limits, for example from 10 to
90% by weight for the collecting agent combinstion and
from 90 to 10~ by weight for the co-adsorbents. Usually,
the active compound quantity of the collecting agent
combination is greater than that of the co-ad~orbent6,
but this does not exclude converse ratios.
In most cases, the collecting agent mixtures or combina-
tions render the phosphorus minerals hydrophobic in such
a selective manner that the other minerals present in the
ore remain hydrophilic, i.e. are not collected in the
froth on the surface of the flotation pulp. Depending on
the mineral composition of the particular ore, however,
it cannot be excluded that, to improve the success of the
separation, one or more deadening agents for the gangue
minerals might have to be employed. Examples of suitable
inorganic- or organic-chemical deadening agents are soda
waterglass, hydrofluoric acid (HF), sodium fluoride
(NaF), sodium silicofluoride (Na2SiF6), hexametaphosphates
or tripolyphosphates, ligninsulfonates and hydrophilic,
relatively low-molecular weight polysaccharides such as
starch (corn starch, rice starch or potato starch, after
alkaline digestion), carboxymethylstarch, carboxymethyl-
cellulose, sulfomethylcellulose, gum arabic, guar gum,
substituted guar derivatives (for example carboxymethyl
guars, hydroxypropyl guar6 and carboxymethyl-hydroxy-
propyl guars), tannins, alginates, phenolic polymers
(e.g. resole, novolak), phenol/formaldehyde copalymers,
polyacrylates, polyacrylamides and the like.
As froth flotation agents in the process according to the
invention, all products known for this purpose can be
used/ if required, such as e.g. aliphatic alcohols and
alcohol mixtures, terpene alcohols (pine oils), alkyl
polyalkylene glycol ethers or polyalkylene glycols.
The pH of the flotation pulp also plays a part in the
froth flotation of phosphate ores. Usually, it is between
2~37~
g
7 and 11, the flotation in the case of apatite ores being
preferably carried out at pH values from 9 to 11, and
preferably at pH values from 7 to 9 in the case of
phosphorite ores. The optimum pH of the flotation pulp,
which can be decisive for the success of the flotation,
differs from ore to ore and must be determined by labora-
tory tests and plant tests. Soda (Na2CO3), caustic soda
(NaOH) or caustic potash (ROH) can be used for regulating
the pH.
The results of the flotation tests are given in the
Examples which follow.
The following reagents were used as components for the
collecting agent mixtures (A+B) according to the inven-
tion:
A: Collecting agents of the formulae la and/or lb:
Collecting aqent Al: sodium mono-C2H5 nCl6 18-alkenyl-
succinate
Collecting agent A2: sodium mono-iC3H7 nCl6 l~-alkenyl-
succinate
Collecting agent A3: sodium mono-C2H5 nC14 16-alkenyl-
succinate
Collecting agent A4: sodium mono-iC3H7 nC14 16-alkenyl-
succinate
Collecting agent A5: sodium mono-CH3 nC18-alkenyl-
succinate
Collecting agent B3: mixture of
55% by mass of sodium N-talloyl-N-
methyl-aminoacetate and
45% by mass of the sodium salt of
tall oil fatty acid (content of
unsaponifiable matter 5.4%, content
of rosin acids 14.7%)
Collecting agent B4: mixture of
75% by mass of sodium N-talloyl-N-
methyl-aminoacetate and
- 10 - 2~7~,?3
25~ by mass of collecting agent B8
Collecting agent B5: mixture of
66.7% by mass of sodium N-talloyl-
N-methyl-aminoacetate and
33.3% by mass of collecting agent
B8
Collecting agent B6: mixture of
66.7% by mass of sodium N-talloyl-
N-methyl-aminoacetate and
33.3~ by mass of collecting agent
B9
Collecting agent B7: sodium N-talloyl-aminohexanoate
Collecting agent B8: sodium salt of tall oil fatty acid
(content of unsaponifiable matter
2%, content of rosin acids 1.8%)
Collecting agent B9: ~odium oleate (technical grade,
iodine number = 80-100)
Collecting agent BlO: sodium Cl2l5-alkylsulfonamidoacetate
Collecting agent B11: sodium N-tallow fatty alkyl-N-
sulfosuccinyl-aspartate
Collecting agent Bl2: sodium petroleum sulfonate (alkyl-
aryl-sulfonate) with about 80% of
active substance
In all the phosphate flotation examples which follow,
about 400 g of natural phosphate ore in each case were
floated using a type D-12 laboratory flotation machine
from Denver Equipment, USA, in a flotation cell of 1.0 l
volume (rougher and cleaner).
The natural ore used for the tests can be characterized
as follows:
P2O5 content about 15.3%, corresponding to about 36% by
mass of apatite; gangue minerals: titanite, titano-
magnetite, feldspar, feldspathoids (essentially nephe-
lite), pyroxenes (essentially aegirite) and mica;
grinding to 80% by mass smaller than 110 ~m.
11- 2~3~
Examples of pho~phate flotation
The ore type A was ground wet to 80% by weight smaller
than 110 ~m. A water having a total salinity of 690 mg/l,
whose content of dissolved salts was of such a qualita-
tive and quantitative composition as results in the waterof an industrial flotation plant, was added to the
grinding and to the flotation. Each flotation test
comprised the following stages:
Conditioning of the flotation pulp with 150 g/tonne of
soda waterglass as a dispersant for a period of 3
minutes; conditioning of the flotation pulp with the
collecting agent, the added quantity of which was varied
(cf. results), for a period of 3 minutes;
rougher flotation for a period of 2 minutes;
three-fold further purification (cleaner flotation) of
the frothed product obtained in the rougher flotation
(rougher concentrate), flotation period 2 minutes each
time.
The symbols in the tables mean C = concentrate; F = feed;
M1, M2 and M3 = middlings and T = tailings.
Example 1
The collecting agents A2 and B4 were tested alone and in
a 1:1 mixture with one another at various added quan-
tities. The recovery of the collecting agent mixture
A2+B4 is higher than would be expected from the calcu-
lated average of the recoveries from A2 and B4 if used
alone.
Fxample 2
The 1:1 mixture of the collecting agents A1 and ~4 also
gives a higher recovery than would be expected from the
calculated average between the recovery values of A1 and
B4 if used alone.
- 12 ~ 7~3
~xample 3
In this Example, the combination of the collecting agents
A2 and B3 was examined. This is a three-component com-
bination, since the collecting agent B3 contains two
components. The recovery of the 1:1 mixture A2+B3 is not
only higher than the average calculated from the indivi-
dual recovery values of collecting agents A and ~, but
also higher than the recovery values of the better
collecting agent B3.
~xample 4
The recovery of the 1:1 mixture Al+B5 is higher than the
average calculated from the individual recovery values
and at the same time also higher than the recovery of the
better collecting agent B5. The mixture A2+B5 is likewise
a three-component combination, since B5 comprises two
components.
Example 5
The recovery of the 1:1 mixture Al+B6 likewise exceeds
the average from the individual recovery values Al and B6
and the recovery of the better collecting agent B6. As in
Examples 3 and 4 this is again a three-component combina-
tion.
Example 6
The recovery of the 1:1 mixture Al+B8 likewise exceeds
the average of the individual recovery values of Al and
B8 and also the recovery of the better collecting agent
A1. The collecting agent B8 is also a constituent of the
collecting agent B5, cf. Example 4.
Example 7
Recovery of the 1:1 mixture Al+B9 exceeds the average
2~3 ~f~g~
- 13 -
calculated from the individual recovery values of Al and
B9. ~he collecting agent B9 is also a constituent in the
collecting agent B6, cf. Example 5.
Example 8
The recovery of the l:l mixture Al+B7 is substantially
above the average calculated from the recovery values of
the individual collecting agents and also substantially
above the recovery of the better collecting agent Al.
Example 9
As in Example 8, the recovery of the 1:1 mixture A2+B7 in
Example 9 is also substantially above the average of the
recovery values of the individual collecting a~ents and
also above the recovery of the better collecting agent
A2.
lS Example 10
The recovery of the 1:1 mixture Al+B10 is considerably
above the average of the individual recovery values of
the collecting agents Al and BlO.
Example 11
The recovery of the l:l mixture Al+B12 is considerably
above the average calculated from the individual recovery
values of the collecting agents Al and B12.
Example 12
The recovery of the 1:1 mixture Al+Bll is above both the
average calculated from the individual recovery values
and above the recovery of the better collecting agent Al.
- 14 - 2 ~3 l~g 3
~xample 13
Tests supplementing Example 8 were carried out with the
Al~B7 combination in mixing ratios of 1:3, l:1 and 3:1 at
a collectin~ agent dosage of 70 g/tonne of raw ore. In
the tests, the best recovery results were obtained at an
Al:B7 ratio of 1:1.
Example 14
Tests supplementing Example 6 were carried out with the
Al~B8 combination in mixing ratios of 1:3, 1:1 and 3:1 at
a collecting agent dosage of gO g/tonne of raw ore. In
the tests, the best recovery results were obtained at an
Al:B8 ratio of 3:1.
~xample 15
Tests supplementing Example 12 were carried out with the
Al+B11 combination in mixing ratios of 1:3, 1:1 and 3:1
at a collecting agent dosage of 90 g/tonne of raw ore.
In the tests, the best recovery results were obtained at
an Al:B11 ratio of 1:3.
The results obtained with the mixtures according to the
invention are listed in the Tables which follow. For
comparison with these, the Tables also contain the values
achieved with the individual components not according to
the invention.
- 15- 2~37~
-- N N a~ ~ 0 _ ~D 0 ~ 0 ~ N 1~ _ 1~ lD 0 ~D 0 1~ 0 ~t 0 ~ O
0 U~ J O ~ N In .r 117 ID ~r 0 U~ ~ N ~) ~ ~ U ) ~i O U:~ Ul _ 1~ U~
0 ~ U~ (D N ~ '-t ~ O O 1/~ 0 _ 1~ ~ ~ ~ O O N 1~ 0 N 1~ O) ~ 1
_ ~D er 0 _, _ _ _ _ _ _ 0 N 0 ~D 0 li~
0 ~ _ U1 0 U~ _ ~D ~ ~ ~ _ 0 0 ~ ~ _ ~ ~ ~ U~
L _ _I _ _ _ _ _ O CD ~ I~ ID O~ O O 1
N
~: t~ 0 1~ ~t _ D 0 _ O O O ~q N _ ~n 0 _ O OD C~. O ~ _ D ~D _ N
a~ o 0 IO N 0 0 N ~D N _ _ O N ~ O 0 ~ 0 N 0 0 tD N
O D N 0~ 0 0 ~ 0~ _ --I 0 0 U') 0 0) 0~ 0 _ 0 N ~D 0 0 ~ ~ )~ ~D
_ 1~ 0 0 ~ N ~0D ~ 0 ~D 0 ID 1~ U') ~ 0 ¢1 0 -- ~ D 0 ~ ~ 0 N
~-- NU~_ 1~0~ N~ ~0N et0 er N~ 1~ I O~
N__ N__ ~__ ~__ N__ ~__ ~_ N__ ~N~
_ _ ~ ~ n .Ir O _ ~ N ~ 0 r~ ~ ~ ~ _ ~ N ~I~ O~O ~t~_
. ~0~ ~_ ~~ N-~ ~0~ 00~ ~~ ~~~ N__
~N ~O~ ~ ~_ _~ ~ ~_ ~O~ ~ ~O~
~NN ~~ ~NN ~NN NN_ ~NN NN~ ~N ~~
~ ~O_ OO~ ~_~ ~ _~N ~_~ 00~ OO~ N__
O 0 ~ .r 0 r~l~'i 0r~ 0 ~ 0 ~ ~J N 0 ~ ~ ~r~ ~ N ~ ~ 7 0 0 ~`
0
~ 0~ ~N 0~ O0~ ~ 0~ ~N ~N 0
o~ v) ~n a) o~ cn o~ o o~ cn cn cn ~
1~ N N N O~ _ ~ O ~ N ~ _ _ N ~ ~'J O ~ N O~ _ N
_ _ _ _~ _ _ _ _ _ _ _ _ _ _l _ _ _ _ _ _ _ _l _ _ _ _ _
_
N N O~ ~ ~N~ O~ ~O ~NN _~
~N~ ~ ~ N~ ~ N _ ~ ~ ~ 0 ~ N ~ ~ ~ 0 ~ ~
~~ N~N ~0N O~ O00 0~ O~ ~O_ ~0 N 0 N0
~1 _ _ ~ ~ N _I N~n~n N O ~ _ _ O N O~ n _ N O ~ N _ N_~
_O
~N N~ _~_ O~_ 0~N ~O O~_ ~O~ _~_ ~
~D ~i ~ 0 ~ ~ ~ ~ 0 ~r ~ ~ ~ .J n ~n ~ 0 1~ U~ 0 u~
o
O~ _~ ~OO ~N~ _~ ~0~ O~ ~O
~N ~ 0~ N ~ ~ ~ ~ ~ N 0~ N ~ ~ N
~ NON ~N~ ~N 0N0 _N~ 0~N ~ ~N~ ~
_ _N~ _N N _ N ~ _ NN 0N~ ~~ - N ~ _ N N NN
~ ~ ~n a~ ~ U~ I` ' ~ ~ I~ ~
~ _ __ __ _ _~
~-
-
l_~ ~ ~ ~ _ ~ ~
~ ~ N Ir) N ~ ~ _ ~r 1~ m
cc 0 ~ ~ ~ ~t 0 e ~ m
~,~3~3
-- 16 --
i-- N ~ In 0 ~ ~~t N O Ir~ ~ N ~ _ ~ In U) ~ N rJI _~ 0 _ ~ N 1~ 0 D ~ 0 L~ ~ ~ 0 ~ a~ ~O ~ 1~ 0 111 0 -t l~i 0 ~D ~ 1~ ~t
O- ~ r~ _ I~ ~r _ O ~D ~O (~ N _ r~ ~ Il N O N 0 1~ _ 1~ ~ _
;~ ' ~ D ~ 'O 1~ Ll -- 0 ~ ~ 0 ~o _ ui ~ 1~ o 1
1~) _. _ _ _ _ _ _
N r~ 07 ~1 er ~ _ O~ U) 11~ ~ O _ ~ ~ _ 0 0 _ 0 ~ 0 ~t 0 -- 0 N 1~
L ~D ~ I~J _ ~ In 0 0 ~ n N 0 ~ N 0 U7 _ 1~ 11~ 1~ Il) N
0~ ~1 _ _ __ _ _ _ ~
r~ ~ N N _ ~) tJI ~ ~ 0 0 ~ N _ ~1 0 _ ~ r~ l,r) _ N _ O) O 0) 1-7
r~ _ 0 _ ~ ~ 0 ~ _ N U~ r~ _ 1~ ~ O~ 0 1~ O 1~ Il) _ 1~ ~ r~ 1~ O
0 tD It~ 0 V~ 1~ ID N 0 O _ 0 0 a~ ~ ~t O _ U> O )t> 0 C~ O) tD ~
N 0 1~ U) N 0 U~ ~ -- -- 0 It~ 1~ 0 0 ~D 1~ U~ r~ 0 U7 1~ ~ ~ U~ ID
._ . _
I-- 0 0 ~ ~ 0 ~O In r~ _ 0 N ~r 0 ~t _ ID 0 ~ ~t 0 ~t 0 et O ~ N
~__ N__ N _ _ ~ _ ~ N__ N _ _ N _O N__ N__
_ N00 ~ 0~0 ~ ~0~ ~0~ ~_O ~0~ ~_O
00~ ~0~ ~0~ _O~ ~0~ N0~ ~N0 ~0~ ~O~
_ _ _ _ N _ _ _ _ _ _ _ _
N O0 N n 0 ~ ~ _ 0 ~ r) ~ 0 1~ 0--I~~O U~ 0 r~ O
~N N 0 NN ~ ~ NN ~ N NN_ NNN NN_ 0N0 ~ N N
C ~ ~ o 0 _U) N ~ 0 ~r a~ ~ 0 _ Ln N 0 ¢~ r~ ~ 0 1~ _U)N ~f~_L.t)
0~ ~ 0~-0 0~0~ ~ ~0 ~O ~N ~
_ J ~ In ~ ~ _ 0 m 0 ~t ~ ~ ~r ~ _ 0 ~O ~r N t~ u~ ~r 4'~ ~ _
0 000 et0 ~r00 000 ~~0 000 0~ 0~
N~ ~ ON_ N~ ~O N~_ N~ O~O
___ __~ ___ ___ ___ ___ ___ ___~
_ _
~N~ ~ N ~ ~ ~ _ ~ N~ ~_~ __~ ~N~ _~
O~JN 47N_ ~D~_ O~ N_ ~ .J~ ~nN_ ~0CD
~ ~ O O _ _ o o _ _ ~ o o _ _ o 0 0 ~ ~ _ o _ _ o ~ u~ ~3 ___ ___ ___ ______ ___ ___ ___ ___
~e
~N ~ U~ U 0 0 O1~ ~t O~ ~ I~ ~t 0 0 O ~D N ~ I~ O e~ a~ 0 O ~ 0 et
~ ~` ~ ~ 47 -t .J~D ~n ~ ~ ~ ~ D ~ ~ ~ ~ ~ m ~r
o
~i: N 0 ~D D N ~ U7 U~ 0 1~ Ir> N ~D N ~ a~ ~r 0 /D q 1~ ~D N ~ O I 1~
0 ~r ~ ~t ~ N1~ U~ ~ 0 ~D ~ ~t 0 N 1~ 0 ~ ~ ~ N ~ ~ N 1~ In ~t
U~ (D 0 _ N ~N 0 ~D_ 0 O _ N ~ N ~ ~ ~ ~t ~ _ N ~ ~ O N
UN~ 0N N 0 ~0 N ~N~ N ~ N N ~ 0 ~Nn 0 N N ~ N N ~ _ N N
_.
~0 o~O0 o0_~ ~03 ,n,~æ o0_~ ~0o_ ~0o_ o0_~o o0_~
0
.
~ ô ~ o ~
~+ o ~ ~0
X ,~ ~ o ,~S-- -- 0
~3~33
-- 17 --
1-- 0 0 N 0 _ 1~ 0 N N N tD 11~ 0 _ r~ 0 1~ N ~ OD _ 0 ID
~ ~r ~ 0 tD ~ ~ 0 0~ 1~ 0 ~ 0 ~ N _ 0 ~ r O N _
tD 0 0~ _I r~ ~r _ LO N N U~ N _ 1~ ~ O _ O N _ _ tD N ~-1 0 _ O
:~e ~ N 0 tO j tD er 0 ID j ~ 1~ ~ j tD el N 11') j
N 0 _ tO ~t ~ _ 0 N 0 ~r 117 ~ ~ 0 _ ~ ~ _ N ~t N tO--tO 0 0--
t_ j 1~ tD j 1~ 117 ~r N oi _ i _ _ _ _ _ _ _
0~
C-- _ ~r~ O N _ 1:1~ 0 0 _ 0 N N N _ 0~ 0 0~ O _ 0 0 ~t _ tO 0 ~ O
:E O 1~ tO _ 1~ ~ ~ 0 0 N ttl ~i _ ~ ~r N _ O) N 0 11'~ tn N 0 N _ 0
t~ _ _ __ _ _ __ _ __ __
O tlD O 1~ 0 ~ U~ ~ 1~ t N ~ 0 0 0~ _ N tD ~r O 1~ O 0 ~ _ N tD
Ll') 1~ t U~ 0 Cl~ ~r ~ 0 o 0 ~ N 0 N ~ tD Y- ~ 0 1~1 1.0 tD N ~ tD
_ _
I_ ~ ~ N ~r 0 ~ 1~ Y'l tO N 10 0 ~ 0 ~ 0 tn U~ N r N 1~ ~n ~ In U~ U~
N _ _ N _ _ 1-~ ~ N ~r _ _ N _ _ tD ~t N N _ _ N _ _ tO ~ C~J
_ 0~ O t ~ 0~ tr~ r ~ 0 1~ N 0 D~ 0 tO--0 0 t~ et O tD--0
~: tO O O ~ 0 tO 0 ~ t~ N _ N _ _ ~ (o to 0 .t -- N _--
N tn 0 ~ u~ tn r~ ~ et n o lo - u~ tn r~ ~ O N o tn t.~ tr~ ~ tn l~ O N
. t~ N ON tN N _ o~ N N t~ N N t~l tr~ N 0 N N
t _ N r_ _ In N ~D N tn t~ o l~ _ n N n ~ tn tn ~t N o o tn m -t tn
~ t~ ~ ~ t~ t~ ~ t~ tr~ t~ 0 m N 1~ t N 1~ ~ t tD m t 0 ~ m ~_ m n
t~
t ~ 0 tn tr~ r~ n ~ tD ~ N 0 t ~ r tn tD ~.r lo ~ tr~ tD ~ N tn tD ~
~ tn t tn tn t7~ r~ t tn t~ ~ trl t~ ~ tn tr~ tn ~ tn ~ t~ tn tn tn tn
LL N _ _ N tr~ ~ N N N O N N N 0 0 O O _ O 0 N tn _ tn O O _
~n ~n n m m 'n 'n 'n 'n t t t m U~ m m 'n m 'n ~ n ~ t .r m m tn
-
I-- _ t.~ N tD N lo tn _ O ~ O tn tD N tD N O 0 tD tn _ tn N N N O tt~
t.~ in in t`~ tn in m In m 'n tD tn i~J m in m to io tn ~n n i~ In er in to i~ Un~
to_ tn_~r 0tnl~ om0 N~r 01nl~ t~ - o ~NI~ 1~0N tl~_O
8 _ N O ~ _ O In t~ N t~ _ O _ _ O In ~i N N N tn ~i N _ In ~r N
3 ___ ___ ___ ___ ___ ___ __ ___ __._
~Z tt~ tn N tn tn o ~t t~ tD o r~ t~ tn tn o n ~ tn ~ er o _ tn _ n ~r tn
~ n ~t ~ tn ~ ~t r~ to tn r~ ~ t~ m ~ ~ t~ l~ ~ to ~ tr~ 0 t~ m
D
_ t.~ tn to N t~ tD In tD _ tD ~ tD N ~ -- 0 tn ~ tD O tn tD -- ~?
~t~N ~t~N n~tr~ tnt~N ~N u~Int~ ~tt~N to~ InIn~
O _ ~t t.~ _ N ~ --to ~? ~r _ N, ~r tn. , . O O tD 0 N tn tn m
N ~ tn N N 0 ~ ~ N t ~ N ~ N t~ _ ~ m ~ N N tr) ~ ON N ~ ~n ~
cn cn ~ ~ 3 ~ n ~ m l~ tn tn _ tr~ t~7 m 1~ ~ O O _ ~ o o m+~u _ _ _
.
t~ ~ 0 o~
t ~ u _ ~u ~ tu
o.tn In G~ m O.r~
tu ~ ~ m ~c cnO ~ ~1 _ ~ 0 ~ ~ ~ t'D
S'`J ~3
-- 18 --
1_ ~ O 0 0 _ 1~O~ ~D _ O 1~ tr~ 0 _ 1~ _ o _ u~ ~ :n 0 ~ r~
_ _ _ _ 0 If) ~ 0 0 ~ ~ ~, _ N 1~ ~ 0 ID ~r 0 1-') N
r~ o o _ 1~ ~0 ~ l CO 01 0 ~ D ~r ~ _ _ 1~ ~ ~ N
S~ _ _ C~ _ __ _ N ~ _ _ _
~ ~ _ ~~t ~ _ ~ 1~ ~ 0 _ 0 ~ ~ _ _ a~ ~D ~ u~ l~ 0
D ~ _ _ _ ~ ) ~ ~ 0 _ _ N _ N _ 0 0 _ 1~ Ui _ _
S~
~: N O ~_ ~ ~ ~ .S 0' ~ Vl 0 _ ~ 'S ~ 0 ~JI ID _ r~ ~ N _ 10
~ __ _l__ _ __~ _ _ __
O ~ _u~ 0 o~ ~ ~ O _ u~l 0 ~ U~ _ _ ~O ~ u~ 0 O~
~ ~ -- ~ i 0 ~ 0 D 0 0 r~ ~J 0 _ ~J ~ ~D 0 n N O ~r ~i O
-
~_ (DOV~~0~ D0 ~ t0~ NmN ~~~ ~0er I~
~NON__ ~NN N__ N__ 1~0~ ON_ N__ O~_O
V~ D et Il') et 1~ ~ D ~ 0 _ ~ ~ Il') o It~
: __ _N__ ~CO~~0CS~ NN_ 0 0 l~ er 0 u~
N _ ~t ~t U) 0~ ~1~ 0 0 O 0 0 U> 0 ~ 1~ N0 1~0N Al') O~ 1~ O 0 _
~NNNN-- ~N ~N_ NN_ ~NI~ ~NN NN_ ~NN
D
~:~ t~ 111 0 _ 0N _O~ NO~ _0N ~_~ ~0 _UIN O~ O ~r
~ 1~0~I~N r_LON ~0N 1~00 r~ ID er /~ ON I~I~N
S`~
O o~ ~ 0 ~r ~ ~ N NO al ~ 0 ~ 0 1~ 0 0 1~ 0 1~ 0 ~ 0 CD er
0~ 0 ~ ~ ~ o~ ~ ~r ~ ~ ~ 0 ~ o~
1~ r~ _ 0 N~l~ _NO~ ~ LO 0 N~ NN~t ~0 N~ ~lN
,_ _ _ ~ _ _ _ In ~ ~ _ _ _ ~ _ u~ u~ _ ~ _ _ _ _, _ _ ~ n ~
1_ 01r~DN0 _OI~ ~00 ~NID 00N ___ UDNID 0~N
I.ONU~ 01~ ~UO InN_ ~--0 0~ 10N_ I~N
V~_ NO~ 01n~ 0~0 1~0 0LI')t_ 00~ C)I~N 0 IO 1~ 0 0 et
~NO~__O 0NO~ ~__ __O t~ 1/`> 0 N_O _ _ O ~ O O~
~S _I____ __ ___ ___ ___ ___ ___ __
~ 0 0 ID o~ 0 00 O) 0 CT~ o o ~ a~ o l~ _ 0 o~ 0 1~ o~ o~ o 0 I~N
O~ 1~0N ~ D~.J 0U7~t In~r~` ___ Lt7U')0 0~e~
C~
2 _IJ'I~ ~DN ~ a~ 0 0 1~ _ O U~N~ 0~D~ ~JNr~ ~N~ O 0N
n ~ tN ~N Ir) 0'~ ,n~ r~N ~1~0 I,t)~N ~N
O 0~0_N~ Na~J7 __11~ _N~ NU~O _~ _N':t ~r 0 O
_NNNN~ ~0N I~O NN~ N~`O~ 000
-.- . ~
~ v~~a~a~ g O~oo ooo o~g ~o~O O~ O~u~
~ _ _ _ _ _ _ N _ _ _ _ _ _ N _ _ _ _ _
D .
-
~D
o ID o o SUNO _
D ~ _ ~ _ ~,_ N ~ 0
19- 2~378~
-- _ _ ~ _ N U') _ O 0
N ~ O 0 0 r 0 0 0
0 0 N ~ a~ a~ _ a) _
/U 1~ 0 ~ 0 ~ 0 0 O~ N
c~ o~ ~ n ~ N t~
_ _ _ o ~n 0 cn
I~N
0~ tD ~- _ 0 N -- 01 _
~r N O 't r~ 0 0 ~ O~ N
___ _
~00~ 00~0~ 00U~
N CD ~r ~ ID 1~ ~ 0 10
_
I_ 1~ O O N 1~ 0 N N 0
~ N 0 N _ _ N N N
~: o _ o~ o~ ~ 0 a) _ ~r
_ _ _ 1~. _ O _ N N
N ~ N ~ 0~ O 1~ 0 0 ~
X o 0 a~ 1~ N N N C~l
~ c.~ _ 1~ ~ ~ 0 N
o ~: ~ ~ ~ ~ ~ 7
N 0 0 ~r -7 ~ In ~ 1~') 1
~ 0 0 0 0 0 0
0 N ~ N 0 0 0 0 0~ 0~
~ ~ 4~ ~ t ~ ~t
_~ __
~ 0 a~ ~ u~ ~ o u~
;~----
~ _ 1~ U:l Il') N 0~ ~t 01 N 0
3 _ i _ ~n N N O N ~
~,N 0~ ~D _ ~ 0 0 11~ 10 .t
~: I~ O~ ~ U') ~O
~o v~ o~ o o o
~ n ~
O N ~ _ 01 0 ~ _ 1'1 ~
_ N _l _ N N N N N
_
~ ~ o o 0 a)
,~
O~ ~ ~
70 0 ~ 4. ~0 ~ ~ N ¦~'$ 0 ~7 N
~ ~ 0 o 0 3 ~ N U> 1~ 1~3 ~t N 11'1 1
