Note: Descriptions are shown in the official language in which they were submitted.
~ 2~3 ` , 3,300
This invention is directed to a process ~or
~locc~lating pnos~natlc slime~ Tne proce~s comprises
aclding an aqueo~s solution of a water soluble ter-or
nlgr,er poiymer to a phospha~io slime under floc formin~
conditions and tnereafter allowing the suspended solids
to settle from tre suspen~ion tO provi~e an essentlally
clear aqueous supernatant.
~ ater solu~le nol~o-a~ld co2oly~,ers of acrylami~e
have been widely used in thickening or clewatering solia~
Fro~ eway-. Copol~lllers of acr~lan,i~e are use~ul in
flocculating phosphatic slimes. However, there is a
need for materials witn im~roveo ~loccula~ion e~ficiency.
It has now been found that wnen a ter-or higher
polymer is prepared from monomers wherein one o~ tne
monomers is water-insoluble or very slightly water
soluole, the resulting ter-or nigne~ poiymer has
increased flocculation efficiency wnen used as ~
flocculant for pnospna~ic slimes. T~le~e ter-or niyner
polymers are particularly efective for flocculating
pnosi?~natic slimes containing wideLy differir,g anlounts of
individual clay components.
'rHE INV~NTIO~
This invention is directed ~o a process for
flocculdtiny pnospna~ic slimes wnich com~rises (a)
forming a concentrated aqueous solution rom a water
soluble ter-or nigner polymer water-in-oil emulsion, tb)
diluting said concentrated aqueous solution of ter-or
higner polymer fornlec~ in step (a? with additional water,
(c) mixing the diluted solution of (b) with phosphatic
7~2~3
. 13,3~0
containing slimes under appropriate floc forming
conai~ions and (d) allowing tne suspenaed solids tO
settle from said slime to form an essentially clear
aq~eous supernatan~.
Tne con~entrate~ aqueous s~luti~n formed rrom
the water-soluble ter-or nigher polymer water-in-oil
en~lsion contains ~ron- about 0.15 tO a~u~ 9.0 ~ei~nt
percent, prefera~ly from a~out 0.30 to about 6.0 weignt
percent; sald weigr.t ~ercent oase~ on tne total weignt
of the emulsion.
Tne conuell~ra~ea aqueous solution is tnen
rurther. d.~luted witn water. The diluted solution then
con~ains ~rom a~ut 0.0003 to a~out 0.3 weignt ~erc2nt,
preferably from about 0.0006 to about 0.015 weight
percen~, saia weignt percenl based on ~ne totai weignt
of tne emulsion.
Tne ailu~d s~l~tion i9 ll~iXe~ in wnole or in
part with tne pnosphatic slime. The solution may be
mixe~ witn tne pnos~natic sLime at one or ll,ore ad~ition
points. The flow rate of diluted flocculant solution is
a~jus~ed ~o acnieve an eflective floccul~n~ aOSG9e ~nicn
is measured in pounds of emulsion per ton of dry slime
soli~s.
Tne floc orminy conditions inclu~e a~2ropria~e
choice o~ flocculant dosage, concentration of dilute
flocculant solution, selection of acceptable mixing
energy to achieve desira~ly large size flocs and
appropriate contact oetween flocculant solution and
slime.
Upon addition of tne diluted ~locculant
` 13,300
~7Z~3
solu~ion under the floc forming conditions, rapid
separation of suspended solids begins to occ~r. Wi~h
time ~he ~onoentr~t~on o~ s~sp~ded solids increases
~ignificantly an~ ~n essentially clear supPrmatant
results.
The ter-or higher polymers are prepared by
waterinooil polymeri%ation proceses which are well
known in the art. Preferably the ter-or higher polymers
are produced by the pt~cess as desc~ibe~ in Canadian
) Patent Application Serial Nn. ~n~, sl~,
~iled in the nam2s of Y. Fan et al titled ~A Process For
Producing a Polymer Water~n-Oil Emulsion" and f ile~ on
AUgUSt 13, 1982. In said Canadian Patent
Application 5e~ial No- 409,514 a
semi-con~inuous process for producing a polymer
wa~er-in-oil emulsion is described which process
comprises:
(a) combining: ~i) an aqueous solution
comprising at least one water-soluble monomer, and ~ii)
!0 a mixture compri5ing a hydrophobic liquid, a hydropho~ic
monomer and an oil-soluble surfactant:
~ b) homogenizing the mixture fro~ (a) to
form a wate~in-oil emuls~on;,
~ c) deoxygenating said homogenized
water-in-oil emul~iQn;
(d) continually adding the homogenized
water-in-oil emulsion to a reactor while adding thereto
a ~eoxygen~tea ini~iator -olution;
~ e~ heating the mixtu~e rom td) under
polymerization conditions ~ to ~r~ ~ polymer
~ 4 -
.. ......
7~
13,30C
water-in-oil emulsion; and
(f~ recoverin~ a polymer ~ater~ -oil
emulsio~.
A water-soluble surfactant is generally adaed
to tne recovered water-in-oil emulsion (f). These
water-in-Gil emulsions are mixea witn wâ~er to form an
oil-in-water emulsion which libera~es the polymer
formerly occupyillg ~n~ inter~-al pnase or tne water-in
oil emulsion.
In tne first step of tne ~rocess, an a~ueous
solution containin~ at le33t one water-soluble monome
is com~ined witn a mixt~re containing a hydrophovic
liquid, a hydropnobic monomer and an oil-soluble
sustacGant. ~nis comDination of materials is
homogenized to form a water-in-oil emulsion.
Thè aqueoùs soiution contains a mixture of
water soluble monomers~ ~ln~se monomers have a water
solu~ y of at least 5 weight percent an~ lnclude
acrylamiae, metnacrylamide, acrylic acid, methacrylic
acid, vinyl sulfonic acid~ 2-acrylamido-2-nle~-lylpro?ane-
sulfonic acid and their alkali metal salts, aminoalkyl
acrylate, aminoalkyl metnacrylate, dialkylaminoalkyl
acrylate, dial~ylamino methacrylate and their
quarternized salts ~itn aimethyl sulfate or metnyl
chloride, vinyl benzyl dimethyl ammonium chloride,
al~ali metal and ammonium salts of 2-sulfoethylacrylate,
al~ali metal and ammonium salts of vinyl benzyl
sulfonates, maleic anhydride, acrolein, N vinyl
pyrolidane, and the like. The preferred monomers are
acrylan~ide ana acrylic acid.
~ ~ 13,3~0
~8~3
If ~cry1ic acid is used as a monomer it is
reaet~d witn a D~Se, preferaD1y witn an ~quivalent
~unt of b~se, ~ucn as ~odium hydroxide, so that the
~aium acryla~e s~1ution ~.as a p~ of ~ron, Sbout 5.0 to
'~b~ut 10.~l preferably from about 6~5 to ~bout 8.5,
~e~en~ing on tne typ~ ~nd Dnloun~ ~f ~ase emp10yed. ~nis
~o~ution i5 c~mbined With another water soluble ~onomer,
~ucn as acri1al~ioe, ~n~ enen with water to sorm the
~ueou3 pnase,
O ~ne a~e~u~ pnase oom~ris~s fr~ about 65 to
~bout 80, preX@rab1y irom ~bout 70 ~o about 7~ weight
percent of tne ~ot~l composition.
- ~ne ~ixture whicn i~ combined witn the aqueous
~ol~tion containing tne water-so1uD1e mono,ners contains
a hydrophob1c 1iquid, ~ nyd~ophobic monomer and An
Oil-fiiOlUDle 3~.triaCt~lnt.
~n~ nydropnobic li~uids su1ta~1~ for use n~rein
inclu~e ~odecanes, hexadecanes, benzene, xylene,
toluene; ~,in~ral ~ils, kerosen~s, petrolaum, and
2D mixtures thereof. A pr~fe~red hydrophobic 1iquid i5
I50par~ oid by Hu~bie Oil and ~efinery Company).
Tne hydrophobic monomer(s) which may be used in
u~s inven~io~ nave a wa~er ~olubility ~f less than
~eight percent and $nclude one or more ~f vinyl e ters,
~ucn a~ vinyl ace~ate, ~lkyl ~crylates, sucn as
ethylacrylate, ~lkyl metnacryl~tes ~uch as methyl
~etnacr~la~e, vinyl eehers sucn 3~ butylvinyl ether,
acrylonitrile, ~tyrene ~nd its derivatives, ~uch as
~-~etnyls~yrene; ~-vinyl c~rDazole, an~ the li~e.
~ne surfac~ants 6uitable ~or use hereln are
- 6 -
~J
~87~
.3,30û
usually ol the oil-~oluble type having a Hydropnile-
Lip~nile Balanc~ (HL~) value of Irom a~vu~ 1 t~ a~o~t
10, preferably from about ~ to about 6. These
surf~c~an~s ar~ ~orll,aliy ~eferred to ~s ~ne wat~r-in-oil
type.. Tne surf~ct~nts include fa~y acld estess, such
as sorDita)~ ~onolaur~te, ~or~lt~n ~ons~earate, ~or~itan
~onooleate, sorbit~n trioleate, mono and diglycerides,
sucn as u,ono an~ ai~lycerl~es oDtaine~ ~ron, tne
glycerolysis of edible fats, polyDxyethylenated fatty
0 aci~ ester~, fiucn ~s polyox~etnylena~e~ (4) sorDitan
monos~cearate, polyos~ye~:hylenated linear alcohol, SUCh as
Tergito~)15-S-3 ana 'l'ergito~)25-L~3 ~botn supplied ~
Union Carbide Corp.), polyoxyethylene sorbitol esters,
~uon a~ polyoxyetnyl2n~ sorbitol Dees~ax ~erivativ~,
polyoxyetnylenated alcohois ~uch as polyoxyeth~lena~ed
~2) ce~yl ether, an~ the lik~.
The mix~ure of tne aqueous pnase and oil phase
~on~ainj ~rom a~o~t 15 to abour 50, preferaDly ~o-n
about 29 to abou~ 40 weign~ percent o~ the hydrophobic
liqul~ and nyo~o~noDic mono~er~s), based on tne total
weight o~ t~e composition.
ffl e a~u~ous ~olueion ~ ) colltair;ing tne
water-soluble monomers is cQmbined with the mixture
con~aining a ny~ro~ho~ic liquid, a hydrophobic
monomer(s~ and an oil-soluble urfactant~ Tnis mixture
is nomogeni~ed to form a water-in-oil emulsion.
Homogen~zation takes place by subje~ting the mixture to
nign ~near ~ix~ng tecbniques whicn are genesally
well-known ~n the art. These include the use o~
oMogenlzers, nl~n speed ~ixers and any otner ~ecnniques
~3~8~ 3
13,~0~
for obtaining nigh shear mixing. The homogenization is
carried ~Ut at a teln~2rat~re of ~rom about 10 tO about
40C, preferably from about 15 to 25C. The
hon,ogenlzation may be carrled ou~ either continuously or
in a batcn process.
Tne emulsions so pre~area nave a ratner narrow
particle size distribution. ~he diamaters of the
ma~ority of tne particles range from a~out 0.2 to aDou~
5.0 microns, preferably from about 1 to 3 microns.
Tne water-in-oil emul~ion 90 produced comprises:
(a) An aqueous phase comprising from
abou~ 45 to about 60, preferably fron, about 48 to about
78 weight percent and containing water-soluble
monomer(s) wnerein the monomers constitute ~rom about 20
to about 60, preferably from about 30 to about 50 weight
percent;
(~) a nydropnooic liquld and nyaropiJo~ic
monomer(s) comprising rom about lS to about 50,
preferaDly froln about 20 to aDout 40 weight percent;
(c) an oil-soluble surfactant comprising
from about 0.1 to a~out 5, pr~ferably from about 1 to
about 3 weigh~c percent.
After forml~g the water-in-oil enulsion, it is
generally deoxygenated, by for example~ subjecting the
emul~ion to d vacuum or fronl aoout 50 to about 500,
preferably from about 100 to about 200 mm of mercury
under an inert gas atmosphere at a ternperature of from
about 10 to about 40C, either continuously or as a
bacch process.
A reactor is continuou~ly charged witn tne
~ ~8 ~ ~ 1 3 13,300
deoxygenated water-in-oil emulsion. Preferably, an
initial cr.ar~e of ~e~ween about 20 to about 50 percent
of tne dPoxygenated ~mulsion is added to tne reactor.
Most ~rererabiy, tne reactor is cnargea wi~n an an,oùnt
of deoxygenated water in-oil emulsion so as to cover the
agitator Dlades t~erein. Tne amount cnarged to the
reactor depends on the geo~etry and size of the reactor.
Also, a catalyst or initiator use~ul in
polymerizing ethylenically unsaturated monomers is added
L0 to tne r~actor. rnes~ catalysts include one or more azo
and/or peroxide containing compounds, SUCh as t-butyl
hyurop~ro.~;~.de, t-bueyl perbenzoate, benzoyl peroxide,
ammonium persulfate, cumene hydroperoxide,
2,2'-azobis(isobutyronitrile), 2,2'-azobis(2,4-dimethyl-
valeronitrile), redox catalysts, and others known in the
art~ These ca~alysts are added to ~he reactor eitner
directly or in the form of a solution, i.e., the
catalyst is dissolved in a solvent, sucn as a
hydrocarbon liquid, i.e., toluene. The catalyst
~ solution contains from about 1 to about 10, preferably
from about 3 to about 6 weight percent of the catalys~.
Frolll about 1 to a~out 99, preferably from a~out
20 to about 60 percent of the catalyst solution is
initially added`to tne reactor containing the
water-in-oil emulsion.
Tne remaining water-in-oil emulsion and
catalyst solution are then continually fed into the
reactor.
Tne polymerization is carried out at a
temperature of fronl about 30 to about 70C, preferably
_ g _
~ 13,300
from about 40 to about 55C, most preferably from about
4~ to about ~2~, ~o~ a~ut 1 to abo~t 10 nours,
preferably from about 2 to about 6 hours. The reaction
time aepending on tn~ size of tne reactor and the
polymeri~ation conditions~
The polynl~rlzation is gener~ carried out at
atmospneric pressure, although subatmospheric and
superatlllvspheric press~r~s may oe used. Tne
polymerization is preferably carried out under an inert
atmospnere, sucn as a ~,elium, argon or nitrogen.
The polymeri~ation reaction generates
consiaer~Dle ~eat wnicn must be removed. Generally, tne
heat is dissipated by normal cooling facilities.
Tne polymerization reaction rate may ~e
controlled hy tne introduction of small quantities of
air (atn,ospnsrlc air an~/or oxygen) into tne reaction.
The air may be introduced, i.e., sparged, either
in~ern,ittently or continuously into the reactor to
control the reaction temperature. When a continuous air
sparginy is employed, the amount of oxygen in the
reaction medium must be carefully controlled so as to
acnieve the desired rate of polymeriza~ion. An oxy~en
content of frorn about 0.01 to about 1.0, preferably from
about 0.02 to about 0~50 parts per million is
desirable. When the air is introduced intermittently, a
flow rate of from about 0.01 to abou~ 1.0, preferably
from about 0.05 to about 0.5 cubic inches per minute,
per pound of reaceor charye is ~esirable. l~he duration
of air injection may vary from a fraction of a second to
a few seconds, and it may be repeated as many times as
- 10 --
(
13, 30'J
necessary unt~l a desired r~e of polymeri2ati~n is
acnievea.
A~ter kne polyr~lerizdtion i5 co~n?lePe, an
antioxidan~ ~ay ~dde~ ~D t~e ~e~ction mass. ~ny orgar.ic
~n~iQ~i~ant ~uic~le ~or ~he inni~i~ion o~ ~ree ra~ical
~e~ctions may be used. ~he antioxidant is generally
dis~olved ~n a s~i~able soivent~ Tne preferred
antioxidants inclu~e aubstituted p~en~ls, such as lono
tnio~is~henol~ sucn as San~onox-R, and nydroquinone
derivatives~ such as ~he monomethyl eeher of
nyaro~uinone~ ~.e ~uit~ble ~olvents incla~e toluene,
benzene, xylene, diethyl ether, methyl acetate, and the
like. Tne antioxi~an~ is pre~ent in the 501~tion in
amounts of ~rom about 1 to ~bout 30, preferably from
aDout 5 to ~bout 10 ~ercent.
~ne antio~idant solution is ad~ed to tne
reaction mass in anlounts of ~ron, about 0.0~ to abou~ 5
p~s ~er hundred p~r~s of resin.
Adaition ~f tn~ ~n~ioxi~an~ ~ay be conlmenced
either ~ the ~nd o~ ~n~ polymerization or after the
~e3csion ~ix~u~a ~as been ~ooled to ~mbie~t ~emperature~
~he r~acti~n ma~s ~s ganerally ~ooled to about
25C ~nd th~ polymer ~ater~in-oil en.ul~ion recoverea.
Tbe polymer water-in-oil emulsion is des~ribed
in Canadian Patent ~pPlication Seri~J. N~. -
410,303 fll~d in the ~ames of N. ehu ~t al, titled
~lynler ~ter-ln-Oil En~ulsiPnsa 9 and.~iled on
AuguAt ~7, 19~20
She ~olymer w~t~r~in-oil ~mulsion ~s Jescribed
said Canadian P~ell~ hnnlic2tion Serial Nn- 6~ n ~ ~n~ -
1 ~
11~'7~13 13,300
eomprises
(a) ~n aqueous phase constituting from
abo~t 60 to ~bout ao, preferably from about 68 to about
78 weight percent, and containing therein f~om about 30
to about ~0, prefera~ly from ab~ut 35 to about 55 ~eiyht
percent of polymer and from abo~t 30 to about 70,
preferably from about 45 to about 65 weight percent of
water;
~ b) ~ hydroph~bic liquid constit~ting
1~ from abou~ 15 to about 50, preferably from about 19 ~o
~bout 31 weight,percent, and
~c) ~n oil~soluble surfactant
constituting from about 0.5 to a~out 5, preferably from
about 1 to about 3 weight percent, said weight percents
(baseo on the total weight of ~he em~lsion).
The polymers produced have an intrinsic
viscosi~y o~ rom about 2 to about 40, preferably from
~bout 10 ~o about 35, and most preferably from about 18
~o Dbout 30 dl/g as measured in a one normal aqueous
sodium chlo~ide solution at 25~C.
The preferred terpolymers are acrylamide
containing terpolymers having an intrinsic viscosity of
at le~st ~bout 15 dlfg. There are described in ' Canadi~n
Paten~ Application Serial No. 410,359
filed in the names of Y. Fan et al, titled "High
~olecul~r Weight Water Soluble Polymers" and filed on
August 27, 1982.
The acryl~mid~ containing polymers in said '
Canadian Patent ApPlication Serial No.
410,359 ~re of t~e ~oll~winq formula:
. - 12 -
, "' ,.
%~ ~
13,300
2 - C ~ l2 C ~ ~ 2 - C
C - O ~ C - O ~ ~ , c
wherein R, Rl and 23 are independently hydrogen or
methyl, R2 is an alkali metal ion, such as Na+ or
K ~ R4 is OR5, where R~ is an alkyl group having
o
up to 5 carbon atoms, -0-C-R , wherein R is either
O
methyl or ethyl, C-0-R , phenyl
substituted phenyl, CN, or ~ ~ , and
R6 is an alkyl group having up to 8 carbon atoms,
wherein(a) is from 5 to about 90, preferably from about
30 to about 60 percent, (b) is from 5 to about 90,
preferably from about 30 to about 60 percent, ~c) is
from about 0.2 to about ~0, preferably from about 1 ~o
about 10 percent, and (d) is an integer of from about
1,000 to about 1,000,000.
Under certain conditions, the alkoxy or acyloxy
groups in the polymer may be partially hydrolyzed to the
corresponding.alcohol group and yield a tetrapolymer o~
the following general formula:
- 13 -
~7~3
13, ~1~0
/' ~ Rl \ / R3 /R3 ~ I
---CH2 - C _ CH2-- C--t CH 2_ c--~ H2 c _
N H 2 a c - o j ~ R 4 ~ _ ~ ~ ' d
wherein ~ R~, R3, R4, a, ~, c, an~ d are as
previously aelln~d an~ e is from a~out 0.1 to aDout 20
percent;
The preferr~ polylners are terpolyl~,ers of tne
follswing formul~:
~C~2- C ~ ~ CH~-C ~ 2
I C=O C=O I 0I j
\ NH2 O- / \ C=O /
. \ f \ R2 / g ~ R7~ / ~ ci
whereln ~ is ~a+ or K~, R7 is metnyl, ethyl, or butyl,
and f is from a~out 5 to about 90, prererably rrom a~out
30 to about 60 percent, 9 is from about 5 to 90,
prefera~ly rrom about 30 to 60 percent h is rrom about
0.2 to about 20 percent, and d is as previously define~
'rhe preferred tetra~olymers are of tne
following formula:
_ 1
/ ~ / R3 \ / R3 1 !
_ r CH2-C ~._ CH2-f~ --r CH2-C-- ._ f C~2-F
I _
C=~ C=0 ¦ 0 OH
NH2 0 _ / C=0 ~é
\ / f \ X2 / 9 \ ~7/ h-~ _ d
-- 14 --
13,300
wner~in ~l, R~, ~3, ~7, f, 9, n, d and e are as previous
defined.
After tne water-in-oil enlulsion lS preparea, a
water-soluble inverting surfactant may be added
there~o. Tne surfac~ants whicn may ~e used include
polyoxyethylene alkyl phenol, polyoxyethylene (lO mole)
cetyl etn~r, polyoxyetnylene al~yl-aryl etner,
quaternary ammonium derivatives, potassium oleate,
N-cetyl N-etnyl morphollnium etnosulfate, sodiunl la~ryl
; 10 sulfate, ~ondensation products of higher fatty alcohols
wi~n e~nylen~ vxi~e, SUCh as the reaction proauct of
oleyl alcohol with lO ethylene oxide units; condensation
produc~s of al~ylphenols and ethylene oxi~e, sucn as tne
reaction pro~ucts ~f isooctylphenol with 12 ethylene
oxide units; condensation products of nigher ~atty acia
amines with five, or more, ethylene oxide units;
e~hylene oxide condensation products of polyhydric
alcohol partial higher fatty esters, and their inner
annydrldes (mannitolan~yaride, called ;Yiannitan, and
sorbitol-anhydride, called Sorbit`an). The preferred
surfactants are ethoxylated nonyl phenols, etnoxylated
nonyl phenol formaldehyde resins, and the like.
The invecting surfactant is used in amounts of
from about 0.1 to about 20, preferably from about l to
about 10 parts per one hunared parts of tne polymer.
The water-in-oil emulsion containing the
inverting sur~actant is then inverted in tne presence of
water as described above.
l~L~7~ , 3GO
EXAMPLES
Tne following exan,ples serve to giv~ s~ecif~c
-illustrations of the practice of this invention but they
are not int~nd~ ~n any way to linllt ~ne scope of this
invention.
Exampl~ 1
Preparati~n of monomer emulsion feed:
ti) ~oaiunl acr~late solution: Arl
acrylic acid solution containing 158.2 gm of acrylic
acia and 186.54 gm of deionized water was neutralize
with a fres~ly prepared 4~ percent sodium hydroxide
solution (abo~t 22~.09 gm) to a rinal pH o~ 6.5. Tne
neturalization was carried ou~ at a eemperature not
exceeding 20~ to prevent yreln~t~e polymerizatlon ~ro,T,
t~king place.
~ii) Acrylamide solution: Tne
~olu~ion was prepa~ed by adding 205.69 gm of acrylamide
cryst~ls under vigorous ~tirsing eo 251.95 ~m of
deioniz~d water at a temperature below 25C. Air s~a~
p~esent ~uring tne dissolution to lnnibit.polymerization.
liii) Oil-~oluble monomer and
~ur~ac~an~ mi~t~e; ~ hon,ogenous solusion was pr~p~red
by dissolving 18.92 gm of a sorbitan monooleate (Span~-80
~uppli~a by Imperi~ e~fli~al Industries) into 339.5 gm
Of Isopar~M while S~irring. Thereafterp 21.27 gm of
vin~l acetate was rapidly ad~ea and the system stirred
for an addi~cional ive minute~; to yield a uniform
tu~.
(iv) ~ono~er emulsi~n fe~a: ~nto a
~ 16 -
~72~3 ` 13.3~0
Waring blender, containing mixture tiii), was added,
under vl~oro~s stirring, solu~ions ~i) and (ii). Tn~
latter was combi~e~ ~it~ 0~06 gn~ 3f ethylenedia~,ine
tetr~acet~c aci~ p~ior to it~ addition t~ ensure
compo~itional uniformity of t~e finished monomer
emul lOn.
~ he n,onomer emul ion as prepared above was
thoroughly deoxygenated by stirring under a vacuum for
10 minu~es ana s~eql~ent~y Drea~lng tne vaccun, wltn
nitrogen; this pr~cedure was repeated ~wo more times.
~nerea~ter, tne ~on~n,er emul ion was Kept at 25~C or
below under a nitrogen atmosphere until its complete
addition. Tne storage tank waa ~quipped witn a cooling
coil ~jacket), ~ temperature measuring device, and an
~ir-in~ection aip ~ube wnicn can ~e us~ to stop tn5
polymerization in case of an acciden~al initiation.
Initiator soiution r~ed: Tnis solution was
prepared by dissolving 0.78 gm of 2,2'-azobis(i~obuty-
ronitrlle) (Vazo-64 supplied by E. I. duPont de ~emGurs
& Co. ~ dissolved in 17.78 gm of ~oluene. Tne solution
was purged witn nitrvgen be~ore and ~urlng the course of
polyme~izatiDn.
Innl~itor ~lutivn: ~ne solution was prepare~
by d~ssolving 0.7B gm of a ~hiobisphenol (Santonox~R
~up~lied vy Monsan~o Chemical Co.~ in 10 gm of toluene.
The ~eactor consisted of a two-liter Pyre
gl~ss reactor equippe~ witn a ~urbine agitator, two
~dd~t~on funnels, a condenser, a thermometer, and a
nitrogen inlet and outl~t ~ube. ~n external
heating~cooling bath ~l/as em}?~oyedY The turbine agitator
-- 17 --
13
13,300
had ~ four-one-inch blade impeller and the blades were
pitcne~ at a 45 angle to tne driving shaft.
The reactor was charged, under a nitrogen
atmosphere, witn 28~.32 gm (2~ percent) of the monomer
emulsion. While the ni^rogen flow continued, heating
was applied to ~ring the reaction ~emperature to 55C.
Once the temperature was stabilized, 3.91 gm of the
initiator ~olution was quickly added. Tnereafter, ~otn
the monomer emulsion and the catalyst solution streams
were continuousl~ ~e~ into the reactor at rates sucn
that feeding was complete in about two hours. The
induction time wa~ usually very short and an exotherln
may occur immediately after the initiator addition.
After cnarglng was co-nplete, the polymerization was
allowed to continue for two additional hours. During
this period, su~rlcient cooling was provided to
dissipate the heat of polymerization. The reactor
tem~erature was maintained at 55+2C. At the end of
polymerization, the inhibitor solution was added and the
reactor was allowed to cool to room temperature (about
25C). The product was discharged through a two-layer
chees~ clotn. Tne conversion was usually quan~itative
and the finished emulsion contained about 30 percent by
weignt of polymer. Tne polymer had an lntrinsic
viscosity of 18 . 4 dl/gm. as measured in a one normal
agueous sodium cnloride solution. The emulsion was
highly uniform and contained very fine particles which
had diameters ranging from about 0.2 to about 5 microns.
18 -
~ 3 . 13,3~0
Example 2
Preparation of ~onomer emulsion feed
li) Sodiuln acryl~;~ sol~tion: An
acrylic acid solution contai~ing 124.B4 gm ~crylic acid
nnd 2~7.86 gn~ of deio~ ed water was ne.ltralized witn c,
freshly prepared 40 percent sodium hydroxide solution
(a~out 17 ~. 3!~ ~m) ~o a f ir~al p~ o~ 6 . ~. Tne
neutrali2ation was carried out at temperatures not
exceealng 20~ ~o prev~n~ premature polyn,erization fron,
taking place.
(ii) Acr~lan,id~ solu~ion: This
~olution was prepared by adding 205.93 gm of acrylamide
crystal~ to ~61.6 gm of w~ter under vigoroua stirrlng at
tempera~ures below 25C. ~ir was present during the
dissol~tion to inniD~t polyt,lerization.
i) Oil-soluble monomer and
surfactan~ mix~ur~: A ho~ogenous solu~ion was prepared
by dissolving 19.12 gm of Span~-BO into 339.43 gm of
Isopar~ unaer agitation~ Therea~ter, ~6.6 gm of etnyl
acrylate was ~apidly added and the 6ystem stirred for an
ad~i~iona1 fiv~ minutes ~o y~ila a unifor~, mixture.
Tne ~onomer emulsic~n feed was prepared and
~deoxygenated, tt~e initiator solution ree~ ano inniDitor
601ution were prepared and ~he ~nonomers polymerized ~11
by tne procedur~ as described in Exan~ple 1.
The product was a milky white waeer-in-o~l
~mulsionJ Examin~tion ~y an optical microscope s~owed
~hat the aY~rage di3me~er of th~ ~uspended part~cles ~as
about 1 ~o 2 ~i~:rons. T 1~ polymer l~ad ~n i~strinsic
~i3cosity of 16 . 4 dl/g~ as ~easu~ea in a one normal
-- 19 --
~'7~3 ~. 13,3U~
aqueoiis sodium chloride solution.
Exan,~ile ~
A portion ~f the product prepared in Example 1
was ~horougn~y mixed witn a water soluble surfactant,
i.e., 2i poly~xyetnylenated nonylphenol (Tergitol NP-10
~upplie~ by Univn Carbide C~rporation) to yield an
emulsion containing about 5.0 parts per one hundred
parts ~f polymer. The ~oly-~ por~ion of tne em~lsion
can be rapidly dissolved in water ~ith stirring. An
lQ aqueou- sol~ition ~ontaining 0.3 percent of tnis polymer
had a typical Brookfield viscosity to about 2,400
centipoise (BrooKfield Vi~cometer ~;odel HB'r, Spinale No.
2, 10 ~PM and at 25~C.).
Exalnple 4
A portion of the product macie in Example 2 was
mixeci witn a water soluble surf actant , i e ., c
polyoxyethylenated nonylphenol (Tergitol ~P 13 suplied
by Unlon Carbide Cor~. ) to yield an ei~iulsion containing
about 5.0 parts of surfact~nt per one hundred parts of
poly~ier. ~n aqueous solution con~aining 1 p~rcent by
weight of this emul~ion had a Brookfield viscosity of
about 2,200 csn~ipoise (~s measured ~iy tne proceciure in
Example 3).
In~o a 500 ml, 4-neGked, resin flaskt fit~ed
wit~ ~ condenser, a thermo~ter, a niechanical stirrer~
~ an additiona~ funnel and a nitrogen inlet tube, ~ere
i addea 75g ~f ~sopa~ M and 4.4 9 of Span~ O unoer
- 20 -
~3'72~3
13,300
nitrogen gas. In a separate beaker, 2B.2g of acrylic
acid disso1ved ~n SOg of distilled water was ne~ralized
(pH 6.7) with 39.29 c~ a 4~ pe~cent sodium c~oride
~olukion. ~ne so~iun, acr~l~te s~lution ~as com~ineG
wien an aqueous 601ution made with 47.19 of acrylamide
and 799 of distil1ed wat~r. Tne aqueous solution was
purged witn nitrogen and then ~dded to ~Ae Isop~ ~M -
Span B0 ~ixt~re w~n rap~ stirrin~ ~o proauce an
emulsion. The emulsion was fitirred under a nitrogen
0 ~tmo~pnere for aDou~ nourO 15.19 of etnyl acryla~e
ana ~.20g of 2,2'azobis(isobutyronitrile) were added.
Tne react;on mix~ure was neated ~o 40C and 0.029 of
~odium bisulfite in 10 ~1 distilled water was 3dded.
The ~emperature oX the emulsion was ~radually increas~
to 43~C. At the san~e time, a solution made with lSg of
Iso~a~)~, an-i 4 . 49 o~ Span~80 was slowly a~d~d ~o t~e
~eaction mixture. The polymerization was carried out a~c
a tempera~ure of 43-45~C ~or 4 hour~ and ~hen at 55C
for 1 nourO A smooth emul ion was obtained at ~he end
of tne react~on. A gas chromatroyrapnic stuay of ~he
emulsion indicated that only four percent of the a~oun~
of ~thyl acrylate usea was left unreact~d~
A portion of ~ne polymer in the emulsion was
precipita~ed by aa~iny the emulsion to isopropanol. Tne
polymer was isolated by fi~t~ring. The poly~er had an
lntrinsic viscosity of 16.1 dl~g as measured in a one
norm~l aqueous sodium chloride solution.
A clear aqueous solution was obtained wnen tne
~solted polymer ~as di~sGlv~d in water indicating that
no bonlopol~ler of et~yl ~ryla~e ~as formed~
- 21 -
~ 3 13,300
~xamples S to 9
The ~roce~re descr ibed in Example 4 and 5 w~re
usëd to psepare ~he polymer emulsions of Examples 6 and
~. Tne emuisi~nC ob~ain~ ~ere used as flocc~lants in
phoephate slimes.
Aqueous so-~tions of tnie polymer emulsions
containing 0~3g vf ~ne poly~er were made by dissolving
tne ~iesire~ amount o~ tne water-in-oil polyl"er emi~lsion
in i~istilled water containing about 0.149 of a
polyox~e~nylenated nonylpnenol ~n inverting s~rfactant
(Tergito ~ NP-13) and diluted to lOOg. The stock
solutions ~ere use~ as Plocculants in pnospnate slimes.
The performance of the polymer emulsion as a flocculants
in phos~ia~ slin-es (~lime l an~ Slin,e 2 were two
phosphate slimes obtained rom a phosphate mining
company) was 3neaSIre~ by tne time in seconds ror ene
~alling interface to travel 30 percent of the height of
tne sediA,~neation tube (de-ign~ted t70). Tne resul~s
~re shown in Tæble 1. Control A contains no polymerO
'
22 -
~7~3L3
~ Z
u
Q)
_
O ~ O~
r~ Q~ 8 ,~ co
U~ ~ o
.. o _1 8
o ~
0 .
E ~ a
~ v
o
~:: ~ c~
4 ~ Ei
Q~ U~
O
~ u~
: ~ D~
v
_~ ~ ~ Ln o O
~_~
U~ L17
J~ Ll
O ~
...,
e O u~ O O
,a _,
Cl ~1 ~1 Ln N
O U L
:E: ~:
a u o o o
~_I .
'~ ~`J U'~ ~ O
U~ ~
.,
~n
o ~ ~ U~
8 L~ ~
~ t) x
~ !~ _l
o
_~
Q ~o r~ c~ ~ o
00~' 1
'7~.3 ~3, 300
.
Exa3l,~1e 1 was exactly repeate~ except ~n~ the
~ollowing changes were ~ade: ~1) Vaz~-;64 was replaced
~i~n one-~al~ ~ne anaount c~f Vazo^52 f;~,2'-azobis
~2,~ dime~hyl-valeronitri~e) ~upplied by E. I. duPon~ de
taemo-~rs ~ Co. ) and tne polymeriza~ion was carried out at
52~C; ~2) tne pH of the ~odium acryl~te solution W25
ad~u~led to ~ insteaa of 6. S. I~-e resul~ant
terpolymer ha~ ~n intrinsic visiosity of 29.7 dl/g as
~eas,~red in a or.e normal aqueous sodlum chlori~e
~olution~ A 0. 3 percent ~olution prepared as~d fl~easured
according to Example 3 exnibited a ~rookf ield viscosity
of 2,720 centipoise.
Ex am~1e 11
Example 10 was exactly repeated except ~hat ~he
followl ng cnanges wer~ ne pi~ of tne sodiu~r,
~crylate ~olution was adjusted ~o 9.4 instead of 8.6;
(2~ ~ con~mercial ~ai~on-c~ll Sû percent caustic sol~tion
was used to neutr~ e the acrylic acid. The resultant
;~o terpolyiDer n~d an intrinsi~ viscosity of ~1 dl/g as
~easured ~n a ~ne normal ~queous sodium chloride
~olution. A 0.3 percent solution prepare~ accor~ir)g ~o
Example 3 ~xhiblted a Brookfield viscosity of 2,650
cen~ipoise.
xam~le 12
Example 10 was exactly repeated except that the
~11vwing cnange~ were n.~da~ 50 percen~ aqueous
~crylamide ~olution ~Cy~namid~ O supplied by American
~yanamid ~o.~ was substi~uted for th~ acryla~ide
- 24 -
~ 7~3 13,300
crystals; an equal amo~nt of water was reduced from the
oriyinai formulation such tna~ ~n~ oil/water phase ratlo
remained unchanged; (2) acrylic aci~ was neutralized to
a pH of 6.5 instead of P~.6. Tne resultant terpolymer
had an intrinCic ~iscosity of 21.7 dl/g as measured in a
one normal aqueous sodium chloride solution. A 0.3
percent solution prepared according to Example 3
exr,ioitea a BrookIield viscosity af 2,848 centipoiae.
ExamEle 13
10 Flocculation tests of the terpolymers prepared
in Example 10-12 were carried out according to the
proceaures describea in Exani~12s 6-9. Tne t70 values
of all tnree samples were tound to be below B seconds as
COlllpare~ tO several nours with that of the control.
comparison, the supernatant of the control suspended
particle~ even after several nours of stanaing.
Example 14
A thr~e foo~ diameter Enviroclear thickener was
used into which phospnatic slimes and sand were mixed~
The sand to clay ratio was 1.56. A flocculant
concentrate in water (0.25 weight percent) was formed
from a terpolymer emulsion containing 55 Il,ole percent of
acrylamide, 32.5 mole percent of sodium acrylate, and
12.5 mole percent of etnyl acrylate. Tne flocculant
concentrate was pumped at a rate of 0.92 gallons per
minu~e and n,ixed witn dilution water rlowing at a rate
of 3 gallons per minute. The diluted flocculant
solu~ion (0.007~ weignt percent based on we gnt of the
emulsion) was mixed with sand and phosphatic slime (3.69
- 25 -
~137~3~
13,300
percent solids). The flow rate of phosphatic slime was
9.52 gallons per minute.
The flocc~lant dosage was 1.32 pounds of
emulsion per ton of dry slime solids. This procedure
~esulted in an increase of percent slime solids from
3.~9 to 19.9.
Control_B
The procedure of Example 14 was exactly
repeated e~cept that a flocculant concentrate in water
(0.25 wei~h~ percent) was formed from a copolymer
emulsion containing 75 mole percent of acrylamide and 25
mole percent sodium acrylate. The flocculant
concentrate was pumped at a rate of 0.1 gallons per
minute and mixed with dilution water flowing at a rate
of 3 gallons per minute. The diluted flocculant
solution (0.008 weight percent based on the weight of
the emulsion) was mixed with sand and phosphatic slimes
(3.S0 percent solids). The flow rate of phosphatic
; slime was 8.6 gallons per minute.
The flocculant dosage was 1.75 pounds of
emulsion per ton of dry slime solids. This procedure
resulted in an increase of percent solids from 3.50 to
15.1~
It can be seen that the terpolymers of the
present invention ~Example 14) are more effective
flocculants than the copolymers of Control B.
- 2~ -
~'7~3 13,300
Example 15
Example 1 was r~pea~ed witn tn~ exc2p~ion tr,at
(1) Vaz~-~4 was ~eplaced with o~e-half the amount of
6~,
Vazo-5~; ( ) the polymer~zation wa~ carrieà out ~t 5~C.
acc4r~ing ~ e following ~rocedures:
Polyn~rization re~ctor (lab ~atch): a
two-lit~r Pyr~x glass reactor equipped wieh a turbine
agitator, ~n a~dition ~unn~l, a conaenser, a
thermometer, ~ nitro~en inlet and outlet, and an
1~ external n~a~in9/coolin~ Dath was em~loye~. Tne tur~ine
a~itator had a four-one-inch-blade impeller an~ the
blaa~s.we;~ pitcneG at a 45C. angle to tne driving
shaft, and was operating at 650 revolutions per minute
during ~ne Co~rse of polymerization.
The ~onomer emulsion was transferred into ~he
glass ~eactor an~ was ae~ass~a ~y stirring it unaPr
vacuum for 10 minutes and subsequently breaking ~he
V~UUIll witn nitrogen thiS procedure was repeat~d ~wo
~ore times.
About 20 percent of tne Va~o~52/ioluen~
~olution was i~troduced in~o t~e degassed monomer
emulsion in tne ~eactor. While tne nitrogen flow
continued, ~xternal heating was applied to bring the
reacrlon tem~era~ure to 52C. Onoe tne polymerizatlon
be~anS tne remainin~ initia~or ~olution was added
~ontinuou~ly into tne reactor ~t a rate such that She
~ddition was completed in two hour. When the iflitiator
~ol~tion adai~ion was ~inisnedt t~e polymerization WdS
allowed to proceed for t~o additional ho~rs. ~urin~ th~
~ntire co~rse of polynleriæa~i~n~ s~fficient ~oolin~ was
- 27 -
~7Z13 13,300
provided ln order to dissipate the ~eat of
polyn,erization. At ~he end of ehe polymerization, the
emulsion was coQled to roonl temperature (ab~ut 25C),
and tne inhiDitor solution was ~dded. ~ne water-in oil
~emulsion produoed ~as a fairly viscous, milky white
liq~-dO qh~ con~ersion was ~ua~tttatiYe. Tne polyn,er
pr~du~ed bad ~n intrinsic visoosity of 32 dl/g as
~easure~ in a on~ normal aqueous sodium chloride
~olution.
Fxam~le 16
~ ne pro~edure of Exa~ple 1 was used to prepare
~n emulsion ~on~ining an a~rylamide/sodium
acrylate/Yinyl acetate terpolymer. Tne terpolymer
con~ai.~ed ~4.2 ~no~e per~ent of ~crylamide, 41.1 mole
percent ~odium ~crylate and 4.7 mole Fer~ent of vinyl
acetate. T~e terpolymer l~ad an intrinsic viscosity or
13 dl/g as measured in a one normal aqueous ~odium
cnloride solution.
An ~queous solu~ion of the poly~er emulsion
containing ~.3 9 of tne polymer was made by dissolvins
~he desired a~ount of the waeer-in-oil polynler emulsion
In distilled ~at~r containing ~bout 0.14g of ~
polyetnylenated nonylphenol surfactant (Tergi~ol NP-13)
and dilu~ed to 1009. ~he ~olution was used as a flo~-
~ulant in pnos~ha~2 slinles. Tne per~Drmance of the
polymer emul~ion as ~ floGculant in a phosphate slime (a
phosphate sli~e o~tained ~rom a phosphate n~ining
cQmpany3 W~5 ~asured by the time in seconds for ehe
f~lling ineerface ~o travel 30 percent o~ tne heigh~ of
~ 28 -
13
13,300
the sedimentation tube (designated t70). The results
are shown in Table II.
Example 17
The procedure of Example 16 was repeated to
prepare a terpolymer having an intrinsic viscosity of 15
dl/g as measured in a one normal aqueous sodium chloride
solution. An aqueous solution of the polymer emulsion
was prepared and tested as described in Example 16.
The results are shown in Table II.
Example 18
~ he procedure of Example 16 was repeated to
prepare a terpolymer having an intrinsic viscosity of 17
dl/g as measured in a one normal aqueous sodium chloride
solution. An aqueous solution of the polymer emulsion
was prepared and tested as described in Example 16.
The results are shown in Table II.
Example 19
The procedures of Example 16 was repeated to
prepare a terpolymer having an intrinsic viscosity of 19
dl/g as measured in a one normal aqueous sodium chloride
solution. An aqueous solution of the polymer emulsion
was prepared and tested as described in Example 16.
The results are shown in Table II.
Example 20
The procedure of Example 16 was repeated to
prepare a terpolymer having an intrinsic viscosity of 22
dlJg as measured in a one normal aqueous sodium chloride
solution. An aqueous solution oE the polymex emulsion
~B7~13
13,300
was prepared and tested as described in Example 16.
The results are shown in Table II.
Example 21
The procedure of Example 16 was repeated to
prepare a terpolymer having an intrinsic viscosity of 28
dl/g as measured in a one normal aqueous sodium chloride
solution. An aqueous solution of the polymer emulsion
was prepared and tested as described in Example 16.
The results are shown in Table II.
TABLE II
I.V. of Polymer
Example (dl/g) Performance, t70(sec
... ~
16 13 41
17 '5 30.5
18 17 20
19 19 13
22 11.5
21 28 11.5
- 30 -
