Khảo sát phương pháp xử lí tăng khả năng hấp thu các ion kim loại nặng trong nước của khoáng bentonite Việt Nam

DAI HOC QUOC GIA HA NOI
TRUING
DAI HOC KHOA HOC Tl/NHIEN
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BAO CAO DE TAI
KHAO SAT PHUONG PHAP
XlTLI
LAM
TANG KHA
NANG
HAP
THU
CAC ION KIM LOAI NANG TRONG
NUdc
CUA KHOANG BENTONITE VIET NAM
Ma sd:
Chii
tri de tai:
PGS.
TS. Ng6 Sy Luang
Can bg phdi hgp:

1.
TS. Than Van Lien
2.
ThS. Ha Van Van
3.
ThS. Pham Van Tien
4.
CN Nguyen Thuy Mai
DAI HOC QUOC GlA HA
NOi
TPUNG
TAt^
THOr.'G
TIN THO
VlFN
DT J4 t
Ha Noi 2005
PHAN L BAO CAO TOM TAT DE TAI BANG TIENG VIET
1.
Ten
detai:
Khdo sdt phuang phdp xir ly ldm tdng khd ndng hdp thu cdc ion kim
logi
ndng trong
nUdc ciui
khodng bentonite Viet Nam.
Ten tieng Anh:
Research of treatment method to improve the ability of absorption for heavy metal
ions on Vietnamese bentonite.
2.

Chu tri de tai: PGS. TS.
A^^^
Sy Luang
Hgc ham, hgc vi: PGS. TS. Dan vi cong tac: Khoa Hod hgc Tel:
8241169
3.
Cac can bg tham gia de tai:
1.
TS. Than Van Lien
2.
Thac sy Ha Van Van
3.
Thac sy Pham van Tien
4.
CN Nguyen Thuy Mai
4.
Muc tieu va ngi dung nghien cuu:
Bentonite
la loai khoang set tu nhien, cd cau
true
Idp,
cd dicn tfch be mat
Idn nen
cd
khci
nang hap thu tu m6i trudng nudc nhieu chat v6 ca va huu co. Vl vay
bentonite
dugc ung
dung trong nhieu
ITnh

vuc cd lien quan den kha nang hap thu cua no: xu
li
moi trudng, lam
sach cac chat Idng khoi cac tap chat, che dung dich khoan, lam chat don.
Nudc ta cd
triT
lugng bentonite tuong ddi
Idn,
gdm mot sd mo nhu: Di linh - Lam
Ddng, Thuan hai - Binh thuan, v.v Theo danh gia sa bg ham lugng montmonllonite trong
khoang bentonite cua nudc ta kha thap. Vi vay viec nghien cuu cac phuong phap lam tang
ham lugng montmorillonite, ddng thdi hoat hoa de lam tang kha nang hap thu cua loai vat
lieu nay
nluTm
muc
dich
tang kha
lulng
su dung ngudn tai nguyen nay phuc vu cho cac nganh
kinh te qudc dan la mot van de rat dang dugc quan tam.
Mot trong nhung ung dung quan trgng cua khoang bentonite la
sir
dung nd lam vat
lieu hap thu ion kim loai nang trong
ITnh
vuc xu
If
n^oi
trudng nude. Do vay, viec
nghien

cuu
cac phuong phap hoat hoa lam tang kha nang hap thu eua bentonite
ddi
vdi cac ion kim loai
nang la mdi quan tam cua nhieu nha khoa hgc trong va ngoai nude.
Bentonite cd mat trong dat, do cd kha nang hap thu
nen
nd hoat dons nhu cac ludi loc
tu nhien. Khi nudc tham qua cac Idp dat thi bentonite
giiTr
lai cac ion kim loai \'a cac chat huu
CO.
Vi vay, bentonite tu nhien bao gid cung da chi'ra
sfin
(du ft hoac nhieu)
mot lugne
nhat
dinh cac chat da bi hap thu va
vice
loai bd cac chat nay de lam tang kha
naiio hap
thu cua
bentonite trudc kin
sudung
la nhiem vu quan trgng.
De lam tang ham lugng
ciia
montmorillonite trong khoang bentonite, ngirdi ta
thudni
sir

dung cac phuang phap tuyen khoang va phuang phap thudng dugc
sir
dung la tuyen
trgn^
luc.
Hien nay cd mot sd phuang phap mdi dugc ap dung, vf du nhu tuye'n bang xyclon.
De hoat hoa lam tang kha nang hap thu cua bentonite, ngudi ta thudng su dung mot sc
phuong phap sau:
- Phuang hoat hoa bang nhiet:
Dicing
nhiet do cao de loai nudc hap phu,
loai
cac
cha
huu ca khoi khoang bentonite.
-
Phuang phap hoat hoa bang dung dich kiem: Dung dung dich kiem cd ndng do
thfcF
hgp de xu
If
khoang bentonite.
- Plurang phap hoat hoa bang dung dich axit vo ca: Dung dung dich axit v6 co (thudng
la axit
sunfuric,
axit clohydric) cd nong do thfch hgp di xu
If
khoang bentonite.
Ccic phuang phap hoat hoa ndi tren dugc su dung mot
each
thfch hgp tuy theo thanh

phfin,
ham lugng montmorillonite trong bentonite va dac biet la tuy thugc vao muc dfch
sii
dung. Trong dd phuang phap hoat hoa bang cac dung dich axit sunfuric la dugc su dung
nhieu
nhai
va cd hieu qua nhat.
4.L Muc tieu nghien cuu
- Ddi tugng nghien cuu la bentonite vung Di Linh - Lam D6ng va
vising
Tuy Phong -
Binh
thuan. Day la nhung
vising
co khoang
bentonite
co tru lugng thugc loai
Idn
nhat nude ta
hicn nay.
-
Tim phuoug
phap thfch hgp nang ham lugng montmorillonite trong bentonite.
-
Tim
dieu kien tdi
iru
cho qua trinh hoat hoa bang axit nham lam tang kha nang hap
thu
ciia bentonite

ddi vdi cac ion kim loai nang trong mdi trudng nirdc. Nhu vay san pham
bentonite sau khi hoat hoa nham muc dfch xu
If
moi
trudng:
tach loai cac ion kim loai
nans
tu
moi
truoug nuac,
- Khao sat kha nang hap thu cac ion kim loai nang
ciia
bentonite trong dung dich
nudc.
4.2,
Ndi dung nghien cuu.
- Phan tfch thanh
phfin
khoang va thanh phan hoa hgc cua man bentonite nghien ci'ru.
-
Kluio
sat phuang phap lam sach va hoat hoa bentonite bang axil
H^SOj
cd ndng do
va dieu kien thfch hgp de lam tang kha nang hap thu cac ion kim loai nang
tromz
nude.
- Khao sat kha nang hap thu ciia bentonite sau khi xu ly va so sanh vdi kha nang hap
thu
ciia

bentonite nguyen khai chua xu
ly.
5.
Ciic kel qua da dat dugc
g. Anh hudng cua cdc chdt dien li trong moi trudng nudc
Chuang
II.
Phuang phap nghien
cu*u
2.1.
Phuang phap hoat hoa quang
2.2.
Phuang phap phan tfch thanh phan hoa hgc
ciia
bentonite
a. Xdc dinh hdm
SiO^
b. Xdc dinh hdm
FeiO:^
c. Xdc dinh hdm luang
AFOj
d^Xdc
djnh MgO vd
CaO
2.3.
Phuo'ngphdp
xdc dinh sdt, mangan trong dung dich
a.
Phuo'ng phdp trdc r/uang xdc dinh ndng do ion sdt trong dung dich vdi thudc
thir

thioxianat.
b. Xdc dinh mangan bdng phuo'ng phdp trdc c/uang
2.4. Phuang phap xac dinh hap dung cua cac ion kim loai tren bentonite
Chuang III - Ket qua va thao luan
3.1.
Khao sat cac yeu td anh hirdng den kha nang hap phu cac ion kim loai nang
trong moi Irudng nirdc cua bentonite.
34.FF
Anh hudng cua pH dung dich
dcdi
khd ndng hdp phu
Fc'^
vd
Mm^
tren
bentonite.
3.1.2.
Anh hudng cua thdi gian khuay tdi
sUhdp
phu
Mm^vd
Fc'^
tren bentonite
3.1.3.
Anh hudng
ciia
ndng do chdt
bi
hdp phu
3.F3. Anh hudng

ciia
ty le the tich
ciui
dung dich hdp phu vd khdi lugng
be/itonite.
3.2. Mau khoang bentonite
sir
dung de nghien cuu
3.3.
Khao sat qua trinh hoat hoa bentonite
3.3.1.
Logi axit
3.3.2. Ndng do axit
3.3.3.
TvleRIL
3.3.4. Nhiet do hogt hod
3.3.5. Tdc do khuay tron
3.3.6.
Thai
gicm
hogt hod
Ke't luan
Tai lieu tham khiio
MOiDAU
Bentonite la loai
khocing
set tu nhien, cd ca'u tnic
Idp,
co dien tfch be mat
Idn nen

cd kha nang ha'p phu nhieu chat vo ca va
hxiu
ca
[1,51.
Vi vay bentonite
la
loai vat lieu
dugc ii'ng dung trong nhieu
ITnh
vuc khac nhau.
Nudc ta cd tru lugng bentonite tuang ddi
Idn,
d mot sd mo nhu: Di linh - Lam
Dong, Thuan hai -
Binh
thuan, v.v Quang bentonite Viet Nam cd ham lugng
montmorillonite kha thap, chat lugng kem, do do viec nghien cuu lam tang chat lugng de
cd the
sir
dung tdt han ngudn lai nguyen nay de phuc vu cho cac nganh kinh le qudc dan
la mdt va'n de ra't dang quan tam.
De tang cudng cha't lugng cua khoang bentonite, cd hai van de can dugc tien hanh:
- Lam tang ham lugng montmorillonite trong khoang bentonite. Giai doan nay
thudng
ditgc
tien hanh bang cac phuang phap tuyen khoang th6ng thudng, chu yeu la
phuang phap tuyen trgng luc.
-
Hoat hoa khoang bentonite sau khi lam giau de tang kha nang hap phu cua no. De
hoat hoa bentonite, ngirdi ta thudng

sir
dung cac phuang phap hoat hoa nhict, hoat hoa
bang dung dich kiem, hoat hoa bang dung dich axil, trong dd phirong phap hoat hoa bang
dung dich axit vo ca, nlur
H2SO4,
HCl dirge
sir
dung ph6 bie'n nhat.
De danh gia chat lugng bentonite sau khi lam giau va hoat hoa, phuang phap phd
bie'n
la
danh gia qua kha nang hap phu cua bentonite ddi vdi cac ion kim loai nang trong
dung dich nirdc. Dong
tlidi
muc dfch
sir
dung bentonite lam vat
lieu
hap phu tach loai cac
ion dd khdi m6i tnrdng nudc gdp phfin chdng 6 nhiem m6i trudng cung la mdi quan tam
hang dau ddi vdi cac nha nghien cuu trong nirdc va tren
the
gidi trong
ITnh
vuc nay
[5-8].
Xuat phat tu y tudng do, chung t6i dat van de khao sat kha nang lam giau va hoat
hoa bentonite bang phuong phap axit, cu the la
H2SO4.
Muc tieu nghien cuu dirac dat ra

trong de tai nghien cuu nay
la tim
dugc phuong phap xu If lam tang kha nang hap phu cua
bentonite ddi vdi cac ion kim loai nang trong
in6i
tnrdng nudc.
Cac ngi dung nghien ci'ru dugc dat ra trong de tai nghien cuu nay la:
- Phan tfch thanh phan khoang va thanh phan
hoii
hgc
ciia
mau bentonite nghien
cuu.
- Khao sat phuong phap lam giau dc tang ham lugng montmorillonite trong
khoan"
bentonite.
-
Khao sat phuang phap xu ly axit
H.SO^
cd nong do va d dieu kien thfch hop de
lam tang kha nang hap phu cac ion kim loai nang trong nudc.
- Khao sat kha nang hap
phii
cua bentonite sau khi xu ly va so sanh vdi kha nang
hap phu cua bentonite nguyen khai chua xu ly.
Cac thf nghiem nghien
cu*u ciia
de tai nay dugc tien hanh d phong thf nghiem Vat
lieu mdi thugc bg mon Hoa Vo ca - Khoa Hoa hgc - Tnrdng DHKHTN - DHQG HN va
phdng thf nghiem thugc Trung tam Xu

If
quang - Vien C6ng
nghe
Xa - Hiem thugc Vien
Nang lugng nguyen
tir
Viet Nam. Kinh phf cua de tai
dagc
DHQG HN cap qua de tai cap
DHQG mang ma sd . Chung t6i xin chan thanh cam an DHQG HN da cap kinh phf de
chung toi hoan thanh cac ngi dung nghien cuu cua de tai nay.
4
CHUONG I.
GICJI
THIEU VE BENTONITE
I.GI6I
THIEU VE BENTONITE
LI
Thanh phan hoa hgc cua bentonite.
Bentonite la loai khoang set tu nhien, co thanh phan chfnh la montmorillonite. Vi
vay cd the ggi bentonite theo thanh phfin chinh la montmorilonite. Cong thuc dan gian
CLia
montmorillonite
ALOv4Si02.nH20
I'mg
vdi nua te bao don vi cau tnic. Cong thuc ly
tudng cua montmorillonite la
SiyAl402o(OH)4
cho mot dan vi ca'u tnic. Tuy nhien thanh
phfin cLia

montmorillonite luon khac vdi thanh phan bieu dien ly thuyet do cd
sir
thay the
ddng hinh cua cac ion kim
locai
nhu
Fe"*"", Fe^"^,
Mn"""
vao vi trf cua
Si"*""
trong tu dien
Si04
va
ciia
Al"^^
trong bat dien
AlO^
Nhu vay thanh phfin hoa hgc montmorillonite, ngoai
sir
co mat cua Si va AI, ta cdn
iha'yeo sir
xua't hien
ciia
cac
nguyen
td khac nhu: Fe, Zn, Mg, Na, K, v.v , trong do ty
le
ALQvSiO.tu
1:2
den 1:4.

Ngoai thanh phfin chfnh la montmorillonite, trong bentonite con chua mot sd
khoang set khac nhu
liectorit,
saponit va mgl sd khoang phi set: canxit, pirit, manhetit, cac
mudi kicm va mot sd cha't huu ca khac.
1.2. Cau tnic cua montmorillonite
Trong c6ng
thi'rc ly lirdng
cua montmorilonite, cac nguyen tu Si
nfim
d mang tu
dien, con cac nguyen tu Al nam d tam mang bat dien (trong tnrdng hgp mang nhom
silicat la trung hoa dien) va cong thi'rc khai trien cua nhu sau hinh 1.
O
o
^
^o
o o o
.
:
S
i
1
i
c O : O x
I
Hinh!.
Cong thirc khai trien khong gian
ciia
montmonllonite li

tirdng
Do montmorillonite cd cau tnic 2:1 dang diocta nen cau tnic lap montmorillonite
da dugc hinh thanh
tir
hai mang tir dien lien ket vdi mot mang bat dien d giua, tao
nen
mgl
Idp nhdm silicat vdi cac khe trdng d giua. Cac cation co kha nang trao d6i bi hydrat hoa
va nudc bi ha'p thu cd the chie'm cho d cac khe trdng giua cac lap nhom sislicat. Chieu
rdng
CLia
khe trdng
giiJa
cac
Idp
cau tnic ca ban
ciia
montmorillonite la 9,6 A,
chidu
rong
dd cd
th^
bi thay ddi ft hay nhieu tuy thugc vao sd lugng, ban
chfi't
cation trao doi va
lugng nude hap thu, thudng c6 the den 15 A. So d6 ca'u tnic khong gian mang
lircri ciia
montmorillonite, dugc trinh bay tren hinh 2, la mgl cau tnic trung hoa dicn. Neu
Si"^^
ti'r

dien hay
AL"^
bat dicn bi thay the dong hinh bdi cac cation duong thap hon thi cac phan
mang dd tfch dien am. Dien am cao hay thap tuy thugc vao sd lugng va ban chat cua cac
cation thay the. Dien tfch am cua mang se dugc
bi^i tri^r
bang cac cation mang dicn tfch
duang
Na"^,
K"*^,
Ca^"^,
Fe""^,
Mn""^
d khoang kh6ng gian giua cac
Idp.
Nhu vay kha nang
trao ddi cation cua montmorillonite la tuang dirang vdi dien tfch
ciia
cac
Idp.
Ci*
iioo trs.c ^i -f nW^c
O.Va
« SLLLc J hojc nhom
Hinh 2. Sa dd cdu
true
khong gian
nigng
ludi cua montmorillonite
1.3. Cac kha nang bien

tinh
Bentonite
7.3.7 Bien tinh giir nguyen cdu
true
cda lop
aluniinosilicat
Dac trung ca ban cua bentonite la tfnh chat trao ddi. Tfnh chat dd cd dugc la do
sir
thay the ddng hinh
Si'*''
bang
Ah^"*"
trong mang
ti'r
dien va
Ah^^
bang
Mg"""
trong mang ludi
bat dien lam xua't hien dien
tich
am trong mang ludi cau
true.
Kha nang thay doi manh
hay yeu
phii
thugc vao lugng dien tfch
am
be mat va sd
lugng

ion trao ddi. Neu sd lugng
dien tfch am
be
mat cang Idn, sd lugng cation trao ddi cang
Idn
thi dung lugng trao d6i
cLia
bentonite cang
Idn.
Kha nang trao ddi ion
ciia
nhdm silicat con phu thugc vao dien
ti'ch
va ban kfnh
cation trao doi. Dien tfch cation cang thap thi cang de trao ddi hon cation dien tfch cao
Me^>Me2-^>Me^L
Ddi vdi Ccic cation
ciuig
dien tfch, ban kfnh cang nho
thi
kha nang trao d6i cang
Idn cd the xap xe'p theo trat tu sau Li > Na > K > Cu > Fe > Al.
Tuy nhien kha nang trao d6i cua nhom silicat
chii
yeu van phu thugc vao dien tfch
am
be
mat va
luanc
dien tfch am

iron"
manti
ludi. Bentonite
^6m
be mat Irons va be mat
ngoai. Kha nang trao doi ion be mat ngoai phan anh kfch thudc tinh the, phu thugc vao
kfch thudc tinh the, phu lhuoc vao su
di'rt
gay lien ke't va khuyet tat be mat. Kfch thudc hat
cang nhd
thi
kha nang trao doi cang Idn. Kha nang
tiao
d6i
be
mat trong phan anh lugng
dien tfch am trong mang ludi va khii nang
hfip
phu cua bentonite. No phu thugc vao lugng
cation bu
tri^r
trong mang ludi. Sd lugng cation cang
Idn ihl
kha nang trao dcii cang Idn.
Dung lugng cation dao dong
lir
80
-^ 150
mgdl/lOOg.
Dung lugng trao ddi anion dao dong

tu
15H-40mgdI/100g.
Ngoai ra,
sir
trao doi ion
ciia
bentonite con lien quan den
sir
thay the cac nguyen
lir
hydro trong cac nhdm hydroxyl
ciia
montmorilonite. Theo mot sd nghien ci'ru, dinh
ciia
cac tir dien
Si04
hirdng ra phfa ngoai
ciia
Idp
cfi'u
true.
O
dinh
nay cac nguyen tir
ciia
oxy
bi thay the bdi cae nhom hydroxyl va cac nhom nay dam nhiem viec duy
tri
lien ket yeu
giua Ciic

Idp
va gop phfin vao su
can
bang dien ti'ch. Trong montmorilonite con co cac
nhdm hydroxyl
nfim
d dinh
ciia
cac bat dien
AlO^.
Trong sau dinh
ciia
bat dien co hai
dinh la nhom OH cdn bdn dinh kia la oxy( hinh3).
0
.OH
OH
Al
/ \
0 0 0 0
I
I I I'
I II
Hinh 3. Vi
ni ciiu ciic nlioni
OH c6
rroiii;
maii;.^
luai can
Hue ciia l)eiiionlfe

1
0
d
1
H
6^
0
1
in
1
0
-A/
/ \
?
f
Trong dd nhdm hydroxyl
ciia
lien ket Si-OH (1) kh6ng co kha nang trao doi
hydro, nhdm hydroxyl trong lien ket Al -
0H(11)
cd tfnh axit yeu nen kha nang trao doi
yeu. Nhdm hydroxyl trong lien
le't
Si-0-Al(l
11)
cd tfnh trao ddi manh
nen
cd tfnh quyet
dinh den dung tfch trao doi cation
H"'.

1.3.2. Bien tinh ldm bien ddi cdu triic
Idp
aluniinosilicat
Khoang bentonite tu nhien chi'ra nhieu tap chat nhu cac mudi can
xii
(CaCOO,
dolomit
(MgC03),
mot sd oxyt:
FcjO^
, FeO,
Ti02,
v.v va cac tap chat khac.
Qua trinh hoat hoa bentonite dugc thuc hien bang each dimg kiem hoac axit hoa
tan mot sd oxyt luang tfnh nhu
AI2O3,
Fe203,
de tao tren be mat set nhung 16 xdp va trung
tam hoat dong, Viec sir dung nong do kiem hoac axft cao cd kha nang hoa tan nh6m oxyt
lam thay doi cau
true
bentonite.
1.4. Dac tinh cau
true
bentonite va kha nang hap phu
Chfnh
V]
bentonite co ca'u tnic
Idp
va do phan tan cao

nen
no cd cfiu
true
xdp phuc
tap va be mat rieng
Idn.
Ca'u tnic xdp anh hudng rat
Idn
de'n tfnh cha't hap phu
ciia
cac
cha't, dac
iiung ciia
nd la tfnh chat chon loc chat bi hfip phu.
Chl
co phan tir nao cd dudng
kfnh
dii
nhd so vdi 16 xdp
thi
mdi chui vao dugc de tham gia va qua trinh ha'p phu. Dua
vao dieu nay ngudi ta cd the tien hanh hoat hoa sao cho co the
diing
bentonite lam vat lieu
tach chat. Day cung la diem khac nhau giua
bentonite
va cac chat
ha'ji
phu khac.
Nhd du dicn tfch tren cac nguyen tir

ciia
cac nut mang tinh the eho nen bentonite la
mot chat
hfi'p
phu phan cue va vl vay no se uu tien hfip phu cac chat phan cue. Tuy nhien,
bentonite van cd the hap phu cac chat khong phan
cue
do
lire
van der Walls va tuang tac
hfip phu
chii
ye'u la tuang tac cam ung. Be mat bentonite eo dien tfch tuong ddi
Idn
bao
gdm be mat ngoai va be mat trong. Be mat trong bao
g6in
be mat
ciia
cac lap nhom silicat
chdng len nhau va dugc ngan each bang cac cation kim loai den bu dien tfch tren be mat
Idp bentonite.
Be
mat ngoai dugc xac dinh bdi be mat
ciia
cac mao quan chuyen tiep. Cac
mao quan nay dugc lao
nen
do su tiep
xiic ciia

cac hat bentonite va cd kfch thudc khoang
40 A
-^
90 A. Dien tfch
ciia
be mat ngoai phu thugc vao kfch thudc cac hat bentonite, hat
cang nhd thi dien tfch be mat ngoai cang
Idn.
Kha nang trao ddi ion
Idn
cung vdi kha
nang hfip phu tdt ma ta cd mgl loai vat lieu xir ly kim loai nang ra't hieu qua tir bentonite.
II.
NHUNG UNG DUNG CHU YEU CUA BENTONITE
Do cd kha
lulng
hfip phu lot nhieu cha't v6 co va hiru co,
nen
bentonite cd nhieu
Uim
dung kha da dang va phong
phii
trong
sir
phat trien
ciia
xa hgi.
2.1.
Sudung
bentonite

lam
chfit hap phu
Bentonite dugc dung rong rai trong nhieu nghanh cdng nghiep vdi vai trd la chat
hap phu:
Trong cong nghiep lgc dau, lugng bentonite dugc sir dung rat
Idn,
bao gom
bentonite tu nhien va bentonite da hoat hoa. Lugng bentonite tu nhien lieu tdn cho qua
trinh lgc dau la 25% lugng dau phai lgc ciing vdi mgl lugng bentonite da hoat hoa bang
10%
khdi lugng dfiu.
Trong cong nghiep tinh che dfiu thuc vat de xan xua't dau an, md, bo, xa phong,
viec
SIX
dung bentonite lam chfit hfip phu la uu viet han han phuang phap cu la phirong
phiip
ririi
kiem. Lugng
bentonite
mfit di trong qua trinh tinh che
chi
bang
0,57t:
lugng dfiu
dugc tinh che'. Ngoai ra phuong phap
dimg bentonite
con co muc hao phf dfiu thfip do
tranh dugc phiin ung thuy phan
Trong cong ngiep dieu che' than cdc phuc vu cho cong nghiep luyen kim, bentonite
dugc sir dung de tinh che benzen tho

vfi
ciic ban
sfin phfim
khac.
Nhd
CO
dac diem hfip phu dac biet tdt, bentonite con dugc sir dung rong riii de
si'ui
xufit nhien lieu long t6ng hgp, xiin
xufil cfic
chfit mau, xiin xufit ciic vitamin
2.2.
Sii
dung
bentonite de
che dung dich khoan
Benlonite co the'
liio
ra ciic dung dich khoan vdi chfit lugng dac biet
ciio
va chi phf
nguyen
lieu thfip. Vl the, cimg vdi
vice phi'it
trien
ciui ngiinh
tham do va khai thiic dfiu,
lugng benlonite sir dung cho viec che
tiio
dung dich khoan

ngiiy
cang lang.
Ngiiy
nay d
My, lugng bentonite sir dung cho
vice
che
tiio
dung dich khoan
chicTn
tdi 40% t6ng siin
lugng bentonite
ciia
nudc nay.
2.3.
Sii
dung bentonite lam chat
dgn,
chat mau
Trong cdng nghiep siin xufit
Ci'ic
vat lieu t6ng hgp.
Vlgt
lugng
Idn ciia
bentonite
dimg
cho cdng nghiep xa phong, c6ng nghiep xiin xuat
viii
sgi.

Vice
sir dung bentonite
trong
Viii
thap ky gfin day cung da
liim
thay doi dang ke nganh c6ng nghiep gifiy. Trudc
kia gifiy thudng chua sfip
xi
55%
xenlulo vfi
ham lugng
ciiolin
nguyen chfit cd trong giay
khong the" vugt
quii
45%. Neu
iron
them 10%
benlonite
kiem (cation trao ddi la kim loai
kiem,
chii
yeu la
Na"") viio
caolin
thi
co the nang ham lugng chfit don
nixy len
tdi 60%;

Neu tron them
207o
bentonite kiem thi ham lugng chfit dgn co the' nang len diin 64% va
neu dimg 100% bentonite thi chfit dgn len tdi 84%, nghTa la giiim lugng xenluno cfin co
trong
giiVy
di ba
\i\n.
2.4.
Sir
dung bentonite trong cong nghiep ruou bia
Viec sir dung bentonite
hoiit hoii liun
chfit hfip phu da lam
giam 3(}9(
den
40%
chi
phf cong nghiep che bieii rugu vang
vii
ciic
che
pham ur rugu \ ang.
Bentonite
co kha nang
hap thu khong chi cac axft
hiru
ca,
ciic cha't beo, cac san phu khong mong mudn trong qua
trinh len men ma cdn cii ion sat va ddng

lii nhij*ng
tac nhan
gfiy
ra benh ha rugu. dac bietm
trong qua trinh xir
If
vdi chat ha'p phu la bentonite thi huong vi rieng
ciia
rugu khong bi
mat di.
2.5.
Sir
dung bentonite trong cong nghiep tinh
che
nudc
O nhieu viing chua cd nha may nudc tren the gidi viec sir dung bentonite de lam
sach Ciic ngudn nudc mat, nhu nudc song ngdi, kenh muang va ciic ngudn gieng khoan cd
y nghTa thuc tien quan
irgng.
Bentonite ddng thdi
liim
kel
tiia
cac
\'an
due,
ihiiy
cho viec
dimg phen dat hon nhieu, ma nd cdn cd kha nang hfip phu mgl
loiU

cac ion
gfiy
dgc va
mdt
luan"
Idn
cac vi
khufin,
chfit huu co cd trong nudc. Bentonite
U\
mdt chat trao doi cd
trong tu nhien, nd cd kha
nfmg
khir tfnh cung
ciia
nude vdi giii
thiinh
tuo'ng ddi re. Kha
nang lang
cdn
\a lirng trong nudc, ddng thdi vdi tiic dung trao doi ion va hfip phu chfit huu
ca, trong dd cd cac vi khuan gay benh
tiio
ra gia tri dac biet
ciia
bentonite trong cong nghe
sir ly nude.
2.6. Mot sd ling dung khac cua bentonite
Cung lir Ciic
di)c

tfnh
ciia bentonite iii
tfnh tnrang nd manh, tfnh deo ngirdi ta cdn sir
dun"
bentonite
tronc
Ciic
coniz
trinh thuy loi nhu de dieu
iniroim mi'uie
va
nlu~rng
cong
trinh phdng
thii
bfmg dfit. Vdi
khi\
nang chiu dugc nhiet do cao, benlonite dugc diing
liim
tiic nhan lien ke'l trong siin xufit dan va
liim
khu6n diic. Dac biet bentonite cdn dugc diing
lam phu
giii
trong thiic an lieu
hoii
cho dong vat, vdi vai trd tang thdi gian luu
Irir thu'c
an
trong ca quan tieu hoa giiip tieu

hoii
thi'rc an
vfi
giiip dieu tie't axit. Bentonite cdn dugc sir
dung
liim
chfit chdng
fim
bang
ciich
sfiy kh6
vii
do dac tfnh
hiil
am trd lai mil co
irng
dung
nfiy
(bentonite cd
khii
nang hfip phu lugng nude gfip khoang 10
Ifin
khdi lugng
ciia
chiing).
Do nhung irng dung phong
phii ciia
bentonite ma tren the gidi ngudi ta ed nhu cau
khai thac va sir dung bentonite rfit
Idn.

Nam 1995 lugng
sfm phfim
tir bentonite dugc udc
lugng
tuoug
ddi chfnh xiic
Iii
9,8 trieu tfin, trong do My la nirdc sir dung bentonite thuan
Na nhieu nhfit. Ciic nudc khiic nhu Hy
Liip
, Thd NhT Ky.
Due
cimg vdi My tieu thu
khoiing 84% t6ng siin lugng bentonite tren
loiin
the gidi, trong do Australia dong gdp mot
nirii
sd
niiy.
Nam 1985, t6ng
siin
lugng bentonite va set dugc udc
iinh viio
khoiing 1452
trieu tfin set dimg de ho
viii.
Gia thimh
ciia
bentonite vao nam
1997^1998

la vao khoang
98
USD/tfm,
sau do, do
nlui
cfiu thay d6i himg nam ma
giii beionit
dao dong tir 50
-^
250USD/tfm.
0
Viet Nam c6 Ciic md cd
tiu
lugng
Idn
nhu: Tam Bd - Di Linh
-
Lam D6ng; Thuan
Hai -
Binh
Thuan; Gia Quy - Long Dfit - D6ng Nai. Trong dd mo Tam Bd - Di Linh -
Lam Ddng dugc udc tfnh cd tru lugng len tdi
24.10^'
m-^
va da dugc lien himh tham dd ty
my, bat dfiu khai thac quy mo cong nghiep
nen
chung t6i chgn mau bentonite co nguon
gdc Di Linh - Lam D6ng de nghien ci'ru.
III.

CAC PHUONG PHAP HOAT HOA BENTONITE
Bentonite tu nhien da
lii
mgl chfit hfip phu trao doi nhung
dc
nang cao tfnh hfip phu,
tfiy
trfing vii
hoiU tfnh xiic
Uic
ngirdi ta cfin
tim
Ciich lam tang be mat
ciia
no.
Tfil
Cii cac
Ciich lam vdi muc dfch nhu vay dugc ggi la
sir hoiil
hoa benlonite. Cd nhieu phirong phiip
hoiit
hoii bentonite ap dung cho tirng
loiii
bentonft
vii
muc dfch
hoiit
hoii, nhung co ba
phuong phiip chfnh la: hoiU
hoil biuig

kiem,
hoiit
hoa bang nhiet
vii hoiit
hoii
bi-ing
axit v6
ca.
3.1.
Hoat hoa bang nhiet
Nguyen tiic
ciia
phuong phiip nay
lii
dimg nhict de tach nudc
lien
ket ra khoi
miing
ludi tinh the
ciia
dfit set va ddt chiiy Ciic chfit
bfin,
chfit
miin
Irong do, ddng thdi
liim riin
mil mgl phiin cac tinh the dc tao thiinh trong
niiing
ludi dfit set nhung khe
lanh liim

ti'mg
be mat va tang do xdp.
Nirdc lien ket bat dau hi tiich
la
d ngiiy nhiet do thfip
(^1
10" C) va
den
khoiing
200"C till CO
the tiich ra
hoiin
toim.
Tuy vay, khi
hoiit
hoii
bentonite
bang nhict, kh6ng dugc nung den nhiet do
qiui
cao
vl d Ciic nhiet do cao bentonite sc bi giiim
kh;i
nang hfip phu
vii
la}' trang. Ddi vdi moi
loiii
dfit set thf ed khoimg nhiet do thfch hgp rieng thudng tir khoiing
110-150'^C.
3.2 Hoat
hoii

bang axit vo co
Day la phuong phiip
hoiit hoii
bentonite hieu qua nhfit nen thudng dugc sir dung
mot Ciich rgng rai trong thuc le. Trong quii Irlnh hoat hoii bentonite bang axit, ngudi ta co
the dimg Ciic axit vo ca thong dung nhu: HCl,
HNO3,
H2SO4.
Trong nhung axit do
Ihl
tac dung
ciia
HCl la
miinh
nhat, vl ngoai khii nang hoa tan
Ciic oxit kim
loiii
no con
khii
nang
hoii
tan mot phfin
SiOi
d nhiet do cao. Tuy
vfiy.
HCl de
bay hoi
nen gfiy
kho khan cho thao tac hay dieu chinh nhiet do. Tuy vay, lgi dung chfnh
die'm ye'u

niiy
mil nguoi ta sang che mot day chuyen
hoiU
hoii bentonite bang HCl. trong
do cho
phep
thu hoi va tai sir dung HCl de
liim
giiim chi phf, tang hieu
quii
kinh te. Khii
nang hfip phu,
ti"iy
trfmg va
ho;it
ti'nh
xiic
tiic
ciia bentonite
da hoiU hoa phu thugc rfit nhieu
vao dieu kien hoat hcxi nhu: bim chfit axit hoat hoa, nong do
iixit
dimg cho hoat hoii, thdi
cian
hoat hoii, tv le bentonite tren axit, nhict do hoat hoii, do phan tan cua bentonite, v.v
Mdi yeu td deu cd anh hudng nhat dinh den chfit lugng cua bentonite
hoiit
hoii. De nghien
CU'U iinh hirdng cua mot ye'u td nao dd ngudi ta thudng dung phuong phiip c6 lap, nghTa
lii

cd dinh cac yeu td cdn lai. Ddi vdi moi loai bentonite va vdi mdi muc dfch ngirdi ta se
tim
thay mot dieu kien thfch hgp nhat de
hoiit
hoa bentonite mot ciich tdi uu nhfit de cho nd cd
kha nang hap phu tdt nhfit.
3.3.
Hoat hoa bang kiem
Diing kiem hoa tan mot sd oxit ludng tfnh nhu:
ALO3,
FC2O3
de
tiio
tren be milt
nhung
16
xdp
vii
trung
lain
hoat dong. Tuy nhien mgl sd lien ket nh6m silicat bi
dirt tiio
ca'u tnic khac va mot sd chfit khiic kh6ng bi
hoii Um
bi
loiii
do sa lang.
Miit
khac khi
hiim

lugng kim
loiii
kiem
Idn thi
hoiU tfnh xiic tiic
ciia
nh6m
siliciit gii\m
do ion Na dfiu doc
cac tam axil. Do vay phuang phiip
hoiit
hoii bang kiem ft
dirge
dimg, chi trong nhung
trudng hgp dac biet nao do ngudi ta mdi
sir
dung phuang phiip
niiy.
3.4 . Phuong phap khac
Hoiit
hoii bang chfit huu co:
tii
biet rang
ditt
set thong thudng d dieu kien tu nhien
hay
hoiit hoii
bang chat vo ca, thudng hfip phu
chii
yeu chiit 6 nhiem v6

cc^,
nha vao
khii
nang bien ddi
ciia
no vdi
chi'it
v6 co'. Nhung ngiiy nay chfit 6 nhiem huu co ngiiy cimg
nhieu chfit 6 nhiem huu co do
sir
phiit tricn
ciui
khoa hoc ky thuat, nhieu ngimh cong
nghiep, giao thong van
tiii,
VI
vay, de hi'ip phu
Ciic
chfit huu co
tii
phiii lien hanh
hoiit
hoa da't set vdi chfit huu co. Chfit huu co d day thudng dimg
lii chfil hoiit
dong be mat. Khi
da't set dugc
hoiit
hoii bang chfit huu
co'
no

tiio
tren be mat
ciiii
dfit mot
Idp
bao
phii
tdi uu
cua chfit huu ca tren be mat dfit set.
VI
vay, nd co khii nang bien doi vdi ciic chfit huu ca.
Vdi
sir hoiit
hoii vdi chfit huu co thfch hgp, no co the tao ra mot
cha'l
hfip phu dong thdi
cii
chfit huu CO
vii
vo ca
mii
kh6ng cd
sir ciinh
tranh, bdi vl chiing hfip phu ddng thdi len
Idp
be
iriiAt.
Kim
loiii
khong nhung di

viio miing
ludi
ciia
dfit nhd nhung khoang trdng chua bi
che
Ifip
bdi nhung chfit huu co', ma cluing con
Uio
lien ket vai nhung nhdm chuc cua chat
huu
CO.
Til)'
nhien
hiin
che' la chat
hoiit
dong be miit kh6ng cd nhieu trong c6ng nghiep.
4.
SLT
HAP PHU CAC ION KIM LOAI NANG TL/
MOI TRU(:)NG
NUOC
COA
BENTONITE
4.1.
Co
che hap phu
Quii Irlnh hiT'p phu tren bentonite dugc thuc hien theo
hiii
each khac nhau

|9,10|:
a. Hfip phu cation vao khe
giuii ciic
Idp:
Do bentonite co cfiu tnic lap,
hii
cd the co
su thay the cac ion
AI^^
va
Si'"''
trong mang ludi
ciia
bentonite bang cac ion cd dien ti'ch
duong be
hou
lam cho
niiing
ludi mang dicn ti'ch am. d6ng thdi tren be mat
ciia
cac lap eo
the cd t6n tai Ciic nhom OH co
khii
nfmg trao d6i ion
H^
ddi vdi ciic
cation cd mat trong
12
dung dich nudc. Viec hfip phu cac cation vao trong
viio

trong ciic khe giua cac lap phu
thugc vao kfch thudc
ciJa
khe trdng, kfch thudc
ciia
ciic cation, ban chat cua cation.
b.
Ha'p phu cac ion len tren be mat
ciia
cac
hiit
bentonite: trong trudng hgp nay, cac
cation cd tham gia hinh thimh cac phirc chat cfiu ngi thdng qua nhom
Si-O"
va
Al-O'
Uii
be mat cua bentonite. Trong trudng hgp nay cd the co cii
sir
su
tnio
ddi ion
vii
hfip phu
bang luc van der Walls. Vi vay dung
htgng
hfip phu trong Inrdng hgp nay phu thugc nhieu
vao dien tfch be mat cua
hiit
bentonite.

Ca hai kieu hap phu tren
deu
dugc thuc hien trong dieu kien m6i tnrdng axit yeu
(pH<4).
Bdi vl quii trinh hfip phu
lii
toil nhiet
nen
quii trinh hfip phu xiiy ra tdl khi nhiet do
tha'p.
Do ion kim loai dugc sonvat hoii tdt vl vay de cho ion kim
loiii
dugc
hfip
phu chiing
phiii mfit mot phan
Idp
vd hydrat hoa
ciia
chiing. Qua trinh de hydrat hoa
niiy
ddi hoi nang
lugng. Nang lugng
ciui
quii Irlnh de hydrat hoii dugc cung cfip bdi su hi'ip phu toil nhiet. Su
loiii
bo nudc khoi ion
la
qua trinh thu nhiet, dudng nhu
sir

thu nhiet
ciui
(.|iia
trinh de
sonvat
vircrt
qua nhiet do do su hfip phu phiit ra nen gia tri
ui'mg
lugng tu do
AG'*
am, qua
trinh hfip phu
lii tudien
bien.
4.2.
Khii
nang hfip phu.
Khii nang hfip phu
ciui
bentonite phu thugc vao
thimli
phfm
vii
ciT'u tnic
ciia
benlonite, vao dien tfch
vii
biin kfnh
ciia
ion kim

loiii.
Ion cd hoii tri thfip de trao doi han cac ion hoii tri
ciio.
Ion cimg hoii tri, biin kfnh
Ciing nhd
thi
khii nang trao ddi cang
Idn.
Do bentonite
lii
vat lieu xdp co cfiu tnic
Idp,
chung eo ciic dien tfch
bii
trir trong
mang ludi
nen
co khii nang hfip phu Ciic ion im
loiii.
Kha nang hfip phu
ciia benlonite
phu
thugc
viio
dien tfch
am
L~>e
mfit vii
lugng cation
bii

trir trong miing ludi. Bentonite cd the
hap phu tdt cac ion kim
loiii
nang, khii nang hfip phu ddi vdi Ciic ion la khac nhau. No phu
thuoc vao dicn tfch va biin kfnh ion. Ion cd hoii tri
thiYp
de trao doi hon ciic ion hoii tri cao.
Ion ciing hoii tri, ban kfnh cang nhd
thi
kha nang trao d6i cang
Idn.
4.3.
Cac yeu td
linh
hudng den kha nang
hiVp
phu ciic ion kim
ioiii
nang.
a.
pH
pH
ciia
dung dich nudc
lii
mot yeu
id
quan trgng
iinh
hudng den su hfip phu

ciia
kim loai
tren
benlonite. Su
hfip
phu
ciia
kim
loiii
giiim khi pH giiim thap bdi vl nhom Al-O
va Si-O dugc nhan nhieu hon mot proton, vl vay chiing luu giu kim
loiii
kem hon. Tac
dong
niiy
manh ddi vdi Cu, Pb, Cd
vii
kem ro ret ddi vai nhung kim loai khac. Nhung
neu
pH cao quii no se lam giam be
mi)t lich dicn
am tren dat
set.
mii
su
hfip
phu xay ra
chii
13
yeu do

sir
thu hut ion kim
loiii ciia
Ciic be mill dien tfch am nay nhd
lire
culong. Khi pH
tiing cao
quci
(pH > 5) dung lugng tfch dien tfch
am tren
be mat
ciia
benlonite giiim di,
dan d€n
khii
nang hfip phu kem di. Theo
kliiio
sat pH thfch hgp de hfip
plui
tdt nhfit la 4.
[51
b. Nhiet do
Vi qua trinh hfip phu la toii nhiet
nen
khi nhiet do tang
thi
kh6ng ed lgi cho qua
trinh hfip phu, su hap phu thuan lgi khi nhiet do thfip, nhung cac ion kim
loiii
trong dung

dich nudc bi bao
phii
bdi ciic lap sonvat, vl vay de hfip phu lap
somiit niiy
phiii bi pha va,
qua trinh pha va nay thuan lgi khi nhiet do lang. Nhu vay trong
qiui
irlnh hfip phu nhiet do
cd anh hirdng trai ngugc nhau,
tfing
nhiet do thi thuan lgi cho
sir
phii vd lap sonvat bao
bgc ion,
liim
de dang hon
liim
cho
sir
hfip phu ion, nhung
kii
khong thuan lgi
ve
mat nhiet
dong hgc
ciui
qua trinh hfip phu. Con neu nhiet do mil thfip
Ihl qufi
trinh hfip phu thuan lgi
ve

mat dong hoc nhung neu mil nhiet do thfip
qiui thi
lap sonvat
biio
bgc kim
loiii
kh6ng
bi phii bd
nen sir
hfip phu khd
sfiy
ra. Cho nen trong quii trinh hfip phu nhiet do cfin phiii
cd giii tri thfch hgp de cho su hfip phu
xiiy
ra tdt nhfit
c.
Th&i
gian
Thdi gian cd imh hirdng
miinh den
dung lugng hfip phu
ciui
bentonite.
vdi n6ng do
vii
the tfch
eiia
ion kim
loiii,
khdi lugng

ciui bentonite
xiic dinh
den
khoiing
iha'i
gian
niio
dd dung lugng
ciia
benlonite kh6ng thay doi. Khi dd ta co
hfip
dung
cue
diii,
thdi gian dd
goi
lii
thai gian bang hfip phu dugc ihiel lap, no phu thuoc
viio
cac ye'u td nhu nhiet do,
pH,
ndng do chfit dien ly, khdi lugng chfit hfip phu ,the tfch dung dich hfip phu.
d. Kich thudc hat
bentonitCj
dieu kien
khiiciy
tron
Sir
hfip phu tang vdi
sir

tang dien tfch be
niilt,
tire
la dicn tich tiep
xiic gifui
ion kim
loiii
va chfit hfip phu.
VI v(iy
de cho
sir
hfip phu
diit
ket quii tdt kfch thudc
hiit phiii
that
nho,
min. Mat khiic ta biet rang bentonite la khoang set no co dac diem la dco
vii
dfnh
nen
trong dung dich no thuong biim ket vdi nhau,
liim
giiim
khii
nang hfip phu, vl vfty phiii tien
hiinh
lac de chiing phan tiin
liim
cho su tiep

xiic
giua ion
vii
bentonite tdt han.
e. Ty le bentoniteldung dich (R/L)
Ty le khdi lugng
ciui
chfit hfip phu
vii
the tfch
ciui
dung dich hap phu imh hudng
den
khii nang hfip phu
ciui
ion kim
loiii
tren bentinit vdi m6i kim
loiii
co mot
ty
le xac
dinh
lii
tdi uu, phu lhuoc
viio
ndng do
ciia
ion kim
loiii,

bim chfit cua chfil hfip phu, nhiet
do,
nong do ciic chfit dien ly
vii
thai gian hi'ip phu.
/. Anh hudng
ciia
cdc chid dien li trong moi trudng nude
14
Anh hudng chfit dien ly ddi vai su hfip phu
ciia
bentonite vdi cac ion khiic nhau la
khac nhau. Nhung, ndi chung ndng do ciic cha't dien ly trong dung dich tang khii nang hfip
phu bi giam di. Do su
tiio
phirc
ciia
cac chfit dien ly vdi
citc
ion kim
loiii,
sir
thuy phan,
anh hudng den su khuech tan
ctja
cac ion kim loai.
Trong ban Bao cao ke't qua nghien ciru
niiy
chung tdi dua
rii

ciic ket
qiui
khiio
siit
mgl sd ngi dung sau:
- Ddi tugng khiio sat
lii mau
quang bentonite dugc Trung tam Cong nghe xir ly
quang, Vien cong nghe Xa - Hiem, Vien Nang lugng Nguyen
tir
Viet
Niim Ifiy
tir md
bentonite kiem tho Di Linh - Lam D6ng
vii
mo bentonite kiem Tuy Phong -
Binh
Thuan.
Quiing d dang cue, cd do fim
10 ^
15%.
- Quang dugc phoi kh6, dap,
nghien
nhd,
loi hoii viio
nudc, khufiy
lien
tuc trong
hai gid, de
yen

r6i lang
giin hty
huyen
phii
ben tren,
loiii
bo
ciil,
soi,
ti.ip
chfit ca hgc d
dudi. Huyen
phii
thu dugc dugc lgc, sau do phoi khd, nghien nhd, sfiy kh6. Cd
hiit
quang
sau khi nghien cd kfch thudc
lii
<
150
pm.
-
Hoiil
hoii bentonite
bi"ing
dung dich
H2SO4
co nong do xiic dinh, d Ciic dieu kien
T, thdi
giiin,

kluuT'y
tron, ty le R/L thfch hop.
- Khiio sal cac yen td imh hirdng
den
den
khii
nang hi'ip phu cac ion kim
loiii nilng
Fe",
Mir"^
ciia
benlonite da dugc
hoiit
hoii.
Trong
quii tinh
ticn hanh thf nghiem, chiing toi da sir Ciic
loiii
thiet bi
siiu
day. Cac
thie'l bi nay mgl sd d Khoa Hoa hgc - Tnrdng DHKHTN
vii
mot sd d Vien
Xii
Hiem -
Vien Nang lugng nguyen tir Viet Nam. Miiy do pH
vii the
oxy hoii - khir
microprocessor

pH meter cua
Diic.
Kfnh hien vi dicn
tir
SANYO
ciia
Nhat. May dap nghien sang phan
cfip hat
ciui
Nguyen lir nang qudc te.
Miiy
do ph6
hfi'p
lhu electron spectrophotometler
Hitiichi
U200I
Cac hoa chat su dung la: axit sunphuric
H2SO4 loiii
PA; Tinh the mangan
(II)
clorua
MnCl2-4H20 loiii
PA; Tinh the mudi
sfil
(11) sun
Lit
ngam nudc:
FeS04.7
H^O
loai

PA; Axit clohydric HCl loai PA; Tinh the
biic
nitrat
AgNO^
loai PA; Tinh the kali
persunphat
K2S20^s 10\>i
P^^
^^'^
sufoxalixilic
loiii
thudc thir;
H2O2.
Mau quang
siV
dung de nghien ci'ru: Quang bentonite duoc Trung
tiim
c6ng nghe
sir ly
qiuTng,
Vien c6ng nghe
Xii
- Hiem, Vien Nang lugng
Nguyen
tu Vet Nam
Ifiy
lir md
bentonite Di Linh - Lam Dong ve
d
diing

cue
co do am 10
^
159i.
Quang dugc
phoT
kho, dap, nghien nho, roi
hoii
vao nudc, khufiy lien tuc trong hai
"id,
de
yen
rdi lang gan
la\'
huyen
phii ben
tren,
loiii
bd
ciil,
soi,
tiip
chfit
co'
hoc.
15
Huyen
phii
thu dugc dugc lgc qua
tfmi

vai min,
siiu
do phoi kh6. cho
viio
may
nghien bi
sir
de nghien trong khoang
Ih.
Bgt nghien lay ra dem
viio
sfiy, cd hat quang sau
khi nghien cd
kich
thudc la <
150
pm.
Thanh phfin khoang
ciia miUi
quang dugc xac dinh
bfing
phuong phap nhieu xa
Ranghen. Thanh phan hoa hgc
ciia
mau quang dugc xiic dinh bfmg cac phuang phap phan
tfch hoii hgc nhu da trinh
biiy
trong ciic muc 2.2.
Mau bentonite
siiu

khi dugc lam
giiiu
va lam
siich
dugc
diinh
gia chfit lugng qua
khii
nang hfip phu Ciic ion kim
loiii
nang tir moi tnrdng nudc. Ciic ion kim
loiii
nang dugc
sudung
de lam ddi tugng khiio siit
lii
ciic ion kim
loiii
chuyen tie'p
dily
I
vii
L'02"''.
II . PHUONG PHAP NGHIEN CUU
2.1 Phuong
pluip
hoat hoii quang
De khiio sat
khii
nang

hoiit
hoii, ciic dung dich
iixit
sunphuric co ndng do thay ddi:
20%,
15%, 10%. Khi nong do
hUSO^
< 10%, theo Ciic tiic
giii ciui
ciic c6ng trinh
|1^5|,
khii nang
hoiil
hoa la khong diing ke. Khi nong do iixit
simLiiic
> 20%, clo tac dong
ciia
axit
qiui niiinh
de xay
ni
hien lirgng phii huy cfiu triic
ciui
bentonite (hien tugng sap
khung).
Thdi gian
hoiit
hoii tir
1-^6
gid; Nhiet do

90-H95°C;
Ty lc bentonite / iixit
ve
khdi
lugng
lii
1:3.
Qiui
trinh
hoiit
hoii
dirge
ticn himh tren thiet hi
hoiil hoii ciui
Trung tam Xir If
quang, Vien
Xii
Hiem,
biio gom
ciic bo phfin
siiu:
Bg
phau dun ciich thuy eo dieu nhiet;
thiet bi khufiy vdi canh khufiy thuy linh; nhiet ke;
binh
phim
I'rng
bang cdc thuy tinh
1,5lfl.
Qua trinh

hoiit
hoii bentonite dugc tien hanh nhu sau: Lfi)' 200g quang bentonite
cho
Viio binh
thuy tinh co dung tfch
lii
1500ml, them
viio
do 200ml nudc cfit. Binh phan
irng dugc cho
viio
thiet bi dieu nhict. Hon hgp bentonite
vii
nudc dugc khufiy bang miiy
khiuT'y CO
ciinh
liim bilng
thuy linh. Dun nong dung dich den nhiet do
90'^C,
cho
tir tir
dung
dich axit
viio binh
giu
ngii\cn
nhiet do
ciui
he, chii y ty le
gifui plui

long
\'a phii
ran lu6n
giud
1:3.
Khi da
dii
thdi gian hoat hoii, Ifiy ciinh khufiy ra, do ngay hon hgp trong cdc
viio
phlu lgc hut chiTn khong, rira phcu bang nirdc cfit
de'n
khi het
SOj""
(thir bfmg
Ba'"")
va pH
nu'Oe Siiu
khi
nVii
biing 4-5. Sau do
siT'y
kho, nghien nho
siing
qua cd simg
150
pm.
2.2.
Phuong phap phan tich thimh phiin hoa hgc
ciia
bentonite.

Nhilm muc dfch xem xet
sir
thiiy doi thiinh phfin ciic cau tir
ciui
benlonite khi
hoiit
hoii
vii liic
chu'a
hoiit
hoa vit irong ciic
dii^u kien
khiic nhau, chiing toi tien himh xiic dinh
thimh phi'in
ciui
mgl sd cfiu tu chinh nlur
Si02,
AUO;,
Fc20t,
CiiO,
MgO.
a. Xdc dinh hdm
3102.'
Ham lugng
Si02
dugc xac dinh bang phuong phiip khdi
lugng. Qua trinh pha tfch dugc tien
hiinh
nhu sau: nung mot phan bentonite vdi nam phfin
hdn hgp chay (4

K2CO3
+ 5
Na2C03)
trong chen
sir
platin d
900"C
khoang 30 phiit,
Ifiy
ra
de nguoi, sau dd dung HCl dac ket
tiia
Si04'"
ve
diuig
Si02.H20.
C6 dac dung dich lam
dong tu keo. Lgc
rira
ket
tiia
bang HCl loang va nudc cat trong dieu kien nong, nung ket
tiia trong
Id
nung d
850"C
trong
Ih,
de nguoi can nhanh ket
tiia.

b. Xdc dinh hdm
Fe20j
Dc Xiic dinh ham
Fe20i
chiing tdi da dimg phuang phiip the ti'ch: dimg
H2O1
oxi
hoii sat (II) len sat
(III),
dun soi de loai
H2O2
du,
them axit
sufoxiilixilic,
dieu chinh pH
den 1,5 hoac 2, dung dich cd mau do
xfim ciia
phi'rc
sfit
sunfoslixilic.
Fe"^"^
-\- Sul
=
FeSul-"".
Chuan do vdi complexon
111
cho den khi mfit
miiu
dd
sam vii

xufit hien
mini
vang
nhiit,
vl
EDTA
tiio
vdi
Fe"''^
phirc ben hon la axit sunfosalixilic.
c.
Xric
dinh hdm lugng
AI2OJ
Diing phirong phiip the tfch chuan do ngugc bang EDTA.
Al^^
tao phi'rc vdi EDTA
tiii
pH
-7
hoac 8 con
Fe"*"^
tiio
phuc vdi EDTA trong
khoang pH tir 1-9 .
VI
vay chiing toi
tieTi
hanh chuan do d pH = 7 .
Ciich

lieTi
himh:
Lfiy
dung dich sau khi da
chufin
do
Fe^"*",
cho du EDTA co nong do
Xiic dinh, dieu ehinh
ve
pH = 7, dun ndng den
70"C,
liic
ky cho
Al"'"^
tao plu'rc het. Sau dd
chuan do lugng
EDl'A dir
vai chi
ihi xylen cki ciim
bang dung
ilich Zu(CH,C00j>
. Tir the
tfch EDTA lieu tdn cho du chi'nh xiic la co
the
tfnh dugc nong do
Al"*'
tong dung dich va
tirdd
tfnh dugc

hiim
lugng
ALO^
d. Xdc dinh MgO vd CaO
Dimg nuac
loc
rira trong
tjiiii
trinh xiic dinh
Si02
tiich Fe
Na
Al ra khoi bang dung
dich NH4OH. Dung dich phim ung dugc dun soi den
70^'C,
lgc rira ket
tiia
bang dung dich
NH4N0,
loang. Lfiy dung dich nudc lgc de xac dinh
Ca""",
Mg'".
VI
Ca-""
tiio
phi'rc vdi EDTA d pH lir 2-
11
cdn
Mg'"
Uio

phirc d pH
==
10 nen trirdc
het ta chufin rieng
Ca'"
d pH = 2
chi
thi
nuircxit
dd.
Cung lfiy mot lugng bang
V2
tir
Vi
dem
chui'in
tdng
Mg~"
vii
Cir" biing
EDTA
vdi
chi thi ETOO trong m6i truong dem NH4OH
+
NH4CI.
Trudc het diing dung dich NaOH
20%
dieu chinh pH ve 10 roi dimg dem ehinh
ve
10,6.

2.3.
Phuong phdp xdc dinh sdt, mangan trong dung dich
Dimg phuong phap
trfic qiumg
de Xiic dinh vl phuang phiip
niiy
cho
kei qiui
[uang
ddi chinh xac va nhanh chong.
OAI
H'JC
QU'.'-^C
GiA
HA
NOi
TRUNG
TAr/
THONG
TIN THU VIEN
PT I
yU9
a
. Phuong phdp trdc quang xdc dinh ndng do ion sdt trong dung dich voi thudc
thu thioxianat. Do ion
Fe"^"
de
tiio
vdi ion
SCN

theo phiin ung
Fe-'"
+
6 SCN'
-
Fe(SCN) ,
Phirc tao thanh cd
mi\u
dd mau cd
cue diii
hfip thu d budc song
X
= 500 nm, do hfip
thu quang ty le vdi ndng do ion Fe "; Cd
mfit
amoni tioxianat 20%,
b
.Xdc
dinh mangan bdng phuong phdp triic quang
Dua
viio
phiin
irng
oxy hoit
Mir"
thimh
Mn04"
iheo
phim irng sau:
2

Mn-"
+ 5/2
S2O,-
+ 8
H.O
= 2
Mn04
+
5S04
-H
16
H"
Phim
irng xiiy
ra trong m6i trudng axit
H2SO4,
HNO3
vdi sU
xiic
tac
ciui
Ag". Ion
Mn04'
dugc
Uio
thanh trong dung dich co mau dam, co
the
do ABS de xiic dinh ndng do
cua nd
duii viio

dudng
chufin
d budc sdng
X -
523nm.
2.4. Phuong phiip xac dinh hfip dung
ciia
cac ion kim
lo;ii
tren bentonite
Dung dich
ciui
ciic ion kim loai co n6ng do khiic nhau dugc chufin bi
bi'mg each
hoii
tan mudi d diing linh the
viio uirdc
cfit r6i axit hoii bang axit sunfuric de'n pH = 4.
Bentonile
dugc
can
vdi khoimg 2g cho vao
ciic binh
non chi'ra 50 ml dung dich. Sau khi
can
nuUi
cfin xac dinh do fim
ciui mfui
de tinh chfnh
Xiic

lugng
benlonite
cho
viio.
Ciic
binh
dugc day kfn cho \ao
nuiy klc
vdi tdc do 140
\ong/phut
trong
thc^i
gian 3h.
Siiu
do
lfiy ra lgc tren pheu thuy tinh \'di giiiy loc bfmg
Xiinh .Ciic
dung ciich dfiu
\'ii
ciic dich loc
tuong irng dugc
deni
plu'm
u'ch
trac
c|Uiing
theo phuong phiip neu
lien.
Thf nghiem ticn
himh d nhiet do phdng.

Lugng ion kim
loiii
dugc hfip phu bdi bentonite, dugc xiic
dinh
tir
sir chenh
lech
nong do trudc va sau hfip
plui.
Dung lugng hfip phu
dirge
tinh theo cong thirc
siiii
a=||Co-CLV|/m
Trong dd: a
lii
dung lugng hfip phu
ciia
bentonite;
CQ
la n6ng do
ciia
ion kim loai
trong dung dich dfiu; C la n6ng do
ciia
ion kim
loiii
khi can bfmg dugc thiet lap; m la khdi
iirgim
benlonite dimg de hfip phu; V

Iii
the tfch dung dich kim
loiii
.
IS
PHAN
III -
KET QUA VA THAO LUAN
Phfin thuc nghiem nghien ciiu bao gom 2 ngi dung sau:
- Khao sat xac dinh dieu kien hfip phu tdi uu
ciia
bentonite trong moi tnrdng nudc
ddi vdi mot sd ion kim loai nang. Nghien eu'u
niiy
nham muc dfch xac ding dugc dieu
kien tdi uu cho qua trinh danh gia chfit lugng bentonite sau khi
hoiit
hoa va diinh gia
khii
nang sir dung betonite lam cha't
hfip
phu
xiia If
m6i tnrdng.
- Khiio Siit qua
tiinh
lam giau
vii hoiit
hoa bentonite nham xac dinh dugc dieu kien
tdi uu cho qua trinh nay ddi vdi khoiing bentonite Dilinh Lam Dong.

Sau day chung toi xin
Ifin
lugt trinh
biiy
cac ngi dung nay;
4.1.
Khiio sat ciic yeu td anh hudng den kha nang hap phu cae ion kim loai
nilng trong moi trudng nudc
ciia
bentonite.
Chiing loi da sir dung bentonite
Iii loiii
khoiing bentonile Dilinh Lam Ddng da dugc
chfit hoii nhu sau: bentonite sau khi dugc
liim
giau bang thiet bi xyclon, dugc
hoiit
hoa
bang
H2SO4
15% (d nong do nay benlonite dugc
hoiit
hoa tdt
nhfii,
cho dung lugng hfip
phu tdt
nhii't)
vdi thdi gian
hoiit
hoii

lii
2h, ty lc R/L = 1 :3, nhiet do hoat hoii la
85-95*^0.
Hiim
lugng montmorillonite trong khoang bentonite
niiy Iii
> 70%.
Dc khao sat khii nang hfip phu, chiing toi sir dung hai ion kim
lo.ai
nilng
lii
Mn~"
va
4.1
.F
Anh hudng cua pH dung dich den khd ndng hdp phu
Fe~^
vd
Mn~^
tren
bentonite.
Pha Ciic dung dich
Mir"
va Fe"" nong do
Iii
3g/l
vii
0,9
g/1
co cac gia tri pH xac

dinh la 2,0; 2,5; 3,0; 3,5; 4,0; 4,5 va 5. Lfiy
biiy binh
non dung tfch
250inl,
theo
viio
mdi
binh 2g bentonite, 50
ml ciia
mot trong ciic dung dich co pH khiic nhau tren. Day kfn
mieng
binh
va lien hanh
hic
vdi tdc do 140 vong/phiit,
ddieu
kien nhiet do phdng, trong
thdi gian 3 h. Sau khi
hlc,
Igc dung dich bang gifiy Igc bang xanh va tien hanh xac dinh
n6ng do
ciui
ciic ion
Mir"
vii
Fe'"
trong dich lgc, hiip dung
eiia
bentonite dugc xac dinh
theo cong thirc: a

=
(
CQ
-
C).V/m.
Ket
quil
thuc nghien dugc dua ra nen bang
1.
Bdng /•
Sir
phu thugc hdp dung bentonite ddi vdi
Fc^
vd
Mn~^
vdo pH cua dung dich.
pH 2,0 2,5 3,0 3,5 4,0 4,5 5,0
Hfipdung
ddi vdi 8,7 10.5 12,6 13,8 14,3 14,2 13,7
Fe'^
mg/g
Hfipdung ddi
vdi 10.2 15,4 19,7 23,5 26,7
23,1
19,4
Mir"*",
nm/ii
19
TiJ*
ke't quii da trinh bay tren bang 1 co the thfiy rang, khi pH dung dich thay d6i tir

2,0 den 5,0 hap dung
ciia
bentinit ddi vdi
Fe"^
va Mn"" deu cd dang bien ddi nhu nhau.
Hap dung
ciia
bentinit ddi vdi
Fe^"^
va
Mn^"^
tang len khi pH tang tir 2,0 den 4,0,
diit cue
dai tai pH nay, sau dd giam xudng khi tang pH tiep. Ket qua
niiy
cung
phii
hgp vdi ke't
qua cira cac tac gia cong trinh [6]. Nhu vay pH tdi uu cho qua trinh hfip phu hai ion
Fe"^"
va
Mn^''"tren
bentonite tir moi tnrdng nudc
lii
4,0.
4.7.2.
Anh hudng cua thdi gian khuay tdi
sir
hdp phu
Mtr^vd

Fc'^
tren bentonite
Tien hanh thf nghiem nhu sau: pha ndng do
ciia
Mir"
va
Fe'^"
vdi nong do la 3g/l
va 0,9 g/1, tien hanh thf nghiem: ddi vdi mdi thf nghiem lay 9
binh
non, can vao m6i
binh
2g bentonite da hoiU hoii, dd
viio
mdi
binh
50ml dung dich Mn'" hoac
Fe'"
vdi n6ng do
nen, chinh ve pH = 4, day kfn cho vao
nuiy Ific
vdi tdc do 140 vdng/ phiit trong thdi gian
khuay khac nhau: 0,5 ; 1 ; 1,5; 2; 2,5; 3; 3,5; 4 h sau
nhQ-ng
khoimg thdi gian
iren,
lay
dung dich ra lgc vdi gifiy lgc bang xanh va lien hanh Xiic dinh nong do
ciui
dich lgc, hfip

dung
ciia
bentonite dirge xiic dinh theo cong
thiic:
a =
(CQ
-
C).V/m
Trong dd, a la hfip dung (mg/g);
CQ
- nong do
ciia
dung dich ban dfiu trirdc khi lac;
C - ndng do
ciui
dung dich sau khi lac;
in-
khdi lugng
ciia
bentonite. Ket
quii
khiio
siit sir
phu thugc giua hfip dung
ciui
Mn'^
vii
Fe""
vdi thdi gian
Lie

khiic nhau dugc dua ra trong
bang 2 va ciic
hinh
4 va 5.
Bdng 2: Sd lieu hdp dung cua
Mn'''
vd
Fe'''
vdi thdi gian lac khdc
nhcui
Tlidi gi
Mn-^
1
1
1
Fe^^
1
an
khiiay(h)
nong do can
bring
(g/1)
hap
dung
(mg/g)
nong do can
bring
(g/1)
hap dung
(mg/g)

0,5
2.53
15.98
0.696
5.1
1
2,31
18.53
0.58
7.99
1.5
2.1395
21.5
0.492
10,2
2
2.046
23.85
0.417
12.07
2,5
1.98
25.85
0.3628
13.43
3
1.925
26.87
0.324
14.4

3,5
1.914
26.9
0.3244
14,39
4
1.92
26.91
0.324
14.4
20
"5.
E
22
-J
• lico [(t:i(J7~l
00 05 10 15 20
25
30 35
':0
45
Thoi
j;i.in
h
Hinh 4: Dd
thi
hieu dien
sir
phu thugc hdp dung
ciia

Mm^
tren bentonite vdo
then
gian
lac.
0
0
0 5
S 20 2
i 30 3S 40
i
b
Thoi
g
1,1II
h
Hinh 5:
Sir
phu thugc cua hdp dung
Fe~^
tren bentonite vdo thai gian lac.
Nhan xet: Tir d6 thi
hinh
4
vii hinh
5 co the thfiy rang: Khi thdi gian thay d6i
tir
0
-=-
3h, lugng

Mn^";
Fe'"
bi hfip phu tang theo thdi gian. Sau 3h, dung lugng hap phu khong
ddi,
dill
gia tri cue
diii.
Qua trinh hfip phu
niiy
la phan i'mg can bang trao ddi ion:
H^(bentonite)
+
Mu""
(Fc'"),^,
o
H".,,
+
Mn-"(Fe-")(bentonite)
(I)
Su chenh lech hoii the
ciia
Ciic ion ngoai dung dich va trong cac khe xdp
tron"
bentonite la dong luc thiic
dfiy
quii trinh trao doi ion
xiiy
ra.
Liic
dfiu, khi n6ng do ion kim

loai
trone
dung dich cao, can bfing chuyen dich sang phiii. Den mot thdi gian nao dd (3h),
21
khi hoa
the'cua
cac ion (H",
Mn^",
Fe"^)
trong
vii ngoiii
bentonite bang nhau, phim
I'rng
diit
den giii tri
can
bfmg, khi dd lugng ion kim
loiii
bi hfip phu
lii cue
dai d nhiet do va ndng
do khao sat.
Ngoai ra, cac ion kim loai cdn bi hap phu vat ly trong nhung khe xdp trung hoa
dien tren be mat bentonite. Qua trinh nay dan gian la su khuech tiin ion lir dung dich vao
trong
16
xdp chu'a nudc, lugng ion kim
loiii
eo the khuech tan
viio

nhung
16
xdp nay la mot
hang sd d dieu kien ndng do, nhiet do khiio siit.
Vay thdi gian 3h !a thdi gian ldi uu cho
sir
ha'p phu
ciui
Mn va Fe tren bentonite.
4.
J
.3. Anh hudng cua ndng do chdt
bi
hdp phu
Pha dung dich
Mir"
va
Fe^"
cd n6ng do khiic nhau, tien hanh hfip phu tren
bentonite trong khoiing thdi gian 3h sau do Xiic dinh dung lugng hfip phu, Ket
quii
khao
Siit
sir
phu thugc giua hfip dung
ciia
Mn (11) trong dung dich tren bentonite
viio
nong do
Mn^"

dugc dua ra trong biing 3
vii hinh
6.
Ket quii khao
siil
su phu thugc giua hfip dung
ciia
Fe
(11)
trong dung dich tren
bentonite vao n6ng do
Fc""
dugc dua
rii
trong biing 4 va hinh 7.
Bdng
3:
Sir
phu thuoc cua hdp dung A vdo ndng do
Mif^.
Mir"
Q,
g/1
Q,,
g/1
A
5
3,86
28.56
4

2.88
28.04
3
1.94
26.61
2
1.03
24.32
1
0.29
17.74
0.5
0.04
11.4
0.25
O.OI
6
ihco
11611"
do
Miidl
J
0 0
3 5
•
15
;
N,)iii:
d.
2 5 3 0 3 5

.111:,
^l\
Hinh 6:
Sir
phu thugc
ciia
dung lugng hdp phu vdo ndng do cdn bdng trong dung
dich ddi vdi
Mm^.
22
Bdng 4:
Sifphu
thugc cua hdp dung A vdo ndng do
Fc
+
U
Co
(g/1)
Q„
(g/1)
A
0.54
0.13
10.85
0.63
0.17
11,45
0.72
0.23
12.25

0.9
0.33
19.62
1.56
0,65
20.05
3.31
1.64
25.64
3.68
2.78
26.04
4.73
3.58
26,64
5.1
4.2
26.8
I
• A I h e o F e
a 11
— 20
<
15
1 2 3
N(MIL;
clo
TL-dh
cm
b.lii-

(g/Li
Hinh 7:
Sir
phu thugc cua hdp dung vdo ndng do cdn bdng trong trudng hgp
Fe'''.
Nhan xel: Tir
ciic
biing 9,10
vii
ciic
hinh
9, 10 co the'
thity
rfmg, dudng dfmg nhict
trao doi hfip phu co diing
dirdng
Langnuiir:
ii.b.C
A
+b.C
n
Trong dd: A
lii
hfip dung; a: lugng chfit bi phu cue
diii hiiy
hap dung cue dai phu
thugc vao bim chfit chfit hfip phu, chfit bi hfip phu
vii
nhiet do; b:
hiuig

sd; C: ndng do can
bang.
Tir can bang
iiuo
ddi ion:
H"(bentonite)+Mn-"(Fe""),^j
<=>
H",^+Mn-"
(Fe*^^)(bentonite)
Sir triio
d6i ion
niiy plui
thugc
viio
bim chfit bentonite, nhiet do,
sir
khuech tiin ion
kim
loiii,
vii
kfch thudc lo xdp tren be mat vat
lieu,
d nhung
dieu
kien khiio siit chi co
nong do ion kim
loiii tluiy
doi,
tiro"ng ling
vdi nong do

cfin
bang hfip phu thay ddi. Do dd:
+ Vdi nhung nong do ion kim
loiii
nho (C nho) bC «1, hfip dung lang tuyen ti'nh
theo C theo mot do thi
dui^ng
thfmg, bdi khi do
sir
khuech Uin
ciia
ion kim
loiii hfiu
nhu
khong bi bien doi.
23