Nghien cihi - Trao i
ITng dung Sam va Xrd trong nghien ciiru khoang vat Kaolin tai mot so aiem mo
Of mien Bac Viet Nam
BUI HOANG BAG, NGUYEN TIEN DUNG, NGUYEN DUY HUNG, TRAN THI VAN ANH Trudng Dai hgc Md - Dia chdt
LE D 6 TRf T6ng Cue Dja chat Viet Nam
I Md dau
Trong nghien cQu dja chat, dae biet la nghien cQu khoang vat d kfch thudc nhd n h u d c khoang vat set thi viec sQ dyng cae thiet bj phan tich hien dai ddng mdt vai tro rat quan trpng. Vdi s u phat trien cQa khoa hpc cdng nghe, d nhieu thiet bj hien dai dupc che tao phuc vy cho ITnh vuc nghien cQu nay nhU: XRD, T E M , S E M , tuy vao muc dfch nghien cQu, cac thiet bj may mdc nay se dQpe lya chpn sQ dung mpt d e h hpp ly.
Cac ket qua phan tfch thu nhan dupc d nhOng Qu viet ndi trdi vdi dp chinh xac eao, hinh anh phan tich true quan... Mdt trong d c may phan tich thdng dung da va dang dupe sQ dyng nhieu trong nghien cliu khoang vat hien nay la may X R D va S E M .
May phan tich nhidu xa tia X (XRD) cd Qu d i l m la nhan biet khoang vat nhanh vdi mdt iQpng mau nho, eo t h i xac djnh dupc d c khoang vat va thanh phan ban dinh lupng. May dien tQ quet (SEM) dupc diing di phan tfch hinh dang eiia khoang vat vdi do phdng dai Idn, kich thudc khoang vat dudc phan tich nhd cd t h i den c d nano met. Ngoai ra, mdy SEM
cd t h i tich hdp cac cdng cy hd trp hOu ich khac nhQ bd nung nhiet dp, hay phan tieh thanh phan hda hpc cQa m l u sii" dung dau dd phd tan xa nang luong (EDS)... Tren the gidi, rat nhieu cdng trinh nghien cQu dac d i l m khoang vat da sQ dyng may phan tfch XRD va SEM phyc vy cae mye dfch khoa hpc Qng dyng khac nhau va mang lai hieu qua cao.
Kaolin (cdng thQc hoa hpc Al2Si205(OH)4)) la nguyen lieu mang nhieu tinh chat ky thuat cd gia trj, dQpc dung trong nhieu ITnh viic san x u i t cua nen kinh te qudc dan nhQ sQ dung iam nguyen lieu trong qua trinh san xua't dd gdm, vat lieu chju IQa, do gdm chju IQa, do gdm mdng, nhdm, sulfat nhdm (phen chua)... va lam chat ddn trong qua trinh san xuat giay, cao su, da nhan tao, sdn, xa phdng, thudc t n i sau... Chat lupng va kha nang sQ dyng kaolin trong d c nganh cdng nghiep khac nhau phy thupc vao thanh phan hoa hpc, dac d i l m cd ly, thanh p h i n k h o i n g vat, hinh thai cQa chung.
Nhdm kaolin bao gdm cac khoang vat: Kaolin, halloysite, dickite, va nacrite. Vdi dieu kien dja chat, dia ly t u nhien thuan ipi, mien Bac Viet nam ed d c md kaolin vdi
nhieu loai hinh ngudn gdc vdi quy md va chat lupng tdt. Tdng hpp d c k i t qua nghien cQu kaolin trong nhieu thap ky qua cho thay, kaolin trong mien Bac Viet Nam thudc 3 k i l u ngudn gde la nhiet dich - bien chat trao ddi, phong hoa va tai t r i m tich. Ddi vdi moi k i l u ngudn gdc, kaolin d nhQng dac d i l m ve chat lupng, thanh phan khoang vat khae nhau.
Nhieu cdng trinh nghien cQu da dupc cdng b d ve dae d i l m chat lupng, tiem nang, sU phan bd, d c loai hinh ngudn gdc cQa kaolin mien Bac Viet Nam.
Bai bao trinh b i y Qng dyng kdt hpp may nhieu xa tia X (XRD) va may dien tQ quet (SEM-EDX) trong nghien cQu khoang vat kaolin cho mpt s d md ngudn gdc dac trung d mien Bac Viet Nam.
Ket qua dat duoc giQp cho viec danh gia day dii, ro net hon v l dac d i l m chat lupng kaolin va gdp phan dinh hudng sQ dung chQng hieu qua hon.
K h a i q u a t c a c k i e u m d k a o l i n m i e n Bac Viet Nam
Viet Nam la mpt trong cac qudc gia ed t i l m nang Idn ve kaolin, phan b d kha rpng rai va phd bien d n h i l u ndi tren lanh thd.
Toi n g u y d n v g Moi t m o n g | Ky 2-Thang 10/2015 1 7
Kaolin mien Bac Viet Nam phan bd khdng ddng deu, tap trung ehCi yeu dpc ta ngan sdng Hdng, tQ Lao Cai qua Yen Bai den Viet Tri, Phu Thp. Cac md kaolin cd eae loai hinh ngudn gdc khic nhau, trong dd tap trung chii ylu trong 3 kilu ngudn gde: Phong hoa, tli tram tich va nhiet djch.
Kaolin ngudn gdc phong hoa nam trong ddi phong hoa cQa d c da pegmatit (Lang Ddng, Ddi Dao, Ba Bd - Phu Thp), Son Man - Lao Cai...), da magma xam nhap (Dai TU - Thai Nguyen...), da phun trao axit (Minh Tan - Hai DUdng)...), da trim tfch lue nguyen (Phao Sdn - Hai DUdng...).
Kaolin ngudn gde tai trim tfch phan bd trong d c trim tfch De tQ khdng phan chia, hlnh thanh trong eac thung iiing glQa nui, d c bac them sdng va them ven bd biln (md True Thdn - Hai Duong), Tdng Ba - Ha Giang), Ddng Quan - Lang Son)...). Kaolin ngudn gdc nhiet dieh bien chat trao doi trong d c da phun trao axit dupc thanh tao do su tiep xuc trao ddi giQa d c dung djch nhiet dich vdi cae da phun trao ryolit, ryolit porphyr, felsit, tuf (Tan Mai - Quang Ninh...).
Mau phan tich va phuong phap nghien cQu
Mau phan tich dupc lay tai ddi phong hoa ciia ba md kaolin cd dae dilm dac trung khac nhau: Kaolin md Lang Ddng phong hoa tU pegmatite cQa phQc he Thach Khoan (mau 1), kaolin md Minh Tan phong hoa tQ d l phun trao ryolit cQa he tang Binh Lieu (mlu 2) va kaolin md TrQc Thdn cd ngudn gdc tai trim tfch (mau 3) (Hinh 1). Cae mlu 1 va 2 tu nhien deu mem bd, cd mau trang den trang due. Mau 3 mau tring dye den nau, dd. Mlu
. • • 5 . , ^ ¥ i ! . '
Hmh 1 Moong khai thac kaolin md Lang Ddng (A), md TrQc Thdn (B).
tu nhien dupc hong khd tU nhien, dupe nghiin mjn va sang qua ray kfch cd <63nm. Phan mau dUdi sdng dupc hda tan trong nUdc d t . Cae thanh phan hat ed kieh cd <2iim dupc taeh dua theo nguyen ly trpng lue (theo hudng dan eua Cyc Dja chat My). Dung djch mau kich c3 <2(im dUdc xit ly vdi dieu kien khic nhau eho viec phan tfch XRD nhu mlu dinh hudng iam khd tu nhien trong khdng khi, mau tam ethyien-giy- col, mau nung den 35°C. Mpt lupng rat nhd mau khd tu nhien dupe phli carbon de phan tfch SEM-EDS.
May SEM dUpc sQ dyng phan tfeh la may Quanta 450, hang FEI tai Phdng thf nghiem Nghien cQu khoa hpe Dia chat, Trudng Dai hpc Mo - Dja chat.
Hlnh anh SEM dupc quet va thanh phan ban dinh lupng dupc xac djnh thdng qua bd dd EDS.
May XRD dupc sQ dung phan tfch (X D5005 Siemens, hang Bruker) tai Khoa Vat ly, Trudng Dai hoe Khoa hpc tu nhien. Cac thdng sd trong qua trinh do gdm sQ dyng bQc xa Cu(Ka1,2), hieu dien the 40 kV, ddng dien 30 mA bQdc nhay 0,02°2e, thdi gian ngung 0,3 giay, va pham vi quet 5-7O°20.
Ket qua nghiin ciiru va thao luan
May nhiiu xa tia X (XRD):
Gian dd XRD cho eac mau cd kich thudc hat <2 jim dudi eac
dilu kiln khac nhau (mlu dinh hudng iam khd tU nhien trong khdng khi, mau tim ethylen-gly- col, mau nung den 350) dupcth^
hien tai hinh 2. Ket qua cho thay khoang vat nhdm kaolin xuat hien trong tat d d c mau cQa ca 3 md vdi cac peak dac trung 7,18-7.42A. 4,44A va 3,58A.
Dudi dieu kidn tim ethylene-gly- col va nung d nhidt dp 350C dc peak dac trung cho khoang vat kaolin khdng thay dli. Ddi vdi mo Lang Ddng (Hinh 2A), ngoai si(
tdn tai khoang vat kaolin, peak tai 10,OA d dilu kien khd tiJ nhien dUpc cho la su t h i hiln sir tdn tai cQa khoing vat halloysite, Mau d md Minh Tan (Hinh 2B) cho thiy ngoai kaolin cdn cd c^c khoing vat khac bao gdm mont- moriollite, museovite va thach anh. Khoang vat montmoriollite dugc nhan biet qua peak 15,1Acf dilu kien nhiet dp phdng va peak nay se dieh chuyln thanh 16,9A do tinh chit trUdng nd ra dufli dilu kien tam ethelen-glycol (Hinh 2B).
May dien tiy quet (SEM):
Hinh anh SEM-EDS cho khoing vat nhdm kaolin cQa ba md duoc t h i hien d hinh 3. Hinh thai cQa khoang vat mo Lang Ddng cd dang hinh dng, dac trung cho khoang vat hallosite, thupc nhdm kaolin. Halloysite trong mau chiem chQ yeu so vdi khoang vat kaolin. Day la dac tinh 18 Tai nguydn yg Mdi traong [ Kjf 2-Tiling 10/2015
quan trpng gdp phan md rdng kha nang Qng dung trong duoe pham, vat lidu composlt, my pham, mdi trudng...Cac tinh t h i kaolin rat diln hinh dang tam hinh lyc lang mdng, lien ket lai vdi nhau dupc t h i hien kha rd md Minh Tan (Hinh 3B). 6 mo TrQc Thdn, cac don tinh t h i kaolin nam lln ldn chdng len nhau. Dieu nay ndi len rang kaolin d day cd ngudn gdc tai tram tieh, duoe thanh tao ndi khac, dupe van chuyln den va tai trim tfeh. Kit qua phan tfch EDS cho thay thanh phan cCia cae khoang vat nhdm kaolin nay gdm oxit silie SiOj va nhdm AI2O3, thanh phin dac trimg cQa nhdm kaolin. Ket qua ham iQpng ban dinh iQpng eCia cac mau theo phan tfch EDS (dp hat <2|j.m) dupc trinh bay d bang 1. Ham lupng oxit Fe va Ti trong mSu md Tnic Thdn eao hon hai md edn lai, dieu nay phii hpp vdi dieu kien thanh tao tai tram tfch ciia md. Md Lang Ddng cd chat lupng kha tdt vdi ham lupng oxit Fe va Ti thap, cd the dap Qng eac tidu ehuan san xuat san pham eao cap.
K i t luan
Phuong phap phan tich XRD va SEM-EDS Id nhiing cdng cu hieu qua d l nghien cQu khoang vat set. Ket qua XRD cho phep nhdn biet sy tdn tai ciia cae khoang vat. SEM-EDS giup chfnh xae hoa khoang vat thdng qua hinh anh ve hinh thai tinh the, cung nhU xae dinh d c nguydn td va ham lupng.
Ket qua ap dung nghien cQu dac diem khoang vat set dd hat <2nm eho mdt sd md ngudn gdc khac nhau cho thay kaolin tdn tai d tat ca cac mau
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I
r;
Hinh 2. Gian do XRD ciia d e mlu dudi dieu kien khac nhau: Mlu djnh hudng lam khd tu nhien trong khdng khi (a), mlu tim ethylen-gly- col (b), mlu nung den 35°C (c).
(A). Md Lang Ddng, (B). Md Minh Tan, (C). Md Tmc Thdn. K=Kaolin, H=Halloysite, Mu=Muscovite, Mo=
Montmorillonite, Q=Thach anh.
Lang Dong Minh Tan True Thon
Ham lirdng (%) Wa^O
0.06 0.01 0.71
MgO 0.33 0.80 0.80
Al,0, 46,45 35.56 31.40
S/O2 52.17 56.42 60.82
KjO 0.15 4.76 3.12
CaO 0.16 0.69 0.26
TIO, 0.29 0.23 1.06
Fe,0, 0.38 1.52 1.84 Bang 1. Ket qua phan tieh EDS cOa cac oxit trong mau theo
cOa cd hat <2fim phan tieh. Md Lang Ddng xae djnh dupc su xuat hien vdi ty le chii ye'u cQa khoang vat thudc nhdm kaolin la halloysite dang hlnh dng. Md Minh Tan cd d c tinh t h i kaolin rat dae trUng, ngoai ra cdn tdn tai khoang vat cd tfnh chat truong nd montmori- olite. Kaolin d mo True Thdn gdm cac tinh t h i don le do qua trinh thdnh tao tai tram tfeh. Ham iQpng oxit Fe va Ti trong mau md True Thdn cao hdn hai md edn iai. Chat lupng kaolin eac md deu cd t h i ap dung trong san xuat gdm sQ thdng thQdng va cao cap. Trong thdi gian tdi can cd nhQng nghien cQu chi tiet
hon, dae biet cho mo Lang Ddng, md rdng kha nang Qng dung ciia khoang vat halloysite dang dng, nham nang cao gia tri kinh te ciia mo.
Tdi lieu tham khao 1. Buatier M.D., et al., 2012.
Origin and behavior of clay miner- als in Bogd fault gouge, Mongolia.
Journal of Structural Geology, 34 (2012) 77-90.
2. Doan Huy Cam, Nguyen PhQOng, 2005."Cac loai hlnh ngudn gdc thanh tao va phan chia nhdm md tham dd d e md kaolin mien Ddng Bae Bd Viet Nam".
Tap chf Khoa hpe ky thuat Md - Dia chat, 10: Tr. 15-19, HaNoi.
Tai nguyen vg Moi tradng | KJF 2 - Thang 10/2015
19
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P^ • : * •l.'>***i
Hinh 3. Anh SEM-EDS ciia khoing vit nhom kaolin:
(A), f^o Lang Dong, (B). Mo IVIinh Tan, (C). Mo TrOc Thdn.
3. Doan Huy Cam, Nguyen Phirong, L§ Do Trf, 2006. Tiim nang l<aoiin mien Dong Bac Bo va l<ha nang sCr dung trong cac nganh cong nghiep. TC Dia chat, A/297: 30-37. Ha Noi.
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hudng cong tac tham do, khai thac phuc vu phat triin l<inh te - xa hpi. TC Dja chat, A/307: 7- 8/2008. Ha Noi.
6. Le Thanh Phudc, La Van Thai, 2012. Tong hgp zeoiite A tCr l^aoiin bang phudng phap thi^y nhiet. Tap chf Khoa hoc- OH Can Thd, 23b, 135-139.
6. Le Xuan ThuySn, 2006.
IVIgt so dac diem phan bo l<hoang vat set d dong bang song Cilu Long. Tap chf dia chat.
7. Ishil(awa T, et al., 2014.
Geochemical and mineralogical characteristics of fault gouge in the Median Tectonic Line, Japan:
evidence for earthquake slip.
Earth, Planet and Space, 2014, 66:36.
8. IVIarathe R.B., 2012. XRD and SEIVI analysis of Tapti River Sediment: A case study. Archives of Applied Science Research, 2012, 4(1): 78-84.
9. l<Jiramon W., et al., 2011.
Characterization of modified kaolin from the Ranong deposit Thailand by XRD, XRF, SEM, FTIR and EPR techniques. V. 46, Iss. 4, P. 539-559.
10. Nguyin Xuan Hal, Le Van Thien, Le Thj Thanh Thi^y.
Nghien cCru sCr dung khoang set cai tao dat trong rau tai xa Van Canh, huy6n Hoai DUc, tinh Ha Tay. Tap chi "Khoa hgc dat", ISSN 0868-3743, so 30-2008, Tr.
133-136.
11. Surace I.R., etai., 2011.
Structural analysis, clay mineralo- gy and K-Ar dating of fault gouges from Centovalli Line (Central Alps) for reconstruction of their recent activity.
Tectonophysic 610 (2011) 80-93.
12. Sunaree B., Darunee B., Thongchal P., Tripob B., 2011.
Characterization of halloysite from Thung Yai District, Nakhon Si Thammarat province, in south- ern Thailand. Songkalanakarin J.Sci.Technol, 33(5), 599-607.
13. http://pubs.usgs. gov/of/
2001/of01-041/index. htm."
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