Characterisation of the ABM samples. Kaufhold & Dohrmann, LUND 2010 (ABM-test)

Transcription

1 Characterisation of the ABM samples

2 Sample set

3 Macroscopic optical observations Gradual color change from heater (e.g. JNB)

4 Macroscopic optical observations Color change only at interface (e.g. ROK)

5 Macroscopic optical observations Color change near interface + brittle appearance (e.g. FEB)

6 Macroscopic optical observations White spots (e.g. IBE) turned out to be anhydrite

7 Macroscopic optical observations No (significant) optical changes (e.g. ASH)

8 Macroscopic optical observations (+ samples) JNB ABM CAN ABM ROK ABM CAL ABM COB ABM Kunigel V1 Deponit Ca N "RAWRA" Calcigel Callovo Oxf. Summary of Bentonite all optical observations Bentonite = ROK???? Bentonite Clay Block No #17 #15 #13 #23 no sample "metallic" crust, hard, a thick (1mm) black a little rusty but thin layer blueish colour until appr. 1 cm depths, direct contact was deep bluegreen thin black crust at contact, underneath pristine clay 1 mm JNB 0 CAN 0 ROK 0 CAL 0 1 cm JNB 1 CAN 1 ROK 1 CAL 1 3 cm JNB 2 CAN 2 ROK 2 CAL 2 5 cm JNB 3 CAN 3 ROK 3 CAL 3 7 cm JNB 4 CAN 4 ROK 4 CAL 4 IBE ABM LOT ABM ASH ABM FRI ABM FEB ABM IKO ABM IBECO Seal MX 80 Asha 505 Friedland Febex Ikosorb Bentonite Bentonite Bentonite Clay Bentonite Bentonite #6 #11 #14 #9 #8 #10 the contact looks "ugly" = thick black layer with white spots and smells rotten the total sample looks dark, contact is brittle smells as a desinfactant (??), no change of colour at contact, sample heterogenous, representative sampling?? pieces fell apart, nice "Harnische", contact very hard "blue heart" alteration (blue seems), contact brittle, thick, black very hard dark corrosion products at contact IBE 0 LOT 0 ASH 0 FRI 0 FEB 0 IKO 0 IBE 1 LOT 1 ASH 1 FRI 1 FEB 1 IKO 1 IBE 2 LOT 2 ASH 2 FRI 2 FEB 2 IKO 2 IBE 3 LOT 3 ASH 3 FRI 3 FEB 3 IKO 3 IBE 4 LOT 4 ASH 4 FRI 4 FEB 4 IKO 4 IBE Kaufhold 0-1 white & Dohrmann, (1mg) LUND 2010 (ABM-test)

9 Sampling #17 7 cm 5 cm 3 cm 1 cm Contact = 1 mm 5 samples /# 5 g : 60 C + mortar mill

10 concentration [wt.%] Fe abundance Different degree of Fe accumulation near (at!!) the surface, none in 1 cm distance JNB CAN ROK CAL IBE LOT ASH FRI FEB IKO 8 6 Where is the Fe??? Distance [cm]

11 Smektit where is the Fe??? Ionenstrom Siderite Quarz No separate Fe-silicate-phases found by XRD (no 7 Å), IR, DTA No indication for Fe-cation exchange (but cannot be excluded) Sample JNB (#17): siderite 1.E-09 1.E-09 DTA-MS (CO 2 ) 470 C siderite JNB 0 JNB 1 JNB 2 JNB 3 JNB 4 1.E-09 8.E-10 6.E-10 JNB 1 mm 4.E-10 2.E wavenumber [cm -1 ] E T [K]

12 where is the Fe??? - SEM Example: CAL (6 8 wt.% Fe 2 O 3 ) Possibly the reason for the color: small Feoxohyd.??? Image width 50 µm

13 where is the Fe??? Example IBE: (4 10 wt.% Fe 2 O 3 ) Again, several Fe-rich spots Disseminated Fe-oxohydroxides (?) µm Image width 10 µm

14 A simple model

15 Corganic Ionenstrom content [wt.%] relative absorbance kaolinite / halloysite smectite / kaolinite / halloysite adsorbed water Organic carbon goethite C-C / C-H vibrations organic matter Organic carbon accumulated at interface 2.5 LECO data confirmed by DTA-MS (CO 2 ) & IR 7.E E E-10 4.E E-10 2.E-10 ROK ROK ROK 0 ROK 1 ROK 2 ROK 3 ROK 4 JNB CAN ROK CAL IBE LOT ASH FRI FEB IKO E-10 0.E wavenumber [cm ] distance [cm] T [K]

16 Organic carbon Organic carbon accumulation possibly related to microorganisms? On the contact of ROK

17 suslfur content [wt.%] sulphur LOT experiment: gypsum redistribution Possibly some 0.9 S-redistribution (samples CAN, FRI,..?) What happend to FEB??? JNB CAN ROK CAL IBE LOT ASH FRI FEB IKO distance [cm]

18 smt crist. anhydrite qtz fsp S accumulation What happend to FEB? FEB 10 cm Anhydrite formation also confirmed by DTA-MS (SO 2 )

19 Mineralogical differences cristobalite Depletion of cristobalite (IBE #6, LOT #11, IKO #10) LOT 10 cm Indication for alkaline conditions (due to corrosion?)

20 ph ph No ph increase at interface! (no information about ph evolution during early heating phase) CAN ROK LOT CAL ASH FEB IBE FRI IKO JNB distance [cm]

21 Al SiO 2 O 2 3 content [wt.%] MgO content [wt.%] Exchangeable and structural cations Ca, Na, K changes according to cation exchange (next presentation) Structural elements (Al, Si) decrease at 1 mm but Mg increased in almost all instances (despite Fe accumulation = dilution ) JNB CAN ROK CAL IBE LOT ASH FRI FEB IKO MgO-increase is known from LOT-A2 parcel! Important: No correspondance to cation exchange data!!! unidentified alteration product - (conceivably trioctahedral minerals?) distance [cm]

22 relative absorbance Trioctahedral domains? - IR New IR-band at contact trioctahedral domains/minerals? Samples (LOT #11, FRI #9, FEB #8, IKO#10, CAN #15?) LOT Saponit yellow = contact 680 cm -1 : saponite? 1 mm 1-7 cm wavenumber [cm -1 ]

23 black = contact blue = 1 cm from contact 1.50 Å montmorillonite Trioctahedral domains - XRD 1.54 Å quartz Å broad trioctahedral FEB LOT ROK MgO +2.5 wt.% IR + trioctahedral band Formation of trioctahedral minerals indicated by XRF and MgO +3.0 wt.% IR + trioctahedral band MgO ±0.0 wt.% IR no changes dioctahedral trioctahedral proved by XRD + IR!! Mechanism??? - dissolution / precipitation - addition-reaction dioct.smt.+mg di/trioct.smt. IKO MgO +2.0 wt.% IR + trioctahedral band CAN MgO ±0.0 wt.% IR very small changes theta (Cu)

24 SUMMARY of mineralogical changes Fe-accumulation (caused by corrosion, color (oxohydroxides), Fe-carbonates!) Organic carbon accumulation (microorganisms?) S-redistribution /accumulation (diss/prec. processes!) Cristobalite dissolution (ph?, bulk/local/time dependent?) Trioctahedral domains (diss./precip. / addition reaction )

25 ++ = significant increase + = increase 0 = not changed - = decrease -- = significant decrease +/- = increase at contact and decrease to host rock JNB ABM CAN ABM ROK ABM CAL ABM IBE ABM LOT ABM ASH ABM FRI ABM FEB ABM IKO ABM Kunigel V1 Deponit Ca N "RAWRA" Calcigel IBECO Seal MX 80 Asha 505 Friedland Febex Ikosorb Bentonit Bentonit Bentonit Bentonit Bentonit Bentonit Bentonit Clay Bentonit Bentonit Japan Milos, Gr. Czech.Rep. Bayern Georgien Wyoming Indien Friedland, D. Almeria, Sp. Marokko #17 #15 #13 #23 #6 #11 #14 #9 #8 #10 ++ = significant increase + = increase 0 = not changed - = decrease -- = significant decrease +/- = increase at contact and decrease to host rock cristobalite missing, XRD Cu Tex new peak no difference no difference no difference no difference no difference no difference no difference no difference broadening siderite, JNB 0 ABM has no CAN ABM ROK ABM CAL ABM cristobalite IBE missing ABM at cristobalite LOT missing ABM at ASH ABM possibly FRI ABM 14 A FEB ABM cristobalite IKO missing ABM at XRD Pulver no difference no difference no difference no difference anhydrite at contact Kunigel clinoptilolitev1 Deponit Ca N "RAWRA" Calcigel IBECO contactseal MX contact 80 Asha 505 Friedland difference? Febex Ikosorb contact full swellability, no full swellability, no 7 full swellability, no full swellability, no full swellability, no full swellability, no full swellability, no full swellability, no full swellability, no Bentonit Bentonit Bentonit Bentonit Bentonit Bentonit Bentonit Clay Bentonit Bentonit 7 A 7 A A 7 A 7 A 7 A 7 A 7 A 7 A 7 A Japan Milos, Gr. Czech.Rep. Bayern Georgien Wyoming Indien Friedland, D. new Almeria, band at 680, Sp. FEB Marokko siderite and Corg at slight change of 680 organic matter at white spots are new band at 680, new band at 680, new band at IR organic matter at contact contact #17 band #15 #13 contact #23 anhydrite #6 trioct. #11 domains? slightly more #14 organics slightly different trioct. domains? #9 #8 organic #10 at contact Final assessment??? (organic?) siderit 470 C, open: less sulphate S at organic matter at contact, organic matter at organic matter at organic matter at organic matter at DTA pyrite DTA and XRD no difference no difference contact but more total S at contact few more sulphate contact contact contact contact difference S - red.? SEM Several approaches possible.. XX XX XX XX XX XRD PulvGlyz full swellability, no Who won???? Fe Mg Ca Fe Na Mg One + option: + ++/ K Ca SO significant 1 increase 1 1towards/at 1 interface Na S LECO / K C anorg significant 1 increase 1 towards/at 1 1 interface SO3 0 +/ /+ +/- + +/ C org S LECO 0 +/ /+ 0/- + +/ Na exch C anorg no change K exch C org Mg exch Na exch decrease + towards/at -- interface Ca exch K exch - 0? 0 -/ CEC Mg exch LOI 2-0- significant 1 decrease 1 0towards/at 0 interface Ca exch / Ba CEC Cr LOI Mo Ba /+ Sr Cr Zn Mo Sr / Zn Fe-Accumulation Milos bentonite performed best / Georgia bentonite lost siderite (RFA) Organik-acc. (LECO, (of DTA, course IR) the importance + of the different + + parameters is + different, therefore the + SO 4 -accumulation anhydrite + (LECO, DTA) parameters need to be weightened / spots e.g. most important parameter CEC = cristobalitedissolution Kaufhold (XRD) & Dohrmann, LUND 2010 (ABM-test) factor + 10 ) er IR-Band