Bentonite Mineralogy Part 1: Methods of Investigation - Posiva

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24 Table 4-2. Summary of additional methods that are recommended in case the information is considered as necessary. The table is based on experience from the research documented in Part 2 of this report. Method Transmission electron microscopy + electron diffraction +EDS Scanning electron microscopy +EDS Differential thermal analysis Infromation Mineralogical and chemical data on single particles or aggregates Identification of minor compounds Observation perpendicular to 001 Identification of minor compounds Chemical data of selected aggregates Distinction between cis- and trans-vacant varieties of smectite More detailed work with XRD, Characterization of smectite/mixed-layer oriented mounts of fine fraction: clay minerals -saturation with Mg, Ca -solvation with glycerol, heating -alkylammonium-method Chemical analysis of purified and NH4-exchanged bentonite Geotechnical methods supporting the determination of smectite content of the sample: - determination of grain-size distribution (amount of clay fraction in the sample) - specific surface area - liquid limit - swelling ability Determination of organic content Determination of layer charge Chemical composition of smectite without interlayer cations Allows the calculation of structural formula of smectite and the distinction between montmorillonite and beidellite In principal, the smectite content of the sample correlates with these attributes, e.g. if the liquid limit of the sample is exceptionally high, it can be assumed that the smectite content of the sample is also relatively high. Organic matter is an important reducing component of bentonites
PART 2. MINERALOGICAL RESEARCH OF SELECTED BENTONITES 5 SAMPLES 25 Bentonite and clay samples originate from five geographical areas: Wyoming (USA), Kutch (Gujarat, India), Milos (Greece), Neubrandenburg (NE Germany) and four localities in Czech republic (see table 5-1). Photographs of bentonites are presented in figures 5-1 to 5-5 and in appendix 1. Producers or vendors supplied the samples. Therefore, the representativity cannot be estimated. Sample sizes ranged from 1 kg to more than 2 kg. Table 5-1. The studied bentonite and clay samples Origin, age & characteristics of Sample Site Material Deposit type the deposit MX-80 Wyoming homogenized bentonite Hydrothermal alteration of volcanic ash, Cretaceous. Occurs in layers between other sediments of marine origin. (e.g. Elzea & Murray, 1990) BH-200 Wyoming raw bentonite Hydrothermal alteration of volcanic ash, Cretaceous. Occurs in layers between other sediments of marine origin. (e.g. Elzea & Murray, 1990) Kutch 8937 India raw, lumps bentonite Hydrothermal alteration of Kutch 8938 India raw, lumps bentonite volcanic ash, Tertiary. Kutch 8939 India raw, lumps bentonite Thickness of the deposit up to Kutch 8940 India raw, lumps bentonite 30 metres, occurs also in layers with basalt (e.g. Shah, 1997) Milos Hx Greece raw bentonite Hydrothermal alteration of Milos Ex Greece raw bentonite volcanic rocks, Tertiary. The Milos Ax Greece powdered bentonite thickness of the deposit varies activated between 10-40 m (e.g. Christidis & Scott, 1996 Friedland NE Germany powdered clay Weathering & sedimentation, Tertiary. Massive (thickness up to 140 m)(Pusch, 2001) Rokle Czech rep. raw bentonite Tuffites & pyroclastic rocks Strance Czech rep. raw bentonite altered to bentonite by Skalna Czech rep. raw sedimentary argillization in lacustrine Dnesice Czech rep. raw sedimentary environment or weathering, Tertiary (Prikyl & Woller, 2002) Different types of deposits. x, H = high grade, E = civil engineering grade; A = activated; characterization by producer
Page 1: POSIVA OY Working Report 2004-02 Be
Page 4 and 5: ABSTRACT In the first part of the r
Page 6 and 7: TABLE OF CONTENTS ABSTRACT TIIVISTE
Page 8 and 9: PART 1. METHODS OF INVESTIGATION- A
Page 12: 8 Mixed-layer clay minerals: Layers
Page 17 and 18: 13 4) Is the sample thick enough an
Page 19: 15 Table 3-3. The factors used for
Page 22: Recommendation: 18 It is recommende
Page 27: - 4 SUMMARY ON RECOMMENDABLE METHOD
Page 31 and 32: 20mm Figure S-3. Kutch bentonite, s
Page 33 and 34: 6 ANALYTICAL METHODS 29 Summary of
Page 35 and 36: 31 Table 6-2. Instrumental detectio
Page 37 and 38: 6.1.5 Coarse fraction 33 In connect
Page 42 and 43: Table 7-1. Minerals in addition to
Page 47: 43 The Friedland sample contains no
Page 54: 50 Figure 7-15. TEM-p holograph of
Page 58 and 59: Table 7-7. Contents of major elemen
Page 61 and 62: Table 7-9. Continued. 57 Sample La
Page 63 and 64: 59 charge. Therefore, more exchange
Page 65 and 66: 61 for the four Kutch samples studi
Page 67 and 68: 63 The Milos bentonites contain poo
Page 69 and 70: 8 SUMMARY 65 The purpose of this st
Page 71: 67 to Henning (1971), the position
Page 74 and 75: 70 in the interlayer positions. The
Page 76 and 77: REFERENCES 73 Backman, C.-M., Bruse
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75 Inoue, A., Kohyama, N., Kitagawa
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77 Pusch, R., 1999. Is montmorillon
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PHOTOGRAPHS OF BENTONITE AND CLAY S
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20mm 81 20mm APPENDIX 1 (3/5) Milos
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20mm 83 APPENDIX 1 (5/5) 20mm Dnesi
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counts/s 5000 26.0 18.0 14.0 11 .0
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counts/s 2000 26.0 18.0 14.0 96 Str
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102 TEM PHOTOGRAPHS OF BENTONITES S
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Sample: Milos high grade 104 APPEND
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Bentonite Mineralogy Part 1: Methods of Investigation - Posiva

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