Porosity, XRD, SEM and SAXS Measurements on Greek Natural - PowerPoint PPT Presentation

Porosity, XRD, SEM and SAXS Measurements on Greek Natural Clinoptilotite Student: Dimitris Katsios Supervisor: Nikos Lygeros EMT-IT Msc Oil & Gas Technology 11/11/2014

Structure of the presentation } What is zeolite? } Possible applications } Current status in Greece } Importance of studying it } Sampling, sample preparation } Results } Conclusions

What is zeolite? } Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts } Discovered in 1756 by Axel Fredrik Cronstedt } Framework structure characterized by the existence of interconnected cages, occupied by the relatively large cations and water molecules

Possible applications } Agriculture and Animal husbandry } Human health } Oil & gas Industry } Nuclear industry } Water purification } Catalysts and sorbents } Construction } Heating and refrigeration } Detergents

Current status in Greece } 10 zeolite deposits have been located in Greece } Five of the at the area of Evros } Important due to quantity and quality } Kokkalo, Petrota, Pentalofos, Metaxades, Kirki } For one of them exploration license has been approved at July 2014 (Olympus S.A.)

Importance of studying } Chemical analysis for hazardous and toxic substances } Compound analysis for zeolite concentration and zeolite types } Porosity analysis for molecular structure and porod’s properties } Based on these results the possible applications can be found, subject to specific constraints and limits (e.g. EC regulations)

Sampling, sample preparation } 2 deposits: Petrota and Kokkalo (North Evros) } 3 samples from each deposit } 3 granularities for each sample (125, 90 and 45 µm) } In order to remove organic matter and other impurities, samples were dived in hydrogen peroxide (H 2 O 2 ) 35% solution for 20 hours } In order to remove the absorbed H 2 O 2 , water and other liquid residues from the samples’ pores, they were calcinated at 500 o C for 5 hours

SEM results } For each sample 3 scans at x200, x1000, x5000 and x10.000 } The crystalline nature of the material is obvious from the sharp edges of the surface supporting the smaller particles } Fractal structure is also observed } The sharp edges and the smooth surfaces of the zeolite crystals are present for the different grain sizes

O3M2 O2M3 P 4M2 P6M3

EDX elememental Kokkalo Kokkalo Element Percent Oxygen 78.45 Silicon 13.26 Aluminium 3.34 Carbon 1.95 78,4517 Potassium 1.03 Calcium 0.67 Magnesium 0.34 Sodium 0.25 Copper 0.20 Iron 0.19 Zinc 0.13 Rhenium 0.09 Titanium 0.05 Tantalum 0.02 Sulfur 0.02

EDX elememental Petrota Petrota Element Percent Oxygen 76.19 Silicon 13.84 Aluminium 3.83 76,1867 Carbon 2.33 Potassium 1.23 Sodium 0.70 Calcium 0.55 Copper 0.29 Zinc 0.27 Vanadium 0.26 Iron 0.25 Magnesium 0.16 Titanium 0.09 Sulfur 0.01

EDX Si/Al ratio Sample Si/Al Values near 4 indicate the existence of hydrophilic zeolites O1 4.34 specifically clinoptilolite and heulandite O2 4.13 O3 3.53 which is accordance with the XRD P4 3.86 results P5 3.59 P6 3.40

XRD elemental results } XRD and EDX results have quantitative but not qualitative differences } The major difference is obtained at the Oxygen percentage } EDX analysis shows much higher quantities (78.45% and 76.19%) compared to those of the XRD analysis (53.26% and 52.96%)

XRD elememental Kokkalo Average Kokkalo Average Kokkalo Oxygen 53.26% Silicon 28.31% Aluminium 7.01% Calcium 2.62% Fluorine 1.64% Hydrogen 1.63% Sodium 1.60% 0,5326 Zirconium 1.43% Potassium 1.36% Nickel 0.41% Rubidium 0.21% Bismuth 0.14% Arsenic 0.13% Gallium 0.12% Cobalt 0.06% Nitrogen 0.04% Magnesium 0.03% Titanium 0.00%

XRD elememental Petrota Average Petrota Average Petrota Oxygen 52.96% Silicon 27.21% Aluminium 7.33% Calcium 3.32% Hydrogen 1.67% Iodine 1.49% 0,5296 Potassium 1.23% Carbon 0.99% Sodium 0.91% Molybdenum 0.85% Fluorine 0.67% Zirconium 0.59% Chromium 0.23% Nitrogen 0.19% Zinc 0.11% Manganese 0.10% Cobalt 0.09% Lithium 0.06%

XRD zeolite percentage } The zeolites (clinoptilolites and heulandites) percentage for the Kokkalo and Petrota Average Petrota Average Kokkalo deposits are 94.7% and 91% respectively 0,9105 0,947 Average Kokkalo Average Petrota

XRD zeolites percentage Sample Zeolites Other O1M3 92.71% 7.29% O2M3 96.89% 3.10% O3M3 94.49% 5.50% P4M3 91.84% 8.17% P5M3 88.61% 11.39% P6M3 92.69% 7.32% ¡ ¡ ¡ Average ¡ Kokkalo 94.70% 5.30% Average ¡ Petrota 91.05% 8.96%

XRD Si/Al ratios Sample Si/Al O1M3 4.85 O2M3 3.81 O3M3 3.65 P4M3 3.62 P5M3 3.99 P6M3 3.57 Average ¡ Kokkalo 4.04 Average ¡ Petrota 3.71

XRD Crystallinity Sample Crystallinity O1 43.6% O2 44.4% O3 54.9% P4 59.4% P5 53.6% P6 59.3% Average ¡ Kokkalo 47.6% Average ¡ Petrota 57.4%

SAXS results } The I(q) vs log(q) curves are characterized by a slight bend between two linear portions after q = 0.01 Å -1 } This indicates that the scattering intensities are caused by different regimes of constant mass/size scaling and size scales of structure } Applying segmented linear regression at the data, the greater change of slope is found at q = 0.03 Å -1

Log(I) vs log(q) graph

D s and D m values } The D s values of the samples fluctuate around 2.45 being for all larger than 2. } This means that the primary particles of the measured zeolites are characterized by micropores inside and a rough pore-solid interface. } The D m of the measured zeolites have similar trends, indicating the similar length scales of the primary particles for the samples.

Explanation } The bend in log I versus log q figure (q = 0.03 Å -1 ) reflects a change of exponential decay in scattered intensity that corresponds to different average structural sizes for heterogeneities according to Guinier’s law in exponential form.

Two segmented linear fitting 
 (log I vs log q)

Radius of gyration } The radii of gyration (R g ) calculated for each q-region are approximately the same at around 270 Å and 24 Å respectively for each sample

Dm Ds and Rg SAXS results R g ¡( Å) R g ¡( Å) D m D s <0.01 ~0.1 q-­‑range <0.03 0.03-­‑0.1 272.15 23.72 O1 2.93 2.42 272.17 23.74 O2 2.89 2.50 270.11 21.14 O3 2.85 2.50 261.5 24.97 P4 2.69 2.46 268.33 24.50 P5 2.81 2.44 269.12 24.74 P6 2.82 2.44

Porod characteristics based on SAXS measurements Sample Qp S/V Dp Pp T O1 1.16E-­‑03 2.59 2.15E-­‑02 3.50E-­‑01 5.12E-­‑03 O2 1.66E-­‑04 3.06 8.11E-­‑03 1.56E-­‑01 3.24E-­‑04 O3 9.68E-­‑04 3.04 1.96E-­‑02 3.75E-­‑01 4.55E-­‑03 P4 9.96E-­‑04 3.46 1.99E-­‑02 4.33E-­‑01 5.42E-­‑03 P5 7.35E-­‑04 2.96 1.71E-­‑02 3.18E-­‑01 2.94E-­‑03 P6 8.65E-­‑04 2.92 1.85E-­‑02 3.40E-­‑01 3.70E-­‑03

Size distribution based on SAXS Average ¡r ¡( Å ) Average ¡r ¡( Å ) Sample Sample O1 18.63 O1 314 O2 19.43 O2 320 O3 19.20 O3 315 P4 19.15 P4 301 P5 18.27 P5 306 P6 18.31 P6 305 Kokkalo 19.09 Kokkalo 316 Petrota 18.58 Petrota 304

Conclusions 1/2 } All the samples examined from both Petrota and Kokkalo deposits found to contain more than 90% clinoptilolite. } No hazardous or toxic concentrations were detected at the compound and chemical analyses. } The characteristics of both minerals are similar to each other, possibly due to the common creation conditions of the two deposits and indicate a high quality zeolitic tuff.

Conclusions 2/2 } Based on the results both deposits can be commercially exploited since no extended chemical treatment shall be needed after the extraction of the minerals. } The wide range of applications of zeolite create the best expectations for economic development not only in primary but also in secondary sector of economy.

Thank you 
 Very much!