Properties of Calcined Lias Delta Clay Technological Effects, Physical Characteristics and Reactivity in Cement

Transcription

1 Department Civil Engineering and Environmental Science Properties of Calcined Lias Delta Clay Technological Effects, Physical Characteristics and Reactivity in Cement Nancy Beuntner Karl-Christian Thienel

2 Outline Introduction Calcination procedure Tests and results Conclusion 2

3 Motivation Cement in future demand in 2050: 5.6 bn tpa cement for OPC: 5 bn tpa greenhouse emission efforts to reduce clinker factor drop to 0.6 alternative SCM 3

4 Lias delta (lower jurassic) clay Geographical origin location of clay pit Sources: Liapor company 4

5 Lias delta clay Raw material Mineralogical composition Clay minerals Kaolinite 25 % Mica 30 % Illite 11 % Chlorite 6 % Quartz 18 % Feldspar 5 % Calcite 3 % Gypsum 1 % Pyrite 1 % 5

6 Calcination process Laboratory scale Particle size < 4 mm 50 g/charge Industrial scale Particle size < 100 mm 180 t/charge Sources: Liapor company 6

7 Calcination process Particle size Laboratory scale Particle size 0 to 4 mm Industrial scale Particle size 0 to 40 mm 7

8 Calcined clay Grinding technology on laboratory in mortar per hand on industrial in a roller mill 8

9 Methods Chemical-mineralogical properties IR-spectra X-ray diffraction Physical parameters BET specific surface Density Pozzolanic Ion solubility activity Activity index 9

10 Infrared spectroscopy industrially calcination laboratory calcination IR-spectra of raw clay IR-spectra of calcined clay P o = I 3620 / I 3700 = 0.96 < 1 disordered structure [1] [1] Bich et.al. Applied Clay Science 44 (2009)

11 Chlorite Mica Illite Kaolinite (001) Chlorite (002) Mica Illite (11-1) Quartz Calcite Zincite* Mica (131) Zincite* X-ray diffraction X-ray patterns of raw clay, laboratory calcined clay and industrially calcined clay. *Zincite is used as an internal standard. 11

12 X-Ray Diffraction Quartz Mica 65.7 % Amorphous 59.3 % Amorphous Illite Feldspar Ore 1.2 % Silicates sec 3.4 % Silicates sec Sulfate Rietveld analysis of Laboratory calcined clay Rietveld analysis of Industrially calcined clay 12

13 Influence of particle size Model of clay particle Particle size < 4 mm Particle size < 40 mm 13

14 Influence of particle size Model of clay particle Particle size < 4 mm Particle size < 40 mm Silicates sec = 1 % Amorphous > 65 % Uncalcined clay < 8 % secondary silicates amorphous and inert mass uncalcined clay and inert mass Silicates sec = 3 % Amorphous < 60 % Uncalcined clay > 10 % 14

15 Influence of calcination temperature Thin section 1000 µm 1000 µm 1000 µm T=750 C T=820 C T=930 C Non-steady temperature profile Non-steady moisture conditions Non-uniform oxidation 15

16 Results Physical parameters Specific surface as a function of heating temperature Density as a function of heating temperature 16

17 Results Pozzolanic activity Ions solubility as a function of heating temperature Activity index* after 28 days as a function of heating temperature *CEM I 42.5 R, Neq 0.6 Replacement 20 % by mass 17

18 Conclusion Presented calcined clay: mixture of different clay minerals, low kaolinit content by 25 mass % Degree of dehydroxilation: depending on particle size and different kind of clay minerals Activity index > 1.0 for calcination temperature C The calcined clay we used: economically and environmentally alternative SCM 18

19 Department Civil Engineering and Environmental Science Thank you for your attention