Ca-exchanged montmorillonite SCa-3 size-fraction <1 µm | LSD

Matter

Database

Experimentalists

Parent matter: Montmorillonite SCa-3
Origins: natural terrestrial
Provider: Clay Minerals Laboratory, Institute of Geological Sciences, Polish Academy of Sciences
Local reference code: CaSCa3_LSD

Preparation: extracted components
Method: Monominerallic sample extracted by removal of carbonates, organics, and Fe-(oxy-)hydroxides by a sequence of acetic acetate buffer, hydrogen peroxide, and buffered sodium dithionite treatments, followed by washing in deionized water, size separation by centrifugation, ionic exchange by five washings with 0.5 M CaCl2 and subsequent dialysis in deionized water and drying at 60C. Sample was stored at room temperature and relative humidity
Phase type: solid
Component type (group): mineral (silicate mineral)

Texture

clay-like

Grain sizes

Grains	Size min	Size max	Size median	Size width	Size mass fraction	Grain shape
#1		1.0 ${\mu}m$			1.0 $\pm$ 0.05	platy

Size method

Size-fraction was separated in a centrifuge (Stoke's Law) but not verified

Number

Mode of mixing

single material

Materials

	Name	Arrangement	Mass (g)	Mass fraction	Abundance comments
	Ca-exchanged montmorillonite SCa-3 size-fraction <1 µm			1.0 $\pm$ 0.01

Title

Purification, size separation, and cation exchange

Matters

Materials

Matter

Ca-exchanged montmorillonite SCa-3 size-fraction <1 µm (this matter)

Processing steps

Step	Date	Type	Process	Changes
#1	2013-03-01	mechanical	Dry sieving at 400µm mesh	Removal of coarse fraction (above 0.4 mm
#2	2013-03-01	chemical	Reaction of 30 g of a sample with 150 ml of hydrogen peroxide for 30 min at 40C. Repeated 3 times.	Removal of organic matter
#3	2013-03-02	chemical	Reaction with 200 ml of Na-acetate buffer (ph 4.5 to 5.5) at 90C for 30 min	Removal of carbonates
#4	2013-03-03	chemical	Reaction with 2g sodium dithionite in 200 ml of sodium citrate - sodium bicarbonate solution at 75C	Removal of free Fe(hydro)oxides
#5	2013-03-04	fluid physical	Washing with deionized water	Removal of excess adsorbed cations and anions
#6	2013-03-05	mechanical	centrifugagion in deionized water	Separation of <1 micron fraction according to Stoke's Law
#7	2013-03-06	chemical	Reaction with 100 ml of 0.5 M CaCl2 repeated five times	Exchange of exchangeable cations for Ca
#8	2013-03-07	fluid physical	Dialysis in deionized water. Water was changed until conductivity of water dropped below 1 microsiemens	Removal of excess adsorbed cations and anions
#9	2013-03-11	thermal	Drying in an oven at 60C	Drying of a sample
#10	2013-03-12	mechanical	Crushing in an agate mortar	Disintegration of a sample in order to create powder

Publications