Feldspar

Feldspar (silicate, chemical formula Na(AlSi₃O₈), where Na can also be replaced by K) is one of the main constituents of the Earth’s crust. Feldspar can be characterised by:

 

• Relatively high Mohs hardness of 6
• Low electrical conductivity
• Easy to wet
• High inertness in various media.

 

And, depending on the grade:

 

• Low content of lamellar mica
• Low fine crystalline silica fraction (no labelling)
• Whiteness

 

Note when using feldspar: depending on the particle size distribution of certain products, they can be labelled STOT RE 2. For more detailed information, visit www.safesilica.eu.

Sibelco feldspar quarry in Cine (Turkey)

 

Basic properties

Property	Value	Unit
Moisture	< 0.5	[%]
Hardness (Mohs)	6 (6.5)	[-]
Refractive index	1.53	[-]
L.O.I.	0.5	[%]
Density	2.6	[kg/ dm3]

 

 

Product overview

Product	Grade	D50 [µm]	D97 [µm]	OA [g/ 100 g]	pH	L*
Feldspar	FF-20	6	n.d.	32	9.8
	FF-30	8	n.d.	28	9.7
	FF-60	19	n.d.	27	9.5
	FF-150	23	n.d.	24	9.4
	PG4	4	17	26	9.5	94.5
	PG W7	7	25	27	8.0	97.0
	PG W13	13	60	22	8.1	96.4
	PG W20	20	80	19	8.2	96.2

Production locations Feldspar

 

Application

Feldspar will provide:

 

• Ease of tinting: due to the combination of refractive index, brightness and color, paints including feldspar will give excellent reproducible colour results when working with tinting systems.
• Texture effect: usage of coarse feldspar grades will ensure texture to the surface of the coating.
• Tint retention: paints including cristobalite show improved tint retention over other minerals when subjected to natural weathering.
• UV resistance and weatherability: due to its inertness, feldspar supports good UV and weatherability performance to exterior architectural coatings.