SUBSTITUTIONS

FOR

POTASSIUM

FELDSPARS

USING

CUSTER SPAR

AS

AN EXAMPLE

PROPOSITION “A”

If a slight increase in the vicinity of 4% of the alumina portion of the

molecular formula of a glaze is acceptable then Custer spar could be

substituted for by Nepheline/Syenite in the following manner.

I . SUBSTITUTION FOR CUSTER FELDSPAR BY

NEPHELINE/SYENITE, SILICA

FIGURE # 1  CUSTER FELDSPAR

							KNAO					AL2O3			SIO2
							1					1.05			7.05
NEPHELINE/		X1					1					1.11			4.65
SYENITE							X								2.40
SILICA		X2.4													7.05
															X
NEPHELINE/
SYENITE	1		X	462	=	462		¸	6.06	=	76.238		¸	100		=	0.762
SILICA	2.4		X	60	=	144		¸	6.06	=	23.762		¸	100		=	0.238
						606					100.000						1.000

FIGURE #2  LEACH WHITE

C/8 – 10R

CUSTER		40.00 %
WHITING		20.00 %
E.P. KAOLIN		10.00 %
SILICA		30.00 %
		100.00 %
ZIRCOPAX		10.00 %

K2O	.170			AL2O3	.404			SIO2	3.909
NA2O	.075
CAO	.755

FIGURE #3  LEACH WHITE (SUBSTITUTION)

NEPHELINE/SYENITE		40 X .762		30.48 %
SILICA		40 X .238		9.52 %
WHITING				20.00 %
E.P. KAOLIN				10.00 %
SILICA				30.00 %
				100.00 %

K2O	.060			AL2O3	.423			SIO2	3.940
NA2O	.185				(+4.7 %)				(+0.79%)
CAO	.755

FIGURE #4  TRANSPARENT

C/8 – 10R

CUSTER		43.50 %
SILICA		28.10 %
E.P. KAOLIN		10.30 %
WHITING		18.10 %
		100.00 %

K2O	.194			AL2O3	.456			SIO2	4.163
NA2O	.087
CAO	.718

FIGURE #5  TRANSPARENT (SUBSTITUTION)

NEPHELINE/SYENITE		43.5 X .762		33.15 %
SILICA		43.5 X .238		10.35 %
SILICA				28.10 %
E. P. KAOLIN				10.30 %
WHITING				18.10 %
				100.00 %

K2O	.071			AL2O3	.474			SIO2	4.174
NA2O	.213				(+3.9%)				(+.26%)
CAO	.715

FIGURE #6  YAC #1

C/8 – 10R

CUSTER		56.80 %
DOLOMITE		13.60 %
WHITING		10.60 %
ZINC OXIDE		3.00 %
E.P. KAOLIN		16.00 %
		100.00 %
RUTILE		2.00 %
RED IRON OXIDE		3.00 %

K2O	.164			AL2O3	.415			SIO2	2.018
NA2O	.076
CAO	.470
MGO	.193
ZNO	.097

FIGURE #7  YAC # 1 (SUBSTITUTION)

NEPHELINE/SYENITE		56.8 X .762		43.28 %
SILICA		56.8 X .238		13.52 %
DOLOMITE				13.60 %
WHITING				10.60 %
ZINC OXIDE				3.00 %
E. P. KAOLIN				16.00 %
				100.00 %

K2O	.060			AL2O3	.432			SIO2	2.047
NA2O	.182				(+4.1%)				(+1.4%)
CAO	.469
MGO	.193
ZNO	.096

The proposed proportion is :        0.762 Nepheline/Syenite

                                                       0.238 Silica                        for 1% Custer Feldspar

PROPOSITION “B”

If the small increase in the amount of alumina is not acceptable we submit a new proposition in which the KNAO portion is decreased and the other fluxes increased while the silica and alumina portions are kept at their original levels.

II.  SUBSTITUTION FOR CUSTER FELDSPAR BY

NEPHELINE/SYENITE, SILICA

FIGURE # 1  CUSTER FELDSPAR

							KNAO			AL2O3				SIO2
							1			1.05				7.05
NEPHELINE/		X.946					.946			1.05				4.399
SYENITE							.054			X				2.651
SILICA		X2.651												7.05
														X
NEPHELINE/
SYENITE	.946		X	462	=	437.052		¸	5.96		=	73.33	¸		100	=	0.733
SILICA	2.651		X	60	=	159.060		¸	5.96		=	26.69	¸		100	=	0.267
						596.112						100.000					1.000

FIGURE #2  LEACH WHITE

C/8 – 10R

CUSTER		40.00 %
WHITING		20.00 %
E.P. KAOLIN		10.00 %
SILICA		30.00 %
		100.00 %
ZIRCOPAX		10.00 %

K2O	.170			AL2O3	.404			SIO2	3.909
NA2O	.075
CAO	.755

FIGURE #3  LEACH WHITE (FIRST SUBSTITUTION)

NEPHELINE/SYENITE		40 X .733		29.32 %
SILICA		40 X .267		10.68 %
WHITING				20.00 %
E.P. KAOLIN				10.00 %
SILICA				30.00 %
				100.00 %

K2O	.061			AL2O3	.414			SIO2	3.990
NA2O	.179
CAO	.760

FIGURE #4  LEACH WHITE (SECOND SUBSTITUTION)

NEPHELINE/SYENITE		40 X .681		27.26 %
SILICA		40 X .240		9.60 %
WHITING				20.00 %
E.P. KAOLIN				10.00 %
SILICA				30.00 %
				96.96 %

K2O	.058			AL2O3	.402			SIO2	3.907
NA2O	.170
CAO	.772

FIGURE #5  TRANSPARENT

C/8 – 10R

CUSTER		43.50 %
SILICA		28.10 %
E.P. KAOLIN		10.30 %
WHITING		18.10 %
		100.00 %

K2O	.194			AL2O3	.456			SIO2	4.163
NA2O	.087
CAO	.718

FIGURE #6  TRANSPARENT (SUBSTITUTION)

NEPHELINE/SYENITE		43.5 X .681		29.62 %
SILICA		43.5 X .240		10.44 %
SILICA				28.10 %
E. P. KAOLIN				10.30 %
WHITING				18.10 %
				96.56 %

K2O	.065			AL2O3	.453			SIO2	4.163
NA2O	.196
CAO	.739

FIGURE #7  YAC #1

C/8 – 10R

CUSTER		56.80 %
DOLOMITE		13.60 %
WHITING		10.60 %
ZINC OXIDE		3.00 %
E.P. KAOLIN		16.00 %
		100.00 %
RUTILE		2.00 %
RED IRON OXIDE		3.00 %

K2O	.164			AL2O3	.415			SIO2	2.019
NA2O	.076
CAO	.470
MGO	.193
ZNO	.097

FIGURE #8  YAC # 1 (SUBSTITUTION)

NEPHELINE/SYENITE		56.8 X .681		38.68 %
SILICA		56.8 X .240		13.63 %
DOLOMITE				13.60 %
WHITING				10.60 %
ZINC OXIDE				3.00 %
E. P. KAOLIN				16.00 %
				95.51 %

K2O	.056			AL2O3	.413			SIO2	2.005
NA2O	.168
CAO	.480
MGO	.197
ZNO	.099

The proposed proportion is :        0.681 Nepheline/Syenite

                                                     0.240 Silica                        for 1% Custer Feldspar

PROPOSITION “C”

Making an average of propositions “A” and “B” we obtain the

following substitution : .721 Nepheline/Syenite and .239 Silica.

III. SUBSTITUTION FOR CUSTER FELDSPAR USING AN INTERMEDIARY PROPORTION OF NEPHELINE/SYENITE

AND SILICA

FIGURE #1  LEACH WHITE

C/8 – 10R

CUSTER		40.00 %
WHITING		20.00 %
E.P. KAOLIN		10.00 %
SILICA		30.00 %
		100.00 %
ZIRCOPAX		10.00 %

K2O	.170			AL2O3	.404			SIO2	3.909
NA2O	.075
CAO	.755

FIGURE #2  LEACH WHITE (SUBSTITUTION)

NEPHELINE/SYENITE		40 X .721		28.84 %
SILICA		40 X .239		9.56 %
WHITING				20.00 %
E.P. KAOLIN				10.00 %
SILICA				30.00 %
				98.40 %

K2O	.057	}(-4.9%)		AL2O3	.414			SIO2	3.927
NA2O	.175				(+2.5%)				(+.5%)
CAO	.766	(+1.5%)

FIGURE #3  TRANSPARENT

C/8 – 10R

CUSTER		43.50 %
SILICA		28.10 %
E.P. KAOLIN		10.30 %
WHITING		18.10 %
		100.00 %

K2O	.194			AL2O3	.456			SIO2	4.163
NA2O	.087
CAO	.718

FIGURE #4  TRANSPARENT (SUBSTITUTION)

NEPHELINE/SYENITE		43.5 X .721		31.36 %
SILICA		43.5 X .239		10.44 %
SILICA				28.10 %
E. P. KAOLIN				10.30 %
WHITING				18.10 %
				98.26 %

K2O	.068	}(-2.9%)		AL2O3	.462			SIO2	4.165
NA2O	.205				(+1.3%)
CAO	.727	(+1.2%)

FIGURE #5  YAC #1

C/8 – 10R

CUSTER		56.80 %
DOLOMITE		13.60 %
WHITING		10.60 %
ZINC OXIDE		3.00 %
E.P. KAOLIN		16.00 %
		100.00 %
RUTILE		2.00 %
RED IRON OXIDE		3.00 %

K2O	.164			AL2O3	.415			SIO2	2.018
NA2O	.076
CAO	.470
MGO	.193
ZNO	.097

FIGURE #6  YAC # 1 (SUBSTITUTION)

NEPHELINE/SYENITE		56.8 X .721		40.90 %
SILICA		56.8 X .239		13.60 %
DOLOMITE				13.60 %
WHITING				10.60 %
ZINC OXIDE				3.00 %
E. P. KAOLIN				16.00 %
				97.70 %

K2O	.058	}(-3.4%)		AL2O3	.422			SIO2	2.003
NA2O	.174				(+1.7%)				(-.8%)
CAO	.475	(+1%)
MGO	.195	(+1%)
ZNO	.098	(+1%)

The proposed proportion is :        0.721 Nepheline/Syenite

                                                      0.239 Silica                        for 1% Custer Feldspar



N.B. From my book "Substitutions for Raw Ceramic Materials"       Available in the USA  from Potters Shop, Brackers, Laguna.        In Canada, from Tuckers in Toronto.

------------------------------------------------

My Books Mes Livres Miaj Libroj

Toxicology Ceramics Glass and Metallurgy
http://toxicologyceramics.blogspot.com/
----------------------------
Toxicologie Céramique Verrerie et Métallurgie
http://toxicologieceramique.blogspot.com/
----------------------------
Substitutions de Matériaux Céramiques Complexes
http://substitutionsceramiques.blogspot.com/
--------------------------
Substitutions for Raw Ceramic Materials
http://substitutionsceramic.blogspot.com/
-------------------------
Sustituciones de Materiales de Cerámica Complejos
http://sustitucionesceramica.blogspot.com/
-----------------------------
Substituiçðes de Materiais Cerâmicos Complexos
http://substituicoesceramicos-poterie.blogspot.com/
----------------------------
Sostituzioni di Materiali Complessi per la Ceramica
http://sostituzioniceramica.blogspot.com/
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Anstataŭoj por Keramikaj Krudmaterialoj
http://anstatauojkrudmaterialoj.blogspot.com/
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Ersätze für keramische Rohstoffe
http://erstzefrkeramischerohstoffe.blogspot.com/
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