US4119472A — Rebonded fusion-cast AZS refractory grain

Claim 1

Independent Claim 227 words

Refractory composition for making refractory articles consisting of : (A) 25-60 wt.% fusion-cast alumina-zirconia-silica refractory coarse grain being at least 89 wt.% -6+20 Tyler mesh, (B) 0-38 wt.% fusion-cast alumina-zirconia-silica refractory medium grain being at least 73 wt.% -10+35 Tyler mesh, and (C) 30-50 wt.% at least one component selected from the group consisting of (1) 0-50 wt.% fusion-cast alumina-zirconia silica refractory fine grain being at least 60 wt.% -35+325 Tyler mesh, and (2) 0-30 wt.% at least one constituent selected from the group consisting of (a) alumina being at least 90 wt.% -325 Tyler mesh, at least 98.5 wt.% Al 2 O 3 and not more than 0.5 wt.% Na 2 O, and (b) -325 Tyler mesh chromic oxide being at least 95 wt. % Cr 2 O 3 . the fusion-cast alumina-zirconia-silica refractory having: (i) a three-phase microstructure of interlocking crystals of corundum phase and baddeleyite phase with intercrystalline glassy phase therebetween, the glassy phase being about 15-30 vol.% of the alumina-zirconia-silica refractory, and (ii) an oxide analysis consisting of 35-60 wt.% Al 2 O 3 plus Cr 2 O 3 with Cr 2 O 3 ≦60 wt.% of Al 2 O 3 plus Cr 2 O 3 , 25-50 wt.% ZrO 2 , 10-18 wt.% SiO 2 , 0.8-1.8 wt.% Na 2 O plus K 2 O, and up to 0.7 wt.% other ingredients.

Claim 2

Dependent Claim 227 words

Refractory composition for making refractory articles consisting of : (A) 25-60 wt.% fusion-cast alumina-zirconia-silica refractory coarse grain being at least 89 wt.% -6+20 Tyler mesh, (B) 0-38 wt.% fusion-cast alumina-zirconia-silica refractory medium grain being at least 73 wt.% -10+35 Tyler mesh, and (C) 30-50 wt.% at least one component selected from the group consisting of (1) 0-50 wt.% fusion-cast alumina-zirconia silica refractory fine grain being at least 60 wt.% -35+325 Tyler mesh, and (2) 0-30 wt.% at least one constituent selected from the group consisting of (a) alumina being at least 90 wt.% -325 Tyler mesh, at least 98.5 wt.% Al 2 O 3 and not more than 0.5 wt.% Na 2 O, and (b) -325 Tyler mesh chromic oxide being at least 95 wt. % Cr 2 O 3 . the fusion-cast alumina-zirconia-silica refractory having: (i) a three-phase microstructure of interlocking crystals of corundum phase and baddeleyite phase with intercrystalline glassy phase therebetween, the glassy phase being about 15-30 vol.% of the alumina-zirconia-silica refractory, and (ii) an oxide analysis consisting of 35-60 wt.% Al 2 O 3 plus Cr 2 O 3 with Cr 2 O 3 ≦60 wt.% of Al 2 O 3 plus Cr 2 O 3 , 25-50 wt.% ZrO 2 , 10-18 wt.% SiO 2 , 0.8-1.8 wt.% Na 2 O plus K 2 O, and up to 0.7 wt.% other ingredients.

Claim 3

Dependent Claim 70 words

Refractory composition of claim 1 wherein the fusion-cast AZS refractory has an oxide analysis consisting of 40-55 wt.% Al 2 O 3 plus Cr 2 O 3 with Cr 2 O 3 ≦50 wt.% of Al 2 O 3 plus Cr 2 O 3 , 30-45 wt.% ZrO 2 , 10-16 wt.% SiO 2 1.0-1.6 wt.% Na 2 O + K 2 O, and up to 0.5 wt.% other ingredients.

Claim 4

Dependent Claim 45 words

Refractory composition of claim 1 wherein the fusion-cast AZS refractory has an oxide analysis consisting of 40-55 wt.% Al 2 O 3 , 30-45 wt.% ZrO 2 , 10-16 wt.% SiO 2 , 1.0-1.6 wt.% Na 2 O, and up to 0.5 wt.% other ingredients.

Claim 5

Dependent Claim 53 words

Refractory composition of claim 1 wherein the fusion-cast AZS refractory has: (A) about 20-30 vol.% glassy phase, and (B) an oxide analysis consisting of 45-50 wt.% Al 2 O 3 , 33-41 wt.% ZrO 2 , 12-16 wt.% SiO 2 , 1.1-1.5 wt.% Na 2 O and up to 0.3 wt.% other ingredients.

Claim 6

Dependent Claim 86 words

Refractory composition of claim 1 wherein: (A) the coarse grain is 33-37 wt.%, (B) the medium grain is 20-25 wt.%, and (C) the at least one component is 40-45 wt.% selected from the group consisting of (1) 15-45 wt.% the fine grain and (2) 0-30 wt.% the at least one constituent selected from the group consisting of (a) the alumina which is at least 98.5 wt.% Al 2 O 3 and (b) the chromic oxide which is at least 95 wt.% Cr 2 O 3 .

Claim 7

Dependent Claim 87 words

Refractory composition of claim 1 wherein: (A) the coarse grain is 33-37 wt.%, (B) the medium grain is 32-37 wt.%, and (C) the at least one component is 30-35 wt.% selected from the group consisting of (1) 0-25 wt.% the fine grain and (2) 10-30 wt.% the at least one constituent selected from the group consisting of (a) the alumina which is at least 98.5 wt.% Al 2 O 3 , and (b) the chromic oxide which is at least 95 wt.% Cr 2 O 3 .

Claim 8

Dependent Claim 262 words

Fired refractory article having a fourphase micro-structure of corundum, badeleyite mullite and glassy phase with the mullite being about 5-25 wt.% thereof and the glassy phase being about 5-20 vol.% thereof, the article being a sintered refractory composition consisting of: (A) 25-60 wt.% fusion-cast alumina-zirconia-silica refractory coarse grain being at least 89 wt.% -6+20 Tyler mesh, (B) 0-38 wt.% fusion-cast alumina-zirconia-silica refractory medium grain being at least 73 wt.% -10+35 Tyler mesh, (C) 30-50 wt.% at least one component selected from the group consisting of (1) 0-50 wt.% fusion-cast alumina-zirconia-silica refractory fine grain being at least 60 wt.% -35+325 Tyler mesh, and (2) 0-30 wt.% at least one constituent selected from the group consisting of (a) alumina being at least 90 wt.% -325 Tyler mesh, at least 98.5 wt.% Al 2 O 3 and not more than 0.5 wt.% Na 2 O, and (b) -325 Tyler mesh chromic oxide being at least 95 wt.% Cr 2 O 3 , and (D) 0-7 wt.% colloidal silica, the fusion-cast alumina-zirconia-silica refractory having: (i) a three-phase microstructure of interlocking crystals or corundum phase and baddeleyite phase with intercrystalline glassy phase therebetween, the glassy phase being about 15-30 vol.% of the alumina-zirconia-silica refractory, and (ii) an oxide analysis consiting of 35-60 wt.% Al 2 O 3 plus Cr 2 O 3 with Cr 2 O 3 ≦ 60 wt.% of Al 2 O 3 plus Cr 2 O 3 , 25-50 wt.% ZrO 2 , 10-18 wt.% SiO 2 , 0.8-1.8 wt.% Na 2 O plus K 2 O, and up to 0.7 wt.% other ingredients.

Claim 9

Dependent Claim 262 words

Fired refractory article having a fourphase micro-structure of corundum, badeleyite mullite and glassy phase with the mullite being about 5-25 wt.% thereof and the glassy phase being about 5-20 vol.% thereof, the article being a sintered refractory composition consisting of: (A) 25-60 wt.% fusion-cast alumina-zirconia-silica refractory coarse grain being at least 89 wt.% -6+20 Tyler mesh, (B) 0-38 wt.% fusion-cast alumina-zirconia-silica refractory medium grain being at least 73 wt.% -10+35 Tyler mesh, (C) 30-50 wt.% at least one component selected from the group consisting of (1) 0-50 wt.% fusion-cast alumina-zirconia-silica refractory fine grain being at least 60 wt.% -35+325 Tyler mesh, and (2) 0-30 wt.% at least one constituent selected from the group consisting of (a) alumina being at least 90 wt.% -325 Tyler mesh, at least 98.5 wt.% Al 2 O 3 and not more than 0.5 wt.% Na 2 O, and (b) -325 Tyler mesh chromic oxide being at least 95 wt.% Cr 2 O 3 , and (D) 0-7 wt.% colloidal silica, the fusion-cast alumina-zirconia-silica refractory having: (i) a three-phase microstructure of interlocking crystals or corundum phase and baddeleyite phase with intercrystalline glassy phase therebetween, the glassy phase being about 15-30 vol.% of the alumina-zirconia-silica refractory, and (ii) an oxide analysis consiting of 35-60 wt.% Al 2 O 3 plus Cr 2 O 3 with Cr 2 O 3 ≦ 60 wt.% of Al 2 O 3 plus Cr 2 O 3 , 25-50 wt.% ZrO 2 , 10-18 wt.% SiO 2 , 0.8-1.8 wt.% Na 2 O plus K 2 O, and up to 0.7 wt.% other ingredients.

Claim 10

Dependent Claim 24 words

Refractory composition of claim 3 wherein selected constituent alumina is at least 5 wt.% and selected constituent chromic oxide is at least 5 wt.%.

Claim 11

Dependent Claim 46 words

Fired refractory article of claim 7 wherein the fusion-cast AZS refractory has an oxide analysis consisting of 40-55 wt.% Al 2 O 3 , 30-45 wt.% ZrO 2 , 10-16 wt.% SiO 2 , 1.0-1.6 wt.% Na 2 O, and up to 0.5 wt.% other ingredients.

Claim 12

Dependent Claim 25 words

Fired refractory article of claim 9 wherein selected constituent alumina is at least 5 wt.% and selected constituent chromic oxide is at least 5 wt.%.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1981-10-09	1982-04-10	1982-10-10	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1985-10-09	1986-04-10	1986-10-10	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1989-10-09	1990-04-10	1990-10-10	$7700.00	Window Closed / Lapsed

Rebonded fusion-cast AZS refractory grain

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