Honeycomb manufacturing method using ground nut shells and honeycomb body produced thereby
A method of manufacturing a honeycomb body is disclosed having the steps of mixing inorganic source materials, a nut shell pore former, and forming aids to form a plasticized batch, wherein the nut shell pore former has a particle size distribution with 20 μm≦d p50 ≦70 μm, and forming the plasticized batch into the honeycomb body having a plurality of channels formed by intersecting walls. Green honeycombs and porous ceramic honeycombs produced by the method are also disclosed.
1. A method of manufacturing a honeycomb body, comprising the steps of:
mixing inorganic source materials, a pore former, and forming aids to form a plasticized batch, wherein the pore former includes nut shells having a particle size distribution with 30 μm≦d p50 ≦50 μm wherein d p50 is a median particle size diameter wherein 50% of the particle volume has a smaller particle diameter, wherein the nut shells exhibit a particle size distribution with d p10 ≧10 μm wherein d p10 is a particle diameter where 10% of the particle volume has a smaller particle diameter, and wherein the nut shells exhibit a value of d pf ≦0.54 wherein d pf =d p50 −d p10 /d p50 , and
forming the plasticized batch into the honeycomb body having a plurality of channels formed by intersecting walls.
2. The method of manufacturing of claim 1 wherein the pore former comprises walnut shells.
3. The method of manufacturing of claim 2 wherein the pore former comprises English walnut shells.
4. The method of manufacturing of claim 1 wherein the pore former is selected from the group consisting of pecan shells, black walnut shells, and English walnut shells.
5. The method of manufacturing of claim 1 wherein the nut shells exhibit a particle size distribution wherein d p10 ≧15 μm.
6. The method of manufacturing of claim 1 wherein the nut shells exhibit a particle size distribution with d p90 ≦100 μm wherein d p90 is a particle diameter where 90% of the particle volume has a smaller particle diameter.
7. The method of manufacturing of claim 6 further comprising d p90 ≦90 μm.
8. The method of claim 1 wherein the nut shells have a median particle size between 35 μm and 45 μm.
9. The method of claim 1 wherein the nut shells are provided in the plasticized batch in an amount between 5-80 wt. % of the inorganic source materials by superaddition.
10. The method of claim 1 wherein the pore former comprises the nut shells in combination with a second pore former.
11. The method of claim 10 wherein the second pore former is a graphite pore former.
12. The method of claim 1 further comprising a step of firing the honeycomb body to produce a cordierite ceramic honeycomb having:
% P 45%,
d 50 ≧10 μm,
d f ≦0.6 wherein d f =d 50 −d 10 /d 50 , and
CTE≦25×10 −7 /° C. from 25-800° C.
13. The method of claim 1 further comprising a step of firing the honeycomb body to produce an aluminum titanate ceramic honeycomb having:
% P≧45%,
d 50 ≧10 μm,
d f ≦0.6 wherein d f =d 50 −d 10 /d 50 , and
CTE≦15×10 −7 /° C. from 25-1000° C.
14. The method of claim 1 further comprising a step of firing the honeycomb body to produce a ceramic honeycomb having 10 μm≦d 50 ≦30 μm.
15. The method of claim 1 further comprising a step of firing the honeycomb body to produce a ceramic honeycomb having d f ≦0.5 wherein d f =d 50 −d 10 /d 50 .
16. The method of claim 1 further comprising a step of firing the ceramic honeycomb body to produce a ceramic honeycomb having d f ≦0.4 wherein d f =d 50 −d 10 /d 50 .