Keith: I checked the California Rice Commission website http://www.calrice.org/a5_ricestraw.htm and only found an arctile on "rice straw". Looks like "rice straw" also in need of alternative uses cause they used to "burn it" but affected air quality. I will do more search on rice husks.
thanks Phillip Wolfe Wolfe <[EMAIL PROTECTED]> wrote: > Keith, Thanks for the info on rice husks as one of > the > world's most under-utilized waste materials. I > imagine > the Rice Cooperative in California knows a lot about > rice husks. I plan to read more about rice husks. > All new to me....thanks again. > > Phillip Wolfe > --- Keith Addison <[EMAIL PROTECTED]> > wrote: > > > Hello Phillip, Peter > > > > Perlite is made from a siliceous volcanic rock for > > > horticultural use > > and also for insulation. "When heated to a > suitable > > point in its > > softening range, it expands from four to twenty > > times its original > > volume. This expansion is due to the presence of > two > > to six percent > > combined water in the crude perlite rock. When > > quickly heated to > > above 1600°F (871°C), the crude rock pops in a > > manner similar to > > popcorn as the combined water vaporizes and > creates > > countless tiny > > bubbles which account for the amazing light weight > > and other > > exceptional physical properties of expanded > > perlite." > > > > So it's very similar to rice husk ash, which, when > > properly prepared, > > consists mainly of myriad tiny glass bubbles. > > > > A major difference is that Perlite is a product, > > rice husk is one of > > the world's most underutilised waste materials. > > > > Perlite is very fragile and makes an unpleasant > > dust. Wear a > > breathing mask. Reject perlite of a suitable > grade > > can often be > > obtained free of charge (or at low cost) from the > > manufacturers. > > > > Best wishes > > > > Keith > > > > > > >Perlites and found with the Borates and all part > of > > >the volcanic geological evolution. We have a lot > of > > >Perlites in our Sierra Nevadas in California. > Same > > >with borates (borax). Borates, perlites, > > colemanites, > > >- all that stuff can be found anywhere you have > an > > >escarpment of raised mountains due to ancient > > volcanic > > >magma "scarns" and earthquake activity especially > > next > > >to an arid desert bowl. > > > > > >What is Perlite? > > >http://www.perlite.info/hbk/0034409.htm > > >Perlite is not a trade name but a generic term > for > > >naturally occurring siliceous volcanic rock. The > > >distinguishing feature which sets perlite apart > > from > > >other volcanic glasses is that when heated to a > > >suitable point in its softening range, it expands > > from > > >four to twenty times its original volume. > > > > > >This expansion process is due to the presence of > > two > > >to six percent combined water in the crude > perlite > > >rock. When quickly heated to above 1600 F (870 C) > > the > > >crude rock pops in a manner similar to popcorn as > > the > > >combined water vaporizes and creates countless > tiny > > >bubbles in the softened glassy particles. It is > > these > > >tiny glass-sealed bubbles which account for the > > >amazing lightweight and other exceptional > physical > > >properties of expanded perlite. > > > > > >The expansion process also creates one of > perlite's > > >most distinguishing characteristics: its white > > color. > > >While the crude perlite rock may range from > > >transparent to light gray to glossy black, the > > color > > >of expanded perlite ranges from snowy white to > > grayish > > >white. > > > > > >Expanded perlite can be manufactured to weigh > from > > 2 > > >lbs/ft3 (32 kg/m3) to 15 lb/ft3 (240 kg/m3) > making > > it > > >adaptable for numerous uses, including > filtration, > > >horticultural applications, insulation, inert > > carriers > > >and a multitude of filler applications. > > > > > > > > >--- Guag Meister <[EMAIL PROTECTED]> wrote: > > > > > > > Hi All ; > > > > > > > > Could I ask a stupid question? What is > Perlite? > > > > > > > > Best Regards, > > > > Peter G. > > > > Thailand > > > > > > > > --- Keith Addison <[EMAIL PROTECTED]> > > > > wrote: > > > > > > > > > Hi Martin > > > > > > > > > > >Hi Keith et al, > > > > > >I used Perlite mixed with refractory cement > > in my > > > > > aluminum casting > > > > > >furnace. The walls saw temperatures > > surpassing > > > > > 2000F, it was working > > > > > >well. The mixture was 50/50, and the > perlite > > is > > > > > very light-weight, > > > > > >reducing the overall mass of the structure. > > > > > >-- > > > > > >Martin K > > > > > > > > > > Perlite gives very similar results to rice > > husk > > > > ash. > > > > > Michael Allen > > > > > and I discussed Perlite in this context when > I > > > > made > > > > > that page on rice > > > > > husk ash. You used the same ratio of cement > as > > I > > > > do > > > > > with RHA, after > > > > > trying it 20 different ways in tests. > > > > > > > > > > Regards > > > > > > > > > > Keith > > > > > > > > > > > > > > > > > > > > >Keith Addison wrote: > > > > > >>Hi Doug > > > > > >> > > > > > >>Nothing to do with soap, but do you know > > about > > > > > this? > > > > > >> > > > > > > > > > > > > > > > >>http://journeytoforever.org/at_woodstove-allen.html > > > > > >>Rice-husk stoves - Appropriate technology: > > > > Journey > > > > > to Forever > > > > > >> > > > > > >>This stuff is great! We're using it to > build > > > > > charcoal-burning > > > > > >>stoves, it's an excellent insulator. Have > a > > look > === message truncated === __________________________________ Do you Yahoo!? Yahoo! Mail - now with 250MB free storage. 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