<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div apple-content-edited="true"> <span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">Thanks to all who have replied. Tim Owen-Kennedy (with whom I'm working in Haiti) advises a good settling pond left to dry, then pull off the surface clay chips that curl into the distinctive pattern. Makes sense, but takes a lot of time, especially in the rainy tropics.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">What I've seen and heard so far essentially describes extensive settling, by gravity or machine, to separate the tiny silt particles from the teensy weensy clay particles. I guess I could imagine two or three adjacent settling ponds on successfully lower grades, such that you could siphon the surface stuff from the first into the second, then again to the third, thus getting finer and finer particle sizes.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">To answer Derek's questions: we'll be dealing with hundreds of pounds at a time, no machinery of any sort other than human powered. Soils around Haiti, as everywhere, vary, and we're not trying to quantify particle gradations. We just want a robust system that anyone can use to "improve" a particular soil to the point where it will pass the ribbon or ball tests.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">That's our challenge. All your help and comments are very much appreciated.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; min-height: 14px; font-size: 12px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">Bruce King, PE</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">Director of <font class="Apple-style-span" face="Sketcher" size="4"><span class="Apple-style-span" style="font-size: 14px; ">EBNet</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; "><font class="Apple-style-span" face="Sketcher" size="4"><span class="Apple-style-span" style="font-size: 14px; ">Ecological Building Network</span></font></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; "><b><i>the art and science of building well</i></b></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; "><a href="mailto:bruce@ecobuildnetwork.org">bruce@ecobuildnetwork.org</a> </div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">PO Box 6397</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">San Rafael, CA 94903 USA</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">(415) 987-7271</div></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; font: normal normal normal 12px/normal Helvetica; font-size: 12px; ">follow us on Twitter: @EBNetwork</div></div></span></div></span> </div><br><div><div>On Jan 3, 2011, at 12:46 PM, Derek Roff wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>Hi, Bruce,<br><br>I appreciate your humor, and your New Year's salutations. Sign me up for the Hawaii Silt Vacation Sweepstakes.<br><br>Can you say more about the volume and efficiency that you need in the system? That would help us propose ideas that would be useful to you. For example, are you trying to process a hundred pounds of soil, a thousand, or ten thousand per day?<br><br>What amount of "waste" soil is acceptable. I'm guessing that your goal is to get at the clay, and that the silt will be a unimportant byproduct. Is that correct? In wondering about efficiency, I'm thinking along these lines: If the soil is naturally 20% clay and 30% silt, then the optimum system would extract 2 pounds of clay from each ten pounds of soil. What if you could only extract 1 pound of clay from each ten pounds, but you got pretty good purity of that clay. Would that be acceptable? Alternatively, what if a process gave you 4 pounds of product from each 10 pounds of soil, but that product was 50% clay? Would that be useful? If not, what sort of purity percentage would be worthwhile?<br><br>Does this process need to be human-powered, or could electrical or gasoline motors be a part of the machinery? What is your "easy enough" process for separating the sand and gravel? Perhaps the clay separation process could be added to the sand/gravel separation phase.<br><br>I have some ideas, and have done some small-scale tests, but I'm not sure they would fit your needs.<br><br>Dere-"particulate"-lict<br><br>Derek Roff<br>Language Learning Center<br>Ortega Hall 129, MSC03-2100<br>University of New Mexico<br>Albuquerque, NM 87131-0001<br>505/277-7368, fax 505/277-3885<br>Internet: <a href="mailto:derek@unm.edu">derek@unm.edu</a><br><br><br>--On Sunday, January 2, 2011 1:46 PM -0800 Bruce King <<a href="mailto:bruce@ecobuildnetwork.org">bruce@ecobuildnetwork.org</a>> wrote:<br><br><blockquote type="cite">Happy New Year, baleheads.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">We have a lot of soil in Haiti that is rich in both clay and silt.<br></blockquote><blockquote type="cite">Easy enough to separate the sand and gravel, but we haven't figured<br></blockquote><blockquote type="cite">out a good way to separate silt from clay. So far we've tried:<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">1) Asking nicely<br></blockquote><blockquote type="cite">2) Offering every silt particle a chance to win a Hawaiian dream<br></blockquote><blockquote type="cite">vacation if it separates itself from the clay<br></blockquote><blockquote type="cite">3) Telling the silt that if it just leaves quietly now, no one will<br></blockquote><blockquote type="cite">get hurt<br></blockquote><blockquote type="cite">and, getting really hardball,<br></blockquote><blockquote type="cite">4) Hanging a few "example particles" of silt by their silica<br></blockquote><blockquote type="cite">crystals in the public square, with warning notes attached.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Still no luck! Anyone have a good low-tech field method for<br></blockquote><blockquote type="cite">separation?<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Thanks,<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Bruce "Hang 'em High!" King<br></blockquote><br><br>Derek Roff<br>Language Learning Center<br>Ortega Hall 129, MSC03-2100<br>University of New Mexico<br>Albuquerque, NM 87131-0001<br>505/277-7368, fax 505/277-3885<br>Internet: <a href="mailto:derek@unm.edu">derek@unm.edu</a><br><br>_______________________________________________<br>GSBN mailing list<br><a href="mailto:GSBN@greenbuilder.com">GSBN@greenbuilder.com</a><br>http://greenbuilder.com/mailman/listinfo/GSBN<br></div></blockquote></div><br></body></html>