<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div>As you guys delve into fly ash cement, I was curious if the levels of some of the ashes radioactive elements (<span style="color: rgba(0, 0, 0, 0.701961); -webkit-composition-fill-color: rgba(130, 98, 83, 0.0980392); text-decoration: -webkit-letterpress;">Cs-137, Sr-90 and K-40) have been measured. The fly ash concentrates these natural occurring isotopes and could be problematic. </span></div><div><font color="rgba(0, 0, 0, 0.7019607843137254)"><span style="-webkit-composition-fill-color: rgba(130, 98, 83, 0.0980392); text-decoration: -webkit-letterpress;">G<br></span></font><br>Sent from my iPad</div><div><br>On Feb 8, 2015, at 6:21 AM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@outlook.com">crispinpigott@outlook.com</a>> wrote:<br><br></div><blockquote type="cite"><div><span>Thomas, what a great and brief reintroduction.</span><br><span></span><br><span>Thanks for the name and reference.</span><br><span></span><br><span>This is a good link:</span><br><span></span><br><span><a href="http://www.philipcoppens.com/davidovits.html">http://www.philipcoppens.com/davidovits.html</a></span><br><span></span><br><span>Perhaps we should be looking for a different solution entirely.</span><br><span></span><br><span>Crispin</span><br><span></span><br><span></span><br><span>-----Original Message-----</span><br><span>From: Stoves [<a href="mailto:stoves-bounces@lists.bioenergylists.org">mailto:stoves-bounces@lists.bioenergylists.org</a>] On Behalf Of T</span><br><span>Hastings</span><br><span>Sent: Sunday, February 08, 2015 17:19</span><br><span>To: Discussion of biomass cooking stoves</span><br><span>Subject: Re: [Stoves] Fly ash cement, Curiosity.</span><br><span></span><br><span>Hi Michael, Crispin and all the list members,</span><br><span></span><br><span>Rather than answering or responding to all the questions and notes raised on</span><br><span>this topic I will try and share with you some of my experience on Fly ash</span><br><span>for stoves.</span><br><span></span><br><span>What I believe Michael has read about and discussed with Zeobond is Fly ash</span><br><span>based geopolymer. These are cement like materials made by mixing Coal fired</span><br><span>power station waste (fly ash) with an alkali activator. The theory is that</span><br><span>the alkali dissolves at least a portion of the fly ash which is mostly</span><br><span>aluminium and silicon. These ions recombine to former a polymer or chain</span><br><span>like structure utilising the alkali cation to balance the charge of the</span><br><span>aluminium atom.</span><br><span></span><br><span>Several companies are developing it as a low CO2 replacement for OPC</span><br><span>(Ordinary Portland Cement) They mix the binder with regular aggregates to</span><br><span>make a OPC substitute.</span><br><span></span><br><span>In Australia, Zeobond have used a fly ash material to make footpaths and</span><br><span>some precast past. The mixing plant they refer to is a cement batching</span><br><span>plant...its big.</span><br><span>Another company in Queensland, Wagners have made very large precast beams</span><br><span>for a government building and are or will be making a airport runway from</span><br><span>their Earth Friendly Concrete.</span><br><span></span><br><span>You can look Wagners up here <a href="http://www.wagner.com.au/capabilities/efc/">http://www.wagner.com.au/capabilities/efc/</a></span><br><span></span><br><span>In South Africa, geopolymer is also making inroads For example 0% cement</span><br><span>concrete - M&R geopolymer concrete a South African first!!</span><br><span><a href="https://www.youtube.com/watch?v=wArEbfC91m0">https://www.youtube.com/watch?v=wArEbfC91m0</a></span><br><span></span><br><span>My own work at Unity Stove is similar but different. For these companies to</span><br><span>be successful they have to produce a product that is comparable in price and</span><br><span>performance to bulk portland cement type concrete for building works. I am</span><br><span>really not how sure their materials will work in furnace lining type</span><br><span>applications like the inside of solid fuel stoves. The KSIAL material</span><br><span>developed by Unity Stove is more expensive to manufacture as it uses a far</span><br><span>greater portion of activator to try and achieve more dissolution of the</span><br><span>aluminium and silica sources. We also use different aluminium and silica</span><br><span>sources ( due in part to fly ash coming in tanker truck loads only) Also to</span><br><span>avoid legal issues KSIAL is based on old patents....yes geopolymers having</span><br><span>been around long enough for patents to expire. Like their materials, KSIAL</span><br><span>it not a DIY just add water product like portland cement so it very hard to</span><br><span>bag some up and hope that an experimenter follows the instructions to mix</span><br><span>and cure correctly.</span><br><span></span><br><span>I am sure it a type of stove material that some of the well funded</span><br><span>organisations working in this field will pick up and run with one day.</span><br><span>As I have been promoting, geopolymer materials such as KSIAL will allow</span><br><span>corrosion resistant stoves to be produced in small workshops using readily</span><br><span>available materials. Stoves can be repaired and or crushed and recycled to</span><br><span>make new stoves. It is compatible with insulating aggregates such as</span><br><span>perlite, scoria and wood ash and can even be foamed to make a stove liner,</span><br><span>pot support and insulation in one piece. Its low thermal conductivity means</span><br><span>the surface may get hot but will not instantly burn skin in the way a metal</span><br><span>stove can.</span><br><span></span><br><span>Anyway Michael, you are definitely on the right track with Fly Ash cements</span><br><span>and I would just love to pop over to the Marshall Islands with a 20'</span><br><span>container of materials and everything needed to start a mini factory and</span><br><span>start making stoves with you.</span><br><span></span><br><span>Regards</span><br><span>Thomas Hastings</span><br><span>Unity Stove</span><br><span></span><br><span></span><br><span></span><br><span></span><br><span></span><br><span>Some keywords for further research if you are interested in researching this</span><br><span>type of material further. Be aware though that Prof.</span><br><span>Davidovits does believe the pyramids are constructed from Geoploymer and has</span><br><span>even reconstructed and demonstated how they could have been built using Nile</span><br><span>silt and Natron.</span><br><span></span><br><span>Davidovits Geopolymer alkali activated cement refractory foam and of course</span><br><span>google Unity Stove to see Geopolymer stoves in use.</span><br><span></span><br><span></span><br><span>_______________________________________________</span><br><span>Stoves mailing list</span><br><span></span><br><span>to Send a Message to the list, use the email address</span><br><span><a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a></span><br><span></span><br><span>to UNSUBSCRIBE or Change your List Settings use the web page</span><br><span><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a></span><br><span></span><br><span>for more Biomass Cooking Stoves, News and Information see our web site:</span><br><span><a href="http://stoves.bioenergylists.org/">http://stoves.bioenergylists.org/</a></span><br><span></span><br></div></blockquote></body></html>