AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |
Back to Blog
Flux formula11/8/2023 ![]() Mints have in general not been happy to accept dore containing much over 20/1000 parts iron (assessed by attraction to a magnet), as this causes segregation which prevents good sampling.įurthermore such dore tends to spit in an induction furnace. ![]() The former makes smelting difficult while the latter causes problems in drilling samples for analysis and also in stamping identifying marks onto the bars. ![]() THE DIRECT SMELTING OF DORe-LOADED STEEL WOOL CATHODESĭ Menne, Consulting Metallurgist, 14 June 1998ģ.0 Forming Low Melting-Point Iron Eutecticsġ1.0 The Preferred Kiln, Crucible and Heat Sourceĭore containing substantial levels of iron has a high melting point and is hard and inhomogenous. This discussion comprises an early draft for my contribution to: That is another reason for the quartz sand in the flux. I should also mention that molten Litharge will dissolve the crucible and the firebricks that line the furnace. If borax is used you should be aware that it attacks the clay crucible so don’t use so much that you get a hole in it. Borax produces a thinner, more liquid melt. Could probably add more sand or, more effective, would be to add a couple of grams of Borax. Another thing that can go wrong is that sometimes the ore produces a melt that is too thick and viscous to pour properly. So, if your prill is 10 gr too light you should add another gram of flour to the next assay. I happen to know that 1 gr of flour will produce about 12 gr of lead from the litharge. If your prill is too small, add more flour. The amounts used are not correct for all ores. This is a good starting flux for quartz or "neutral" ore samples. I know you aren’t going to set up an assay lab but this is what happens when you send in a sample to be assayed. Now that things are back to normal (do I hear muttering out there?), I’m going to give you a recipe for a flux that will, with minor adjustments, work most of the time. Take a trip to the fridge and recover another (or two) of those cool, soothing, foamy, unguents that I know you have squirreled away. I feel this can best be accomplished by a single action. We must cool down the brain cells and we must adjust the attitude of the reader. I think there are two things that we must accomplish. How much more? I’m going to get to that but right now my ESP tells me that some brains out there are beginning to overheat and some folks are thinking bad thoughts about me and why they ever started reading this to begin with. So, what can be done to fix this problem? Simple, we run the sample again and this time we put in a little more flour. There wasn’t enough flour to reduce both the sample and the PbO. If we get a prill that only weighs 18 grams, we know that some of the flour must have been used up in reducing, not the litharge, but the sample. That is plenty close enough for government work. When this PbO is all reduced by the flour/ore it will produce a lead prill of 25.79 gr. So I am going to put 26 gr of PbO in my flux. I know that we want a prill of around 25-28 gr. Well, it helps me because I know something that you don’t. If we reduce it to metallic lead then for every 100 gr of pbO we will be left with 98.2 gr of pure lead. Since they are combined the molecular weight of PbO is 223 (see link for Periodic chart of elements). Lead has a molecular weight of 207 and oxygen 16. Litharge is composed of one atom of lead and one atom of oxygen. Ain’t gonna be no more igerunt prospectors out there. How do I know how much that is? I’m going to tell you. The flux is calculated to contain enough lead Oxide (litharge) so that if it is completely reduced, it will produce a prill weighing (usually) 25-28 grams.
0 Comments
Read More
Leave a Reply. |