bobo
March 31st, 2006, 03:29 PM
A while ago I made some nitric acid of decent enough quality, in smal amounts. The salt I used was first potassium and then sodium nitrate, all ground up pretty small. Still, both would clump up badly, and beyond the skills of a magnetic stirrer to handle. Not that clumping (and bumping) is that much of a problem, really, if you take enough time, but the mass should at least behave like a liquid. In small amounts it can all be handled due to free convection of the liquids, but on a larger scale, viscosity must be low and there must be some sort of mechanical stirrer. Metal is ruled out, so it has to be a thick sheet of teflon, cut to form.
To get the stirrer into the vessel, there are limits to vessel and stirrer shape. You can bend the stirrer, but that will only go so far in stirring as to widen the effective range of the stirrer a little bit. The best thing would be a glass vessel with a top cover like you have them with exsiccators, and three or four necks in it. Since everyone who is into the making of clandestine chemicals wants such glassware, the next best thing would be to use an exsiccator with a NS29 T-branch connected to it as your reaction vessel and cut the teflon in such a way that it is nearly airtight at the neck where the bar goes to the motor while leaving room in another neck for the vapors. Some wax will make it airtight enough for reasonable vacuum and lubricate the hole.
The problem with stirring is, the more viscous it gets the less effect the stirring has. (in sulfuric acid and salt mixes, this would mean it's virtually dead space a few inches from the maximum reach of the stirring bit) This can be compensated by enhancing the stirring surface, but that comes at the price of mechanical torque on the bar (can the motor handle it? Can the bar handle it? So, I can see little other solution for upscaling the process than to decrease the viscosity.
Right here, the commonly available fertilizers are the following.
NaNO3
KNO3
NH4NO3
CaNO3
... and mixtures of said types. It's easier to obtain a mixture of NH4NO3 with CaNO3 than either pure compound, but I could care less. The question now becomes which fertilizer gives the best results. I want it to be nicely liquid in mixture with sulfuric. Also, the sulfate salt should not be problematic either by clogging or by making it even more viscous (do we want it to be more or less soluble? I can't figure that out). CaNO3 and NH4NO3 are the two fertilizers I haven't really used for this matter yet.
The final approach might be using a cosolvent (or rather nonsolvent) which decreases viscosity. This should be high boiling and inert to the acid mix. Now all the hydrocarbons are difficult to handle because of their density and demixing. Chlorinated HC's are better, but the ones available to me are low boiling. Silicone oils of some kind perhaps?
To get the stirrer into the vessel, there are limits to vessel and stirrer shape. You can bend the stirrer, but that will only go so far in stirring as to widen the effective range of the stirrer a little bit. The best thing would be a glass vessel with a top cover like you have them with exsiccators, and three or four necks in it. Since everyone who is into the making of clandestine chemicals wants such glassware, the next best thing would be to use an exsiccator with a NS29 T-branch connected to it as your reaction vessel and cut the teflon in such a way that it is nearly airtight at the neck where the bar goes to the motor while leaving room in another neck for the vapors. Some wax will make it airtight enough for reasonable vacuum and lubricate the hole.
The problem with stirring is, the more viscous it gets the less effect the stirring has. (in sulfuric acid and salt mixes, this would mean it's virtually dead space a few inches from the maximum reach of the stirring bit) This can be compensated by enhancing the stirring surface, but that comes at the price of mechanical torque on the bar (can the motor handle it? Can the bar handle it? So, I can see little other solution for upscaling the process than to decrease the viscosity.
Right here, the commonly available fertilizers are the following.
NaNO3
KNO3
NH4NO3
CaNO3
... and mixtures of said types. It's easier to obtain a mixture of NH4NO3 with CaNO3 than either pure compound, but I could care less. The question now becomes which fertilizer gives the best results. I want it to be nicely liquid in mixture with sulfuric. Also, the sulfate salt should not be problematic either by clogging or by making it even more viscous (do we want it to be more or less soluble? I can't figure that out). CaNO3 and NH4NO3 are the two fertilizers I haven't really used for this matter yet.
The final approach might be using a cosolvent (or rather nonsolvent) which decreases viscosity. This should be high boiling and inert to the acid mix. Now all the hydrocarbons are difficult to handle because of their density and demixing. Chlorinated HC's are better, but the ones available to me are low boiling. Silicone oils of some kind perhaps?