I found some interesting informations, I don't know what are the upper limits of PMs content in water to be completely extracted but seems nice. In Europe law is different so the chemicals we can buy are different. Butyl diglyme in sigma-aldrich is like $110/l- $420/gal, other chemicals also aren't cheap but are more accessible. Ethyl acetate is used in paint removal solution, and is very cheap, buy it legally.
extractions:
gold as chloride
Water phase organic phase efficiency
HCl 6mol/l diethyl ether 95-100%
HCl 7mol/l MIBK* >99%
HCl 7,7mol/l diisopropyl ether ~99%
HCl 0,5-*mol/l MIBK >95%
HCl 10% ethyl acetate 100%
MIBK*- methyl isobutyl ketone, hexone- boiling acetone with barium hydroxide for many hours, reduction of obtained diacetone alcohol(hydroxyMIBK) to get MIBK. I tried to extract AuCl3 with this- works great, separation in couple of seconds- vapors not healthy
. MIBK is partially soluble in water, so it should be used to recycled mixtures. Free halogens should be avoided due to creation of haloketones- very potent lachrymators, high excess of them can form chloro- bromo- or iodoform (trihalomethanes) in so called haloform reaction, of course in certain conditions.
gold as bromide
Water phase organic phase efficiency
HBr 0,5-4mol/l diethyl ether ~100%
HBr 6mol/l diisopropyl ether ~99%
gold as iodide
HI 6,9mol/l diethyl ether ~100%
HCl- is hydrogen chloride, water solution muriatic acid
HBr- hydrobromic acid
HI- hydroiodic acid
For better yields a good idea might be to do 2 or 3 extractions- first one with just a tiny amount of solvent- enough to remove most of gold after some of solvent dissolve in water( yes- all "inmiscible" solvents dissolve in water a bit, even diethyl ether and gasoline). Extraction with another portion of solvent removes rest of Au. The third extraction is just to get sure all gold has gone. Solvent used in second extraction can be now used do the first extraction of another batch, analogically solvent fron the third extraction used to the second extraction of another batch and so on. BUT there's actually no need to do that- just reuse the same portion for extraction after reduction. I hope it is something new for You, I do realize that it can be obvious for many of users. So treat it as a short lecture for newbies. cheers
extractions:
gold as chloride
Water phase organic phase efficiency
HCl 6mol/l diethyl ether 95-100%
HCl 7mol/l MIBK* >99%
HCl 7,7mol/l diisopropyl ether ~99%
HCl 0,5-*mol/l MIBK >95%
HCl 10% ethyl acetate 100%
MIBK*- methyl isobutyl ketone, hexone- boiling acetone with barium hydroxide for many hours, reduction of obtained diacetone alcohol(hydroxyMIBK) to get MIBK. I tried to extract AuCl3 with this- works great, separation in couple of seconds- vapors not healthy
. MIBK is partially soluble in water, so it should be used to recycled mixtures. Free halogens should be avoided due to creation of haloketones- very potent lachrymators, high excess of them can form chloro- bromo- or iodoform (trihalomethanes) in so called haloform reaction, of course in certain conditions.gold as bromide
Water phase organic phase efficiency
HBr 0,5-4mol/l diethyl ether ~100%
HBr 6mol/l diisopropyl ether ~99%
gold as iodide
HI 6,9mol/l diethyl ether ~100%
HCl- is hydrogen chloride, water solution muriatic acid
HBr- hydrobromic acid
HI- hydroiodic acid
For better yields a good idea might be to do 2 or 3 extractions- first one with just a tiny amount of solvent- enough to remove most of gold after some of solvent dissolve in water( yes- all "inmiscible" solvents dissolve in water a bit, even diethyl ether and gasoline). Extraction with another portion of solvent removes rest of Au. The third extraction is just to get sure all gold has gone. Solvent used in second extraction can be now used do the first extraction of another batch, analogically solvent fron the third extraction used to the second extraction of another batch and so on. BUT there's actually no need to do that- just reuse the same portion for extraction after reduction. I hope it is something new for You, I do realize that it can be obvious for many of users. So treat it as a short lecture for newbies. cheers
