BenSon Posted March 30, 2005 Share Posted March 30, 2005 Thanks guys i got it now ~Scott Link to comment Share on other sites More sharing options...
Josefin Posted June 23, 2008 Share Posted June 23, 2008 I have old Aqua regia, don´t excatly know how long it´s been stored, but a guess is for several years. Now I have to neutralize it, beacause the chemicalwaste-firm dont take Aqua regia. But I´m not sure how to do it properly. Any suggestions? I have several amount of KOH -pellets, can I use them? Link to comment Share on other sites More sharing options...
John Cuthber Posted June 23, 2008 Share Posted June 23, 2008 First; be very careful with this. Aqua Regia decomposes in solution to produce chlorine among other things. There have been explosions in the past caused by storing the stuff in closed bottles. The stuff generates gas which bursts the bottle- nasty. Secondly I think mixing it with water to dilute it before you do anything else is probably a wise move. Thirdly KOH will react fairly violently with water, nevermind that acid. I'd buy washing soda instead (and be carefull about all the foaming when you mix them). Take the stuff outside. Open it very carefully. Pour the acid into a few times its volume of cold water in a big plastic bucket then add washing soda slowly while stiring it with a stick. Gloves are pretty much a neccessity here. A face mask and apron aren't a bad idea. If you have any reason to believe that the bottle is pressurised then you might want to leave this to the hazmat experts. Link to comment Share on other sites More sharing options...
frosch45 Posted June 24, 2008 Share Posted June 24, 2008 Might be a good idea too to wait until it is a little bit windy outside too, that way the gasses won't just sit there. Link to comment Share on other sites More sharing options...
YT2095 Posted June 24, 2008 Share Posted June 24, 2008 forget the fizzing in the sodium carbonate (washing soda), that can present it`s own dangers, go to a garden center and get a small bag of garden lime, you can pour it directly into that as a solid. it`s used industrially to neutralise all sorts of acids, it`s a better choice if you`r worried about over pressure, you can bury it the bag as well, of use a long metal rod through the bag touching the bottle and hit the end with a hammer, the bottle breaks inside the lime and is neutralised instantly. it`s also far more environmentally friendly than the sodium analog. Link to comment Share on other sites More sharing options...
John Cuthber Posted June 24, 2008 Share Posted June 24, 2008 For a given sample of acid, calcium carbonate generates exactly as much fizz as sodium carbonate. 1 Link to comment Share on other sites More sharing options...
YT2095 Posted June 25, 2008 Share Posted June 25, 2008 I agree, If garden lime was calcium carbonate Link to comment Share on other sites More sharing options...
frosch45 Posted June 27, 2008 Share Posted June 27, 2008 woh, Wait a second. Define lime.... there are many kinds. Do you mean magnesium carbonate or calcium oxide or what? I have heard of hydrated lime, high calcium lime, dolomitic lime. I thought Quicklime, the product of calcination of limestone, consisted of the oxides of calcium and magnesium.... right? Link to comment Share on other sites More sharing options...
YT2095 Posted June 27, 2008 Share Posted June 27, 2008 it was defined, I said Garden Lime and that can only be one thing, Calcium Hydroxide (slaked lime). Link to comment Share on other sites More sharing options...
frosch45 Posted June 27, 2008 Share Posted June 27, 2008 thats what I thought you meant because it had to be a strong base, but where I live, garden lime can be more than just CaOH Link to comment Share on other sites More sharing options...
YT2095 Posted June 27, 2008 Share Posted June 27, 2008 there Are other garden products that resemble the lime, and some are also called Chalks, but to sell something as "Garden lime" that isn`t calcium hydroxide is breaking the law as false advertising, certainly in the UK it is. Link to comment Share on other sites More sharing options...
frosch45 Posted June 27, 2008 Share Posted June 27, 2008 here we go, I personally went to check it out at the garden center closest to my house, for example, they sell Espoma Garden Lime you can look up the msds yourself if you don't believe me, but it is made up of the carbonates of calcium and magnesium, not CaOH Link to comment Share on other sites More sharing options...
John Cuthber Posted June 28, 2008 Share Posted June 28, 2008 YT2095, The box of "arthur J Borwn's " garden lime that I have is labeled as containing "screened limestone" It fizzes with acids. Shouldn't you have checked what garden lime is before assuming I was wrong? Why would someone choose to use a more dangerous and more expensive material when crushed rock would do? Link to comment Share on other sites More sharing options...
kevinalm Posted June 28, 2008 Share Posted June 28, 2008 In the US, all "lime" for agricultural/garden use is calcium carbonate. (powdered limestone). To get CaOH you would have to specifically get "slacked lime", which isn't very commonly available. Kind of a lift = elevator language thing going on I think. Link to comment Share on other sites More sharing options...
YT2095 Posted June 29, 2008 Share Posted June 29, 2008 we sell 25Kg bags of the stuff in the shop (as well as other fertilisers) it`s called Garden Lime, and it has no carbonates in it and will not "fizz" with acid, it`s CaOH. in fact I use this stuff myself every autumn in conjunction with wood/plant ash and ammonium nitrate to make KNO3 en mass for next years Tomato and Chilli feed. this should clear things up: http://www.sdfern.com/lime.htm seems there are 4 types, and since I mentioned it doesn`t fizz, it Can only be the CaOH sort can`t it Link to comment Share on other sites More sharing options...
John Cuthber Posted June 29, 2008 Share Posted June 29, 2008 "seems there are 4 types" So there's a 3 in 4 chance that the advice you offered the guy with the spare acid is wrong. By the time he found out it fizzed it would be a little late. Link to comment Share on other sites More sharing options...
YT2095 Posted June 29, 2008 Share Posted June 29, 2008 there`s a 2 in 4 chance (you didn`t read the article) that it would proceed in the way You advised, and chance the same it would proceed in a better way. but ALL leave more environmentally friendly product. Link to comment Share on other sites More sharing options...
John Cuthber Posted June 29, 2008 Share Posted June 29, 2008 "there`s a 2 in 4 chance (you didn`t read the article) that it would proceed in the way You advised, and chance the same it would proceed in a better way. but ALL leave more environmentally friendly product. " Pardon? Anyway I think the environmental impact of one bucket of mixed nitrate/ chloride is trivial whether it's the Na or Ca salt. The foaming is only a problem if you don't expect it. Link to comment Share on other sites More sharing options...
daniel limbert Posted June 30, 2008 Share Posted June 30, 2008 aqua regia should be freshly prepaired Link to comment Share on other sites More sharing options...
harryformiller Posted November 21, 2008 Share Posted November 21, 2008 I will like to know if I have agua regia and I evaporate it and then condence the vapors will I keep on having agua regia Link to comment Share on other sites More sharing options...
hermanntrude Posted November 21, 2008 Share Posted November 21, 2008 i will like to know why anyone would want to further concentrate aqua regia. it's one of the most corrosive substances known to man already. why try to make it more concentrated? that's insane Link to comment Share on other sites More sharing options...
nitric Posted November 24, 2008 Share Posted November 24, 2008 well, i can think off the top of my head that they would be trying to dissolve iridium, any way i would not want to even encounter almost pure nitrosyl chloride Link to comment Share on other sites More sharing options...
lukers Posted May 10, 2011 Share Posted May 10, 2011 after the gold has dissolved in the agua regia, what is the process to recover the gold? In lamemens terms.(names of acid, acids in amounts) ty most of these post are years old.. is there anyone out there Link to comment Share on other sites More sharing options...
Genesis Posted October 12, 2012 Share Posted October 12, 2012 Guys, sorry to bring this topic up again but i really need some help If i understand right... to make a Agua regia i need ==== Cloridric acid + Nitric acid===== - ratio: cloridric 3:1 Nitric is that right? or the other way around? -if i have 100 grams of gold, how much agua regia i should need ? Ratio ? Thank u guys so much... i really apriciate it... and sorry my english i m brazilian... not good english over here... Link to comment Share on other sites More sharing options...
elementcollector1 Posted October 12, 2012 Share Posted October 12, 2012 (edited) Guys, sorry to bring this topic up again but i really need some help If i understand right... to make a Agua regia i need ==== Cloridric acid + Nitric acid===== - ratio: cloridric 3:1 Nitric is that right? or the other way around? -if i have 100 grams of gold, how much agua regia i should need ? Ratio ? Thank u guys so much... i really apriciate it... and sorry my english i m brazilian... not good english over here... The ratio is 1:3 (nitric : hydrochloric), respectively. Your chemical equation, taken straight from Wikipedia: Au (s) + 3 NO− 3(aq) + 6 H+(aq) → Au3+(aq) + 3 NO2(g) + 3 H2O (l) andAu3+(aq) + 4 Cl−(aq) → AuCl− 4 (aq). Condensing all that down into this reaction:3 HNO3 + 4 HCl + Au -> 3 H2O + 3 NO2 + HAuCl4 Using this handy-dandy website (http://theodoregray.com/PeriodicTable/MSP/BalanceReactions), we can now conclude that for every 100g of gold, you will need 96 grams of nitric acid (or 136 mL at max concentration) and 75 grams of HCl (or 236 mL at 31.75% concentration). That would make for about 372 mL of strong aqua regia for every 100g of gold.I hope that helped, and remember: Aqua regia is nasty stuff! Use as many safety precautions and protections as you can, nothing short of gloves, goggles, labcoat, and it would help immensely to have a fume hood (or just do this outside). Edited October 12, 2012 by elementcollector1 Link to comment Share on other sites More sharing options...
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