Ammonium chloride +ammonnium nitrat fusion at 142 C°

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Quwannar

Active member
Joined
May 26, 2017
Messages
35
Dear Friends;
Most of expericenced and skillfull miners and metallurgists in this forum are suffering from gold bearing black sand, pyrite and sulfide ore matrix. The first principal is generally to roast ore in 650 C° to convert sulphides into oxides by gassing off SOX, NOX in outdoor and to liberate gold from locked in sulfide matrix despite of many toxic gas danger and higher temperature and long roasting time.
Has anyone tried to make fusing reaction sulfide ores (refractory) that contain gold withi ammonium chloride and ammonium nitrate (may be calcium ammonium nitrate is not explosive) at moderately low temperature of 142 °C.
At standart protocol in order to determine if there is gold or not in sulfide ores . A retired proffessor at Friei University of Walter Franke in Berlin proposed following procedures.
A pinch of refractory gold ore
One part ammonium chloride
Two part ammonium nitrate
Mix all of them
Heat until 142 C°
After cooling drop the HCl onto melted syrup
One drop SnCl2
Finally see purple color.
İf we look at this protocol, we can thermally decompose and then breake sulfide bonds of refractory ores concentrates.
İn addition to this, this stuffs are so cheap and energy consumption would be lower at 142 C.
Question one? What would be thermal decomposition reaction of this two stuff with just pyrite?
NH4Cl2+NH4NO3+FeS2 ====>heat ????
Any considerations would be appreciated.
Erdem
.
 
Dear Friends
Thank you very much for your valuable information.
s far as İ understand, mixture of two stuff in the melted state, is obviously leaching the gold in refractory ore in practice with the assistances of highly fusible properties of them at the moderate temperature in contras to clasicall roasting process. İn the point of view as a pretreatment procedures, Does it mean that we are making the roasting together with leaching of gold?. Because this syrup with dissolution of HCl (in need of excess chlorine make the syrup soluble) does precisely respond SnCl2 to determine the gold presences or not.
The melting point of two stuff are around 140 -210 c.
İf we would like to predict the products of fusion reaction
İt must be gold salt (AuCl2/Cl4) in melted syrup solution. As well as NOx SOx and. Base metal (NO3) nitrate, H2 gas. Base metal nitrates may be problem in further stage or may be advantage.
But in terms of reaction effectiveness, both roasting and leaching of refractory ore, reaction time, speed and easy access to this stuffs make this method very comfortable.
Now i am searching on known as an ordinary fertilizer named the calcium ammonium nitrate in which contain the 26 % NH4NO3 with CaCO3 and has no detonation properties.
Any considerations would be appreciated.
Best regards
Note that Mr. Butcher
İ have learnt many things from your post in this forum. Thank you very much again.
Sincerely yours,
Erdem.
İ would like to go the protocol of Mr. Walter Franke's further in which is a useful tool on determining the gold precences in refractory ore. At the beginning, lets separate problem two parts. First, fusion reaction at 142 C° second the leaching of gold syrup of fusion reaction ammonium chloride + ammonium nitrate.
Mr. Franke's protocol is instructing to use just HCl prior to SnCl2. Why? Again Why just HCl? İ think Thats breaking point. We have a molten syrup in our hand. After we keetp in cooling. And then it will solidify. So What products do we have? Just gold salt and base metal nitrate in theory. İf we crushed and ground the solid syrup, if We diluted with especially NaOCl instead of HCl in pH 7- 8 What results would be?
 
While i was searching in google, İ found the following article. But it was just given the abstract of research conducted in South Aafrica in 1970. And this article is not open. But it is verifying my theory.

https://scholar.google.com.tr/scholar?q=Decomposition+of+oxide+and+sulphide+minerals+and+ores+by+fusion+with+ammonium+salts&hl=tr&as_sdt=0&as_vis=1&oi=scholart&sa=X&ved=0ahUKEwjam4LjyZfaAhVLXCwKHT13ASYQgQMIJTAA#d=gs_qabs&p=&u=%23p%3DCJvv96K2KmMJ
 
Upon heating of fusion, we will have dangerous gases like arsenic which are components of the ore, I also presume some gold may become volatile and also go up in smoke as chlorides (much like roasting gold with salt as a pretreatment to leaching the ore).

The stannous chloride test is extremely sensitive, the HCl will dissolve the gold chlorides (and other metal chlorides into solution), and can also aid in de-NOxing the fusion of nitrates, converting them to nitric and then NOx gases.

The gold is oxidized in the fusion and converted into a soluble chloride, The HCl is just putting it into an acidic solution for the stannous test.
Bleach would dissolve the gold salt into a caustic solution, but would also add an oxidizer.
HCl would work better for putting the gold into solution.

I cannot see this as being environmentally friendly, safe, economically productive, or even a practical way to recover gold from ore concentrates.
 
butcher said:
Upon heating of fusion, we will have dangerous gases like arsenic which are components of the ore, I also presume some gold may become volatile and also go up in smoke as chlorides (much like roasting gold with salt as a pretreatment to leaching the ore).

The stannous chloride test is extremely sensitive, the HCl will dissolve the gold chlorides (and other metal chlorides into solution), and can also aid in de-NOxing the fusion of nitrates, converting them to nitric and then NOx gases.

The gold is oxidized in the fusion and converted into a soluble chloride, The HCl is just putting it into an acidic solution for the stannous test.
Bleach would dissolve the gold salt into a caustic solution, but would also add an oxidizer.
HCl would work better for putting the gold into solution.

I cannot see this as being environmentally friendly, safe, economically productive, or even a practical way to recover gold from ore concentrates.

Dear Butcher;
Thank you very much for the information. There are lots of things that I am able to learn from you. I would like to speculate on this matter with your assistance despite of my poor english. And I am sorry for that.
As we you know, Fusion Reaction for sulfide ores take places at 142 C°. Thats important point.... Ammonium Chloride like table salt (NaCl) in classical roasting technique at 650 -700 C° of sulfide ores is either chlorine source and may be oxidizer ??? or fluxing agent decreasing melting point of reaction. In addition of that Ammonium Nitrate is also strong oxidizer with h and NO3 content.
Another interesting part within fusion reaction take place
a leaching at same time. So gold chloride salt must be part of reaction. If that would not be, in other words if gold salt does not produced in fusion reaction. just HCL will not be able to leach the gold as gold salt. Lets assume that HAuCl occurs at 142C°.so melting point or evaporating point HAuCl is 280 -300 C°. I think it will not boiled off. But over this temparture it is thought that gold salt can be easily boiled off. Perhaps I may wrong.
Moreover roasting process at 650 -700 C° with NaCl if Cl is used as a chlorine source in which break sulfite bond of ores by converting them chloride salt, and after the roasting step, why another leach process does has to be done?
If we would like to built a new leaching plan for a solid melted of fusion reaction products, even if never has experienced so far how can we separate gold salt from other base metal chloride salt? At this point we would need your considerations and directions in case you have time.
Thank you very much in advance.
 
Just my thoughts here:
Sulfides take high temperature, held at red-hot about 750 degrees for a period of time and then oxidation to drive them from ore, to oxidize the ore and its metal contents to metal oxides (those metals that can be oxidized in this environment, gold normally would not oxidize, but its sulfide bond is broken.

Adding salt to the above roasting process provides chloride ions which in the roast help to convert the gold, but some gold is most likely lost to volatilization at these temperatures.
I can not remember but I believe we can distill off gold chlorides around 800 degrees, this is why I believe some gold would be lost.

In the fusion process, we are basically making aqua regia at these temperatures putting gold into a chloride salt, along with the soup of metals in the ore.
My guess is at these temperatures the sulfides are converted and driven off as gasses in the fusion process, as well as most other anions depending on their volatility.

At the fusion temperatures, gold chloride may not become volatile and stay in the fusion as a salt, but my gut feeling is that some gold could still be lost in the cloud of gases.

I could be wrong but I think it could be like water, we do not have to boil water to evaporate some water at lower temperatures, just not as much water is vaporized at a lower temperature (only surface), where boiling breaks the bonds much more and water boils off faster.
 
Dear Butcher,
Thank you very much again.
High grade gold bearing sulfides ores can be easily concentrated by froth flotation. The mass reduction can easiyly be done by this technique in home basement.Depending on sulfide mineral content by cheking arsenide percentage ( the most danger gases)in order to benefite especially grade over 1 troy once gold sulfide con. Is about between 30 -50 kg.per 1 tonnes ore. So when we analyze reaction economy for 30 kg concentrate. We need 30 kg ammonium chloride and 70 kg ammonium nittrate in which cost to 12 usd and 30 usd.
It looks like to be very profitable. If we base the 1 troy ounce, We can calculate the profite and loss rate depending upon How much gold must there in our per ton ore?
Many of friends are already doing aqua regia.they know all trics of AR. But acid leaching is not siutable for ores.
Why don't we develope the protocol of ammonnium salts lfusion eaching for the ore? I think that GRF community have a brillant ability with very diligent members to overcome this issue.
Sincerely yours
Erdem.
 
In testing for gold in the ore, the fusion process only needs to put a very small amount of gold ions into the solution for the stannous chloride test to indicate gold or not.

I am not sure this would be a viable method to drive off all sulfides or loosen the ores bond to the gold at a lower temperature as a pretreatment process for the ore, over traditional roasting or roasting the ore with salt...

Controlled experiments of the two processes on the ore would give more details, Most mines along with assaying will have to run experiments to determine how to recover gold from the ore, not all ore reacts the same, or to find a process that will work with their ore, and they also run experiments to improve processes.


Erdem,
Try doing more research on this, it would make a good experiment to explore further. Who knows it may be worth the time and trouble just to see how it would work? A few lab experiments would answer many questions and give some more questions to look into.
 
Dear friends;
Here is the abstract of a research conducted by Russian scientists in 2016.
They mentioned that they were making gold and silver leaching with fusion of ammonium chloride and ammonium nitrate. After putting of gold and silver into solution, they also claimed that gold were recovered by
diphenylguanidine as the complexing reagent. İts much less hazardous and eco_ friendly substance.
Has anyone tried to use the Diphenly Guanidine as a precipant agent for gold recovery from pregnant solution?
Sincerley yours
Erdem
"The purpose of the research is studying material composition of old flotation tailings of pyrite ores and the development of thermochemical method of their chloro-ammonium processing taking into account the identified composition. The tailings at Uchaly Mining and Processing Integrated Works contain pyrite, quartz, chlorite, gypsum, barite and feldspar according to mineralogical studies. Possibility of two-step thermochemical chloro-ammonium processing of dumped sulphide tailings, that consists of gold and silver unlocking and pyrite sintering in air with ammonium chloride at 250-275 °C, have been studied. The gold leaching by sintering with a mixture of chloride and ammonium nitrate at 200 °C has been carried out. The silver recovery to solution has made up to 83% under these conditions. The recovery of gold from leaching solutions uses diphenylguanidine as the complexing reagent. The gold recovery from the fi rst stage’s cake is up to 85.8–87.5%. The processing of flotation tailings of pyrite ores with low hazard reagents and the absence of harmful emissions will significantly increase ecological friendliness of mineral mining and processing."
http://www.rudmet.ru/journal/1530/article/26301/?language=en
 
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