Cyanide Solutions

[yasin1987]

Hi
Based on my experience with cyanide solutions,
In testing the gold in this solution, I follow Hoke's book
I add 20 drops of hydrochloric acid and 20 drops of cyanide solution
I then boil the resulting solution
And then a drop of stannous chloride

I know the gold color spectrum is pink-purple-black.

But sometimes I see orange, brown and even blue

Could this be molybdenum? Or what elements can it be?

 

[Geo]

Never, ever, add acid to a cyanide solution. It forms deadly hydrogen cyanide gas. Even small amounts can kill you. I will attach the address for the simple wikipedia for cyanide gas. Notice the dangers and health hazards. Dropping sodium cyanide into a vat of sulfuric acid was the method of generating the gas in the gas chamber for execution of convicted murders. Used as a chemical weapon in WWI.
https://en.wikipedia.org/wiki/Hydrogen_cyanide

 

[yasin1987]

Never, ever, add acid to a cyanide solution. It forms deadly hydrogen cyanide gas. Even small amounts can kill you. I will attach the address for the simple wikipedia for cyanide gas. Notice the dangers and health hazards. Dropping sodium cyanide into a vat of sulfuric acid was the method of generating the gas in the gas chamber for execution of convicted murders. Used as a chemical weapon in WWI.
https://en.wikipedia.org/wiki/Hydrogen_cyanide

Well you are right.
But in all these matters, first expertise and then safety should not be forgotten.
For example, just a few ppm of arsenic can kill humans.
This should be done by a specialist and under the hood with special filters.
However, in many cases, with a decrease in the pH of the solution, especially in some minerals, these hazards are present in cyanide solutions.

But sometimes we have to do such an experiment to measure gold or silver in cyanide solutions.

 

[Custommetals]

Cyanide information.

Cyanide​

Zhengwei Cai, in Encyclopedia of Toxicology (Second Edition), 2005

Toxicokinetics​

Cyanide is rapidly absorbed from the skin and all mucosal surfaces; it is most dangerous when inhaled because toxic amounts are absorbed with great rapidity through the bronchial mucosa and alveoli. Once absorbed, distribution of cyanide through the body is rapid. Within a few minutes, cyanide is distributed through the body and its conversion to thiocyanate starts. The majority of cyanide in the body is protein-bound (60%). In sublethal doses, cyanide reacts with sulfane sulfur to form nontoxic thiocyanate through an enzymatic reaction involving rhodanase and mercaptopyruvate sulfur transferase. Within 3 h, 90% of the dose of cyanide is converted to thiocyanate appearing in blood. Cyanide is also trapped as cyano of vitamin B12, oxidized to formate and carbon dioxide, and incorporated into cysteine. In nonfatal cases, metabolized cyanide (thiocyanate) is excreted in the urine. Although cyanide is volatile, excretion through the lungs is not a significant route of elimination of cyanide.