aqueous cyanide is hydrolyzed rapidly, especially in sunlight. it can mobilize some heavy metals such as mercury if present. gold can also be associated with arsenopyrite feass , which is similar to iron pyrite fool's gold , wherein half of the sulfur atoms are replaced by arsenic. gold-containing arsenopyrite ores are similarly reactive .
potassium cyanide is a compound with the formula k cn. this colorless crystalline salt, similar in appearance to sugar, is highly soluble in water. most kcn is used in gold mining, organic synthesis, and electroplating. smaller applications include jewelry for chemical gilding and buffing. potassium cyanide is highly toxic.
the main use of calcium cyanamide is in agriculture as a fertilizer. in contact with water, it decomposes and liberates ammonia: cacn 2 3 h 2 o 2 nh 3 caco 3. it was used to produce sodium cyanide by fusing with sodium carbonate: cacn 2 na 2 co 3 2 c 2 nacn cao 2 co. sodium cyanide is used in cyanide process in gold mining.
amyl nitrite is sometimes used as an antidote for cyanide poisoning. it can act as an oxidant, to induce the formation of methemoglobin. methemoglobin in turn can sequester cyanide as cyanomethemoglobin. amyl nitrite is used as a cleaning agent and solvent in industrial and applications.
copper i cyanide is an inorganic compound with the formula cucn. this off-white solid occurs in two polymorphs; impure samples can be green due to the presence of cu ii impurities. the compound is useful as a catalyst, in electroplating copper, and as a reagent in the preparation of nitriles.
sodium thiosulfate is used in the treatment of cyanide poisoning. other uses include topical treatment of ringworm and tinea versicolor, and treating some side effects of hemodialysis and chemotherapy.. iodometry. in analytical chemistry, the most important use comes because the thiosulfate anion reacts stoichiometrically with iodine in aqueous solution, reducing it to iodide as the .
thiosulfate extensively forms complexes with transition metals hence a common use is dissolving silver halides in film photography developing. thiosulfate is also used to extract or leach gold sodium thiosulfate and silver from their ores as a less toxic alternative to cyanide. nomenclature
a lixiviant for gold and silver leaching can be created by selectively oxidizing thiourea, bypassing the steps of cyanide use and smelting. safety. the ld 50 for thiourea is 125 mg/kg for rats oral .
electrowinning is not a primary method of separation, but is required to get the ore out of solution after leaching. case examples. in the case of gold, after adsorbing onto carbon, it is put into a sodium hydroxide and cyanide solution. in the solution the gold is pulled of the carbon and into the solution. the gold ions are removed from .
it is used to form gold cyanide, which precipitates fine particles of gold during certain printing techniques: in effect, it is a handy way of forming a soluble form of gold. see also love in the time of cholera by gabriel garcia marquez where one of the characters a photographer commits suicide using gold cyanide.
if the gold can not be concentrated for smelting, then it is leached by an aqueous solution: . the cyanide process is the industry standard.; thiosulfate leaching has been proven to be effective on ores with high soluble copper values or ores which experience preg-robbing: the absorption by carbonaceous components which preferentially absorbs gold and gold-cyanide complexes.