What Is Gold Cyanidation?

Gold potassium cyanide is a highly toxic substance. White crystal; loses crystal water when heated to 200 , decomposes into gold element at higher temperature. Soluble in water and organic solvents (such as alcohols, ether, acetone, etc.). Gold potassium cyanide is different from gold potassium cyanide. The oxidation number of gold in this substance is +3.

Chinese name: Gold potassium cyanide

Chinese alias: potassium tetracyanurate

English name: Aurate (1-), tetrakis (cyano-kC)-, potassium (1: 1), (SP-4-1) -Aurate (1-), tetracyano-, potassium (8CI); Aurate (1-CI ), Tetrakis (cyano-C)-, potassium, (SP-4-1)-; Aurate (1-), tetrakis (cyano-kC)-, potassium, (SP-4-1)-(9CI); Potassium cyanoaurate (III) (6CI); Potassium tetracyanoaurate (III) (7CI); Potassium tetracyanoaurate (1-);

International Union Name: potassium gold (3+) tetracyanide

CAS No .: 14263-59-3

EINECS number: 238-145-9

Molecular formula: KAu · (CN) ₄

Molecular weight: 340.13

First, gold chloride is prepared, then gold arsenate, and then potassium cyanide.

1.Preparation of gold chloride

The pure gold was shredded, washed, and dried, and the gold was dissolved with aqua regia under heating (1 g of pure gold requires approximately 2.7 mL of concentrated nitric acid and 8 mL of concentrated hydrochloric acid). After dissolving, heat and concentrate under constant stirring (not to exceed 100 ° C, so as to avoid the formation of monovalent gold compounds that are insoluble in water), remove nitrogen dioxide until a blood-red thick substance (gold trichloride) is obtained, and cool it for use.

2.Equipment of Thunder Acid Gold

Dissolve the blood-red thick substance with 5 volumes of distilled water. Then slowly add ammonia water (1g of pure gold needs about 10mL of concentrated ammonia water) under constant stirring to form a light yellow precipitate (gold arsenate). Evaporate and remove ammonia with constant stirring until no ammonia smell. When removing ammonia, water should be continuously added to prevent precipitation and drying. Then suction filtration, washing with hot water 3 to 4 times, to obtain gold rasic acid. Don't dry it during the preparation of gold acid, and use it as soon as possible to prevent explosion.

3.Preparation of gold and potassium cyanide solution

Pour the gold precipitate together with the filter paper into a 30% to 40% potassium cyanide solution, and slowly heat to dissolve to obtain a colorless transparent solution. 1g of pure gold requires 1.2 ~ 1.5g of potassium cyanide. ^[1]

KAu (CN) 4H ₂ O

Gold potassium cyanide is a reagent for gold plating, which is mainly used in acid range gold plating and

Most of the gold plating is very thin, and the capacity of the plating bath is also small. Although the plating time is short, factors such as fluctuations in the composition of the plating solution and impurities still appear. Common faults and corrective methods are shown in the figure below.

It is a

Molecular weight: 340.113445 [g / mol]

Molecular formula: C ₄ AuKN ₄

Number of hydrogen-bonded donors: 0

Number of hydrogen bond acceptors: 8

Number of rotatable chemical bonds: 0

Accurate quality: 339.942555

Isotope mass: 339.942555

Topological molecular polar surface area (TPSA): 95.2

Number of heavy atoms: 10

Formal charge: 0

Complexity: 10