Potassium ferrocyanide trihyrate

pale yellow solid

Lemon yellow monoclinic columnar crystal or powder, sometimes with cubic metamorphosis. Soluble in water, insoluble in ethanol, ether, methyl acetate and liquid ammonia.

Potassium hexacyanoferrate(II) trihydrate, commonly known as potassium ferrocyanide, is a commonly used anticaking agent. Its cytotoxic and genotoxic effect has been evaluated. The growth of chemical garden in aqueous potassium hexacyanoferrate solution droplets on a superhydrophobic surface has been reported. The inhibition efficiency of potassium ferrocyanide in phosphoric acid solution against the corrosion of mild steel has been investigated.

The anhydrous salt is prepared by drying at 110o over P2O5 in a vacuum desiccator. To obtain the trihydrate, it is necessary to equilibrate the salt in a desiccator over a saturated aqueous solution of sucrose and NaCl. It can also be precipitated from a saturated solution at 0o by adding an equal volume of cold 95% EtOH, setting aside for several hours, then centrifuge and wash with cold 95% EtOH. It is finally sucked air dry with water-pump vacuum. The anhydrous salt is obtained by drying the hydrate in a platinum boat at 90o in a slow stream of N2 [Loftfield & Swift J Am Chem Soc 60 3083 1938].

The cyanide melt method extracts the cyanide melt with water, and then adds ferrous sulfate to form a complex, and removes impurities through pressure filtration. The sodium ferrocyanide and calcium ferrocyanide in the filtrate are at 75℃. Potassium chloride reacts to form potassium ferrocyanide calcium calcium double salt precipitate, and then press filter, the content of yellow blood salt sodium in the filtrate should be less than 5 g/L, the filter cake at a temperature of 70 ~ 80 ℃, plus an appropriate amount of soda ash, To make it decalcify, exclude the precipitated sludge after decalcification, heat the filtrate and add excess potassium chloride to convert all the yellow blood salt sodium in the filtrate into yellow blood salt potassium. After all the above reactions are completed, it is cooled and crystallized, centrifuged, and dried to obtain a potassium ferrocyanide product. 6NaCN+FeSO4→Na4Fe(CN)6+Na2SO43Ca(CN)2+FeSO4→Ca2Fe(CN)6+CaSO4↓Ca2Fe(CN)6+2KCI→K2CaFe(CN)6↓+CaC12Na4Fe(CN)6+2KCl+ CaCl2→K2CaFe(CN)6↓+4NaCI2K2CaFe(CN)6+2Na2CO3→K4Fe(CN)6+Na4Fe(CN)6+2CaCO3↓Na4Fe(CN)6+4KCl→K4Fe(CN)6+4NaClSodium cyanide waste The liquid recovery method preliminarily reacts the recovered sodium cyanide waste liquid with calcium chloride and ferrous sulfate, filters to remove the calcium sulfate precipitate, and the filtrate reacts with an appropriate amount of soda ash to complete the decalcification, remove the calcium carbonate residue, and then react with potassium chloride Conversion to potassium ferrocyanide. After filtering, cooling and crystallization, centrifugal separation and airflow drying, the finished product of potassium ferrocyanide is obtained, whose 6NaCN+FeSO4+CaCl2→Na4Fe(CN)6+CaSO4↓+2NaClNa4Fe(CN)6+4KCl→K4Fe(CN)6 +4NaCl cyanide-containing wastewater recovery method The cyanide-containing wastewater is heated by steam to escape the hydrogen cyanide gas, and then the potassium carbonate solution is used to circulate and absorb the hydrogen cyanide gas in the absorption tower filled with iron shavings, so that the reaction is converted into ferrocyanide Potassium. 6HCN+Fe+2K2CO3→K4Fe(CN)6+H2↑+2CO2↑+2H2O

Moderately strong oxidizer when coupled with ferricyanide.

Moderately strong oxidizer when coupled with ferricyanide. Applied in formation of a xerogel via a cyanogel the gel has potential use in solid-state gas sensors.

Potassium ferrocyanide is a yellow crystal also known as yellow prussiate of potash. It was made by stirring hot potassium carbonate with wool or horn clippings with an iron rod. It is soluble in water 1:4 but not in alcohol. Potassium ferrocyanide was used as a developer for some iron processes and as an additive for alkaline pyro developers.