Name | Potassium hexacyanoferrate |
Synonyms | Tetrapotassium hexac potassiumhexacyanide Potassium ferrocyanide tetrapotassiumferrocyanide Potassium hexacyanoferrate IODINE BROMIDE SOLUTION PHE potassiumhexacyanoferrate(iv) Tetrapotassium hexacyanoferrate hexacyano-ferrate(4-tetrapotassium tetrapotassium iron(+6) cation hexacyanide Potassium hexacyanoferrate (III) trihydrate tetrapotassium,(oc-6-11)-ferrate(4-hexakis(cyano-c)- hexakis(cyano-C)-,tetrapotassium,(OC-6-11)-Ferrate(4-) Ferrate(4-), hexakis(cyano-C)-, tetrapotassium, (OC-6-11)- |
CAS | 13943-58-3 |
EINECS | 680-643-7 |
InChI | InChI=1/6CN.Fe.4K.3H2O/c6*1-2;;;;;;;;/h;;;;;;;;;;;3*1H2/q;;;;;;-2;4*+1;;;/rC6FeN6.4K.3H2O/c8-1-7(2-9,3-10,4-11,5-12)6-13;;;;;;;/h;;;;;3*1H2/q-2;4*+1;; |
Molecular Formula | C24H6Fe4K4N24O3-8 |
Molar Mass | 1058.24 |
Density | 1.85 |
Melting Point | 70 °C |
Boling Point | 104.2 °C |
Water Solubility | 254g/L at 20℃ |
Appearance | yellow granules (rough estimate) |
Exposure Limit | ACGIH: TWA 1 mg/m3NIOSH: IDLH 25 mg/m3; TWA 1 mg/m3 |
Physical and Chemical Properties | Lemon yellow monoclinic columnar crystal or powder, sometimes cubic metamorphosis. |
Use | Used in the manufacture of pigments, printing and dyeing oxidation aids, potassium cyanide, explosives and chemical reagents, also used in steel heat treatment, lithographic, engraving, etc |
TSCA | Yes |
Downstream Products | Sodium Chloride Sodium ferrocyanide |
light yellow monoclinic crystal or powder, odorless. The relative density was 1. 85. Soluble in water, insoluble in ethanol and ether, etc. Stable in air, heated to 70 ° C, began to lose the water of crystallization, 100 ° C into a hygroscopic white powder anhydrous, high temperature to liberate ammonia. It reacts with acids, bases, iron ions, and the like.
with the production of calcium carbide by-product cyanide melt (a mixture of calcium cyanide and sodium cyanide) as the raw material, water is extracted below 80 ℃, and ferrous sulfate is added to the extract to generate ferrous cyanide complex, then add potassium chloride to produce double salt precipitation at 75 ℃, add soda ash to decalcify it, then add potassium chloride, heat and boil to convert sodium salt into potassium ferrocyanide, after filtration, cooling crystallization, separation, drying to give the finished product. Alternatively, sodium cyanide waste liquid is reacted with calcium chloride and ferrous sulfate at 70~80 ℃ to form sodium ferrocyanide and calcium sulfate precipitates, and calcium chloride and potassium chloride are added to the filtered filtrate, reaction at 75 deg C to form potassium ferrocyanide calcium double salt precipitate, after filtration, cooling crystallization, separation, drying to obtain the finished product.
salt was added as an anticaking agent. In the foreign wine production, mainly used as iron removal agent. Because the cyanide ion in potassium ferrocyanide is strongly bound to iron, the toxicity is extremely low. China's provisions can be used for salt, the maximum use of heavy O.Olg/kg (ferrous cyanide root).
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Introduction | potassium ferrocyanide is stable in air, and loses water of crystallization when heated to 100 ℃, and becomes hygroscopic white powder. At high temperatures, nitrogen is liberated and potassium cyanide and ferric carbide are formed. It is heated with dilute sulfuric acid to generate hydrocyanic acid, ferrous sulfate and potassium sulfate. Heat with concentrated sulfuric acid to generate ferrous sulfate, ammonium sulfate, potassium sulfate, and release carbon monoxide. The reaction with ferrous salt solution generates Prussian blue. The corresponding ferrocyanide precipitates of silver, copper or zinc are formed in solutions of silver, copper or zinc salts, respectively. |
Application | potassium ferrocyanide is a raw material for the preparation of potassium cyanide and potassium ferricyanide; Pigment, used for fiber dyeing; china's GB2760-1996 regulations allow the use of food with anti caking agent. |
preparation method | calcium ferrocyanide solution is obtained by co-heating the waste oxide obtained from the gas plant with lime, and then with potassium carbonate solution, the crystals were concentrated to obtain potassium ferrocyanide. |
solubility in water (g/100ml) | grams dissolved per 100ml of water at different temperatures (℃): 14.3g/0 ℃;21.1g/10 ℃;28.2g/20 ℃;35.1g/30 ℃;41.4g/40 ℃; 54.8g/60 ℃;66.9g/80 ℃;71.5g/90 ℃;74.2g/100 ℃ |
identification test | ferrocyanide test was positive (IT-16). Potassium test was positive (IT-27). |
content analysis | accurately weigh about 5g of the sample, place it in a volumetric flask, add water to dissolve, and mix to volume. Take 25ml of this solution and put it in a 500ml triangle bottle, add (18) 20ml of sulfuric acid solution, 3-5 drops of diphenylamine indicator solution (TS-89), six Cyanogen ferric acid three potassium solution (10g/L)3~5 drops, under vigorous stirring, with 0.03mol/L zinc sulfate standard solution slowly titrated to the solution from yellow green to purple blue end point. |
toxicity | ADI 0-0.025 (calculated as sodium ferrocyanide; FAO/WHO,2001). Because of the strong combination of iron and cyano, it is extremely low toxicity. |
Use | as anti-caking agent, China's provisions can be used for salt, the maximum use of 0.005g%kg (ferrous cyanide root). China GB 2760-96, allowed as salt anti caking agent. The maximum amount used was 0.01g/kg (based on ferrocyanide). It is commonly used in some wines in Europe to remove iron and copper. used in the manufacture of pigments, printing and dyeing oxidants, potassium cyanide, explosives and chemical reagents, also used in steel heat treatment, lithographic, engraving and so on |
production method | is obtained by reacting cyanide with ferrous sulfate and calcium chloride, and then reacting with potassium chloride after purification. It can also be obtained by direct reaction of sodium ferrocyanide with potassium chloride. 1 the cyanide melt method uses a by-product of calcium carbide production (a mixture of calcium cyanide and sodium cyanide) as a raw material. Extraction with water below 80 ℃ (hydrolysis reaction will occur if the temperature is too high), ferrous sulfate is added into the extraction solution to generate ferrous cyanide complex: 4NaCN 4Ca(CN) 2FeSO4 → Na4Fe(CN)6 Ca2Fe(CN)6 2CaSO4 ↓ calcium sulfate precipitate was removed by pressure filtration to obtain complex mixed solution. Adding potassium chloride at 75 ℃ to produce double salt precipitate: Ca2Fe(CN)6 2KCl → k2caco3 (CN)6 ↓ CaCl2Na4Fe(CN)6 2KCL → K2Na2Fe(CN)6 ↓ 2NaCl after separation of double salt in decalcification tank heated to 80 ℃, adding soda ash to decalcification: 2 k2caco3 (CN)6 2Na2CO3 → K4Fe(CN)6 Na4Fe(CN)6 2CaCO3 ↓ press filter to remove calcium carbonate, add potassium chloride to the conversion tank, heat and boil to convert sodium salt into potassium ferrocyanide: Na4Fe(CN)6 4KCl → K4Fe(CN)6 4NaCl to remove impurities after reaction, cooling crystallization, centrifugal separation, drying to obtain the finished product. 2. The double salt method uses sodium cyanide waste liquid to react with calcium chloride and ferrous sulfate at 70~80 ℃ to generate sodium ferrocyanide and calcium sulfate; Filter, add calcium chloride and potassium chloride to the filtrate in the salt recovery tank, the reaction at 75 °c produces a calcium ferrocyanide potassium double salt precipitate. The subsequent process is the same as the cyanide melt method. The reactions were as follows: 6NaCN FeSO4 CaCl2 → Na4Fe(CN)6 CaSO4 ↓ 2 NaClNa4Fe(CN)6 4KCl → K4Fe(CN)6 4NaCl |
category | toxic substances |
toxicity grade | poisoning |
Acute toxicity | oral-rat LD50 6400 mg/kg; Oral-mouse LD50: 5000 mg/kg |
flammability hazard characteristics | flammable, fire discharge containing iron oxide, potassium oxide spicy stimulus smoke |
storage and transportation characteristics | warehouse low temperature, ventilation, dry |
extinguishing agent | water, carbon dioxide, dry powder, sand |