Iron blues

Iron blue pigments are microcrystalline coordination compounds of Fe(II)Fe(III) cyano complexes. Conventionally, they were also known 

Iron blue pigments are used to impart a pure black tone and high jetness in printing inks. They are used in paints with deep blue colors but seldom used in tints. Use of these pigments has been greatly reduced due to the availability of more durable copper phthalocyanine blue pigments. 

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Cyanide [57-12-5] Cyanide detoxification Cyanide exchange Cyanide iron blue Cyanide oxidation Cyanides... 

Iron alumimdes Iron-aluminum alloy Iron-aluminum alloys Iron-base alloys Iron blacks Iron blue... 

Inorganic Color Pigments. Iron blue is made in several shades, such as Mdori blue and Pmssian blue. It is economical, but has poor alkaH resistance. It is also used as a toner in some black inks. 

Alkali or alkaline-earth salts of both complexes are soluble in water (except for Ba2[Fe(CN)g]) but are insoluble in alcohol. The salts of hexakiscyanoferrate(4—) are yellow and those of hexakiscyanoferrate(3—) are mby red. A large variety of complexes arise when one or more cations of the alkah or alkaline-earth salts is replaced by a complex cation, a representative metal, or a transition metal. Many salts have commercial appHcations, although the majority of industrial production of iron cyanide complexes is of iron blues such as Pmssian Blue, used as pigments (see Pigments, inorganic). Many transition-metal salts of [Fe(CN)g] have characteristic colors. Addition of [Fe(CN)g] to an unknown metal salt solution has been used as a quaUtative test for those transition metals. 

Cyanide Iron Blues. Cyanide iron blue, also known as Pmssian blue, is one of the oldest industrially produced, inorganic pigments. Chemically, cyanide iron blues are based on the [Fe " Fe (CN) ] anion. The charge is balanced by sodium, potassium, or ammonium cations. Modem... 

Cyanide iron blues can be prepared by several methods. The most common one is the indirect, two-step process. In the first step, a white precipitate (Berlin white), is produced by the reaction of sodium, potassium, or ammonium ferrocyanide and ferrous sulfate ... 

Two blue pigments can be prepared in transparent form cyanide iron blue and cobalt aluminum blue. These pigments are used in achieving a blue shade of the metal effect pigments in metallic paints. Transparent cyanide iron blue is prepared by a precipitation reaction similar to the one used for the preparation of the opaque pigment, but considerably lower concentrations of solutions are used. It is produced by Degussa (Germany), Manox (U.K), and Dainichiseika (Japan). 

Chemical pigments or synthetics may be metal compounds. A good example is white titanium dioxide. Other chemical pigments include cadmium sulfide colors, iron blue, and several synthetic versions of iron oxides. 

Iron Blue. There are three common varieties of iron blue MUoti, Chinese, and Pmssian (they are sometimes caUed toning blues). The three types differ chiefly in color, ease of dispersion, and reactivity characteristics. MUori blues are the easiest to disperse and are the least reactive. They are reddest in mass tone (plum colored) in tints, they ate intense and intermediate in redness between the Chinese and Pmssian varieties. Both the Chinese and Pmssian blues are jet in mass tone, but Pmssian blue is considerably redder and less intense in tint than Chinese blue. Because of their jet mass tones, both are used to shade blacks. Pmssian blues are the hardest to disperse and are somewhat more reactive than Chinese blues. 

Iron blues have good lightfastness in mass tone or deep shades. Iron blues ate coarse in texture, difficult to grind, and withstand only a few minutes at 175°C. 

Chrome green is produced by mechanically mixing chrome yellow and iron blue pigments in water. An iron blue, [Fe(NH4) (FeCN6)], is an oxidized precipitate product of the reaction between an aqueous solution of iron sulfate and ammonium sulfate with sodium hexacyanoferrate. 

Iron blacks, 79 401-402 Iron blast furnace, 76 141-143 Iron Blue, pigment for plastics, 7 370t Iron blue pigments, 79 407 Iron(II) bromide, 74 539 Iron(III) bromide, 74 539-540 Iron brown hematite, formula and DCMA number, 7 347t Iron browns, 79 402 Iron carbide, 4 649t, 690—692 lattice, 4 652... 

Iron Blue, Cl Pigment Blue 27, which has been known by various names over the years, perhaps the best known being Prassian Blue, is ferric ammonium ferricyanide, FeNH Fe(CN)g(xH20. The hrst step in its preparation involves the precipitation of complex iron(ii) cyanides, e.g. potassium hexacyanoferrates(ii) with iron(i) salts, e.g. the sulfate or chloride, in an aqueous solution in the presence of ammonium... 

HC1 coned sulfuric acid. Prepd as described in Ref 2 under Iron blues. Used as an ingredient of some expl compns Refs 1) Lange (1961), No 815 2) Cond-... 

ChemDict (1961), 615 (Iron blues) 3) Kirk Othmer 12(1967), 33—35 (under Iron Compounds by R.S. Casey J.R. Doyle)... 

Molybdates/lead chromates Luster pigments Mixed metal oxide pigments Iron blue pigments Ultramarine... 

Chrome green and fast chrome green mixed pigments are produced by combining chrome yellow with iron blue or phthalocyanine blue (see p. 121). 

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