Cadmium lithopones

Cadmium lithopone n. Pigment red 108 (77202). Range of yellow, orange, and red colors consisting of either cadmium sulfide or cadmium red reduced on barium sulfate. They are usually produced by coprecipitation followed by calcinations. 

Mercury-cadmium lithopones n. See cadmium-mercury Kthopones. 

Cadmium lithopones, otherwise known as cadmoliths are cadmium reds or yellows that contain barium sulfate coprecipitated with the pigment. 

Cadmium lithopones, otherwise known as cadmoliths [1] are cadmium reds or yellows that contain barium sulfate coprecipitated with the pigment Although not discussed here, reds made with mixtures of cadmium sulfide and mercury sulfide, are known as mercadiums [2] and have also been produced as lithopones. 

Mercury-Cadmium Lithopones n See Cadmium-Mercury Lithopones. 

Cadmium mercury sulfide Cadmium selenium sulfide Cadmium lithopone, Cadmium sulfide lithopone Cadmolith Cadmopone Colour Index (1971) 77196, 77199, 77201 Salter (1869) 36,42,244... 

Cadmium group Cadmium lithopone-. Cadmium orange-. Cadmium yellow-, Cadmolith Cadmopone Fiedler Bayard (1986)... 

Cadmium group Cadmium sulfides and selenides group Cadmium sulfide Greenockite Lithopone Titanium dioxide white Aurora yellow. Brilliant yellow, Cadmia-, Cadmium lithopone-. Cadmium sulfide lithopone-, Cadmolith-, Cadmopone-, Daffodil yellow-. Emerald green-, Jaune brilliant-. Lemon cadmium-, Mutrie yellow-. Neutral orange-. Orient yellow Radiant yellow... 

Marston patented the first cadmium yellow lithopone in 1921 in which approximately 5% barium sulfate q.v.) was present. Fiedler and Bayard (1986, citing Ward, 1927) state that by 1927, cadmium lithopones were being produced with >60% barium sulfate, which greatly reduced the cost of manufacturing pure cadmium sulfide. 

Cadmium group Cadmium lithopone Cadmium orange Cadmium sulfide lithopone Cadmium yellow Cadmolith Lithopone Heaton (1928) 380 Keijzer (1990)... 

Cadmium hydroxide is the anode material of Ag—Cd and Ni—Cd rechargeable storage batteries (see Batteries, SECONDARY cells). Cadmium sulfide, selenide, and especially telluride find utility in solar cells (see Solarenergy). Cadmium sulfide, lithopone, and sulfoselenide are used as colorants (orange, yellow, red) for plastics, glass, glazes, rubber, and fireworks (see Colorants for ceramics Colorants forplastics Pigments). 

Figure 2.7 is a flow diagram of lithopone production. The solutions of zinc salts contain impurities (e.g., salts of iron, nickel, chromium, manganese, silver, cadmium) that depend on their origins. The main sources of zinc sulfate solutions are zinc electrolyses and the reprocessing of zinc scrap and zinc oxide. The first stage of purification consists of chlorination. Iron and manganese are precipitated as oxide-hydroxides. 

The zinc salt solutions, which currently mainly come from zinc and copper smelters, contain impurities which have to be completely removed prior to use, because all heavy metals form colored sulfides. For the purification step the solution is oxidized with chlorine (pH 4), which precipitates most of the iron and manganese as the oxide-hydrate and part of the cobalt, nickel and cadmium present as their hydroxides. In the second step, the elements nobler than zinc (Ni, Co, Cd, In, Tl, Pb, Cu, Ag) are precipitated as their metals by adding zinc dust and the metals returned to the copper smelters for noble metal extraction. After purification the solutions are adjusted to a particular zinc content. Mixtures of zinc sulfate and zinc chloride solutions are used for manufacturing lithopone types with more than 30% ZnS. 

Cadmium/mercury lithopones n. Orange, red, and maroon pigments consisting of calcined co-precipitations of cadmium sulfide and mercury sulfide, with barium sulfate. 

Cadmolith, lithopone-type cadmium pigments. Millennium Specialty Chemicals, Colors and Silica... 

Titanium dioxide, zinc oxide, white lead, lithopone, antimony trioxide Carbon black, mineral black, black iron oxide Synthetic iron oxide, red lead oxide, cadmium red Chrome yellow, strontium yellow, zinc yellow, nickel titanate yellow, zinc chromate, earthen iron oxide (ochre)... 

Although not discussed here, reds made with mbctures of cadmium sulfide and mercury sulfide, are known as mercadiums and have also been produced as lithopones. 

The 1920s saw the development of both cadmium oil colors and lithopones, which were designed to reduce the cost of the pigment. Lithopones are virtually the... 

Solutions of sodium sulfide are normally made from sodium sulfide flake (Na2S.H20). If lithopones are required, a solution of barium sulfide is also necessary. The latter can be purchased as black ash , which owes its name to a gray appearance, having been made from the reduction of barium sulfate with carbon. It is difficult to handle, and not as soluble as sodium sulfide. The solutions should be kept warm to prevent crystallization. Sodium sulfide solution is also required to dissolve selenium for the production of cadmium reds. 

Additionally, two cadmium chromates are known (classed with chromate pigments) along with a cadmium tungstate (classed with tungsten pigments). Lithopone forms - that is, pigments coprecipitated with barium sulfate (q.v.) - of the cadmium sulfides are also extant. The composition of cadmium white mentioned in later nineteenth cenmry literature is not well known Salter (1869) describes it as a hydrated oxide or carbonate of cadmium. 

Synonym, variant or common name See cadmium sulfide lithopone. 

The Colour Index (1971) lists two red cadmium pigments. Cl Pigment Red 108 and Cl Pigment Red 113. Compositionally these relate to cadmium sulfide selenides (CdSjcCdSe) and pure cadmium selenides (CdSe) as well as cadmium mercury sulfides (CdS.xHgS) q.v.). Co-precipitates with barium sulfate q.v.) are also known, sometimes referred to as cadmium red lithopone Colour Index, Cl 77202). 

The Colour Index (1971) lists cadmium yellow as Cl 77199/Pigment Yellow 37 and the lithopone form as Cl 77117/Pigment Yellow 35. 

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