Ceramic cadmium pigments

The use of cadmium pigments in ceramics is controlled in the EC Guideline No. 84/500/EC. International standards [Part 1 (Methods) and Part II (Limit Values)] are as follows ceramic surfaces ISO 6486, enamel ISO 4531, and glass ISO 7086. 

The output of cadmium pigments in the industrialized countries in 1995 was approximately 3000 t, of which approx. 2000 t were produced in Europe and 500 t in the United States. Consumption is distributed approximately as follows plastics 90%, ceramics 8% and others 2%. 

Cepria and coworkers used the voltammetry of immobilized microparticles to detect and quantify the cadmium pigments (e.g., cadmium sulfide and cadmium sulfoselenide) used in artists paints, as well as in glasses, plastics, ceramics, and enamels [141]. For this, a simple, fast and reliable technique was developed that proved to be especially applicable for valuable art objects, as it was minimally invasive and required only nanogram quantities of material (see also Section 6.4.1). For quantification purposes, an abrasive stripping scan was used from + 0.3 V to —1.0 V, following a 10 s pre-treatment step at —1.5 V. The Cd oxidation peak was evaluated with respect to an internal AgCl calibration standard. 

Pigments and Glass. Tellurium has served as base for ultramarine-type cadmium sulfoteUuride (82) and cadmium teUuride pigments (83) (see Pigments, inorganic). In addition, smaU amounts of teUurium have been used in glass and ceramics to produce blue to brown colors (see Colorants for CERAMCS). 

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

Pigment Systems. Most of the crystals used for ceramic pigments are complex oxides, owing to the great stability of oxides in molten silicate glasses. Table 3 fists these materials. The one significant exception to the use of oxides is the family of cadmium sulfoselenide red pigments. This family is used because the colors obtained caimot be obtained in oxide systems thus it is necessary to sustain the difficulties of a nonoxide system. 

Ceramic coating Dispersion of pigments (cadmium, chromates, lead)... 

Cadmium sulfate (CdS), also called orange cadmium, is used to produce phosphors and fluorescent screens. It is also used as a pigment in inks and paints, to color ceramics glazes, in the manufacture of transistors in electronics, photovoltaic cells, and solar cells, and in fireworks. 

Nickel salts are used in electroplating, ceramics, pigments, and as catalysts. Sinter nickel oxide is used as charge material in the manufacture of alloy steel and stainless steel. Nickel is also used in alkaline (nickel-cadmium) batteries. 

Cadmium fluoride has similar uses to the zinc halide. Cadmium oxide is used in ceramic glazes the sulfate, as a source of other cadmium compounds and in the radio valve industry the sulfide is important as a yellow pigment for artists, and is used in the paint, soap, glass, textile, paper, rubber and pyrotechnics industries. Cadmium sulfide in admixture with other compounds such as the selenide gives rise to other pigments of value. It is also used in phosphors and fluorescent screens and in scintillation counters. Semiconductors such as CdS... 

Nickel and nickel compounds are widely used in plated coatings, nickel-cadmium batteries, certain pigments, ceramic glazes, and as industrial and laboratory catalysts. Nickel subsulfide is used in refining certain ores and in smelting operations. Nickel is commonly used in alloys such as stainless steel, alloy steel, and nonferrous metal mixtures. Coins, costume jewelry, plumbing equipment, and electrodes are often made from nickel-containing alloys. 

Thallium is a by-product of iron, cadmium, and zinc refining. It is used in metal alloys, imitation jewelry, optical lenses, artists pigments, semiconductors, ceramics, and X-ray detection devices. It has limited use as a catalyst in organic chemistry. In the past, thallium (chiefly thallium sulfate) was used as a ro-denticide and insecticide. Its use as a rodenticide was outlawed in 1965 due to its severe toxicity (a source of accidental and suicidal human exposures). Medicinally, it has been used as a depilatory and in the treatment of venereal disease, skin fungal infections, and tuberculosis. 

Another 25% of the selenium production in 1996 was used in inorganic pigments (principally as cadmium sulfoselenide used in plastics, paints, enamels, inks, mbber, and ceramics), and 10-15% of selenium is used in a broad spectrum of applications including accelerators and vulcanizing agents in mbber production, in stainless steel, and as selenides of refractory metals for use in lubricants. Some of these products may end up as disposed waste. Medical and pharmaceutical uses such as in topical preparations for treatment of dandmff, for... 

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