Pigments arsenical

The principal oxides of arsenic encountered in a pigment context are die trioxides arsenolite and claudetite (both As40g (AS2O3), the former cubic, the latter monochnic) these may occur as the minerals or dieir synthetic analogues. Chemically, a pentoxide also exists (AS4O10), but this does not appear to have been identified as a pigment. Arsenic oxides are readily soluble in water. See arsenic oxide, arsenolite type, arsenolite and claudetite. 

Cobalt compounds have been in use for centuries, notably as pigments ( cobalt blue ) in glass and porcelain (a double silicate of cobalt and potassium) the metal itself has been produced on an industrial scale only during the twentieth century. Cobalt is relatively uncommon but widely distributed it occurs biologically in vitamin B12 (a complex of cobalt(III) in which the cobalt is bonded octahedrally to nitrogen atoms and the carbon atom of a CN group). In its ores, it is usually in combination with sulphur or arsenic, and other metals, notably copper and silver, are often present. Extraction is carried out by a process essentially similar to that used for iron, but is complicate because of the need to remove arsenic and other metals. 

Other salts include lead arsenates and lead arsenites (see Insect control technology), lead chromates and lead sihcochromates (see Pigments), lead cyanide (see Cyanides), lead 2-ethyIhexanoate (see Driers and metallic soaps), and lead fluoroborate (see Fluorine compounds, inorganic). 

The most common toxic metals in industrial use are cadmium, chromium, lead, silver, and mercury less commonly used are arsenic, selenium (both metalloids), and barium. Cadmium, a metal commonly used in alloys and myriads of other industrial uses, is fairly mobile in the environment and is responsible for many maladies including renal failure and a degenerative bone disease called "ITA ITA" disease. Chromium, most often found in plating wastes, is also environmentally mobile and is most toxic in the Cr valence state. Lead has been historically used as a component of an antiknock compound in gasoline and, along with chromium (as lead chromate), in paint and pigments. 

Arsenic G S P A Arsine Arsenous acid and salts Pigment and dye Pesticide and herbicide production Metallurgical processing of other metals Glass and ceramics industries Tanneries... 

Orpiment, Deterioration of Arsenic Sulfide Pigments. Arie Wallert, Molecular Aspects of Ageing in Painted Works of Art, Progress Report 1995-1997, FOM Institute for Atomic and Molecular Physics, Amsterdam, NL, http //www.amolf.nl/research/biomacro molecular mass spectrometry/molart/progress report98.pdf... 

The stable form of arsenic is the gray or metallic form, although other forms are known. Cooling the vapor rapidly produces yellow arsenic, and an orthorhombic form is obtained if the vapor is condensed in the presence of mercury. Arsenic compounds are used in insecticides, herbicides, medicines, and pigments, and arsenic is used in alloys with copper and lead. A small amount of arsenic increases the surface tension of lead, which allows droplets of molten lead to assume a spherical shape, and this fact is utilized in the production of lead shot. 

Sulfides of arsenic and antimony are brightly colored, which has given rise to their use as pigments. Some of the sulfides, selenides, and tellurides of arsenic and antimony also function as semiconductors. 

Conway, H.L. 1978. Sorption of arsenic and cadmium and their effects on growth, micronutrient utilization, and photosynthetic pigment composition of Asterionella formosa. Jour. Fish. Res. Board Canada 35 286-294. 

Iron oxide-coated sand (IOCS), for arsenic removal, 3 279, 284-285 Iron oxide control, in industrial water treatment, 26 133 Iron oxide pastes, 19 402 Iron oxide pigments, 19 397-402 production of, 19 385 transparent, 19 412 economic aspects of, 14 557-559... 

Lead arsenates, 74 797 Lead azide, 70 727-729 74 792 Lead babbitt, 3 52, 52t arsenic addition to, 3 271 Lead-base babbitts, 24 797 Lead-based paint, 74 765 Lead-based paint remediation, 18 75 Lead-based pigments, 79 386. See also Lead chromate pigments Lead benzoate, 74 794 Lead bisilicate, 74 796 Lead blast furnace, 74 737 Lead borate, 74 797 Lead bromide, 74 785 Lead bullion, 74 742, 745... 

Arsenic is highly toxic, and indeed much speculation has surrounded arsenic poisoning as the cause of death of Napoleon Bonaparte, on account of the levels of As in the Emperor s hair (perhaps derived from fungal activity on a green pigment present in the wallpaper of his apartments in St. Helena). Arsenic trioxide has been approved by the Food and Drug Administration (FDA) of the USA for the treatment of acute promyelocytic anaemia in adult patients who fail to respond to other chemotherapy, or have relapsed disease. 

ORIGIN OF NAME Derived either from the Latin word arsenicum or the Greek word arse-nikon, both meaning a yellow pigment. It is possible that the Arabic word azzernikh was also an ancient name for arsenic. 

Arsenic disulfide (AsS) is also known as ruby arsenic because it is a reddish-orange powder. It is used as a depilatory agent, a paint pigment, and a rat poison and to make red glass and fireworks. 

Some of the effects of acute arsenic intoxication are nausea, vomiting, diarrhea, and irritation inflammation and ulceration of the mucous membranes and skin and kidney damage. Among the effects of chronic arsenic poisoning are increased pigmentation and keratinization of the skin, dermatitis, and epidermoid carcinoma. Other effects seen after ingestion, but which are not common from industrial exposure, are muscular paralysis, visual dismrbances, and liver and kidney damage. ... 

Arsenic pentasulfide is used as pigment and as a hght filter in thin sheets. 

Arsenic sesquisulfide occurs in nature as the mineral orpiment. It is used as a pigment in the manufacture of infrared-transmitting glass in semiconductors and photoconductors in pyrotechnics in linoleum and oil cloth for the removal of hairs from hides and as a reducing agent. 

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