Cinnabar

It occurs chiefly as cinnabar, the red sulphide HgS, from which it is readily extracted either by roasting (to give the metal and sulphur dioxide) or by heating with calcium oxide the metal distils off and can be purified by vacuum distillation. 

Mercuryill) sulphide, HgS, again appears in two forms, red (found naturally as cinnabar) and black, as precipitated by hydrogen sulphide from a solution containing Hg(Il) ions. 

Sulfur occurs native in the vicinity of volcanos and hot springs. It is widely distributed in nature as iron pyrites, galena, sphalerite, cinnabar, stibnite, gypsum, epsom salts, celestite, barite, etc. 

Other recovery methods have been used (10). These include leaching ores and concentrates using sodium sulfide [1313-82-2] and sodium hydroxide [1310-73-2] and subsequentiy precipitating with aluminum [7429-90-3], or by electrolysis (11). In another process, the mercury in the ore is dissolved by a sodium hypochlorite [7681-52-9] solution, the mercury-laden solution is then passed through activated carbon [7440-44-0] to absorb the mercury, and the activated carbon heated to produce mercury metal. Mercury can be extracted from cinnabar by electrooxidation (12,13). 

Ore. The assay of mercury ores is not simple, owing to the difficulties encountered in obtaining representative ore samples. Crystalline cinnabar is extremely brittie causing it to break loose from adjacent rock and fall into the sample being collected. This uncontrollable salting of the sample can give results as much as several hundred percent over the actual mercury content of the sample. 

Mercuric Sulfide. Mercuric s A ide[1344 8-5] HgS, exists ia two stable forms. The black cubic tetrahedral form is obtaiaed when soluble mercuric salts and sulfides are mixed the red hexagonal form is found ia nature as cinnabar (vermilion pigment). Both forms are very insoluble in water (see Pigments, inorganic). Red mercuric sulfide is made by heating the black sulfide in a concentrated solution of alkah polysulfide. The exact shade of the pigment varies with concentration, temperature, and time of reaction. 

The toxic effects of mercury and mercury compounds as well as their medicinal properties have been known for many centuries. In the first century AD, Pliny indicated the use of mercuric sulfide (cinnabar or vermilion) in medicine and in cosmetics. This compound was probably known to the Greeks in the time of Aristotle (13). 

Youth Dew (Lauder 1953) Opium (YSL 1977) Cinnabar (Lauder 1978) Sweet vanilla Emeraude (Coty 1921) Shalimar (Guedain 1925) Exclamation (Coty 1988) Tresor (Lancome 1991)... 

Mercury. In recovering mercuiy from cinnabar ores, the ore is crushed to minus 1.5 cm and fed to rotary Idlns, where it is calcined to over 800 K. Since the mercuiy exists as mercuric siilfide (HgS), the sulfur is oxidized to SO9 and the mercuiy vaporized. The gases are passed through cooling chambers, where the mercuiy condenses and is collected. Mercuiy vaporizes at 625 K. 

Mercury from cinnabar ore 225 tons ore/day (95% recovery) (2) 18,0 ft. diam, 8 hearth furnaces Furnaces fired on hearths 3 to 7, inclusive retention time of 1,0 hr, furnaces are oil-fired with low-pressure atomizing air burners all air, both primary and secondary, introduced through the burners draft control by Monel cold-gas fans downstream from mercury condensers. 

The isolation of mercury is comparatively straightforward. The most primitive method consisted simply of heating cinnabar in a fire of brushwood. The latter acted as fuel and condenser, and metallic mercury collected in the ashes. Modem techniques are of course less crude than this but the basic principle is much the same. After being crushed and concentrated by... 

HgS is polymorphic. The red a-form is the mineral cinnabar, or vermilion, which has a distorted rock-salt structure and can be prepared from the elements. )3-HgS is the rare, black, mineral metacinnabar which has the zinc-blende structure and is converted by heat to the stable a-form. In the laboratory the most familiar form is the highly insoluble black precipitate obtained by the action of HzS on aqueous solutions of Hg. HgS is an unreactive substance, being attacked only by cone HBr, HI or aqua regia. HgSe and... 

Leber-brei, m. liver pulp, -eisenerz, n. pyrrho-tite. -erz, n. hepatic ore, esp. hepatic cinnabar (liver-brown cinnabar), -farbe, /. liver color. 

Merkur, m. mercury, -blende, /. Min.) cinnabar. -chlorid, n. mercury chloride, specif, mercuric chloride, mercury(II) chloride, -chloriir, n. mercurous chloride, mercury(I) chloride, -gelb, n. mercury yellow, turpeth mineral. 

Mineral-dl, n. mineral oil specif., petroleum. -Slfimis, m. mineral-oil varnish. -SlrafBnat, n. refined mineral oil. -pech, n. mineral piteh, asphalt, -quelle, /. mineral spring or well, -reich,n. mineral kingdom, -rot,n. cinnabar. 

Zinnober, m. cinnabar, (also, when used as a pigment) vermilion, -ersatz, m. vermilion substitute, -farbe, /. vermilion (color). 

Zinnober-rot, n. vermilion, -salz, n. vermilion substitute. -spat, m. crystallized cinnabar. 

Figure 2 Calculated Hg L3-edge specu a (a) at 1.5 GPa with hypothetical zincblende (full line) and cinnabar (dashed line) structures (b) at 8GPa with hypothetical cinnabar (dashed line) and rocksalt (full line) structures.

---