Mercury sulfids

The toxic nature of mercury and its compounds has caused concern over environmental pollution, and governmental agencies have imposed severe restrictions on release of mercury compounds to waterways and the air (see Mercury). Methods of precipitation and agglomeration of mercurial wastes from process water have been developed. These methods generally depend on the formation of relatively insoluble compounds such as mercury sulfides, oxides, and thiocarbamates. MetaUic mercury is invariably formed as a by-product. The use of coprecipitants, which adsorb mercury on their surfaces facihtating removal, is frequent. 

Sulfur Polymer Cement. SPC has been proven effective in reducing leach rates of reactive heavy metals to the extent that some wastes can be managed solely as low level waste (LLW). When SPC is combined with mercury and lead oxides (both toxic metals), it interacts chemically to form mercury sulfide, HgS, and lead sulfide, PbS, both of which are insoluble in water. A dried sulfur residue from petroleum refining that contained 600-ppm vanadium (a carcinogen) was chemically modified using dicyclopentadiene and oligomer of cyclopentadiene and used to make SC (58). This material was examined by the California Department of Health Services (Cal EPA) and the leachable level of vanadium had been reduced to 8.3 ppm, well below the soluble threshold limit concentration of 24 ppm (59). 

Merkur-oxyd, n. niercury oxide, specif, mercuric oxide, mercury(II) oxide, -silber, n. silver amalgam, -sulfid, n. mercury sulfide, specif, mercuric sulfide, mercury(II) sulfide. 

Schwefel-natrium, -natron, n. sodium sulfide, -nickel, m. nickel sulfide, -niederschlag, m. precipitate of sulfur, precipitated sulfur, -ofen, m. sulfur burner, -oxyd, n. (any) sulfur oxide, -phosphor, m. (any) phosphorus sulfide, -probe, /. sulfur sample mercury sulfide, -quelle, /. sulfur spring, -rducherung, /. sulfur fumigation, -rubin, m. ruby sulfur, realgar, -salz, n. sulfur salt, thio salt, sulfo salt sulfate. 

Toxic pollutants found in the mercury cell wastewater stream include mercury and some heavy metals like chromium and others stated in Table 22.8, some of them are corrosion products of reactions between chlorine and the plant materials of construction. Virtually, most of these pollutants are generally removed by sulfide precipitation followed by settling or filtration. Prior to treatment, sodium hydrosulfide is used to precipitate mercury sulfide, which is removed through filtration process in the wastewater stream. The tail gas scrubber water is often recycled as brine make-up water. Reduction, adsorption on activated carbon, ion exchange, and some chemical treatments are some of the processes employed in the treatment of wastewater in this cell. Sodium salts such as sodium bisulfite, sodium hydrosulfite, sodium sulfide, and sodium borohydride are also employed in the treatment of the wastewater in this cell28 (Figure 22.5). 

Vermilion and cinnabar are two bright red, toxic minerals that share an identical composition (they are both composed of mercury sulfide) but have different crystal structures. Two kinds of vermilion are known one of natural origin and another made artificially. Finely ground natural vermilion may vary in hue from red to liver-brown and even to black. Artificial vermilion was made from mercury and sulfur the method of preparation seems to have been developed by the Chinese and was introduced into Europe only during the eighth century c.e. (Gettens et al. 1972). 

Kristi M, Drofenik M (2008) Sonochemical synthesis of nanocrystalline mercury sulfide, selenide and telluride in aqueous solutions. Ultrason Sonochem 15(5) 695-699... 

Patil, R. S. Lokhande, C. D. Mane, R. S. Pathan, H. M. Oh-Shim, J. Sung-Hwan, H. 2006. Successive ionic layer adsorption and reaction (SILAR) trend for nanocrystalline mercury sulfide thin films growth. Mater. Sci. Eng. B 129 59-63. 

Mercury is a relatively rare chemical element. In the lithosphere it occurs mainly as sulfides, HgS. Mercury sulfide comes in two forms cinnibar, which is black, and vermillion. In some places mercury exists in a small proportion as free chemical species. 

Mercury releases, anthropogenic, 16 47-49 Mercury removal, 1 650 Mercury sulfide (cinnabarite), color and bad gap, 7 335t... 

Elemental sulfur is present in most soils and sediments (especially anaerobic), and is sufficiently soluble in most common organic solvents that the extract should be treated to remove it prior to analysis by ECD-GC or GC-MS. The most effective methods available are (1) reaction with mercury or a mercury amalgam [466] to form mercury sulfide (2) reaction with copper to form copper sulfide or (3) reaction with sodium sulfite in tetrabutyl ammonium hydroxide (Jensen s reagent) [490]. Removal of sulfur with mercury or copper requires the metal surface to be clean and reactive. For small amounts of sulfur, it is possible to include the metal in a clean-up column. However, if the metal surface becomes covered with sulfide, the reaction will cease and it needs to be cleaned with dilute nitric acid. For larger amounts of sulfur, it is more effective to shake the extract with Jensen s reagent [478]. 

English vermilion inorgchem Bright vermilion pigment of precipitated mercury sulfide in paints, it tends to darken when exposed to light. ig-glish vor mil-yon enhanced line See enhanced spectral line. en hanst iTn ... 

Traces of sulfides were determined by CSV at pH 10 in the presence of cobalt(II) ions. Cobalt sulfide was accumulated at —0.5 V (versus SCE), probably in the form of colloidal particles occluded into the mercury sulfide layer [73]. In the cathodic scan, CoS catalyzed evolution of hydrogen, which was reflected in the current peak at about —1.6 V. 

The heat sensitivity (above) may explain the explosions which occur on contact of many readily oxidisable materials with this powerful oxidant. Such materials include ammonia, potassium arsenic, antimony sulfur, charcoal (adsorptive heating may also contribute) calcium phosphide, phosphine, phosphorus hydrogen sulfide, antimony sulfide, barium sulfide, mercury sulfide and tin sulfide [1], Various organic materials (paper, cork, rubber, turpentine, etc.) behave similarly [2]. Mixtures with hydrogen detonate on ignition [1]. 

With this, the complex iron pigment does indeed deserve to be called insoluble, as only one part of dissolved Iron Blue can statistically be found in 100,000,000,000,000,000,000,000,000,000 parts of water (1029). The actual solubility would therefore be less by a factor of 102° as determined by Tananaev el al., which would come pretty close to values calculated for other so-called insoluble compounds, like mercury sulfide (HgS). However, one must consider that the chemistry of Fe3+ in aqueous solutions doesn t justify the terms dissolved or precipitated , since a multitude of complexes do exist in the... 

Between the years 1400 and 1890 the reds that artists used were extracted from plants, such as madder, or from crushed insects, such as the scale insect Dactylopius coccus, or were of mineral origin, such as cinnabar (mercury sulfide, HgS) which could be ground to a powder to produce the pigment vermilion which was much used in antiquity, or red iron oxide (Fe203) which was used by the Neolithic cave painters, or minium (red lead, Pb304). 

---