Bisulfide

Sulfide Solution Concentration. Tire by-product of the black ash process has considerable bearing on the ultimate economic viabiUty of barium production. It is desirable to be able to vary by-products to rnaxiaiize earnings. Sodium sulfide [1313-82-2 Na2S, sold as 60% flake, and sodium bisulfide [16721-80-5] NaHS, sold as 45% solution or as 70% flake, are t)-q)ically co-produced. 

Both sodium sulfide and the bisulfide are used in the flotation process for copper minerals and as a depilatory for animal liides (see Copper Copper ALLOYS Leather). Also, sodium polysulfide can be produced from Na2S, and elemental sulfur can be produced if H2S is generated as an intemiediate. 

Carbon disulfide [75-15-0] (carbon bisulfide, dithiocarbonic anhydride), CS2, is a toxic, dense liquid of high volatiUty and fiammabiUty. It is an important industrial chemical and its properties are well estabUshed. Low concentrations of carbon disulfide naturally discharge into the atmosphere from certain soils, and carbon disulfide has been detected in mustard oil, volcanic gases, and cmde petroleum. Carbon disulfide is an unintentional by-product of many combustion and high temperature industrial processes where sulfur compounds are present. 

Tmergeny Mction Guides, Carbon Bisulfide, Association of American Railroads, Bureau of Explosives, Washington, D.C., pp. C2.1(l—6), 1988. 

SODIUM AZIDE SODIUM BICHROMATE SODIUM BIFLUORIDE SODIUM BISULFATE SODIUM BISULFIDE... 

Zinc compounds such as zinc oxide and basic zinc carbonate are used in some drilling fluids. Their function is to react out swiftly sulfide and bisulfide ions... 

The anion, bisulfide SH further dissociates into anionic sulfide S and cationic hydrogen ion H ... 

Ammonium bisulfide is produced by the reaction of ammonia and hydrogen sulfide [2] ... 

Typically, sour water from the FCC contains a mixture of am nium sulfide and ammonium bisulfide with an aramonia-to-hydrc sulfide ratio between 0.5 and 1.0... 

Myrite. An expl contg a mixt of nitrogen dioxide and carbon bisulfide. Its sensitivity to mechanical influences, brisance, rate of deton, and other expl characteristics were detd at PicArsn in 1940. In view of the fact that it is specially sensitive to rifle bullet impact, and has a rate of deton and brisance considerably lower than TNT, it was concluded that Myrite is not suitable for use as a military expl Ref C.J. Bain, Investigation of the Explosive Myrite , PATR 1030(1940)... 

They indicated that the softness parameter may reasonably be considered as a quantitative measure of the softness of metal ions and is consistent with the HSAB principle by Pearson (1963, 1968). Wood et al. (1987) have shown experimentally that the relative solubilities of the metals in H20-NaCl-C02 solutions from 200°C to 350°C are consistent with the HSAB principle in chloride-poor solutions, the soft ions Au" " and Ag+ prefer to combine with the soft bisulfide ligand the borderline ions Fe +, Zn +, Pb +, Sb + and Bi- + prefer water, hydroxyl, carbonate or bicarbonate ligands, and the extremely hard Mo + bonds only to the hard anions OH and. Tables 1.23 and 1.24 show the classification of metals and ligands according to the HSAB principle of Ahrland et al. (1958), Pearson (1963, 1968) (Table 1.23) and softness parameter of Yamada and Tanaka (1975) (Table 1.24). Compari.son of Table 1.22 with Tables 1.23 and 1.24 makes it evident that the metals associated with the gold-silver deposits have a relatively soft character, whereas those associated with the base-metal deposits have a relatively hard (or borderline) character. For example, metals that tend to form hard acids (Mn +, Ga +, In- +, Fe +, Sn " ", MoO +, WO " ", CO2) and borderline acids (Fe +, Zn +, Pb +, Sb +) are enriched in the base-metal deposits, whereas metals that tend to form soft acids... 

According to these previous studies, the most dominant dissolved states of Au and Ag in ore fluids are considered to be bisulfide and chloride complexes, depending on the chemistry of ore fluid (salinity, pH, redox state, etc.). However, very few experimental studies of Au solubility due to chloride complex and Ag solubility due to bisulfide complexes under hydrothermal conditions of interest here have been conducted. Thus, it is difficult to evaluate the effects of these important species on the Ag/Au of native gold and electrum. Other Au and Ag complexes with tellurium, selenium, bismuth, antimony, and arsenic may be stable in ore fluids but are not taken into account here due to the lack of thermochemical data. 

Assuming that Au is transported dominantly as bisulfide or chloride complexes, the following reaction can be used to determine which species are dominant under near neutral conditions. 

Aq- (Fig. 1.189), while an increase in pH causes a decrease in wrAucr/ Au(Hsr It is apparent in Fig. 1.190 that Au bisulfide species are more abundant than Au cliloride species under the conditions common for ore fluids responsible for Japanese Au-Ag veins. However, Au chloride species may dominate Au bisulfide species in ore fluids responsible for the gold-quartz (auriferous) vein deposits, as shown in Fig. 1.189. 

In addition to the heavy metals stated in Table 22.10, ferro- and ferricyanide are also part of the pollutants in the wastewater generated in a chrome pigment plant. These wastes are generally combined and treated through reduction, precipitation, equalization, and neutralization to be followed by clarification and filtration processes. Most of the heavy metals are precipitated using lime or caustic soda at specific pH. Chromium is reduced by S02 to a trivalent form, wherein it is precipitated as chromium hydroxide at specific pH. Sodium bisulfide is also employed to precipitate some of the metals at a low pH. The treated water is recycled for plant use while the sludge is sent to landfills (Figure 22.7). 

A series of bisulfide salts exist, and they are also basic in solution because even the first step in the dissociation of H2S is slight ... 

Reaction in the simulation begins slowly, but proceeds more rapidly as biomass accumulates, reflecting the reaction s autocatalytic nature. The reaction rate continues to increase until most of the acetate is consumed, at which point it slows abruptly to a near stop. In the simulation, dissolved ferrous iron is present in excess amount. The bisulfide produced as a result of bacterial sulfate reduction reacts with the iron,... 

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