High sulfidation type

Most of epithermal precious-metal vein-type deposits in Japan can be classed as adularia-sericite-type, and low sulfidation-type. Very few hot spring-type deposits (quartz-alunite-type, high sulfidation-type) are found in the Japanese Islands. A summary of various characteristic features of adularia-sericite type (low sulfidation-type) is given mainly in section 1.4. 

Hot spring-type gold deposits (Nansatsu-type by Urashima et al. (1981,1987), high sulfidation-type by Hedenquist (1987), epithermal Au disseminated-type) are distributed in the Nansatsu district of southern Kyushu (Fig. 1.193). The deposits (Kasuga, Akeshi, Iwato) were formed at Pliocene age (5.5-3.7 m.y.) in the calc-alkaline volcanic rocks of nearly same age (Togashi and Shibata, 1984). The deposits, which are similar to Nansatsu-type deposits, occur in Southwest Hokkaido (Date, Hakurhu). 

Figure 1.198 shows grade-tonnage relationship for low sulfidation-type (Se-type) and high sulfidation-type (Te-type and Akeshi-type) in Japan and deposits in Circum Pacific region summarized by Hedenquist et al. (1996). This clearly indicates that grade and tonnages for Akeshi-type and Te-type in Japan are low and small, compared with low sulfidation-type in Japan. It is obvious that low sulfidation-type is dominant Au-Ag deposits in Japan. 

The plot of K2O versus Si02 for volcanic rocks thought to be genetically related to Au mineralization indicates that high sulfidation deposits (hot spring-type deposits appear... 

Primitive achondrites exhibit metamorphic textures, as appropriate for the solid residues from which melts were extracted. In effect, these meteorites represent an extension of the highly metamorphosed type 6 chondrites, which show no eutectic melting of metal and sulfide. In a few cases, some primitive achondrites have recognizable chondritic textures, but often they are so thoroughly recrystallized that chondrules are not identifiable. 

Van Veen et al. (97) reported EXAFS data showing that phosphorus induces an increase in the formation of the NiMoS (type II) phase, which is a more highly sulfided form of the promoted NiMoS phase. In contrast, Sajkowski et al. (83) reported that phosphorus does not affect the sulfidation of Mo/Al catalysts. Mangnus et al. (70) found that the S/Mo ratio in the... 

The thallium content of some types of coal (with a high sulfidic portion) may be emitted as Tl-enriched fly ash in coal burning. Ewers (1988) states that worldwide, 600 tons of thallium are emitted each year by coal-burning power plants, though in... 

In 1948, MaeallumS, a Canadian working in his private laboratory, prepared a phenylene sulfide-type polymer. In his early work Macallum recognized the unusual thermal stability and potential utility of this new polymer. In a sense his work ushered in the investigation of other high temperature polymers in the years to follow. His process for producing phenylene sulhde-type polymers involved the reaction of sulfur, sodium carbonate and dichlorobenzene in a sealed vessel at 275-300°C in the melt. 

Surface photo voltage and interfacial capacitance measurements on in situ cleaved natural and synthetic lead sulfide crystals were combined with voltammetry in order to study the influence of the semiconductor type of galena on xanthate chemisorption. The characteristics of the voltammo-gram for highly w-type and highly p-type galena were found to be the same. It was concluded that xanthate chemisorption induces a donorlike surface state in the forbidden gap of the galena, the occupancy of which is... 

Solid Compounds. The tripositive actinide ions resemble tripositive lanthanide ions in their precipitation reactions (13,14,17,20,22). Tetrapositive actinide ions are similar in this respect to Ce . Thus the duorides and oxalates are insoluble in acid solution, and the nitrates, sulfates, perchlorates, and sulfides are all soluble. The tetrapositive actinide ions form insoluble iodates and various substituted arsenates even in rather strongly acid solution. The MO2 actinide ions can be precipitated as the potassium salt from strong carbonate solutions. In solutions containing a high concentration of sodium and acetate ions, the actinide ions form the insoluble crystalline salt NaM02(02CCH2)3. The hydroxides of all four ionic types are insoluble ... 

The basic flow sheet for the flotation-concentration of nonsulfide minerals is essentially the same as that for treating sulfides but the family of reagents used is different. The reagents utilized for nonsulfide mineral concentrations by flotation are usually fatty acids or their salts (RCOOH, RCOOM), sulfonates (RSO M), sulfates (RSO M), where M is usually Na or K, and R represents a linear, branched, or cycHc hydrocarbon chain and amines [R2N(R)3]A where R and R are hydrocarbon chains and A is an anion such as Cl or Br . Collectors for most nonsulfides can be selected on the basis of their isoelectric points. Thus at pH > pH p cationic surfactants are suitable collectors whereas at lower pH values anion-type collectors are selected as illustrated in Figure 10 (28). Figure 13 shows an iron ore flotation flow sheet as a representative of high volume oxide flotation practice. 

In addition to carbon and glass fibers ia composites, aramid and polyimide fibers are also used ia conjunction with epoxy resias. Safety requirements by the U.S. Federal Aeronautics Administration (FAA) have led to the development of flame- and heat-resistant seals and stmctural components ia civiUan aircraft cabias. Wool blend fabrics containing aramids, poly(phenylene sulfide), EDF, and other inherently flame-resistant fibers and fabrics containing only these highly heat- and flame-resistant fibers are the types most frequently used ia these appHcations. 

The carbonates, sulfates, nitrates, and haUdes of lead (except the yeUow iodide) are colodess. Bivalent lead forms a soluble nitrate, chlorate, and acetate a slightly soluble chloride and an insoluble sulfate, carbonate, chromate, phosphate, molybdate, and sulfide. Highly crystalline basic lead salts of both anhydrous and hydrated types are readily formed. Tetrabasic lead sulfate [52732-72-6] 4PbO PbSO, and the hydrated tribasic salt [12397-06-7] ... 

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