Sulfided metals

Metals treatments Metal sulfides Metal surface cleaners Metal surface treatment Metal surface treatments... 

Antimicrobial agents are used where there is a need to inhibit bacterial and fungal growth. The additives can consist of copper, germanium, zinc and zinc compounds, metal oxides or sulfides, metal zeofltes, as well as silver and copper oxide-coated inorganic core particles (154—159) (see Industrial ANTIMICROBIAL AGENTS). 

Although supported Pd catalysts have been the most extensively studied for butadiene hydrogenation, a number of other catalysts have also been the object of research studies. Some examples are Pd film catalysts, molybdenum sulfide, metal catalysts containing Fe, Co, Ni, Ru, Rh, Os, Ir, Pt, Cu, MgO, HCo(CN) on supports, and LaCoC Perovskite. There are many others (79—85). Studies on the weU-characteri2ed Mo(II) monomer and Mo(II) dimer on siUca carrier catalysts have shown wide variations not only in catalyst performance, but also of activation energies (86). 

Catalysis by Metal Sulfides. Metal sulfides such as M0S2, WS2, and many others catalyze numerous reactions that are catalyzed by metals (98). The metal sulfides are typically several orders of magnitude less active than the metals, but they have the unique advantage of not being poisoned by sulfur compounds. They are thus good catalysts for appHcations with sulfur-containing feeds, including many fossil fuels. 

Toxic or hazardous wastes can be disposed of in fluidized beds by either chemical capture or complete destruction. In the former case, bed material, such as limestone, will reacl with hahdes, sulfides, metals, etc., to form stable compounds which can be landfilled. Contact times of up to 5 or 10 s at 1200 K (900°C) to 1300 K (1000°C) assure complete destruction of most compounds. 

Sulfide Metals Explosives Heat generation and explosion... 

Fig. 1.2 Crystal structures of the major sulfides (metal atoms are shown as smaller or black spheres) (A) galena (PbS) structure (rock salt) (B) sphalerite (ZnS) structure (zinc blende) (C) wurtzite (ZnS) strucmre (D) pyrite structure and the linkage of metal-sulfur octahedra along the c-axis direction in (/) pyrite (FeSa) and (//) marcasite (FeSa) (E) niccolite (NiAs) structure (F) coveUite (CuS) structure (layered). (Adapted from Vaughan DJ (2005) Sulphides. In Selley RC, Robin L, Cocks M, Plimer IR (eds.) Encyclopedia of Geology, MINERALS, Elsevier p 574 (doi 10.1016/B0-12-369396-9/00276-8))...

Sulfides Metal ion(s) + sulfur ion Galena (composed of lead sulfide), a metal ore, from which lead and also silver (which occurs in galena as an impurity, are extracted Pyrite (composed of iron sulfide), an iron ore... 

Metal oxides, metal sulfides, metal nitrides, metal carbides, metal borides, metal alloys, metallic glasses, molecular sieves, salts, acids... 

Hydrazinium nitrate Alone, or Metals Hydrogen sulfide Metals Potassium dioxide Metals Sulfuric acid Copper... 

See Hydrogen sulfide Metal oxides Hydrogen trisulfide Metal oxides... 

On sulfided metallic phases the hydrotreatment reactions also takes place. Noble metal catalysts usually include a zeolitic support. They are particularly used for fulfilling two different objectives, in the case of a gasoline oriented HCK their cracking and isomerization activity is the most important (increasing high octane and conversion yield). In a diesel HCK unit, the noble metal catalyst is mainly oriented to aromatic saturation and cetane improvement. However, in this latter case, also sulfided metal catalysts are used, especially NiW. 

However, residuum hydrotreating catalysts themselves are susceptible to irreversible deactivation caused by the accumulation of sulfided metal impurities. The gradual buildup of these impurities in the pores of a hydroprocessing catalyst causes plugging and deactivation. 

Matrix minerals are complex mixtures of silicates (especially olivine and pyroxene), oxides, sulfides, metal, phyllosilicates, and carbonates. The bulk chemical composition of matrix is broadly chondritic, and richer in volatile elements than the other chondrite components. Some chondrules have rims of adhering matrix that appear to have been accreted onto them prior to final assembly of the meteorite. Small lumps of matrix also occur in many chondrites. Presolar grains, described in Chapter 5, occur in the matrix. 

Estimates of the Mars core composition by the authors listed above suggest it is made of metal plus iron sulfide, the latter varying from 29 to 44 wt.%. Abundances of siderophile (tungsten, phosphorus, cobalt, molybdenum, nickel) and chalcophile (indium, copper) elements in the mantle (Fig. 13.23) are consistent with equilibrium between sulfide, metal, and mantle silicate at high temperature and pressure (Righter and Drake, 1996). 

Zinc Bromate. Zn(Br03)2.6H20 mw 429.28 white deliq crysts mp 100° sp grav 2.566. V sol in w. Prepn is by treating Zn oxide with bromine w. Intimate mixts of the bromate with finely divided Al, As, Cu, C, P, S hydrides of alkali and alkaline earth metals, Sb sulfide, metal cyanides, K thiocyanate or impure Mn dioxide can react explosively (spontaneously in the pre-... 

Two sulfide precipitation methods currently used are the soluble sulfide precipitation (SSP) and insoluble sulfide precipitation (ISP) processes. Soluble sulfides and insoluble sulfides are used to precipitate dissolved metals as metal sulfides. Metal sulfides have lower solubilities than the hydroxides, resulting in lower residual metal concentrations in the treated water (Figure 1). Also, sulfides can be used to precipitate complexed metals in the presence of complexing agents such as ammonia, citrate and EDTA and over a broader pH range than possible for the hydroxide precipitation.3 A typical sulfide precipitation reaction is as follows ... 

The most important source of lubricants is petroleum. There is hardly a chemical species (esters, ethers, sulfides, metal-or-gunic compounds, etc.) which has not contributed to the array of synthetic lubricants noxv available. Some chemicals, such as the pcrlluorocarhvm compounds and the siloxaite polymers were originally synthesized for just this service. 

Hydrogen ligands, 689-711 Hydrogen selenide metal complexes, 663 Hydrogen sulfide metal complexes, 516 Hydrogen telluride metal complexes, 670 Hydroporphyrins, 814-856 basicity, 853 dehydrogenation, 853 demetallation, 854 deuteration, 853 mass spectra, 852 metallation, 854 NMR, 852 non-aromatic, 855 photochemistry, 854 redox chemistry, 855 synthesis, 852... 

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