Sulphates sulphidation

High strength steels Moist air, water, chlorides, sulphates, sulphides... 

Z 1 Niobium 1 Nitrate 1 Osmium 73 a. I Perchlorate Phenols u a o Platinum o 0. 1 5 u 1 Rhodium 1 Rubidium Ruthenium Scandium 1 Selenium Silver I Sodium 1 Strontium 1 Sulphate Sulphides, organic Sulphur dioxide 1 Tantalum 1 Tellurium 1 Thallium Thorium e H 1 Titanium a u ab a 1- I Uranium 1 Vanadium 1 Yttrium 1 Zinc Zirconium... 

Removal of dissolved sulphur compounds (sulphates, sulphides, organic sulphur compounds)... 

The limited applications of this technique, to date include fluoride, chloride, bromide, nitrite, nitrate, sulphate, sulphide, phosphate, amino acetate, chlorodicarboxylic acids, volatile organic acids and chromium(VI). 

Pentamethylene-1 5-dimereuri-dibromide, dichloridcu dihydroxide acetylide, sulphate, sulphide, 209, 210. 

The corrosion product, a mixture of oxide, sulphide at the metal interface and sulphate outside, has a weak adhesive bond to the metal surface and cannot support large deposit masses. It is therefore unusual to find excessive amounts of sintered ash deposits and fused slag in the exact localities where severe high temperature corrosion occurs. Conversely, a strongly adhering matrix of sintered ash deposit in the absence of sulphate, sulphide or chloride phases is not markedly corrosive. 

Sulphur (S) occurs in soils usually as sulphites, sulphates, sulphides and in organic compoimds. However, the most accessible form is sulphate (SO ). The turbidimetric procedure is widely used in the estimation of available S in the soil due to its rapidity. However, erroneous results are obtained in case the soil is rich in organic matter. Soil is shaken with a solution of monocalcium phosphate, containing 500 ppm P. The phosphate ions displaces the adsorbed sulphate. The calcium ions depresses the extraction of soil organic matter, thus eliminating contamination from extractable organic S. The method extract soluble plus a fraction of adsorbed The filtrate is then analysed for S by the turbidimetric procedure. In this method... 

Materiai.s Solutions of sodium chloride, sulphate, sulphide, carbonate, and acetate, of carbonic, acetic and concentrated hydrochloric acids, of calcium and ferric chlorides, of copper sulphate, and of phenolphthalein litmus paper Congo paper. 

Table 3.13. Equilibrium constants of oxides, hydroxides, carbonates, hydrogencarbonates, sulphates, sulphides, silicates and acids in water... 

An alternative means of sulphur isotope fractionation in igneous rocks is by the degassing of SO2 from sub-aerial or shallow submarine lavas. This fractionation is controlled by the sulphate/sulphide ratio of the melt, which in turn is controlled by temperature, pressure, water content and oxygen activity. SO2 outgassed by basic lavas is enriched m relative to die melt because the dominant sulphur species in the melt is sulphide and SO2 is enriched in 5 S relative to sulphide (see Figure 7.26). The process is documented from Kilauea volcano, Hawaii, by Sakai el al (1982) and quantified by 2heng (1990). 

Copper and copper alloys are highly resistant to atmospheric corrosion because of surface films mainly composed of basic copper salts. The corrosion rate is below 2-3 pm/year [8.9]. Tin as well as nickel and nickel alloys also corrode at similar rates. Lead possesses excellent corrosion resistance in atmospheres due to surface-protecting films (insoluble sulphate, sulphide, carbonate and oxide). 

The external corrosion takes place when concrete is exposed to the attack of hazardous liquids among them one should mention first of all the sulphate, sulphide and chloride solutions, as well as gaseous CO2, acid rains and variable temperatures, falling down frequently below zero point... 

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