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These metal sulfides, such as iron(II) sulfide, are often black or brown, leading to the color of sludge. Pyrrhotite is a waste product of the Desulfovibrio bacteria, a sulfate reducing bacteria. When eggs are cooked for a long time, the yolk's surface may turn green. This color change is due to iron(II) sulfide, which forms as iron from the ...
Iron pyrite was heaped up and allowed to weather (an example of an early form of heap leaching). The acidic runoff from the heap was then boiled with iron to produce iron sulfate. In the 15th century, new methods of such leaching began to replace the burning of sulfur as a source of sulfuric acid. By the 19th century, it had become the dominant ...
A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine, Al 4 I 4 (NEt 3) 4. Also of theoretical interest but only of fleeting existence are Al 2 O and Al 2 S. Al 2 O is made by heating the normal oxide, Al 2 O 3, with silicon at 1,800 °C (3,272 °F) in a vacuum. Such materials quickly disproportionate to the ...
Iron sulfide or Iron sulphide can refer to range of chemical compounds composed of iron and sulfur. Minerals. By increasing order of stability: Iron(II) sulfide, FeS;
As aluminium is a small atom relative to these chalcogens, these have four-coordinate tetrahedral aluminium with various polymorphs having structures related to wurtzite, with two-thirds of the possible metal sites occupied either in an orderly (α) or random (β) fashion; the sulfide also has a γ form related to γ-alumina, and an unusual ...
It is known that aluminum improves the sulfidation resistance of iron alloys. [2] The sulfidation of tungsten is a multiple step process. The first step is an oxidation reaction, converting the tungsten to a tungsten bronze on the surface of the object. The tungsten bronze coating is then converted to a sulfide. [3]
These soils contain iron sulfide minerals (predominantly as the mineral pyrite) and/or their oxidation products. In an undisturbed state below the water table, acid sulfate soils are benign. However, if the soils are drained, excavated or otherwise exposed to air, the sulfides react with oxygen to form sulfuric acid. [1]
Aluminium sulfide is a chemical compound with the formula Al 2 S 3. This colorless species has an interesting structural chemistry, existing in several forms. The material is sensitive to moisture, hydrolyzing to hydrated aluminium oxides/hydroxides. [1] This can begin when the sulfide is exposed to the atmosphere.