Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Pyrites industry

The Spanish Civil War and World War II finally ruined the Spanish pyrites industry. Shipments had been blocked during these years, and alternatives had been found. After World War II, many new sulfuric acid plants were constructed in Europe to replace those that had been destroyed, and U.S. expansion was bolstered by economic growth, especially by demand for phosphate fertilizers. These new plants all used elemental sulfur (Contact process). While Spanish pyrites production returned to pre-war levels by 1950 (see Figure 2.5 for the early history of production), their market share had seriously eroded as sulfur demand, overall, had more than doubled. Pyrites mining as a source of sulfur continued in Spain until 2002. [Pg.25]

It is contemplated that as soon as Orkla increases its production of brimstone above 70,000 toimes per year and thereby releases to the pyrites industry any ton-... [Pg.219]

Li Zhenfei et al, Tresent Situation of Pyrite Industry and the Review of Reusing Iron Pyrite Cinder in China , Metallic Ore Dressing Abroad,6(2006), 0- i. [Pg.561]

Industrial Wastewater Treatment. Industrial wastewaters require different treatments depending on their sources. Plating waste contains toxic metals that are precipitated and insolubiHzed with lime (see Electroplating). Iron and other heavy metals are also precipitated from waste-pidde Hquor, which requires acid neutralization. Akin to pickle Hquor is the concentrated sulfuric acid waste, high in iron, that accumulates in smokeless powder ordinance and chemical plants. Lime is also useful in clarifying wastes from textile dyeworks and paper pulp mills and a wide variety of other wastes. Effluents from active and abandoned coal mines also have a high sulfuric acid and iron oxide content because of the presence of pyrite in coal. [Pg.178]

The hrst successful study which clarihed the mechanism of roasting, was a study of the oxidation of pyrite, FeSa, which is not a typical industrial process because of the availability of oxide iron ores. The experiment does, however, show die main features of roasting reactions in a simplihed way which is well supported by the necessaty thermodynamic data. The Gibbs energy data for the two sulphides of iron are,... [Pg.282]

Several important applications of fluid beds exist outside the petroleum industry. Fluid bed roasting of pyritic ores is widely used in the metallurgical industry. Calcination of lime is a commercial process. There are also fluidization processes for various nuclear processing steps. [Pg.28]

Binary systems of ruthenium sulfide or selenide nanoparticles (RujcSy, RujcSey) are considered as the state-of-the-art ORR electrocatalysts in the class of non-Chevrel amorphous transition metal chalcogenides. Notably, in contrast to pyrite-type MS2 varieties (typically RUS2) utilized in industrial catalysis as effective cathodes for the molecular oxygen reduction in acid medium, these Ru-based cluster materials exhibit a fairly robust activity even in high methanol content environments of fuel cells. [Pg.314]

Nedol [New Energy Development Organization liquifaction] A coal liquifaction process in development in Japan by the New Energy and Industrial Technology Development Organization (NEDO), Tokyo. Crushed coal is mixed with a pyrite catalyst and slurried in a hydrogenated heavy oil. Liquifaction takes place at 450°C, 170 bar. The overall oil yield is 59 percent. [Pg.188]

Airborne particles collected with filters distributed across Vitoria, Brazil were analyzed by MB spectroscopy, whereby certain Fe-bearing minerals indicated different pollution sources. For example, hematite comes mostly from iron ore pellet plants, pyrite from handling and storing coal in the industrial area, and magnetite is related to steelwork plants (de Souza et al. 2001). [Pg.301]

The lower explosive limit and minimum explosive concentrations of flax, wool, cotton, jute, hemp and sisal fibres are of the same order of magnitude as those of highly explosive dusts [15], The explosibility of pyrites dusts with sulfur contents above 20% was evaluated experimentally. Dusts of 30% sulfur content gave explosion pressures of 3 bar at pressure rise rates of 16 bar/sec. Mixtures of 60% pyrites and 40% powdered limestone still showed significant pressure effects, and the proportion of limestone actually needed to suppress explosions was considerably above the values currently accepted by mining industries [16], Effects of mixtures of particle sizes in combustible dusts upon minimum ignition temperature (T ") and upon presence or absence of explosion were studied. Presence of 30% of fines in a coarse dust lowers Tf significantly [17], Experimental explosions of polyethylene,... [Pg.133]

Potential controlled flotation separation of chalcopyrite-pyrite ores has been extensively tested to be one of the most probable to obtain industrial application on the basis of the fact that chalcopyrite has strong collectorless and collector floatability whereas pyrite has poor collectorless floatability. [Pg.254]

Figure 10.21 presents the flow sheet for the collectorless flotation and separation of chalcopyrite and pyrite in Tonglushan copper mine in China. The pulp potential is 0.175 V and pH is 11.5. The industrial test shows that the collectorless flotation can obtain better results than the traditional collector flotation. [Pg.268]

The first method chosen to express the coal-mineral association results is in terms of the weight fraction of mineral matter in the individual particles, as determined from their cross section. The resulting distribution is comparable to the so-called "grade distributions" used in the mineral industry [8,9]. Such a distribution is included in Table II for the Upper Freeport coal. The data in the table indicate that pyrite is preferentially liberated as compared to quartz or kaolinite. About 78% of the pyrite is in particles containing more than 80% mineral matter, which should be easily removed by density-based separations. [Pg.35]

Acidity problems tend to be localized in bodies of water near industrial operations that discharge acidic materials or near active or abandoned mines. Acids form when water flows through all kinds of mines, including coal mines and mines for the extraction of various metals. Probably the most common acid-forming process in such cases occurs when iron pyrites (FeS2), found in coal seams and in many metal mines, is oxidized by atmospheric oxygen or oxygen dissolved in water to produce iron(II) sulfate ... [Pg.124]

Sulfuric acid was one of the first chemicals to be produced industrially on a large scale. Until the early 1700s, sulfuric acid was produced in glass jars of several liters in which sulfur and potassium nitrate, KNO, were heated. Pyrite was often substituted for sulfur because of... [Pg.271]

Combustion of Sulfur. For most chemical process applications requiring sulfur dioxide gas or sulfurous acid, sulfur dioxide is prepared by the burning of sulfur or pyrite [1309-36-0], FeS2. A variety of sulfur and pyrite burners have been developed for sulfuric acid and for the pulp (qv) and paper (qv) industries, which produce and immediately consume about 90% of the captive sulfur dioxide produced in the United States. Information on the European sulfur-to-sulfuric acid technology (with emphasis on Lurgi) is available (255). [Pg.145]


See other pages where Pyrites industry is mentioned: [Pg.62]    [Pg.126]    [Pg.185]    [Pg.62]    [Pg.126]    [Pg.185]    [Pg.24]    [Pg.304]    [Pg.438]    [Pg.410]    [Pg.115]    [Pg.334]    [Pg.230]    [Pg.41]    [Pg.263]    [Pg.580]    [Pg.651]    [Pg.460]    [Pg.171]    [Pg.441]    [Pg.32]    [Pg.54]    [Pg.35]    [Pg.313]    [Pg.169]    [Pg.203]    [Pg.499]    [Pg.8]    [Pg.115]    [Pg.101]    [Pg.105]    [Pg.658]    [Pg.304]    [Pg.17]    [Pg.21]    [Pg.578]   
See also in sourсe #XX -- [ Pg.25 , Pg.172 ]




SEARCH



Pyrit

Pyrite

Pyritization

© 2024 chempedia.info