Celestite, production

Economic Aspects. Celestite is mined and then shipped to countries where chemical processing takes place. Spain is the largest celestite-exporting country, as almost all of its output is exported. Mexico is the next largest exporter. About half of its annual output is exported. Most of celestite production from Turkey and Iran is also exported. Iranian exports are beheved to be shipped to the CIS and other Eastern European countries. 

Production. In the commercial production of strontium carbonate, celestite ore is cmshed, ground, and stored in bins before it is fed to rotary kilns. As the ground ore is being conveyed to the kilns, it is mixed with ground coke. In the kilns, the celestite is reduced to strontium sulfide [1314-96-1J, known as black ash, according to the reaction ... 

Strontium Oxide, Hydroxide, and Peroxide. Strontium oxide, SrO, is a white powder that has a specific gravity of 4.7 and a melting point of 2430°C. It is made by heating strontium carbonate with carbon in an electric furnace, or by heating celestite with carbon and treating the sulfide formed with caustic soda and then calcining the product (10). It reacts with water to form strontium hydroxide [18480-07-4] and is used as the source of strontium peroxide [1314-18-7],... 

A common problem in offshore petroleum production is that sulfate scale may form when seawater is injected into the formation during waterflooding operations. The scale forms when seawater, which is rich in sulfate but relatively poor in Ca++ and nearly depleted in Sr++ and Ba++, mixes with formation fluids, many of which contain bivalent cations in relative abundance but little sulfate. The mixing causes minerals such as gypsum (CaSC>4 2H2O), anhydrite (CaSC>4), celestite (SrSOzO, and barite (BaS04, an almost insoluble salt) to become saturated and precipitate as scale. 

Sulfur is an element found in many common minerals, such as galena (PbS), pyrite (fool s gold, FeSj), sphalerite (ZnS), cinnabar (HgS), and celestite (SrSO ), among others. About 1/4 of all sulfur procured today is recovered from petroleum production. The majority of sulfur is the result of or a by-product of mining other minerals from the ores containing sulfur. 

Hattori K. (1989) Barite-celestite intergrowths in Archean plutons the product of oxidizing hydrothermal activities related to alkaline intrusions. Am. Mineral. 74, 1270-1277. 

Strontium (0.02% of lithosphere) occurs as strontianite, SrCOg, and celestite, SrS04. The metal which has the c.c.p. structure is without economic importance except in pyrotechnics. The radioactive strontium-90 is long-lived and, being easily assimilated and incorporated in bone, is a dangerous product of uranium fission. 

Pressure generally increases the solubility of minerals. An accurate evaluation of the pressure effect on solubility may require that we consider both molar volumes and compressibilies of reactants and products. In the following problem we compare the solubility of celestite (SrS04) in a surface water at 1 bar pressure and 25°C to its solubility in groundwater at 6000 ft depth at a temperature of 75 C and pressure of 180 bars. The reaction of interest is SrS04(celestite) = + SO ". To... 

Strontium ore is found in nature as the minerals celestite and strontianite. High grade celestite ore is imported from Mexico into the United States. After the strontium is extracted from strontium ore, it is concentrated into strontium carbonate or other chemical forms by a series of chemical processes. Strontium compounds, such as strontium carbonate, are used in making ceramics and glass products, pyrotechnics, paint pigments, fluorescent lights, medicines, and other products. 

There are four stable isotopes of strontium that are found naturally. In addition there are about twenty radioactive isotopes, including strontium-90, a deadly by-product of nuclear-bomb detonations. The natural forms of strontium are relatively nontoxic. Similar to calcium both physically and chemically, elemental strontium is a soft, shiny metal. Like calcium and other alkaline earth metals, it is easily oxidized and thus not found naturally in its free elemental state. Instead, it almost always is found in the + 2 oxidation state, forming such compounds as strontium oxide (SrO), strontium sulfate (SrS04, from the mineral celestite), strontium carbonate (SrCOj, from the mineral strontianite), and strontium chloride (SrC. Strontium nitrate, Sr(N03)2, is used to produce the brilliant red color seen in some fireworks and signal flares and is also used in making tracer bullets that can be seen when fired at night. Other strontium compounds are sometimes used in the manufacture of special glasses. Yet overall, strontium is not a very important element industrially or commercially, see ALSO Davy, Humphry... 

Black Ash Method, Reduction with Carbon. To enable the chemical reduction of SrSo4, celestite is mixed with powdered coal and then heated up to about 1,100°C. The chemical reaction follows the equation SrS04 + 2C SrS + 2CO2 and produces carbon dioxide and strontium sulfide. In the next process step, the strontium sulfide is dissolved in water, before carbon dioxide passes through SrS + H2O + CO2 SrCOs + H2S the solution, forming and precipitating strontium carbonate firom the solution. The by-product sulfur is recovered as elemental sulfur. 

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