Minerals celestite

Strontium has a valence of +2 and forms compounds that resemble the compounds of the other alkaline-earth metals (see Barium compounds Calcium compounds). Although many strontium compounds are known, there are only a few that have commercial importance and, of these, strontium carbonate [1633-05-2] SrCO, and strontium nitrate [10042-76-9], Sr(N03)2, are made in the largest quantities. The mineral celestite [7759-02-6], SrSO, is the raw material from which the carbonate or the nitrate is made. 

The two principal strontium minerals are its carbonate, strontianite, SrCOs, and the more abundant sulfate mineral celestite, SrS04. 

Strontium carbonate occurs in nature as strontianite and can be mined from its deposit. It is, however, usually made from the mineral celestite. Celestite is fused with sodium carbonate at elevated temperatures or boiled with a solution of ammonium carbonate ... 

Strontium sulfate occurs in nature as mineral celestite, which is the principal ore of strontium. The sulfate is the starting material for producing strontium metal and practically all its salts. The sulfate also is used in pyrotechnics and in ceramics. 

One of the most important sources of strontium is the mineral celestite, SrS04. By reduction with charcoal this can be converted into strontium sulphide,... 

Properties White precipitate or crystals of the mineral celestite odorless. D 3.71-3.97, mp 1605C. Slightly soluble in concentrated acids very slightly soluble in water insoluble in alcohol and dilute sulfuric acid. 

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. 

Strontium is a silvery and soft metal that is very reactive. When it is finely divided into a powder, it burns spontaneously in air. Its primary sources are two minerals, celestite and strontianite. In 1789, the Irish scientist Adair Crawford (1748-1795) first identified the element (along with the mineral strontianite) and named the element for Strontian, the village in Scotland where he made the discovery. (Crawford was actually studying the chemical reaction between a mineral called witherite (BaC03) and hydrochloric acid (HCl) at the time, but was frustrated when he failed to get the... 

Figure 3.2 Strontium can be extracted from the mineral celestite (SrS04).

Strontium, element number 38, has a density of 2.63 g/cm3 and is the 16th most abundant element on Earth. Barium, element number 56, has a density of 3.51 g/cm3 and ranks 14th in abundance. Both elements are silvery-colored metals. Because alkaline earths react so readily with any water in the environment to form ions and compounds, neither element would ever be found as the native metal. In all of their ores, they occur as +2 ions. The principal sources of the two elements are the minerals celestite (SrS04), strontianite (SrC03), and barite (BaS04). 

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... 

Strontium white n. Another name for the ground mineral, celestite. 

Occurrence. The principal strontium mineral is celestite, naturally occurring strontium sulfate. Celestite and celestine [7759-02-6] both describe this mineral. However, celestite is the form most widely used in Knglish-speaking countries. Celestite has a theoretical strontium oxide content of 56.4 wt %, a hardness of 3—3.5 on Mohs scale, and a specific gravity of 3.96. It is usually white or bluish white and has an orthorhombic crystal form. 

Celestite, Mineral Dossier No. 6, Mineral Resources Consultative Committee, HMSO, London, 1973. 

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. 

The Amethyst fluid is richer in strontium and calcium than the other fluids, but nearly depleted in barium. Celestite becomes saturated first, and more of this mineral forms from this fluid than from the Forties fluid. Anhydrite becomes saturated later in the mixing process and precipitates,... 

In the three simulations, the sulfate minerals form at mixing ratios related to their solubilities. Barite, the least soluble, forms early, when small amounts of seawater are added. The more soluble celestite forms only after the addition of somewhat larger quantities of seawater. Anhydrite, the most soluble of the minerals, forms from the Amethyst fluid at still higher ratios of seawater to formation fluid. 

Occurrence. Strontianite (SrC03) and celestite (SrS04) are the only minerals of economic importance. 

Sediments formed by the abiogenic precipitation of solutes from seawater are termed hydrogenous. Unequivocal examples of hydrogenous sediments are ones formed from the evaporation of seawater. The minerals deposited are collectively called evaporites and are the subject of Chapter 17. Others form with the assistance, to varying degrees, of marine microbes. For example, bacteria seem to play a role in the formation of Fe-Mn nodules and crusts. Some hydrogenous minerals, such as barite, celestite, glauconite, and francolite, are produced from the precipitation of elements... 

Strontium metal is not found in its elemental state in nature. Its salts and oxide compounds constitute only 0.025% of the Earths crust. Strontium is found in Mexico and Spain in the mineral ores of strontianite (SrCO ) and celestite (SrSO ). As these ores are treated with hydrochloric acid (HCl), they produce strontium chloride (SrCy that is then used, along with potassium chloride (KCl), to form a eutectic mixture to reduce the melting point of the SrCl, as a molten electrolyte in a graphite dish-shaped electrolysis apparatus. This process produces Sr cations collected at the cathode, where they acquire electrons to form strontium metal. At the same time, Cl anions give up electrons at the anode and are released as chlorine gas Cl T. 

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. 

Strontium and its compounds are mostly derived from celestite, SrS04. The mineral is converted to its carbonate by heating with sodium carbonate. Alternatively, the mineral may be reduced to sulfide by heating with coke. The carbonate or the sulfide is then converted to other strontium salts. 

CELESTITE. The mineral celesiite (also known as celesTinc) is composed of stromium sulfate, SrSOj. occasionally with calcium and barium. It crystallizes in the orthorhombic syslem in tabular or prismatic crystals. More rarely it may he pyramidal or simply fibrous or granular. Two essentially perfect cleavages may be observed, one parallel to the hase. the other parallel to the prism. Its fracture is uneven hardness. 3-3,5 specific gravity, 3.97 luster, vitreous color, white, but may be slightly reddish or bluish transparent to translucent. 

It is conceivable that a polysaccharide sulfate acts as the substrate in the mineralization of a protozoan group, the acantharid radiolaria, that deposit a celestite (SrS04) skeleton with small amounts of barite (BaS04) in solid solution295). Other polysaccharides are known with carbonate groups and they are likely candidates in carbonate deposition. Thus, a number of polysaccharides exist that can selectively... 

Strontium The principal minerals of strontium are strontium sulfate, celestite, SrSO, and strontium carbonate, strontianite, SrCOj. 

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

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