Aluminum sulfate minerals

Potassium alum is manufactured by treating bauxite with sulfuric acid and then potassium sulfate. Alternatively, aluminum sulfate is reacted with potassium sulfate, or the mineral alum stone, alunite, can be calciaed and leached with sulfuric acid. Alunite is a basic potassium aluminum sulfate... 

Sodium alum occurs naturally as the mineral mendo2ite. Commercially, it is produced by the addition of a sodium sulfate solution to aluminum sulfate. Small amounts of potassium sulfate, sodium siUcate, and soda ash can be added to improve product handling and performance. After adjustment of the ratio of aluminum sulfate to sodium sulfate, water is evaporated to give a hard cake ia the cooling pans. This cake is further heated ia roasters and ground to a fineness of 99% through a 100-mesh (- 150 fiva) sieve. 

A number of reagents containing oxide components are used in zeolite manufacture [19]. Silica is provided by addihon of sodium or other alkali silicate solutions, precipitated, colloidal, or fumed silica, or tetraalkylorthosihcate (alkyl = methyl, ethyl) and certain mineral silicates such as clays and kaolin. Alumina is provided as sodium aluminate, aluminum sulfate soluhon, hydrous aluminum oxides such as pseudo boehmite, aluminum nitrate, or aluminum alkoxides. Additional alkali is added as hydroxide or as halide salts, while organic amines and/or... 

The term alumen plumosum has had a long association with asbestos. Alumen (= alum) is a general term for naturally occurring hydrous alkali aluminum sulfates. These are efflorescent mineral materials of fibrous, feathery appearance. Confusion with the more durable silicate composition asbestos was not settled until 1741, by Tourneforte following a visit to asbestos deposits in Asia Minor. 

Rubidium is recovered from its ore lepidolite or pollucite. Mineral lepidolite is a lithium mica having a composition KRbLi(OH,F)Al2Si30io. The ore is opened by fusion with gypsum (potassium sulfate) or with a mixture of barium sulfate and barium carbonate. The fused mass is extracted with hot water to leach out water-soluble alums of cesium, rubidium, and potassium. The solution is filtered to remove insoluble residues. Alums of alkali metals are separated from solution by fractional crystallization. Solubility of rubidium alum or rubidium aluminum sulfate dodecahydrate, RbAl(S04)2 I2H2O falls between potassium and cesium alum. 

In addition to the effect of pH on mobility, the type of acid entering environmental systems may also be important. Nitric acid was found to leach more aluminum from soil columns representative of high-elevation forest floor soils than did sulfuric acid (James and Riha 1989). This is most likely due to the higher solubility of aluminum nitrate than aluminum sulfate. However, in mineral horizons below the forest floor, the study found that concentrations of aluminum leached by these acids did not differ from concentrations of aluminum leached by distilled, deionized water at a pH of 5.7. The authors concluded... 

The relative reactivity of the different mineral phases of cement with water is usually given as C A>C S>C S>C AF. Aluminate phases and their hydration products therefore play an important role in the early hydration process. Because of the high reactivity of calcium aluminate, the aluminate hydration reaction is carried out in the presence of sulfate ions. The latter provide control of the reaction rate through the formation of mixed aluminum sulfate products (ettringite and monosulfoaluminate) Calcium sulfate which is added to the cement clinker hence controls the properties of the aluminate hydration products. Sulfates thus play a crucial role in cement hydration and the influence of chemical admixtures on any process where sulfates are involved may be expected to be significant [127],... 

As an inexpensive source of acid, a large amount of the sulfuric acid that is produced is used for the manufacture of other mineral acids. It is also used to produce sulfates, such as ammonium sulfate (a low-grade fertilizer), sodium sulfate (used in the production of paper), and aluminum sulfate (used in water treatment), as well as organic sulfates (used as surfactants). Sulfuric acid is also a good catalyst for many reactions, including the transformation of ethanol into ethylene or ethyl ether. 

Like many elements, aluminum s name derives from the Latin because the Roman Empire used two of its naturally occurring minerals, alum (a potassium-aluminum sulfate) and alumina (aluminum oxide). It was isolated in 1825 by H. C. Oersted after decades of suspicion that it existed. 

There are a number of mineral and metallic salts which have a long association with the alchemical art. The fifteenth century alchemist, Isaac Holland describes The Hand of the Philosophers as being an assembly of important salts in alchemical works. These salts include Niter (potassium nitrate), Sal Ammoniac (ammonium chloride), Vitriol (copper or iron sulfate), Alum (potassium aluminum sulfate), and common salt (sodium chloride). 

Bigham J. M. and Nordstrom D. K. (2000) Iron and aluminum hydroxysulfates from acid sulfate waters. In Sulfate Minerals—Crystallography, Geochemistry, and Environmental Significance, Rev. Min. Geochem. (eds. C. N. Alpers, J. L. Jambor and D. K. Nordstrom). Mineralogical Society of America, Washington DC, vol. 40, pp. 352—403. 

Derivation (1) From alunite, leucite, or similar mineral. (2) Also derived by crystallization from a solution made by dissolving aluminum sulfate and potassium sulfate and mixing. 

TABLE 12.7 Solubility products of some secondary aluminum oxyhydroxides and sulfate minerals observed resulting from the interaction of acid mine waters with geological materials... 

Sulfate Minerals (Figure 6.6) Fifteen sulfate minerals are present in the thermodynamic database. The calculations show that many are supersaturated in our water samples. Several members of the alunite-jarosite group are grossly supersaturated, but alunite and jarosite are known to be supersaturated without precipitating in some acidic surface waters (Alpers et al., 1994). Aluminum hydroxy sulfates, Al(OH)SC>4 (jurbanite), and Al4(OH)ioSQ4 (basaluminite), are also supersaturated at some points... 

Aluminum potassium sulfate occurs naturally in the form of the minerals alunite and kalinite. Where these minerals are available, the compound can be mined and purified to obtain potash alum. Where the minerals are not available, the compound can be produced synthetically by combining aqueous aluminum sulfate with aqueous potassium sulfate. The two compounds react with each other in solution to form the double salt, aluminum potassium sulfate, which can then be extracted by allowing the solutions to evaporate, during which the desired compound crystallizes out. 

The pH found in Example 5-2 is quite low, showing that the mercuric ion has the property of a weak acid of approximately the same strength as acetic acid. The acid strength of some metal ions is quite considerable. For example, the pH of equimolar H3PO4 and solutions are similar. The strong acid properties of hydrated metal ions become evident in processes such as coagulation/flocculation, where hydrated aluminum sulfate (alum) or ferric chloride is added to a natural water that is buffered with bicarbonate. The metal ion "titrates" (or reacts with) a stoichiometric amount of alkalinity, just as the addition of an equal amount of strong mineral acid would. 

Selection of an alumina precursor for detailed study was guided by a combination of fundamental value and local interest. Basic aluminum sulfate is an intermediate product in the acid alumina process( °) developed in the Mineral Chemistry Division of these Laboratories, and the thermal decomposition of this material has been studied by Davey While... 

Aluminum sulfate occurs in nature as the mineral alunogenite, and is a powerful astringent acting much like alum. It is also used as an antiperspirant and is the effective ingredient in some commercial antiperspirant products. It is also a pharmaceutical necessity for the preparation of Aluminum Subacetate Topical Solution USP. 

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