Calcium minerals

Wu, L., W. Forsling, and P. W. Schindler (1991), "Surface Complexation of Calcium Minerals in Aqueous Solution. 1. Surface Protonation at Fluorapatite-Water Interfaces," J. Colloid Interface Sci. 147/1, 178-185. 

Y. Pan, P- F rotational-echo double resonance nuclear magnetic resonance experiment on fluoridated hydroxyapatite. Solid State Nucl. Magn. Reson. 5 (1995) 263-268. L. Wu, W. Forsling, P.W. Schindler, Surface complexation of calcium mineral in aqueous solution, surface protonation at fluorapatite surface, J. Colloid Interface Sci. 147 (1991) 178-185. 

Wu, L., Forsling, W. Schindler, P. 1991. Surface complexation of calcium minerals in aqueous solution 1. Surface protonation at fluoroapatite-water interfaces. Journal of Colloid and Interface Analysis, 147, 178-185. 

Calcium Mineralization of bone and teeth synaptic transmission muscle contraction blood clotting Men women 1000 mg/d... 

Since calcium oxide is more than sparsely soluble and its reaction with phosphoric acid or a soluble phosphate is highly exothermic, researchers have used less soluble salts of calcium to react with the phosphates and form a phosphate ceramic [4-12]. In the acidic medium of the phosphate solutions, the salts of calcium dissolve slowly and release Ca (aq) into the solution, which subsequently reacts with phosphate anions and forms calcium phosphates. The best calcium minerals for forming CBPCs are combination of oxides of calcium and insoluble oxides such as silica or alumina, e.g., calcium silicate (CaSi03) and calcium aluminate (CaAl204), or even a phosphate of calcium such as tetracalcium phosphate (Ca4(P04)2 0). These minerals are reacted with acid phosphate salts to form phosphate cements. 

Among all the minerals used by organisms, three categories are widely dominant silica, calcium phosphates, and calcium carbonates. Calcium phosphate minerals are usually associated with vertebrates , where they form bone and the dentine and enamel of teeth. However, phosphate minerals are present in some invertebrate shells, such as Brachiopods, whereas vertebrates used calcium carbonate minerals in eggshells and otoliths. Calcium minerals represent about 50% of all biogenic minerals. 

The city s Public Works Department is investigating new sources of water. One proposal involves drilling wells into a nearby aquifer that is protected from brackish water by a unique geological formation. Unfortunately, this formation is made of calcium minerals. If the concentration of calcium ions in the water is too high, the water will be "hard," and treating it to meet local water standards would be too expensive for us. 

A large volume of work has been reported on rapid devolatilization of coal (heating rates approximating process conditions (21,22). Recently, the effects of coal minerals on the rapid pyrolysis of a bituminous coal were reported by Franklin, et al ( 23). They found that only the calcium minerals affected the pyrolysis products. Addition of CaCO3 reduced the tar, hydrocarbon gas and liquid yields by 20-30%. The calcium minerals also altered the oxygen release mechanism from the coal. Franklin, et al. attribute these effects to CaCOj reduction to CaO, which acts as a solid base catalyst for a keto-enol isomerization reaction that produces the observed CO and H2O. 

The ore processed in the Kerr-McGee mill is primarily a sandstone, with uranium minerals in the material bonding the sand grains. The ore contains about 0.2 w/o UaOg, 0.01 to 0.03 w/o M0O3, and 0.05 to nearly 0.20 w/o VjOs. Uranium and molybdenum are leached and recovered, with uranium recovery exceeding 97 percent. Some vanadium is also leached, but was not being recovered in 1971. The ore also contains acid-soluble calcium minerals, equivalent to from 2 to 5 w/o CaO, which are the principal consumers of sulfuric acid. 

Goulding a and Campbell DR (1984) Effects of oral loads of sodium chloride on bone composition in growing rats consuming ample dietary calcium. Mineral Electrolyte Metab 10 58-62. 

Inorganic Materials. During petrification, the types of inorganic substances that replace organic substances will depend on the burial environment. Phosphates and silicates have been found in petrified wood from the marine environment, and calcium minerals in samples from terrestrial and cave environments. High iron contents are always associated with shipwrecks. All these impregnates will influence the analytical methods and conservation treatments. 

Most common is the theory of chemisorption of collectors at the surface of solid particles. However, it is, as a rule, at the same time noted that simultaneously concurrent processes take place, which are connected both with adsorption of surfactants at 1/g interfaces and with their interaction with ions in the flotation pulp. Thus, it is shown in [66] that saturated C 2—Cj4 fatty acids are selectively chemisorbed on calcium carbonate surfaces which provides them with an effective hydrophobisation. At the same time, C5—Cg acids are adsorbed mainly at 1/g interfaces which produces a substantial influence on the stability of the flotation foams. Free and Miller [67] have thoroughly investigated the behaviour of sodium oleate in the flotation of a calcium mineral, fluorite. It has been established that calcium dioleates are formed both in the bulk and at 1/s interfaces. In this case, an effective hydrophobisation of the surface of fluorite particles takes place both due to the interaction of oleate with calcium ions on the active sites and by adsorption of calcium dioleates formed in the solution. It has been once more confirmed [68] that classical collecting agents, xanthogenates, e.g. ethyl xanthogenate, form on the... 

Many calcium minerals, for instance, limestone, gypsum, alabaster, that is, mainly, carbonate and sulphate minerals, have been known for a very long time. In the old days people... 

Calcium is the fifth most abundant element in the earth s crust, where it occurs to about 3%. It is never found uncombined in nature important calcium minerals are limestone (CaCOj), gypsum (CaS04), fluorite (CaF2), and apatites, e.g., hydroxyapatite [Ca,o(P04)6(OH)2l. Calcium also is dissolved in seawater as free Ca. ... 

Besides calcium minerals, the growth of a few other inorganic salts on solid surfaces has also been studied. Silica is another important biomineral [81, 182], yet it has not been studied extensively in the context of surface mineralization. Tahir et al. synthesized a new nitrilotriacetic acid (NTA)-terminated alkenethiol, which can self-assemble on gold surfaces. Using the well-known coordination of Ni + and NTA, the enzyme silicatein could be immobilized on the surface of gold nanoparticles. Exposure of these functional particles and control experiments in the absence of silicatein showed that silica precipitates only on silicatein-modified... 

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