Carbonate CaCO

Calcium carbonate [471-34-1]—Cl Pigment White 18, Cl No. 77220, EEC No. E 170. A fine, white, synthetically prepared powder consisting essentially of precipitated calcium carbonate, CaCO. ... 

Non-reinforcing fillers (passive) Ground calcium carbonate (CaCO ) Reduce formulation cost adjust rheology, and mechanical properties. 

Permanent hardness can also be due to the presence of CaS04, in which case the addition of soda (sodium carbonate), NaiC03, produces sodium sulfate, Na2S04, and calcium carbonate, CaCO, this precipitate once again is removed by sedimentation. 

I grain per gallon.= i grain calcium carbonate (CaCOs) per U. S. gallon of water... 

I part per million, , . = i part calcium carbonate (CaCO,) per i,000,000 parts of water... 

Calcium carbonate (CaCO,) calcium sulfate or gypsum (CaSOJ and iron(II) carbonate (FeCO ) are the most common types of scales formed in drilling. If hydrogen sulfide is present, then there is a possibility of iron sulfide (FeS) scale depositing. 

FIGURE E.5 Each sample contains 1 mol of formula units of an ionic compound. From left to right are 58 g of sodium chloride (NaCl), 100 g of calcium carbonate (CaCO,), 278 g of iron(ll) sulfate heptahydrate (FeS04-7H.0), and 78 g of sodium peroxide (Na. O,). 

The formation of calcium carbonate (CaCOs), calcium sulfate, and barium sulfate scales in brine may create problems with permeability. Therefore it is advantageous that newly made fractures have a scale inhibitor in place in the fracture to help prevent the formation of scale. Formulations of hydraulic fracturing fluids containing a scale inhibitor have been described in the literature [1828]. 

Historically, the alkali industry is based on limestone, or chalk. The chemical name for limestone is calcium carbonate (CaCOs). It is a very common mineral in seashells. Therefore, limestone is a naturally occurring sedimentary rock formed when seas or lakes evaporate. When limestone is heated, it produces carbon dioxide... 

Calcium carbonate (CaCO ) can be in the form of an odorless crystal or powder and is one of calcium s most stable compounds, better known in its natural state as limestone, marble, chalk, calcite, oyster shells, and the minerals marl and travertine. Calcium carbonate is the source of lime and is used as a filler for many products, including paints, plastics, and foods (bread), and as an antacid. 

In the total inorganic carbon balance of equation 8.94, we neglected the presence of some species. Table 8.9 shows that this approximation is reasonable although, for accurate calculations, we should also have considered bicarbonates CaHC03 and MgHCO and the soluble carbonate CaCO . Note also that sulfates occur in negligible molar proportions and that carbonate alkalinity coincides with total alkalinity. 

CALCIUM/CALMODULIN-DEPENDENT PROTEIN KINASE Calcium carbonate (CaCOs), BIOMINERALIZATION SOLUBILITY PRODUCT Calcium hydroxide (Ca(OH)2),... 

Calcite is a calcium carbonate, CaCOs, with a rhombohedral cell consisting of the large planar CO3 groups, which contain a Ca ion at the center of an... 

Industrial calcium carbonate (CaCOs) is mainly produced by extraction/milling of natural ore. Suitable ore-bodies include chalk, limestone, marble, and travertine. Sufficiently pure ore-bodies are selected to allow direct exploitation. The main applications include paper, paints, plastics, pharmaceuticals, etc. Luminescence and LIBS (Fig. 8.3) sorting may be used for calcium carbonate ore radiometric sorting. 

If the chalk is made of calcium carbonate, CaCO, it is made of the same active ingredient found in many antacids. The calcium carbonate is a base that reacts to neutralize any excess acids. Be careful, though, never to take too much calcium carbonate because the stomach is designed to always be somewhat acidic. 

Lime (calcium oxide, CaO) is used in the manufacture of mortar. It is manufactured in large quantities in Europe (see Figure 4.6) by heating limestone (calcium carbonate, CaCOs). 

As this solution passes over and through rocks containing limestone (calcium carbonate, CaCOs) and dolomite (magnesium carbonate, MgCOs), the weak acid in the rain attacks these rocks and very slowly dissolves them. The dissolved substances are called calcium and magnesium hydrogencarbonates. 

This brings us full cycle from limestone (calcium carbonate, CaCOs), through calcium oxide (CaO) and back to calcium carbonate (limestone). This is known as the limestone cycle (Figure 13.11). 

Barium is not very mobile in most soil systems. The rate of transportation of barium in soil is dependent on the characteristics of the soil material. Soil properties that influence the transportation of barium to groundwater are cation exchange capacity and calcium carbonate (CaCO) content. In soil with a high cation exchange capacity (e.g., fine textured mineral soils or soils with high organic... 

Calcium carbonate CaCO, chalk stationery store... 

Carbonates with simple Carbonates CaCO, Calcite... 

The fact that protons are used as a motive force can contribute to an increase in the pH of the soil solution, due to the uptake by bacteria. Moreover, the pH can also be increased due to the fact that reactions involve the transformation of oxalic acid into carbonic acid, i.e. of a strong (pKi = 1.25, pK2 = 4.27) to a weak (pKi = 6.35, pK2= 10.33) acid (Braissant et al., 2002). This alkalinization facilitates precipitation of calcium carbonate (CaCOs). By modifying a general equation for oxalate metabolism by oxalatrophic bacteria (Harder et al., 1974), the following balanced equation can be proposed ... 

All these results are related to observations and measurements in the field as well as from oxalotrophic bacterial cultures in the laboratory (Braissant et al, 2004). There is no theoretical model available to explain the oxalate-carbonate transformation and its consequences on the soil solution properties, i.e. alkalinization facilitating precipitation of calcium carbonate (CaCOs) and CO2 release into the atmosphere. This kind of model should be able to explain the process of oxido-reduction reactions, pH regulation and the evolution of the various phase concentrations involved in the system, i.e. oxalate, carbonate, water and CO2. This is the aim of the next section. 

The aqueous solution, which may or may not be associated with the two mineral species, calcium oxalate (CaC204) and calcium carbonate (CaCOs). These two species are defined by their solubility products. Concentrations of the various chemical species in solution (including carbonates - HCOs , C03 oxalates - 204 , C204H Ca and CO2) can vary depending on to the outside environment. Therefore, the system is considered as open. 

Consider a vessel containing solid calcium carbonate, CaCOs. When heated, the carbonate decomposes into lime (solid calcium oxide), CaO, and gaseous carbon dioxide, CO2. Experimentally, the concentration of CO2 is found to be constant at a definite temperature and, therefore, independent of the amounts of the other phases. Describe the type of system and equilibrium. 

We shall study two forms of calcium carbonate CaCO calcite and aragonite. Thus, it is possible to see the behavior of identical chemical entities in different crystalline environments. Both crystals are of an ionic nature and contain CO3 groups as covalent entities with their own internal modes. 

Of all the minerals that have been associated with biomineralization, carbonates are the most obvious. From the coralline materials found in atolls to the shells of mollusks and gastropods, the average person knows these creatures, and possibly that the hard materials contain calcium, if not that the mineral is calcium carbonate, CaCOs. It is the carbonate minerals that provide the distinctive shapes allowing immediate recognition, and the precise compositions are often the means by which one designates a particular invertebrate species. 

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