Calcium carbonateEssential Chemical Industry
· Calcium carbonate. Three types of calcium carbonate-containing rock are excavated and used by industry. They are limestone chalk and dolomite. Limestone and chalk are both forms of calcium carbonate and dolomite is a mixture of calcium and magnesium carbonates. All have impurities such as clay but some rocks are over 97 pure.
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· solutions 1 . In case of pure water presence most of the disruptive effects would not arise. On the other hand water often becomes a transport medium for different types of salts that significantly contribute to materials deterioration 2-5 . Soluble salts may derive from acid rains or marine environment but they are more often
Get PriceInfluence of calcium aluminate cement (CAC) on alkaline
· In this paper the effect of calcium aluminate cement (CAC) additions on the alkali activation of red clay brick waste (RCBW) was studied at room temperature and at 65 ºC. RCBW was partially replaced with CAC (0 to 50 wt. ) and blends were activated with NaOH and sodium silicate solutions.
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· The precipitation of calcium carbonate (CaCO3) from saturated solutions prepared using calcium chloride and sodium hydrogen carbonate under the influence of ultrasound (20 kHz intensity ranging from 1.5−18.5 W cm−2) has been studied. For short reaction times or treatment at low intensity precipitates containing up to 90 vaterite were recovered longer (>30 min) times or higher
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· phases or OPC modified by calcium aluminate calcium sulphate and/or admixtures 1-7 occasionally forming new phases with the metallic cations. In addition G. Qian and co-workers have extensively studied the S/S processes of toxic metals in fly ash-calcium sulfoaluminate cement Friedel s salt or fly ashes 8-10 .
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· The samples were alite embedded in epoxy resin and having received a flat mirror polish. They were exposed to solutions of different concentrations of calcium hydroxide ranging from 0 to 20 mmol L −1 and regulated at 20°C ± 1.5°C in the presence or not of comb-copolymers. Varying concentration of calcium and hydroxide provides a useful
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· Calcium phosphates are minerals composed of calcium cations and phosphate anions. They are known as the major inorganic material in approximately 60 of all native human bones (Table 1).The existence of calcium phosphates in bones was first discovered in 1769 and in the 1800s calcium phosphates that exist in bones were subdivided into different categories (Fig. 1) 11 12 .
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· By varying the conditions under which nucleation occurred calcium ions were found to inhibit nucleation and further research showed that the substitution of calcium ions into the burkeite crystal lattice was the reason for the observed behavior. †
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· Lime treatment of sulphate-bearing clay soils has been shown to adversely affect their properties. In the current work the effects of soaking untreated and lime-stabilized kaolinite samples in water and sodium and calcium sulphate on swelling and unconfined compressive strength are investigated and compared. Specimens were treated with 1 3 or 5 lime and cured at 35 °C for 1 7
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· The mineral formation–transition mechanism microstructure evolution crystal structure pulverization property and chemical reactivity of the CaO–Al2O3–SiO2 clinker with MgO and Na2SO4 dopants during the sintering process at 1300 °C for 2.0 h were systematically studied using CaO Al2O3 SiO2 MgO and Na2SO4 as raw materials when the molar ratio of CaO to Al2O3 is 1.4 the mass ratio
Get PriceSulphate attack in Concrete Its Effects Causes and
· Magnesium sulfate attacks calcium silicate hydrate as well as calcium hydroxide and calcium aluminate hydrate. The consequences of sulfate attack include not only disruptive expansion and cracking but also loss of strength of concrete due to the loss of cohesion in the hydrated cement paste and of adhesion between it and the aggregate particles.
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· effect of organic compounds on the interconversions of calcium aluminate hydrates. HYDRATION OF MONOCALCIUM ALUMINATE J. F. Young Department of Civil Engineering University of Illinois Urbana Illinois 61801 (Refereed) ABSTRACT Organic compounds can sorb into the structure of C2AH8 as was found previously for C4AH13 and thereby restrict its conversion to C3AH6.
Get PriceSulphate attack in Concrete Its Effects Causes and
· Magnesium sulfate attacks calcium silicate hydrate as well as calcium hydroxide and calcium aluminate hydrate. The consequences of sulfate attack include not only disruptive expansion and cracking but also loss of strength of concrete due to the loss of cohesion in the hydrated cement paste and of adhesion between it and the aggregate particles.
Get PriceCalcium Chloride Solution AMERICAN ELEMENTS
The calcium atom has a radius of 197 pm and a Van der Waals radius of 231 pm. Calcium was discovered and first isolated by Sir Humphrey Davy in 1808. It is the fifth most abundant element in the earth s crust and can be found in minerals such as dolomite gypsum plagioclases amphiboles pyroxenes and garnets.
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· However in order to understand the effects of calcium carbide it is important to realize the state of the art of lighting in the late 18 th century. It was in 1792 that William Murdoch (Figure (PageIndex 4 ).15) first began experimenting with the use of gas derived from the heating of coal and other materials for lighting.
Get PriceComposition of Calcium Carbonate Polymorphs Precipitated
· The precipitation of calcium carbonate (CaCO3) from saturated solutions prepared using calcium chloride and sodium hydrogen carbonate under the influence of ultrasound (20 kHz intensity ranging from 1.5−18.5 W cm−2) has been studied. For short reaction times or treatment at low intensity precipitates containing up to 90 vaterite were recovered longer (>30 min) times or higher
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· Chemical mechanisms and kinetic modeling of calcium aluminate cements hydration in diluted systems Role of aluminium hydroxide formation. Organic compounds in the processing of lateritic bauxites to alumina Part 2 Effects of organics in the Bayer process. Quantitative analysis in alkaline aluminate solutions by Raman spectroscopy
Get PriceComposition of Calcium Carbonate Polymorphs Precipitated
· The precipitation of calcium carbonate (CaCO3) from saturated solutions prepared using calcium chloride and sodium hydrogen carbonate under the influence of ultrasound (20 kHz intensity ranging from 1.5−18.5 W cm−2) has been studied. For short reaction times or treatment at low intensity precipitates containing up to 90 vaterite were recovered longer (>30 min) times or higher
Get PriceUse of Boron Compounds as Grinding Aids with Alcohol
· Milling aids have been predominantly developed to increase the performance or grinding capacity of cement products and alcohol amines have been used as grinding aids in cement grinding processes for many years. Moreover the setting point of cement produced with grinding aids is most often changed. In this study the effects of alkanolamines and boron compounds in different mixing
Get PriceCalcium Chloride Solution AMERICAN ELEMENTS
The calcium atom has a radius of 197 pm and a Van der Waals radius of 231 pm. Calcium was discovered and first isolated by Sir Humphrey Davy in 1808. It is the fifth most abundant element in the earth s crust and can be found in minerals such as dolomite gypsum plagioclases amphiboles pyroxenes and garnets.
Get PriceTHE EFFECT OF THE SODIUM SULPHATE SOLUTION
· solutions 1 . In case of pure water presence most of the disruptive effects would not arise. On the other hand water often becomes a transport medium for different types of salts that significantly contribute to materials deterioration 2-5 . Soluble salts may derive from acid rains or marine environment but they are more often
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The use of artificial saliva solution as hydration medium enhances the hydration process of both synthesized calcium aluminate based materials due to the formation of more hydrated compounds. Curing of calcium aluminate cement in hot and humid conditions resulting in hardness loss and high porosity due to the conversion process in which the compounds CAH 10 and C 2 AH 8 (hexagonal
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There are several kinds of kidney stones which makes it very important to analyze the stones after getting them out of the body in order to determine the best way to prevent their re-formation in the future.Most kidney stones are composed of calcium compounds.This could be due to many reasons such as excessive calcium intake for a long period of time hypervitaminosis D (excess vitamin D
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· phases or OPC modified by calcium aluminate calcium sulphate and/or admixtures 1-7 occasionally forming new phases with the metallic cations. In addition G. Qian and co-workers have extensively studied the S/S processes of toxic metals in fly ash-calcium sulfoaluminate cement Friedel s salt or fly ashes 8-10 .
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· retainer but the use of other alternative binders is receiving growing attention. For instance the use of calcium aluminate cement (CAC) to safely encapsulate hazardous materials has been recognized to be highly effective (Navarro-Blasco et al. 2013). The relatively low pH of this kind of cement matrix (10.5-11.5) in
Get PriceSolidification/stabilization of toxic metals in calcium
· phases or OPC modified by calcium aluminate calcium sulphate and/or admixtures 1-7 occasionally forming new phases with the metallic cations. In addition G. Qian and co-workers have extensively studied the S/S processes of toxic metals in fly ash-calcium sulfoaluminate cement Friedel s salt or fly ashes 8-10 .
Get PriceCALCIUM Overview Uses Side Effects Precautions
· Calcium carbonate is taken by mouth as an antacid for indigestion (dyspepsia). Calcium carbonate and calcium acetate are also taken by mouth to reduce phosphate levels in
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· Geopolymer incorporating calcium aluminate cement can cure at ambient conditions. • CAC replacement ratio significantly affects the strength development of geopolymer. • Taguchi method can be used to develop optimised geopolymer mixture. • Geopolymer concrete with CAC has reasonably good mechanical properties.
Get PriceMolecular and submolecular scale effects of comb
· The samples were alite embedded in epoxy resin and having received a flat mirror polish. They were exposed to solutions of different concentrations of calcium hydroxide ranging from 0 to 20 mmol L −1 and regulated at 20°C ± 1.5°C in the presence or not of comb-copolymers. Varying concentration of calcium and hydroxide provides a useful
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