Basic Shaped RefractoriesIspatGuru
Magnesia spinel bricks are produces with the addition of small amounts of alumina to improve thermal shock resistance. Fused magnesite tends to have superior properties to sintered magnesite and as such is incorporated into refractory products used in high wear areas such as slag lines etc. Dolomite is a calcium magnesium carbonate mineral (CaCO3.
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A Review on Recent Advances on Magnesia-Doloma
Also the hydration resistance of MgO-CaO refractories can be improved by treating in a CO 2 atmosphere or by surface phosphate coating which leads to the formation of a dense layer on the surface of CaO and protects Cao grain from hydration.For example Min Chen et al. reported the effect of porosity on carbonation and hydration resistance of CaO materials.
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(PDF) Improvement of humidity resistance of magnesium
Improvement of humidity resistance of magnesium powder using dry particle coating. Powder Technology 2004. Ajit Mujumdar
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(PDF) Waterproof Magnesia Binder for Composite Materials
Improving water resistance is also possible through the interaction of atmospheric ca rbon dioxide with magnesium hydroxychloride resulting in the formation of a surface layer of magnesium
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Effect of hydromagnesite addition on the properties and
It was found that the addition of hydromagnesite increased the compressive strength and water resistance of MOS cement. This effect is mainly due to the reaction between hydromagnesite and free MgO present in the cement that forms magnesium carbonate (MgCO 3 ·Mg (OH) 2 ·3H 2 O) and acts as an additional binding phase.
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INFLUENCE OF MAGNESIA ADDITION ON HYDRATION OF
1. By increasing the percentage of magnesia in doloma the hydration resistance of doloma refractories increases remarkably. 2. The two stag calcinations process can be applied successfully for production of mag-dol refractories. 3. The main reason for the increase in hydration resistance in
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PAPER OPEN ACCESS Study on the improvement of water
(MPC) to improve its mechanical water resistance. The mechanism of steel slag on MPC was studied through the composition and microstructure test of MPC hydration products. The results showed that the strength of magnesium phosphate cement gradually decreased with the increase of immersion time after adding steel slag.
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Chelants to inhibit magnesia (MgO) hydrationScienceDirect
Jul 01 2011 · Magnesium oxide (MgO) presents excellent refractoriness and high resistance to basic slag. However in the presence of water MgO undergoes an expansive hydration reaction generating Mg (OH) 2 which can lead to swelling and cracking.
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Premier Magnesia
Premier Magnesia LLC is a global market leader in magnesia-based products and solutions for dozens of applications ranging from agricultural to industrial and environmental markets. We are one of the worlds principal manufacturers and suppliers of high purity calcined magnesium oxide and magnesium hydroxide products. For over 50 years the Company and its predecessors have owned and operated
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Effect of Nano-Sized Fe2O3 on Microstructure and Hydration
The hydration resistance of the samples was measured on the size fraction of 5±10 BS mesh. The atmosphere of the chamber was maintained at 25oC and 95 relative humidity for 72 hours. The percentage of weight gain before and after hydration was the measure of hydration resistance (Equation 1). The microstructure was
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(PDF) Improvement of humidity resistance of magnesium
Improvement of humidity resistance of magnesium powder using dry particle coating. Powder Technology 2004. Ajit Mujumdar. Rajesh Dave. Dongying
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The resistance to high temperature of magnesia phosphate
Oct 10 2015 · And the addition wollastonite has little influence on the hydration products of these two magnesia phosphate cements. Therefore the incorporation of wollastonite is a potential method to improve the heat-resistance of MAPC or MKPC. This paper aims to study the effect of wollastonite addition on the behavior of magnesium ammonium phosphate
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A simplified mechanistic analysis of the hydration of magnesia
Aug 01 2001 · The kinetics of the hydration of magnesia to produce magnesium hydroxide is described by a kinetic model with no diffusive contribution including an additional resistance to the reactive flux due to the transient variation of the porosity of the material during reaction. The proposed model has been applied to data from the literature and obtained by hydration of MgO samples with
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AN EXPERIMENTAL STUDY ON HYDRATION OF VARIOUS
An experimental study on hydration of various magnesia raw materials CeramicsSilikáty 59 (1) 48-58 (2015) 49 The reaction velocity in liquid water and water vapour environment increases with temperature. It was reported that a 10°C rise in temperature induces the increase in
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Effects of LaCrO3 Composite Additive for the Hydration
Effect of different blending amount of LaCrO3 a composite additive on the hydration resistance and crystallization properties of magnesia-calcium refractory were studied by measuring hydration rate using X-ray diffraction and scanning electron microscopy. The results show that the LaCrO3 at a low addition (≤1 ) can significantly decrease the hydration resistance of the MgO-CaO material
Get PriceImproved Hydration Resistance of Synthesized Magnesia
Hydration resistance of synthesized MgO–CaO clinker was improved by surface modification using oleic acid stearic acid or complex acids as modifiers with phosphoric acid as a reference.
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Effect of hydromagnesite addition on the properties and
It was found that the addition of hydromagnesite increased the compressive strength and water resistance of MOS cement. This effect is mainly due to the reaction between hydromagnesite and free MgO present in the cement that forms magnesium carbonate (MgCO 3 ·Mg (OH) 2 ·3H 2 O) and acts as an additional binding phase.
Get PriceINFLUENCE OF MAGNESIA ADDITION ON HYDRATION OF
1. By increasing the percentage of magnesia in doloma the hydration resistance of doloma refractories increases remarkably. 2. The two stag calcinations process can be applied successfully for production of mag-dol refractories. 3. The main reason for the increase in hydration resistance in
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(PDF) Improving hydration resistance of magnesia-doloma
Using a co-clinker of magnesia-doloma as a starting material would provide more homogeneity in the properties of the product and has been published recently. On the other hand addition of iron
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Effect of Additives on the Hydration Resistance of
Dec 20 2004 · Both the hydration rate and the powdering rate were measured. The important role of the higher‐valence cations in improving the hydration resistance of the MgO–CaO materials was revealed. This behavior is believed to be due to the formation of vacancies in solid solutions of CaO or MgO with higher‐valence cations.
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A novel approach for magnesia hydration assessment in
Magnesium oxide (MgO) or magnesia is one of the most important raw materials in the refractory industry. Because of its high refractoriness (melting point of 2800°C) and corrosion resistance the presence of this oxide in refractory compositions promotes an increase in the performance of pre-shaped linings for steel production C.M. Peret J.A. Gregolin L.I.L Faria V.C. Pandolfelli Patent
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Hydration mechanisms of magnesia-based refractory bricks
This coating effect is most evident when the content of A I 2 O 3 is between 2 and 4 w t 34 . When the content of A1 2 0 3 exceeds 4 wt the magnesia resistance to hydration is lower due to the increase in the porosity of the magnesia clinker caused by the volume expansion of the spinel. 2.6.2.5.
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Hydration resistance and mechanism of regenerated
Impurity elements Si Fe Al in the spent MgO-CaO bricks had enhanced the hydration resistance through decreasing free CaO content and improving the density of regenerated samples.
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IMPROVING HYDRATION RESISTANCE OF MAGNESIA
IMPROVING HYDRATION RESISTANCE OF MAGNESIA-DOLOMA REFRACTORIES BYIRON OXIDE ADDITION F. Kashaninia 1 H. Sarpoolaky 1 R. Naghizadeh 1 A. R. Bagheri 2 and M. Zamanipour 2 hsarpoolaky iust.ac Received May 2011 Accepted November 2011
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A novel approach for magnesia hydration assessment in
Magnesium oxide (MgO) or magnesia is one of the most important raw materials in the refractory industry. Because of its high refractoriness (melting point of 2800°C) and corrosion resistance the presence of this oxide in refractory compositions promotes an increase in the performance of pre-shaped linings for steel production C.M. Peret J.A. Gregolin L.I.L Faria V.C. Pandolfelli Patent
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Process for producing a shaped sintered magnesia article
A shaped sintered magnesia article having an enhanced hydration resistance and an improved mechanical strength is produced by evenly coating fine individual magnesia particles with silica coating layers containing an organic substance in an amount of 0.01 or less in terms of carbon based on the molar amount of silicon in the silica coating layers by shaping the silica-coated magnesia
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