An Alternative Process Design For Production of …

2019-1-10 · understand which temperature should be chosen for the calcination. Figure 2. DTA/TG Analysis of dolomite [8] According to Figure 2, the mass loss started from 750 oC to 1150 oC. Therefore, 1150 oC was chosen as the optimized calcination temperature. 450 g of sample was used for the calcination step conducted in an electric resistance furnace.

Calcined Dolomite: An Efficient and Recyclable Catalyst ...

2018-12-13 · Abstract. Calcined dolomite was utilized as a low-cost and efficient catalyst for the Knoevenagel condensation of aldehydes with active methylene compounds such as malononitrile and ethyl cyanoacetate to afford substituted α, β-unsaturated carbonyl compounds.Calcination temperature was an important variable which changed the surface areas, textural characteristics and basicity of dolomite ...

Carbon Dioxide Absorption and Release Properties of ...

After calcination, the pyrolysis products of dolomite were allowed to cool to room temperature in an Ar atmosphere. For absorption tests, the samples were heated up to 673 K in an Ar atmosphere with a heating rate of 10 K·min −1 and were kept at this temperature for 21.6 ks in a CO 2 atmosphere.

Use of calcined dolomite as chemical coagulant in the ...

2018-6-11 · Therefore, the calcination should be performed in such a low temperature that a minimum amount of CaCO 3 and a maximum amount of MgO would be decomposed. Results indicated that calcined dolomite have some potential in the nitrogen and phosphorus precipitation from synthetic samples. Keywords: dolomite, coagulant, struvite, fertilizer. 1 ...

Thermal decomposition of dolomite under CO2: insights …

Thermal decomposition of dolomite in the presence of CO 2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an ...

2 analysis on the performances of dolomite and limestone

2016-2-18 · 63 calcination temperatures. The ultimate mechanism governing the thermal decomposition of 64 dolomite is however not well understood yet [19–21]. The Tamman temperature indicating 65 the initiation of sintering of MgO (Tt ≃ 1276 C) [16] is only slightly above the Tamman

Effect of dolomite decomposition under CO2 on its ...

In this work, the multicycle CO2 capture performance of dolomite and limestone is analysed under realistic CaL conditions and using a reduced calcination temperature of 900 °C, which would serve to mitigate the energy penalty caused by integration of the CaL process into fossil fuel fired power plants.

Reaction mechanisms for H2O-enhanced dolomite calcinatio…

Thermal decomposition of dolomite under CO2: insights from ...

(PDF) Thermal decomposition of dolomite under CO2 ...

quickly only at temperatures about 30 C above the equilibrium calcination temperature 236 [7, 8, 41]. On the other hand, Fig. 3b shows that dolomite undergoes decomposition under 237

Research Article Carbon Dioxide Absorption and Release ...

2019-7-31 · A er calcination, the pyrolysis products of dolomite were allowed to cool to room temperature in an Ar atmosphere. For absorption tests, the samples were heated up to K in an Ar atmosphere with a heating rate of K min 1 and werekeptatthistemperaturefor. ksinaCO 2 atmosphere. e ow rate of CO 2 was mL min 1.Forcyclictests,the

The effectiveness of dolomite and Ni-catalyst mixtures …

2011-8-10 · Calcination tests with a dolomite sample of about 200 g have been carried out in nitrogen atmosphere at 8500C in a proper designed laboratory- quartz reactor with ID 55 mm. At that temperature dolomite is fully calcined. In the carbonation tests, the bed of dolomite, previously calcined and kept at room temperature and under N2 atmosphere,

Thermo gravimetric study of calcination of dolomite at ...

Calcination and carbonation behaviour of dolomite has been studied in a pressurised thermo balance at pressures in the range of 1.1 to 2.3 MPa and for temperatures ranging from 730 to 840 degrees C. The atmosphere consisted of nitrogen containing up to 20 vol.-% carbon dioxide. The calcination of dolomite has been studied as a function of temperature, particle size, and P-CO2.

(PDF) Performance of Dolomite Calcination in a Bench …

Calcination of dolomite involves heating the raw material at sufficient temperature in order to release the carbon dioxide from its carbonate minerals. This process is commonly …

Effect of natural dolomite calcination temperature on ...

2013-5-1 · Natural dolomite was calcined at 700–900 °C under air and an Ar gas flow atmosphere to characterize its sorbency potential for borate.A sequential decarbonation occurred with increase in calcination temperature, that is, transformation of CaMg(CO 3) 2 to MgO and CaCO 3 up to 700 °C and CaCO 3 to CaO from 700 to 900 °C. The surface molar ratio of Ca/Mg decreased from 1.6 to 0.6 by ...

(PDF) Thermal decomposition of natural dolomite

The loss of mechanical strength of dolomite might be explained by the occurrence of secondary calcination, converting the partially-calcined dolomite (MgO-CaCO 3 ) to full-calcined dolomite …

Reaction mechanisms for H2O-enhanced dolomite …

2021-6-15 · The dry thermal calcination process and the two H 2 O-enhanced calcination schemes are further described below.. 2.1.Dry dolomite calcination in the absence of H 2 O (blue box). For the reaction mechanism modeling, we assume that the thermal calcination of dolomite occurs in two consecutive steps [42,,, ], since the calcination temperature of calcium carbonate increases with the increasing ...

Effect of natural dolomite calcination temperature on ...

Natural dolomite was calcined at 700-900 °C under air and an Ar gas flow atmosphere to characterize its sorbency potential for borate. A sequential decarbonation occurred with increase in calcination temperature, that is, transformation of CaMg(CO 3) 2 to MgO and CaCO 3 up to 700 °C and CaCO 3 to CaO from 700 to 900 °C. The surface molar ratio of Ca/Mg decreased from 1.6 to 0.6 by ...

Assessing the reactivity of magnesium oxide calcinated at ...

In Tyrol, Austria, dolomite rock was commonly used as raw material for historic mortars and plasters. During calcination of dolomite rock, almost equal amounts of calcium oxide and magnesium oxide are produced. While the reactivity of calcium oxide is well known, the reactivity of magnesium oxide is still not completely understood. Within this study, the reactivity of magnesium oxide obtained ...

Thermo gravimetric study of calcination of dolomite at ...

The calcination of dolomite has been studied as a function of temperature, particle size, and P co 2. An investigation concerning possible mass transfer restrictions for the experimental system and a model investigation of the calcination rate in CO 2 atmosphere has been made. Further, the effect of calcination on the BET surface and the BET ...

THE CAUSTIC CALCINATION OF DOLOMITE AND ITS USE …

The effect of time, temperature, and pressure of carbon dioxide upon three types of dolomite is brought out. Dolomites are either double salts or solid solutions or mixtures of the two. The effect of lime and silica is pointed out. Dissociation, tensile strength, volume change, time of set, and weather test data are given.

Effect of dolomite decomposition under CO2 on its ...

2017-12-18 · the mechanism of dolomite decomposition under CO2 is responsible for enhancing the kinetics of calcination and reactivity of dolomitic CaO [21, 32]. Thus, dolomite decomposes directly into MgO and CaO at a temperature about 700ºC regardless of the CO2 partial pressure in the calcination …

Performance of Dolomite Calcination in a Bench-Scale ...

The effect of temperature on the conversion of dolomite calcination at various particle sizes is shown in Figure 4. The rotation frequency used in the experiment is 29.75

30 Characterization of Dolomitic Lime as the Base …

2016-10-10 · ond temperature interval of 706 – 824 °C, degrada-tion of the dolomite and consequently the creation of CaCO 3 and MgO, with a weight loss of 22.1 % was observed. Although the decomposition of dolo-mite in this temperature area was rapid, there was still dolomite present up to about 900 °C. In the last

Thermal decomposition of dolomite under CO2: insights …

2015-10-19 · Thermal decomposition of dolomite in the presence of CO 2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an ...

Thermochemical energy storage using phosphatic pebbles ...

2021-7-6 · Thermogravimetric analysis and powder X-ray diffraction indicated that the dolomite calcination is not fully complete at lower temperature, and at least 700 °C heat is required for the release of CO 2 from the dolomite pebbles. Overall, the results show that the waste dolomite phosphatic pebbles are suitable for potential use in high ...

Calcination of calcium –based sorbents at pressure in a ...

2020-4-29 · calcination rate of the most usual calcium-based sorbents in a wide range of operation conditions as temperature, CO2 partial pressure and total pressure. For this purpose, two limestones with different physical and chemical properties, and a dolomite have been used. Scanning Electron Microscopy (SEM) analysis of the samples has been used to

(PDF) Thermal decomposition of natural dolomite

The loss of mechanical strength of dolomite might be explained by the occurrence of secondary calcination, converting the partially-calcined dolomite (MgO-CaCO 3 ) to full-calcined dolomite (MgO-CaO).

Effect of natural dolomite calcination temperature on ...

The effect of calcination temperature and dolomite-to-quartz mass ratio on the properties of calcined raw material were investigated. After calcination, the influence of dolomite-quartz powders ...

Thermal behavior of natural dolomite | SpringerLink

2014-12-3 · The dolomite''s decomposition occurs in a single stage which is a continuous and a slow process. At the temperature of 923 K, the complete decomposition takes 7 h and 25 min. The degree of dolomite conversion (α) was calculated based on the mass reduction measured at a given time and after the complete conversion, as illustrated in Fig. 4.

Dolomite Stabilized Zirconia for Refractory Application ...

Therefore, higher is the calcination temperature for ZrO2-dolomite mixture, higher will be the fraction of stabililized ZrO2 phase. From Table 2 it is observed that (t+c) increases with increasing the calcinations temperature and it increases rapidly in the temperature 1000-1300°C, the increase is relatively small from 1300°C and 1400°C.