The calcination reaction of two limestones and a dolomite with different porous structures was studied by thermogravimetric analysis. The effects of calcination temperature (1048-1173 K), particle size (0.4-2.0 mm), CO2 concentration (0-80 %) and total pressure (0.1-1.5 MPa) were investigated. SEM analysis indicated the existence of two different particle calcination models depending on the sor...

A bench work study was carried out to investigate the use of kaolinitic clay containing 29.4% Al2O3 extremely abundant in Saudi Arabia for the production of pure alumina by calcination at 700 o C for 1h (recommended by previous investigators) then leached by hydrochloric acid. The effects of leaching temperature (25 o C to boiling temperature), period of activation (10-150 minutes), acid concen...

The conversion of thermally pretreated CaO along successive carbonation/calcination cycles has been investigated, as a ected by looping-calcination conditions, by means of Thermogravimetric Analysis (TGA). Sorbent samples have been subjected in-situ to a thermal preheating program based on Constant Rate Thermal Analysis (CRTA) by virtue of which decarbonation is carried out at a low controlled ...

The effect of the calcination conditions on the catalytic activity for N2O decomposition of 2.5% RhOx/CeO2 catalysts has been investigated. Ramp and flash calcinations have been studied (starting calcinations at 25 or 250/350 °C, respectively) both for cerium nitrate and ceria-impregnated rhodium nitrate decomposition. The cerium nitrate calcination ramp has neither an effect on the physico-che...

in this work, hydrochloric acid is used to remove iron impurities in the bauxite ore contained in the diasporite mineral located in the sari region. the bauxite ore was calcined at different temperatures and times, and then dissolved in a hydrochloric acid solution. after determining the optimum calcination conditions in 1 h at 900 °c, the response surface methodology (rsm) with four factors in...

7 Even though an increasing number of pilot-scale plants are demonstrating the potential ef8 ficiency of the Ca-looping technology to capture CO2 at a commercial level, a still standing 9 matter of concern is the loss of carbonation reactivity of the regenerated CaO by calcination, 10 which is expected to be particularly marked at realistic conditions necessarily implying a high 11 CO2 partial ...

The parameters to prepare U3O8 by calcination from ammonium uranyl carbonate were optimized by using response surface methodology. A quadratic equation model for the value of total uranium and U4+ of triuranium octaoxide was built and the effects of main factors and their corresponding relationships were obtained. The statistical analysis of the results indi...

8 We analyze the role of limestone crystallinity on its CO2 capture performance when subjected 9 to carbonation/calcination cycles at conditions mimicking the Ca-looping (CaL) technology 10 for post-combustion CO2 capture. The behavior of raw and pretreated limestones (milled and 11 thermally annealed) is investigated by means of thermogravimetric analysis (TGA) tests under 12 realistic sorbent...

The calcination reaction of limestone (CaCO3) to yield lime (CaO) is at the heart of many industrial applications as well as natural processes. In the recently emerged calcium-looping technology, CO2 capture is accomplished by the carbonation of CaO in a gas-solid reactor (carbonator). CaO is derived by the calcination of limestone in a calciner reactor under necessarily high CO2 partial pressu...

There is an increasing interest in the application of photocatalytic properties for disinfection of surfaces, air, and water. Titanium dioxide is widely used as a photocatalyst, and the addition of silver reportedly enhances its bactericidal action. However, the synergy of silver nanoparticles and TiO(2) is not well understood. The photocatalytic elimination of Bacillus atrophaeus was examined ...