Reduction of clinkerisation temperature by addition of salts containing fluorine

2006 ◽  
Vol 33 (8) ◽  
pp. 1090-1097 ◽  
Author(s):  
Larbi Kacimi ◽  
Angélique Simon-Masseron ◽  
Abdelhamid Ghomari ◽  
Zoubir Derriche
Keyword(s):  
Setting Time ◽  
Physical And Mechanical Properties ◽  
Specific Area ◽  
Mineralogical Composition ◽  
Optical Microscope ◽  
Strength Properties ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
Burning Temperature ◽  
X Ray

The influence of some salts containing fluorine (CaF2, NaF, and KF) on the reduction of burning temperature of Portland clinker from three Algerian cement factories (units of Zahana, Beni-Saf, Chlef) has been studied in this paper. X-Ray fluorescence, optical microscope technique, and powder X-ray diffraction were then used to characterize each clinker and its raw mixture in terms of chemical composition and clinker mineralogical composition. The effects of these mineralizers on structural and morphological properties of clinker minerals and on the presence of alite were investigated by scanning electron microscopy combined with microprobe analysis. Physical and mechanical properties (density, specific area, setting time, hydration heat, expansion, and mechanical strength) of some samples were studied. The results show that the presence of the mineralizers under study induced a decrease of the burning temperature. For example, NaF improved the crystallization of clinker minerals with high alite rate. These characteristics explain the improvement of physical and strength properties of the new clinkers.Key words: clinker, alite, structure, hydraulic activity, clinkerisation temperature, mineralizer.

Study of the Characterization of Smectitic Clays from a Town in the State of Paraíba

2015 ◽  
Vol 820 ◽  
pp. 51-55
Author(s):  
I.A. Silva ◽  
I.D.S. Pereira ◽  
W.S. Cavalcanti ◽  
F.K.A. Sousa ◽  
Gelmires Araújo Neves ◽  
...  
Keyword(s):  
Specific Area ◽  
Mineralogical Composition ◽  
Exchange Capacity ◽  
The State ◽  
Chemical Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Technological Improvements ◽  
The Town

The State of Paraíba has gained prominence in the production of raw bentonite in Brazil, where a new deposit has been found in the town of Sossego-PB, besides the deposit in the town of Boa Vista-PB. With the raise in the demand, the traditional reserves are depleting after several years of exploration, and this fact may result in a higher dependence on imported clays, thus existing a great interest in the discovery and characterization of new deposits, also guaranteeing technological improvements for the region. So, the objective of this work is to characterize the new deposits of the State of Paraíba, aiming at analyzing the characteristics the prove their classification as smectitic clays. The characterization was made through the analysis of chemical composition by X-ray fluorescence (EDX), X-ray diffraction (XRD), thermogravimetric analysis and thermal differential analyses (TG and DTA), cation-exchange capacity (CEC) and specific area (SA). The results prove that the studied samples presented, in their mineralogical composition, smectite, kaolinite and quartz, besides thermal and chemical behavior typical smectitic clays.

Synthesis of Mullite by the Pechini Method

2015 ◽  
Vol 820 ◽  
pp. 107-112
Author(s):  
Aluska do Nascimento Simões Braga ◽  
Rosiane Maria da Costa Farias ◽  
Danubia Lisbôa Costa ◽  
Gelmires Araújo Neves ◽  
Hélio de Lucena Lira ◽  
...  
Keyword(s):  
Pechini Method ◽  
Synthesis Method ◽  
Physical And Mechanical Properties ◽  
Morphological Properties ◽  
Synthesis Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nanosized Materials ◽  
The Past ◽  
Successful Technique

In the past few years there is a considerable interest in the study and application of the mullite, due to its chemical, physical and mechanical properties, in which are correlated with the synthesis method used. Aiming to achieve better structural and morphological properties, many synthesis methods are being studied, in which the Pechini method is highlighted, which is today one of the most viable methods and successful technique used in the preparation of nanosized materials. Thus, this study proposes the production of mullite powders by the Pechini method. The influence of different routes of synthesis was investigated. The material was sintered at 1100oC/2h, 1200oC/2h and 1400/2h, and characterized by X ray diffraction (XRD) and thermal analysis (TG/DTG and DTA). The results showed that the synthesis route did not interfere in the formation of the formed phases, and the mullite for both routes, was formed from 1200oC.

Mineralogical Composition and Microstructure of Sinter in Ansteel

2014 ◽  
Vol 685 ◽  
pp. 37-42
Author(s):  
Jie Liu ◽  
Ming Shun Zhou ◽  
Li Wei Zhai ◽  
Hui Zhang ◽  
Li Bing Xu
Keyword(s):  
Electron Microscope ◽  
Glass Phase ◽  
Mineralogical Composition ◽  
Optical Microscope ◽  
Dicalcium Silicate ◽  
Calcium Ferrite ◽  
X Ray Diffraction ◽  
Metallurgical Property ◽  
X Ray ◽  
Scanning Electron

In order to improve the qualities of sinter of Ansteel, the sinter’s metallurgical property was examined and analyzed that from the second workshop and the fourth workshop of ironmaking plant. And mineralogical composition and microstructure in high basicities sinter were investigated and analyzed by the X-ray diffraction, the optical microscope and the scanning electron microscope in laboratory. It was found that the differences between in sinter’s mineralogical composition and microstructures are according with the differences in chemical composition and the metallurgical indexes. Both the sinter’s minerals are mainly composed of hematite, magnetite or maghemite, calcium ferrite, dicalcium silicate, silicate glass phase. The content of the carbon in the fourth workshop is higher. So, it should decrease the content of the carbon that makes the microstructure of the sinter more rational.

Physical and Mechanical Properties of Cement Paste Were Used Partially with Fly Ash and Kaolin Waste

2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Room Temperature ◽  
Physical And Mechanical Properties ◽  
Partial Replacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lime Water ◽  
Diffraction Patterns ◽  
Iron Mold

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.

scholarly journals Features of the hydration process of the modified blended cement for fiber cement panels

2018 ◽  
Vol 170 ◽  
pp. 03030 ◽  
Author(s):  
Rustem Mukhametrakhimov ◽  
Liliya Lukmanova
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Blended Cement ◽  
Physical And Mechanical Properties ◽  
Hydration Process ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
Structure Form ◽  
Silicate Phase ◽  
X Ray

The paper studies features of the hydration process of the modified blended cement for fiber cement panels (FCP) using differential thermal analysis, X-ray diffraction analysis, electron microscopy and infrared spectroscopy. It is found that deeper hydration process in silicate phase, denser and finer crystalline structure form in fiber cement matrix based on the modified blended cement. Generalization of this result to the case of fiber cement panels makes it possible to achieve formation of a denser and homogeneous structure with increased physical and mechanical properties.

Sedimentary Clays as Geopolymer Precursor

2018 ◽  
Vol 39 ◽  
pp. 97-111
Author(s):  
F. Mostefa ◽  
Nasr Eddine Bouhamou ◽  
H.A. Mesbah ◽  
Salima Aggoun ◽  
D. Mekhatria
Keyword(s):  
Sodium Hydroxide ◽  
Mineralogical Composition ◽  
Cementitious Materials ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
Calorimetric Analysis ◽  
X Ray ◽  
Before And After ◽  
Mechanical Performances

This work aims to study the feasibility of making a geopolymer cement based on dredged sediments, from the Fergoug dam (Algeria) and to evaluate their construction potential particularly interesting in the field of special cementitious materials. These sediments due to their mineralogical composition as aluminosilicates; are materials that can be used after heat treatment. Sedimentary clays were characterized before and after calcination by X-ray diffraction, ATG / ATD, spectroscopy (FTIR) and XRF analysis. The calcination was carried out on the raw material sieved at 80 μm for a temperature of 750 ° C, for 3.4 and 5 hours. The reactivity of the calcined products was measured using isothermal calorimetric analysis (DSC) on pastes prepared by mixing an alkaline solution of sodium hydroxide (NaOH) 8 M in an amount allowing to have a Na / Al ratio close to 1 (1: 1). Also, cubic mortar samples were prepared with a ratio L / S: 0.8, sealed and cured for 24 hours at 60 ° C and then at room temperature until the day they were submited to mechanical testing. to check the extent of geopolymerization. The results obtained allowed to optimize the calcination time of 5 hours for a better reactivity of these sediments, and a concentration of 8M of sodium hydroxide and more suitable to have the best mechanical performances.

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

Crystallization of simonkolleite (Zn5Cl2(OH)8 ∙ H2O) in powder samples prepared for mineral composition analysis by quantitative X-ray diffraction (QXRD)

Nafta-Gaz ◽  
2021 ◽  
Vol 77 (5) ◽  
pp. 293-298
Author(s):  
Urszula Zagórska ◽  
◽  
Sylwia Kowalska ◽  
Keyword(s):  
Quantitative Analysis ◽  
Internal Standard ◽  
Mineralogical Composition ◽  
Hydrocarbon Exploration ◽  
Composition Analysis ◽  
Internal Standard Method ◽  
X Ray Diffraction ◽  
Method Error ◽  
X Ray ◽  
Significant Difference

The analysis of mineralogical composition by quantitative X-ray diffraction (QXRD) is one of the standard research methods used in hydrocarbon exploration. In order to improve it and to obtain better results, the methodology of quantitative analysis used at Well Logging Department is being periodically (more or less) modified. After the introduction of the improvements, comparative analyses were performed on archival samples. Reflections from an unidentified phase which did not occur in the tested Rotliegend sandstone samples were noticed on X-ray diffractograms of archival samples. Reflections of a mineral called simonkolleite were identified in the X-ray diffraction database. Chemically it is a hydrated zinc chloride of the formula: Zn5Cl2(OH)8 × H2O. Analysis of the composition of samples in which simonkolleite crystallised, indicated that the mineral is being formed in the result of the slow reaction of zinc oxide with halite (NaCl) and water vapour. An attempt was made to determine the influence of the presence of this mineral on the results of the quantitative analysis of mineralogical composition. The above methodology was applied on a group of ten samples. The results of the quantitative analysis conducted for archival samples stored with added zincite standard containing simonkolleite and for new, freshly grinded (without artifact) samples were compared. The comparison of the obtained results showed a slight influence of this mineral on the quantitative composition of the remaining components. The difference between the results usually did not exceed the method error. At the same time a significant difference in the calculated content of the internal standard was noted – on average 1% less in archival than in new samples. This shows that the reaction occurring in the archival samples will affect the evaluation of the quality of the obtained quantitative analysis, at the same time excluding the possibility of determining the rock’s amorphous substance content with the internal standard method.

scholarly journals Extraction of γ-Alumina from Low-Cost Kaolin

Resources ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 63
Author(s):  
Khalil Ibrahim ◽  
Mohammad Moumani ◽  
Salsabeela Mohammad
Keyword(s):  
Low Cost ◽  
Morphological Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Aluminum Metal ◽  
Alumina Particles ◽  
Two Stages ◽  
Method Of Extraction ◽  
Microcrystalline Powder ◽  
Made In

A combined process is proposed for the utilization of local kaolin to produce alumina particles. The applied process is made in two stages: calcination at 700 °C with sodium chloride and leaching with sulfuric followed by hydrochloric acids. The optimal extraction efficiency can be obtained when the conditions are as follows: leaching temperature is at 140 °C, leaching time is 3 h 45 min and concentration of sulfuric acid is 40 wt.%. The results show that the purity of alumina reaches 79.28%, which is suitable for the production of aluminum metal. It is evident that this method of extraction of alumina from the kaolin ash is practical and feasible. The structural and morphological properties of the calcined microcrystalline powder was characterized by X-ray diffraction and scanning electron microscope (SEM).

scholarly journals A prototype handheld X-ray diffraction instrument

2018 ◽  
Vol 51 (6) ◽  
pp. 1571-1585 ◽  
Author(s):  
Graeme Hansford
Keyword(s):  
Sample Preparation ◽  
Mineralogical Composition ◽  
General Purpose ◽  
Performance Criteria ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fine Grained ◽  
Back Reflection ◽  
Promising Area ◽  
Sample Position

A conceptual design for a handheld X-ray diffraction (HHXRD) instrument is proposed. Central to the design is the application of energy-dispersive XRD (EDXRD) in a back-reflection geometry. This technique brings unique advantages which enable a handheld instrument format, most notably, insensitivity to sample morphology and to the precise sample position relative to the instrument. For fine-grained samples, including many geological specimens and the majority of common alloys, these characteristics negate sample preparation requirements. A prototype HHXRD device has been developed by minor modification of a handheld X-ray fluorescence instrument, and the performance of the prototype has been tested with samples relevant to mining/quarrying and with an extensive range of metal samples. It is shown, for example, that the mineralogical composition of iron-ore samples can be approximately quantified. In metals analysis, identification and quantification of the major phases have been demonstrated, along with extraction of lattice parameters. Texture analysis is also possible and a simple example for a phosphor bronze sample is presented. Instrument formats other than handheld are possible and online process control in metals production is a promising area. The prototype instrument requires extended measurement times but it is argued that a purpose-designed instrument can achieve data-acquisition times below one minute. HHXRD based on back-reflection EDXRD is limited by the low resolution of diffraction peaks and interference by overlapping fluorescence peaks and, for these reasons, cannot serve as a general-purpose XRD tool. However, the advantages ofin situ, nondestructive and rapid measurement, tolerance of irregular surfaces, and no sample preparation requirement in many cases are potentially transformative. For targeted applications in which the analysis meets commercially relevant performance criteria, HHXRD could become the method of choice through sheer speed and convenience.

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