Production of quicklime from Ashaka limestone through calcination process

This study is on the production of quicklime from Ashaka limestone through calcination process. Effects of temperature, particle size and time on quicklime yield were determined. The experiment was carried out at temperatures of 800, 900, 1000, 1100 and 1200 0C, particle sizes of 80mm, 90mm, 100mm, 300mm and 425mm and times of 0.5hr, 1hr, 2hrs, 3hrs and 4hrs. Analyses of the results showed that quicklime was successfully produced from Ashaka limestone through the calcination process. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Recorded model F-value of 134.35 implies that the model is significant. The predicted R² of 0.9597 is in reasonable agreement with the adjusted R² of 0.9844; the difference is less than the critical value of 0.2. Optimum yield of 73.48% was obtained at optima operating conditions; temperature of 1000 0C, particle size of 90 µm and time of 3 hrs.

Processing of Ogbolokuta limestone through calcination technique for quicklime production

Report on processing of Ogbolokuta limestone through calcination technique for quicklime production is presented. The limestone was washed to remove impurities, dried, ground in to powder form and classified with the aid of the automatic vibrating sieves of 80mm, 90mm, 100mm, 300mm and 425mm. X-ray fluorescence spectroscopy was used to determine the chemical compositions of the limestone, while its mineralogical composition was determined by X-ray diffractometer. Scanning electron microscope was used to study the surface morphology of the sample. Sample size area was grossly estimated by Langmuir method, while density functional theory was used to obtain different pore structural morphology of the sample. Analyses of the results showed that CaO (65.7%) is the predominant chemical constituent, and calcite is the main mineral of the limestone. Quicklime was successfully produced from Ogbolokuta limestone through calcination process. Calcination of the limestone enhanced its surface morphology. The quicklime yield was temperature, particle size and time dependent.

Alternative Clinker Technologies for Reducing Carbon Emissions in Cement Industry: A Critical Review

Currently, the production of one ton of ordinary Portland cement (OPC) releases considerable amounts of CO2 into the atmosphere. As the need and demand for this material grows exponentially, it has become a challenge to increase its production at a time when climate-related problems represent a major global concern. The two main CO2 contributors in this process are fossil fuel combustion to heat the rotary kiln and the chemical reaction associated with the calcination process, in the production of the clinker, the main component of OPC. The current paper presents a critical review of the existent alternative clinker technologies (ACTs) that are under an investigation trial phase or under restricted use for niche applications and that lead to reduced emissions of CO2. Also, the possibility of transition of clinker production from traditional rotary kilns based on fuel combustion processes to electrification is discussed, since this may lead to the partial or even complete elimination of the CO2 combustion-related emissions, arising from the heating of the clinker kiln.

Clay calcination technology: state-of-the-art review by the RILEM TC 282-CCL

The use of calcined clays as supplementary cementitious materials provides the opportunity to significantly reduce the cement industry’s carbon burden; however, use at a global scale requires a deep understanding of the extraction and processing of the clays to be used, which will uncover routes to optimise their reactivity. This will enable increased usage of calcined clays as cement replacements, further improving the sustainability of concretes produced with them. Existing technologies can be adopted to produce calcined clays at an industrial scale in many regions around the world. This paper, produced by RILEM TC 282-CCL on calcined clays as supplementary cementitious materials (working group 2), focuses on the production of calcined clays, presents an overview of clay mining, and assesses the current state of the art in clay calcination technology, covering the most relevant aspects from the clay deposit to the factory gate. The energetics and associated carbon footprint of the calcination process are also discussed, and an outlook on clay calcination is presented, discussing the technological advancements required to fulfil future global demand for this material in sustainable infrastructure development.

Effect of argon annealing method on structural and ferromagnetic properties in Fe-doped SnO2 powders

Nanocrystalline powders of Fe-doped SnO2 (Sn1-xFexO2) (x = 0.00, 0.01, 0.03, 0.05) were prepared by a hydrothermal method. The powders were calcined in argon atmosphere at 600 °C for 2 h, causing phase transition from diamagnetic and weak ferromagnetic behavior to a ferromagnetic state. No trace and other magnetic impurity phases was detected in the samples with Fe content up to 3%. The calcined samples of Fe-doped SnO2 revealed the room temperature ferromagnetism with highest magnetization values of 434.07 memu/g at 15 kOe for x = 0.05. The room temperature ferromagnetism of samples originated from oxygen vacancies that occurred in the argon calcination process. In particular, oxygen vacancy shows a significant role in ferromagnetic coupling corresponding to F-center interaction.

Sintesis dan Karakterisasi Lihium Iron Phosphate (LiFePO4) Menggunakan Metoda Solid State Reaction Sebagai Katoda Pada baterai Lithium-Ion

ABSTRAK Perkembangan baterai tak luput dari kebutuhan energi yang kian meningkat. Meskipun sumber energi tidak terpaku pada baterai, namun baterai banyak diminati karena dapat menampung cukup banyak energi, relatif aman, dan bersifat portable. Penelitian ini bertujuan untuk mensintesa dan mengetahui karakteristik salah satu jenis katoda baterai lithium-ion yaitu Lithium Iron Phosphate (LiFePO4) dengan variasi mol reagent berdasarkan perbandingan stoikiometri dan suhu proses kalsinasi 600°C, 700°C, dan 800°C selama 3x3 jam menggunakan metode solid state reaction dengan Li2SO4.H2O, FeSO4.7H2O, dan KH2PO4 sebagai reagent. Produk hasil kalsinasi 800°C dengan variasi 0.1 mol dijadikan sampel untuk dianalisa dan dikarakterisasi karena memiliki penurunan berat endapan BaSO4 tertinggi. Hasil karakterisasi menggunakan FTIR menunjukan gugus fungsi P-O yang cukup kuat, sementara hasil karakterisasi menggunakan SEM/EDX menunjukan partikel yang terbentuk memiliki ukuran sekitar 160nm hingga 14µm dan terdapat atom S yang merupakan impurities dalam produk. Pola difraksi hasil uji XRD menunjukan terbentuknya sejumlah fasa seperti LiFePO4, LiFeP2O7, dan Li3PO4. ABSTRACT The development of batteries is inseparable from the increasing energy needs. Although energy sources are not available for batteries, batteries are in great demand because they can store a lot of energy, are relatively safe, and are portable. This study aims to synthesize and determine the characteristics of one type of lithium-ion battery cathode, namely Lithium Iron Phosphate (LiFePO4) with various mole reagents based on stoichiometric ratios and calcination process temperatures of 600oC, 700oC, and 800oC for 3x3 hours using the solidstate reaction method with Li2SO4.H2O, FeSO4.7H2O, and KH2PO4 as reagents. The 800oC calcined product with 0.1 mol variation was sampled for analysis and characterization because it had the highest weight loss of BaSO4 deposits. The results of characterization using FTIR showed that the functional group P-O are quite strong, while the results of characterization using SEM/EDX showed that the particles formed had a size of about 160nm to 14µm and contained S atoms which were impurities in the product. The diffraction pattern of XRD test results shows the formation of phase numbers such as LiFePO4, LiFeP2O7, dan Li3PO4.