scholarly journals Coupled Preparation of Ferronickel and Cementitious Material from Laterite Nickel Ores

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4992
Author(s):  
Ruimeng Shi ◽  
Xiaoming Li ◽  
Yaru Cui ◽  
Junxue Zhao ◽  
Chong Zou ◽  
...  
Keyword(s):  
Direct Reduction ◽  
Cementitious Materials ◽  
Tricalcium Silicate ◽  
Cementitious Material ◽  
Raw Material ◽  
Tricalcium Aluminate ◽  
Thermodynamic Conditions ◽  
Nickel Ores ◽  
Main Components ◽  
Factsage Software

Nickel slags can be produced through ferronickel preparation by the pyrometallurgical processing of laterite nickel ores; however, such techniques are underutilized at present, and serious environmental problems arise from the stockpiling of such nickel ores. In this study, a modification to the process of ferronickel preparation by the direct reduction of carbon bases in laterite nickel ores is proposed. The gangue from the ore is used as a raw material to prepare a cementitious material, with the main components of tricalcium silicate and tricalcium aluminate. By using FactSage software, thermodynamic calculations are performed to analyze the reduction of nickel and iron and the effect of reduction on the formation of tricalcium silicate and tricalcium aluminate. The feasibility of a coupled process to prepare ferronickel and cementitious materials by the direct reduction of laterite nickel ore and gangue calcination, respectively, is discussed under varying thermodynamic conditions. Different warming strategies are applied to experimentally verify the coupled reactions. The coupled preparation of ferronickel and cementitious materials with calcium silicate and calcium aluminate as the main phases in the same experimental process is realized.

Investigation on a New Hydraulic Cementitious Binder Made from Phosphogypsum

2013 ◽  
Vol 864-867 ◽  
pp. 1923-1928
Author(s):  
Yue Xu ◽  
Jian Xi Li ◽  
Li Li Kan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Active Carbon ◽  
High Strength ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cementitious Material ◽  
Saturation Ratio ◽  
Tricalcium Aluminate ◽  
Cementitious Binder

A new kind of high strength cementitious material is made from phosphogypsum (PG), active carbon and fly-ash. Through the orthogonal research, it was showed that the calcination temperature, retention time, dosage of active carbon and fly ash on the compressive strength of cementitious binder are the most important. The result also showed that, in the conditions of temperature 1200°C, time retention 30 min, dosage of active carbon 10%, dosage of fly ash 5%, the compressive strength of the cementitious material for 3d and 28d could reach to 46.35MPa and 92.70MPa, the content of sulfur trioxide was 11.60% accordingly. A lot of active mineral materials, such as dicalcium silicate, tricalcium silicate, tricalcium aluminate were formed in the calcination. The C-S-H gel, calcium hydroxide and ettringite were found in 3d and 28d hydrates. It is found that the lime saturation ratio and silica modulus need to be control between 0.40~0.65 and 4~8 in order to produce high strength cementitious material.

The Experimental Study on Performance of the High-Content Slag Cementitious Materials

2013 ◽  
Vol 634-638 ◽  
pp. 311-316
Author(s):  
Ping Yang ◽  
Zhi Gui Qin ◽  
Wei Xia Zhao ◽  
Xi Nan Cai ◽  
Xiao Lin Yuang
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Mass Production ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Hydration Heat ◽  
Raw Material ◽  
Heat Temperature ◽  
Economic Profit ◽  
Easy Operation

The research adopts the raw material of 89% slag with the composite activators and the compressive strength, hydration heat, temperature and expansion property of the material are studied. And the new cementitious material is obtained with the properties of low-heat and small expansion, convenience-confect, easy-operation and need no mass production. This material has the remarkable economic profit and good application foreground especially in the mass grouting engineering.

scholarly journals Experimental Study on the Preparation of Cementing Materials by Direct Reduction Coupling of a Hematite-Carbon Base

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1086 ◽  
Author(s):  
Ruimeng Shi ◽  
Junxue Zhao ◽  
Xiaoming Li ◽  
Chong Zou ◽  
Yaru Cui ◽  
...  
Keyword(s):  
Experimental Study ◽  
Iron Ore ◽  
Raw Materials ◽  
Direct Reduction ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Raw Material ◽  
Experimental Conditions ◽  
Reduction Of Iron ◽  
Direct Reduction Of Iron

The reduction of iron in hematite and process coupling of cementing material generated from gangue components are explored in this paper, and a technical proposal for preparing directly reduced iron and cementing materials considering the processes of energy and material flows is proposed. An experimental study preparing cementing materials, such as tricalcium silicate and dicalcium silicate, by roasting the components, was performed. In this study, hematite was used as the raw material and powdered carbon was added, as the reducing agent, with CaO; at the same time, the gangue components of iron ore were used as the principal raw materials for the process of directly reduced iron preparation by direct reduction of iron ore. The FactSage software package was used to perform thermodynamic calculations of the reduction of iron and its influence on the formation of tricalcium silicate and dicalcium silicate. The feasibility of the direct reduction of iron to elemental iron and preparation of cementing materials by roasting of gangue components under the studied thermodynamic conditions was discussed. Different temperature control strategies were used to verify the reaction coupling test. The results showed that zero-valent iron could be produced by roasting and reducing hematite under certain experimental conditions, and cementing materials, such as tricalcium silicate and dicalcium silicate, could be produced simultaneously by reacting the gangue components with CaO. Fe2O3 exerted an adverse effect on the formation of tricalcium silicate, and sufficient reduction of the iron was a precondition for the formation and stability of tricalcium silicate.

scholarly journals Effects of high salinity wastewater on the properties of coal gasification residue-based cementitious material

2021 ◽  
Vol 25 (6 Part A) ◽  
pp. 4161-4169
Author(s):  
Feng Wu ◽  
Hui Li
Keyword(s):  
Coal Gasification ◽  
High Salinity ◽  
Tap Water ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Raw Material ◽  
Strength Development ◽  
The Sustainable Development ◽  
Salinity Wastewater ◽  
Mixing Water

High salinity wastewater and coal gasification residue are the by-products which need to be utilized as resources for the sustainable development of coal-to-chemicals technology. Using coal gasification residue as the main raw material, supplemented with 10% Portland cement, and high salinity wastewater as the mixing water instead of tap water to prepare cementitious materials. The XRD, TG-DTG, FTIR, SEM, and MIP were used to analyze the influence mechanism of high salinity wastewater on the properties of cementitious materials. The results show that high salinity wastewater was beneficial to the strength development of the cementitious material. When 25% high salinity mastewater was used instead of tap water, the enhancing rates of compressive strength was 294%, 177%, and 186% curing at 3, 7, and 28 days. This is main due to the sulfate and chloride in the high salinity wastewater can promote the formation of C-S-H gels, Friedel?s, salts and C-A-S-H gels in the hydration process of pastes, which can promote the densification of structure. The pores distribution and structure were optimized, increasing the proportion of capillary pores and decreasing macropore to promote the micro-structure more dense. This study can provide a new idea for the comprehensive utilization of industrial waste and achieve the purpose of ?waste control by waste?.

Pengurangan Kadar Minyak Pada Abon Ikan Produksi Savitri Dan Tiaras Dengan Penerapan Alat Peniris Serbaguna Di Kota Kupang

2018 ◽  
Vol 2 (2) ◽  
pp. 20
Author(s):  
Muntasir Muntasir ◽  
Pius Weraman
Keyword(s):  
Raw Material ◽  
Added Value ◽  
Filter Model ◽  
Simulation Tools ◽  
The Public ◽  
Fish Meat ◽  
Efficiency Increase ◽  
Main Components ◽  
Design And Manufacture

Community Partnership Program in small home industry of making fish floss brand "Savitri" and "Tiaras" inKupang city in the form of application of electric centrifugation filter model has been implemented. One of the problemsin the production of Savitri and Tiaras fish floss is that there is still a lot of oil in the frying product which is only drainedon a simple sieve and then placed for some time on traditional tools of filter and paper that can cause low quality and lowquality, so it is necessary to reduce the oil yield frying fish floss product. In order to increase the added value and sellingvalue of the products, it is necessary synergy between Universities and Partners in the form of application of the results ofscience and technology to the public. The main components of the composer of the versatile filter are the cylindrical plateas the bucket of the filter, the cylinder filter, the electric dynamo as the centrifuge system rotator and the load-bearingconstruction. The method of this program is the provision of materials, design and manufacture of tools, demonstrationtools and the provision of a versatile filter cylinder system centrifuge model by the team, simulation tools, specialcounseling at the location of partners and suggestions as a follow-up in the endurance of production. The output of thisprogram can provide added value in the form of the use of this tool can improve labor efficiency, increase productivitypartners by producing 40 kg to 50 kg raw material, raw fish marlin, fish meat after cleaning, processed, fried, in andpacked into 80-100 packs of fish floss with the price of Rp. 40,000.00 per package weighing 250 grams. With estimatedpartners will earn a profit of Rp 3,200,000 - 4,000,000.00 per production or 12,800,000.00 - 16,000,000.00 per month incash and consumptions, as well as the abundance of non-greasy, clean and hybrid fish products

scholarly journals Effect of a Nitrite/Nitrate-Based Accelerator on the Strength Development and Hydrate Formation in Cold-Weather Cementitious Materials

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1006
Author(s):  
Akira Yoneyama ◽  
Heesup Choi ◽  
Masumi Inoue ◽  
Jihoon Kim ◽  
Myungkwan Lim ◽  
...  
Keyword(s):  
Calcium Nitrate ◽  
Hydrate Formation ◽  
Frost Damage ◽  
Cementitious Materials ◽  
Heat Of Hydration ◽  
Cold Weather ◽  
Strength Development ◽  
Hardened Cement ◽  
Tricalcium Aluminate ◽  
Nitrite Nitrate

Recently, there has been increased use of calcium-nitrite and calcium-nitrate as the main components of chloride- and alkali-free anti-freezing agents to promote concrete hydration in cold weather concreting. As the amount of nitrite/nitrate-based accelerators increases, the hydration of tricalcium aluminate (C3A phase) and tricalcium silicate (C3S phase) in cement is accelerated, thereby improving the early strength of cement and effectively preventing initial frost damage. Nitrite/nitrate-based accelerators are used in larger amounts than usual in low temperature areas below −10 °C. However, the correlation between the hydration process and strength development in concrete containing considerable nitrite/nitrate-based accelerators remains to be clearly identified. In this study, the hydrate composition (via X-ray diffraction and nuclear magnetic resonance), pore structures (via mercury intrusion porosimetry), and crystal form (via scanning electron microscopy) were determined, and investigations were performed to elucidate the effect of nitrite/nitrate-based accelerators on the initial strength development and hydrate formation of cement. Nitrite/nitrate-AFm (aluminate-ferret-monosulfate; AFm) was produced in addition to ettringite at the initial stage of hydration of cement by adding a nitrite/nitrate-based accelerator. The amount of the hydrates was attributed to an increase in the absolute amounts of NO2− and NO3− ions reacting with Al2O3 in the tricalcium aluminate (C3A phase). Further, by effectively filling the pores, it greatly contributed to the enhancement of the strength of the hardened cement product, and the degree of the contribution tended to increase with the amount of addition. On the other hand, in addition to the occurrence of cracks due to the release of a large amount of heat of hydration, the amount of expansion and contraction may increase, and it is considered necessary to adjust the amount used for each concrete work.

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.

scholarly journals Influence of Dimethacrylate Monomer on the Polymerization Efficacy of Resin-Based Dental Cements—FTIR Analysis

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 247
Author(s):  
Aleksandra Maletin ◽  
Ivan Ristic ◽  
Tanja Veljovic ◽  
Bojana Ramic ◽  
Tatjana Puskar ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Clinical Practice ◽  
Chemical Structure ◽  
Cementitious Materials ◽  
Degree Of Polymerization ◽  
Cementitious Material ◽  
Ftir Analysis ◽  
Dental Cement ◽  
Polymerization Mechanism ◽  
The Difference

The degree of polymerization for dimethacrylate resin-based materials (BisGMA, TEGDMA, UDMA, HEMA) ranges from 55 to 75%. Literature data indicate that polymerization efficacy depends, among other factors, on the type of methacrylate resin comprising the material. The aim of this study was to evaluate the polymerization efficacy of four dental cement materials characterized by different polymerization mechanisms using FTIR analysis. In the present study, the FTIR method was adopted to analyze the degree of polymerization efficacy of four resin-based dental cement materials, two of which were self-cured and two were dual-cured cements. The IR spectral analysis was performed 24 h after the polymerization of the cementitious material. RelyX ARC cement exhibits the lowest polymerization efficacy (61.3%), while that of Variolink II (85.8%) and Maxcem Elite is the highest (90.1%). Although the efficacy of self-cured cements appears to be superior, the difference is not statistically significant (p = 0.280). Polymerization efficacy largely depends on the chemical structure of the material in terms of the presence of a particular methacrylate resin and less on the polymerization mechanism itself, i.e., whether it is a self-cured or dually cured dental cement. Thus, in clinical practice, cementitious materials with a higher proportion of TEGDMA compared with BisGMA are recommended.

scholarly journals Transcriptomic Analysis of Fertilization Effects on the Biosynthesis of Sesquiterpenes in Essential Oils from Phoebe Bournei Twigs and Leaves

2021 ◽  
Author(s):  
Li Liu ◽  
Gongxiu He ◽  
Xu Wang ◽  
Dangquan Zhang
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Plant Biomass ◽  
Raw Material ◽  
Compound Fertilizer ◽  
Expression Of Genes ◽  
Leaf Essential Oil ◽  
Main Components ◽  
Fertilization Effects ◽  
Phoebe Bournei

Abstract Background: Phoebe bournei is a potential medicinal plant whose essential oil (EO) from leaves has potential inhibitory activities against some bacterium, tumor, and has a certain potential for hypoglycemic activity. Fertilization is a common and effective method to increase plant biomass, which can increase the raw material of essential oil, but has a certain impact on the composition and biological activity of plant essential oil. Results: The main components are sesquiterpenes in the essential oils from leaves and twigs. The yield of the essential oils and the content of their main components can be modulated by compost and compound fertilizer, to different degrees, and minor differences were registered among the categories of the components in essential oils. However, changes were strongly mirrored in some main components of essential oils. The content of the primary (+) - calarene in the leaf EO were strongly increased by compost, but the opposite happened by compound fertilizer. On the contrary, the effect of compound fertilizer was more significant on the main components of twig essential oil than compost. The transcriptome sequencing results of P. bournei showed that the total number of DEGs in twigs and leaves treated with compost were significantly more than that with compound fertilizer. No change was found in the expression of genes regulating principal components. However, the expression of several key genes regulating the upstream substrates for the synthesis of the sesquiterpenes was significantly changed: the expression of two key speed limiting enzymes genes (DXS and HMGR) and two important branch-point enzyme genes (FPPS and GGPPS) was significantly down regulated, while the expression of gene (HMGS) was significantly up-regulated.Conclusion: The expression levels of genes (DXS2, HMGR, FPPS and GGPPS) were significantly down regulated in leaves treated with compost, resulting in the changes of the yield and main components of the leaf essential oil. The effect of compost was more significant on the synthesis of the essential oil from P. bournei leaves than that of compound fertilizer.

scholarly journals X-ray diffraction analysis of MTA-Plus, MTA-Angelus and DiaRoot BioAggregate

2014 ◽  
Vol 08 (02) ◽  
pp. 211-215 ◽  
Author(s):  
Yeliz Guven ◽  
Elif Bahar Tuna ◽  
Muzaffer Emin Dincol ◽  
Oya Aktoren
Keyword(s):  
Crystal Structure ◽  
Tantalum Oxide ◽  
Xrd Analysis ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Glass Slide ◽  
Phase Identification ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tricalcium Aluminate

ABSTRACT Objective: The purpose of this study was to investigate and compare the crystalline structures of recently released MTA Plus (MTA-P), MTA Angelus (MTA-A), DiaRoot BioAggregate (BA) by X-ray diffraction (XRD) analysis. Materials and Methods: Phase analysis was carried out on powder and set forms of tested materials. The powder specimens placed into sample holders that were packed with a glass slide and the set samples prepared according to the manufacturer's instructions were placed into molds. The samples after being set for three days at 37°C and 100% humidity in an incubator were mounted onto the XRD machine and phase identification was accomplished using a search-match software program. Results: XRD findings indicated that major constituents of MTA-P were bismuth oxide, portlandite, dicalcium silicate and tricalcium silicate. The crystal structure of MTA-A were similar to those of MTA-P except for the absence of portlandite. Additionally, MTA-A had tricalcium aluminate differing from MTA-P. BA mainly differed from MTA-P and MTA-A by the radiopacifier (tantalum oxide-TO) in its composition. Conclusions: The majority of constituents of the tested materials have shown similarity except for the presence of tricalcium aluminate in MTA-A and the inclusion of TO in BA. In addition, set MTA-P showed a strong peak of portlandite.

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