scholarly journals Synthesis of M-Hexaferrites Material Based on Natural Iron Sand with Metal Co Doping Using the Coprecipitation Method

2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Susilawati Susilawati ◽  
Aris Doyan ◽  
Lalu Muliyadi
Keyword(s):  
Hydrochloric Acid ◽  
Calcination Temperature ◽  
Mole Fraction ◽  
Coprecipitation Method ◽  
Distilled Water ◽  
Metal Doping ◽  
Co Doping ◽  
Chloride Hexahydrate ◽  
Natural Iron

The synthesis of M-hexaferrite with metal doping Co (BaFe12-3xCoxO19 ) based on natural iron sand at Ketapang beach in Pringgabaya Subdistrict, East Lombok using the coprecipitation method has been successful. The basic ingredients used in this study were natural iron sand and BariumCarbonate (BaCO3) powder, while the doping material used was Cobalt (II) Chloride Hexahydrate (CoCl2.6H2O) powder with a variety of mole fraction (X = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0). The solvent uses 37% hydrochloric acid (HCl), 25% NH4OH solution, and distilled water. The sample formed was then calcined at 200 0C, 400 0C, 600 0C, 800 0C and 1000 0C. The resulting sample shows that there is an effect of Co doping and calcination temperature in the formation of barium M-hexaferrite. The higher the mole fraction of Co doping ions and the calcination temperature, the darker the color of the powder produced. 

scholarly journals SINTESIS BAHAN M-HEXAFERRITES DENGAN DOPING LOGAM Co MENGGUNAKAN METODE KOPRESIPITASI

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Khaerunnisa Khaerunnisa ◽  
Susilawati Susilawati ◽  
Lalu Rudyat Telly Savalas ◽  
Muhammad Taufik ◽  
Wahyudi Wahyudi
Keyword(s):  
Mole Fraction ◽  
Filter Paper ◽  
Homogeneous Solution ◽  
Basic Material ◽  
Distilled Water ◽  
Hot Plate ◽  
Magnetic Stirrer ◽  
Chloride Hexahydrate ◽  
Brownish Black ◽  
Black Color

Has successfully carried out the synthesis of M-hexferrites with doping metal Co. using coprecipitation method in which the basic material used in this study is BaCO3, FeCl3.6H2O, and CoCl2 (Pa) in the form of powder with a purity of 99.99% by mole fraction 0, 0 , 2, 0.5, 0.8 and 1. BaCO3 dissolved in HCl with 0.1 N. The process of dissolving BaCO3 using a hot plate and stirred using a magnetic stirrer until the temperature reaches 70°C for 2 hours, to prepare a solution and dissolve Iron CoCl2.6H2O (III) Chloride Hexahydrate FeCl3.6H2O, then a third mixing a solution of BaCO3, CoCl2.6H2O and Iron (III) Chloride Hexahydrate FeCl3.6H2O it in a beaker and stirred using a magnetic stirrer to form a homogeneous solution (brownish black color) and then adding a solution NH4OH precipitating the burette so that the precipitate obtained with high homogeneity. The samples were cooled and washed with distilled water, filtered with filter paper until pH neutral (pH = 7), the material is dried precipitated by using an oven temperature of 80°C. Furthermore, the process of grinding in order to obtain a brownish powder and calcined at varying temperatures of 400, 600 and 800ºC for 4 hours.Keywords: Barium M-heksaferit, cobalt, coprecipitation

scholarly journals Obtaining Alumina from Kaolin Clay via Aluminum Chloride

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3938 ◽  
Author(s):  
Vyacheslav I. Pak ◽  
Sergey S. Kirov ◽  
Anton Yu. Nalivaiko ◽  
Dmitriy Yu. Ozherelkov ◽  
Alexander A. Gromov
Keyword(s):  
Hydrochloric Acid ◽  
Calcination Temperature ◽  
Aluminum Chloride ◽  
Classical Method ◽  
Acid Leaching ◽  
Chlorine Content ◽  
Aluminum Production ◽  
Residual Chlorine ◽  
Alumina Production ◽  
Chloride Hexahydrate

A method of alumina production based on hydrochloric acid processing of kaolin clays from the East Siberian deposits was studied. Hydrochloric acid leaching was carried out at 160 °C. The leaching solution was subjected to a two-stage crystallization of aluminum chloride hexahydrate (ACH). The precipitated crystals were calcinated in air at a temperature above 800 °C to produce alumina. The main part of water and chlorine during thermal decomposition of ACH was removed at 400 °C. The influence of temperature and duration of ACH calcination on the residual chlorine content in alumina was studied. The optimal temperature of ACH calcination was 900 °C with a duration of 90 min. It was shown that the increase in calcination temperature contributed to the decrease in chlorine content in the final product. However, an increase in calcination temperature above 900 °C led to the transition of the well-soluble γ-Al2O3 phase to the insoluble α-Al2O3, which negatively affected the further electrolysis of aluminum. The size of alumina particles was not affected by the calcination mode. The rate of dissolution of the prototype Al2O3 in Na3AlF6 was higher than for the alumina obtained by the classical method. Alumina content, particle morphology, and particle size distribution for the obtained alumina were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and laser diffraction methods. The obtained alumina is suitable for aluminum production according to the studied characteristics.

scholarly journals Pressureless Sintering of YIG Ceramics from Coprecipitated Nanopowders

2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Calcination Temperature ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Secondary Phase ◽  
Coprecipitation Method ◽  
Pressureless Sintering ◽  
Densification Behavior ◽  
Sintering Process

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.

Taste by Touch: Some Experiments with Octopus

1963 ◽  
Vol 40 (1) ◽  
pp. 187-193
Author(s):  
M. J. WELLS
Keyword(s):  
Hydrochloric Acid ◽  
Fresh Water ◽  
Sea Water ◽  
Olfactory Organ ◽  
Distilled Water ◽  
Quinine Sulphate ◽  
Human Tongue ◽  
Half Strength

1. A method of teaching Octopus chemotactile discriminations is described. 2. The animals can be shown to be capable of distinguishing by touch between porous objects soaked in plain sea water and sea water with hydrochloric acid, sucrose or quinine sulphate added. 3. They can detect these substances in concentrations at least 100 times as dilute as the human tongue is capable of detecting them in distilled water. 4. They can be trained to distinguish between equimolar (0.2 mM) solutions of hydrochloric acid, sucrose and quinine. 5. They can also be trained to distinguish between sea water and fresh water or half-strength sea water or sea water with twice the usual quantity of salt. 6. The function of the ‘olfactory organ’ is discussed. 7. Chemotactile learning is discussed in relation to the means by which Octopus finds its way about the territory around its ‘home’

scholarly journals Effect of calcination temperature on Microstructures, magnetic properties, and microwave absorption on BaFe11.6Mg0.2Al0.2O19 synthesized from natural iron sand

2019 ◽  
Vol 13 ◽  
pp. 100393 ◽  
Author(s):  
Martha Rianna ◽  
Timbangen Sembiring ◽  
Marhaposan Situmorang ◽  
Candra Kurniawan ◽  
Anggito P. Tetuko ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Microwave Absorption ◽  
Calcination Temperature ◽  
Natural Iron

scholarly journals Selected elements cations exchange in acidic medium on sorbents surface based on modified brown coal

2017 ◽  
Vol 33 (1) ◽  
pp. 139-150 ◽  
Author(s):  
Agata Stempkowska ◽  
Piotr Izak ◽  
Joanna Mastalska-Popławska
Keyword(s):  
Hydrochloric Acid ◽  
Chemical Modification ◽  
Brown Coal ◽  
Elevated Temperatures ◽  
Exchange Capacity ◽  
Distilled Water ◽  
Desorption Process ◽  
Second Stage ◽  
Before And After ◽  
Static Conditions

Abstract Studies on the sorption and desorption of selected Na+, Ca2+, Mg2+, Mn2+, Cu2+ and Cr3+ cations by materials based on modified brown coal were carried out. The chemical modification of the sorbent material consisted of grinding involving different inorganic substances and organic polymers. Samples were subjected to chemical modification at elevated temperatures for several hours. For comparative purposes, as apart from brown coal, pure humic acids are known for the highest cations exchange capacity, samples of brown coal before and after purification were also analyzed. The ion capacity was determined under static conditions, measuring the difference in the concentration of cations in the sorbent before and after sorption and then after rinsing the sorbent with distilled water (A), and after the desorption process with hydrochloric acid (B). Studies have shown that sorbents based on modified brown coal have rather significant exchange capacities in the range of 270-450 meq/100 g for the first stage and 90-200 meq/100 g for the second stage. It was also found that purified humic acid (450-200 meq/100 g) has the highest exchange capacity and modified brown coal obtained at 250°C has the lowest. The measurement of desorption showed that approximately 10% of the cations are already leached by distilled water and the residue is desorbed under the influence of 10% hydrochloric acid, but the total amount of cations is compatible with the measurement process of the second stage. The sorption affinity to various cations is different. In the case of the sorption measurements, modified sorbents show the highest sorption affinity with respect to calcium, while the unmodified raw brown coal with respect to chromium. The next stage of the measurement showed that the valence of the cation has the highest impact on the sorption affinity.

scholarly journals Analysis of Metal Contents in Portland Type V and MTA-Based Cements

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Maura Cristiane Gonçales Orçati Dorileo ◽  
Matheus Coelho Bandeca ◽  
Fábio Luis Miranda Pedro ◽  
Luiz Evaristo Ricci Volpato ◽  
Orlando Aguirre Guedes ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Hydrochloric Acid ◽  
Absorption Spectrometry ◽  
Distilled Water ◽  
Quantification Limit ◽  
Metal Contents ◽  
Teflon Tube ◽  
Level Of Significance ◽  
Type V ◽  
Concentration Levels

The aim of this study was to determine, by Atomic Absorption Spectrometry (AAS), the concentration levels of 11 metals in Type V gray and structural white PC, ProRoot MTA, and MTA Bio. Samples, containing one gram of each tested cement, were prepared and transferred to a 100 mL Teflon tube with a mixture of 7.0 mL of nitric acid and 21 mL of hydrochloric acid. After the reaction, the mixture was filtered and then volumed to 50 mL of distilled water. For each metal, specific patterns were determined from universal standards. Arsenic quantification was performed by hydride generator. The analysis was performed five times and the data were statistically analyzed at 5% level of significance. Only the cadmium presented concentration levels of values lower than the quantification limit of the device. The AAS analysis showed increased levels of calcium, nickel, and zinc in structural white PC. Type V PC presented the greatest concentration levels of arsenic, chromium, copper, iron, lead, and manganese(P<0.05). Bismuth was found in all cements, and the lowest concentration levels were observed in Portland cements, while the highest were observed in ProRoot MTA. Both PC and MTA-based cements showed evidence of metals inclusion.

scholarly journals Synthesis of nanosized magnetic NiFe2O4 material by a coprecipitation method

2016 ◽  
Vol 19 (4) ◽  
pp. 137-143
Author(s):  
Tien Anh Nguyen ◽  
Dat Tien Nguyen
Keyword(s):  
Calcination Temperature ◽  
Crystal Size ◽  
Coprecipitation Method ◽  
Boiling Water ◽  
Cubic Structure ◽  
Hydrolysis Of

Nanosized NiFe2O4 spinel material has been synthesized by the coprecipitation method by hydrolysis of Ni(II) and Fe (III) cations in boiling water. The DTA/TGA, XRD, SEM, TEM, VSM results showed that NiFe2O4 crystals formed after calcinating at 700 oC for 2 h exhibited the cubic structure, with the size of 30-50 nM. Mr, Ms and Hc values were 1.06 emu/g, 14.94 emu/g and 61.57 Oe, respectively. The crystal size significantly increased with increasing calcination temperature.

scholarly journals The Effect of Periogen Solution on Dental Calculus in vitro: A Pilot Study

2017 ◽  
Vol 6 (1) ◽  
pp. 33-34
Author(s):  
Marta Radnai ◽  
Zsolt Rajnics
Keyword(s):  
Pilot Study ◽  
Hydrochloric Acid ◽  
Acid Solution ◽  
Oral Hygiene ◽  
Direct Contact ◽  
Photometric Method ◽  
Distilled Water ◽  
Dental Calculus ◽  
Carbamide Peroxide

ABSTRACT Introduction Calculus can accommodate teeth and prosthetic restorations when the patient's oral hygiene is poor. Hardened calculus cannot be removed by patients, it needs professional cleaning using ultrasonic scaler or hand instrument. Solutions dissolving and preventing accumulation of dental calculus may help to keep dentures clean. The aim of this investigation was to examine the effect of Periogen on dental calculus in vitro. Materials and methods Calculus was collected via scaling from patients during a routine dental checkup. The samples were stored in carbamide peroxide solution (5%) for 24 hours, then rinsed and stored in distilled water. First, the Ca2+ content of the calculus was determined by photometric method after treating with cc. hydrochloric acid solution for 1 hour. The calculus samples were put in Periogen solution, prepared according to manufacturer's instruction for 16 hours, then crushed and put in Periogen solution with the same concentrate for 4.5 hours. The Ca2+ dissolved from calculus was measured using same photometric method. Results Calculus samples contained 26 mg/100 mg Ca2+, which is similar to dentin (27–28 mg/100 mg) and to enamel (36 mg/100 mg). The Ca2+ dissolved from calculus after treating with cc. hydrochloric acid for 1 hour was considered 100%. Ca2+ dissolution was 1.5% after 16 hours (0.09%/h) and 5.45% (1.21%/h) for the next 4.5 hours after pulverizing the sample. This showed Periogen Ca2+ dissolution was 385 µg/100 mg after 16 hours direct contact with the material. Conclusion The experiment showed that pulverizing the previously hard calculus was done easily after soaking it in Periogen. The ability of Periogen to soften the calculus needs to be further investigated. How to cite this article Rajnics Z, Radnai M. The Effect of Periogen Solution on Dental Calculus in vitro: A Pilot Study. Int J Experiment Dent Sci 2017;6(1):33-34.

Desulfurization performance of MgO/ rice straw biochar adsorbent prepared by co-precipitation/calcination route

BioResources ◽  
2020 ◽  
Vol 15 (3) ◽  
pp. 4738-4752
Author(s):  
Jiali Chen ◽  
Lianhan Huang ◽  
Liming Sun ◽  
Xiaofan Zhu
Keyword(s):  
Adsorption Capacity ◽  
Calcination Temperature ◽  
Rice Straw ◽  
Active Sites ◽  
Weight Ratio ◽  
Preparation Conditions ◽  
So2 Adsorption ◽  
Chloride Hexahydrate ◽  
Rice Straw Biochar ◽  
Co Precipitation

A solid adsorbent for SO2 adsorption was prepared from magnesium salt/rice straw via co-precipitation/calcination. The effects of various preparation conditions, including the calcination temperature, the weight ratio of Mg/rice straw, magnesium salts, and amine precipitants, were investigated relative to their effects on the desulfurization performance of adsorbents. Maximum sulfur adsorption capacity (260 mg/g) was obtained with MgO/rice straw biochar adsorbent using tetraethylenepentamine (TEPA) as the precipitants, and the preparation conditions included a calcination temperature of 400 °C, a Mg/rice straw weight ratio of 1.2, and magnesium chloride hexahydrate (MgCl2·6H2O) as the magnesium source. The rice straw biochar-supported MgO sample displayed a high SO2 adsorption capacity due to its excellent textural properties, large specific surface areas, small crystallite size, numerous surface active sites of MgO nanoparticles, and introduced N-H groups. The physical and chemical properties of samples were investigated by field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET) analyses, Fourier transform infrared spectrometer (FT-IR), elemental analysis (EA), and X-ray diffraction (XRD).

Sign in / Sign up

Export Citation Format

Share Document