Investigating the strengthening of quartz ceramics by hydrothermal treatment

Refractories ◽  
1993 ◽  
Vol 34 (11-12) ◽  
pp. 587-591
Author(s):  
S. M. Itkin ◽  
V. V. Vikulin
Keyword(s):  
Hydrothermal Treatment ◽  
Quartz Ceramics

Ultrasonic control of the hydrothermal treatment of quartz ceramics

1991 ◽  
Vol 48 (9) ◽  
pp. 414-416
Author(s):  
Yu. V. Zemlyanskii ◽  
S. M. Itkin
Keyword(s):  
Hydrothermal Treatment ◽  
Ultrasonic Control ◽  
Quartz Ceramics

Kinetic Principles of the Vegetable Raw Materials Hydrothermal Treatment

Food Industry ◽  
2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Albert H-H. Nugmanov ◽  
Olesya A. Aleksanyan ◽  
Miguel A. S. Barzola
Keyword(s):  
Hydrothermal Treatment ◽  
Raw Materials ◽  
Vegetable Raw Materials

MATHEMATICAL MODELLING OF MECHANICAL BEHAVIOUR OF CELLULOSE-BASED FIBRES EXPOSED TO GAMMA RAYS AND HYDROTHERMAL TREATMENT

2015 ◽  
Vol 14 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Cristina M. Ursescu ◽  
Angelica Olaru ◽  
Teodor Malutan. ◽  
Maria Geba ◽  
Corina Malutan
Keyword(s):  
Mathematical Modelling ◽  
Hydrothermal Treatment ◽  
Gamma Rays ◽  
Mechanical Behaviour

Hydrothermal Treatment Management of High Alumina Waste for Synthesis of Nanomaterials with New Morphologies

2017 ◽  
Vol 66 (5) ◽  
pp. 172-179 ◽  
Author(s):  
H. H. Abo-Almaged ◽  
A. F. Moustafa ◽  
A. M. Ismail ◽  
S. K. Amin ◽  
M. F. Abadir
Keyword(s):  
Hydrothermal Treatment ◽  
High Alumina ◽  
Treatment Management ◽  
Synthesis Of Nanomaterials

Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems: synthesis and crystal structures of Rb2[(UO2)(Cr2O7)(NO3)2] and two new polymorphs of Rb2Cr3O10

2021 ◽  
Vol 236 (1-2) ◽  
pp. 11-21
Author(s):  
Evgeny V. Nazarchuk ◽  
Oleg I. Siidra ◽  
Dmitry O. Charkin ◽  
Stepan N. Kalmykov ◽  
Elena L. Kotova
Keyword(s):  
Crystal Structure ◽  
Aqueous Solutions ◽  
Crystal Structures ◽  
Hydrothermal Treatment ◽  
Ambient Conditions ◽  
Screw Axis ◽  
3D Framework ◽  
Solution Acidity

Abstract Three new rubidium polychromates, Rb2[(UO2)(Cr2O7)(NO3)2] (1), γ-Rb2Cr3O10 (2) and δ-Rb2Cr3O10 (3) were prepared by combination of hydrothermal treatment at 220 °C and evaporation of aqueous solutions under ambient conditions. Compound 1 is monoclinic, P 2 1 / c $P{2}_{1}/c$ , a = 13.6542(19), b = 19.698(3), c = 11.6984(17) Å, β = 114.326(2)°, V = 2867.0(7) Å3, R 1 = 0.040; 2 is hexagonal, P 6 3 / m $P{6}_{3}/m$ , a = 11.991(2), c = 12.828(3) Å, γ = 120°, V = 1597.3(5) Å3, R 1 = 0.031; 3 is monoclinic, P 2 1 / n $P{2}_{1}/n$ , a = 7.446(3), b = 18.194(6), c = 7.848(3) Å, β = 99.953(9)°, V = 1047.3(7) Å3, R 1 = 0.037. In the crystal structure of 1, UO8 bipyramids and NO3 groups share edges to form [(UO2)(NO3)2] species which share common corners with dichromate Cr2O7 groups producing novel type of uranyl dichromate chains [(UO2)(Cr2O7)(NO3)2]2−. In the structures of new Rb2Cr3O10 polymorphs, CrO4 tetrahedra share vertices to form Cr3O10 2− species. The trichromate groups are aligned along the 63 screw axis forming channels running in the ab plane in the structure of 2. The Rb cations reside between the channels and in their centers completing the structure. The trichromate anions are linked by the Rb+ cations into a 3D framework in the structure of 3. Effect of solution acidity on the crystallization of polychromates in uranyl-bearing systems is discussed.

scholarly journals Alkali-Hydrothermal Treatment of K-Rich Igneous Rocks for Their Direct Use as Potassic Fertilizers

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 140
Author(s):  
Aaron Mbissik ◽  
Abdellatif Elghali ◽  
Muhammad Ouabid ◽  
Otmane Raji ◽  
Jean-Louis Bodinier ◽  
...  
Keyword(s):  
Hydrothermal Treatment ◽  
Inductively Coupled Plasma ◽  
Structural Changes ◽  
Raw Materials ◽  
Hydrothermal Process ◽  
Atomic Emission ◽  
Igneous Rocks ◽  
Gravimetric Analysis ◽  
African Countries ◽  
Naoh Solution

Due to the increasing demand for conventional sources of potassium (K) and their inaccessibility by African countries, K-rich igneous rocks are increasingly studied as potential alternative sources. In this study, six potassic igneous rocks (syenites and trachytes) from the Tamazeght, Jbel Boho, Ait Saoun, and El Glo’a regions (Morocco) were sampled and characterized. Then they were hydrothermally treated to enhance their K release for potential use as potassic fertilizers. The raw materials are mainly formed by microcline (up to 74%), orthoclase (20–68%), albite (36–57%), biotite-muscovite (15–23%), and titanite, calcite, hematite, and apatite as accessory minerals. These samples were crushed and milled to reach a particle size <150 µm and mixed with 4 N NaOH solution in an autoclave. The liquid/solid (L/S) ratio was about 44 mL/50 g. The powders were allowed to react with the solution at 170 °C for 7 h. For all tests, NaOH reacted completely with the powders and no liquid was observed after the treatment. X-ray diffraction (XRD), thermal gravimetric analysis (TGA), infrared spectroscopy (IRTF), and scanning electron microscopy (SEM-EDS) were carried out on treated samples to characterize the mineralogical and structural changes due to the alkali-hydrothermal treatment. Indeed, the treated samples revealed the presence of sodic neoformed phases such as thermonatrite, sodalite, analcime, and cancrinite. The treated material was leached for a week using deionized water and the elements released were measured using inductively coupled plasma–atomic emission spectroscopy (ICP-AES). The hydrothermal process showed a strong effect on structure breakdown as well as on the release of K and other nutrients such as P, Fe, Si, Mg, and Ca. Therefore, the alkali-hydrothermal treatment allowed the release of 50.5 wt% K. Moreover, the release of Mg, Ca, Fe, P, K, and Si were significantly increased. Mg, Ca, Fe, P, K, and Si release within raw materials was about (0.5–3.6), (3.5–31.4), (0.01–0.4), (0.01–0.3), (20–55), and (4.6–8) mg/kg, respectively, whereas treated samples showed a higher release of these elements. Quantitatively, Mg, Ca, Fe, P, K, and Si releases were about (10–11.8), (60–70), (7–20), (1.2–15), (218–1278), and (1119–2759) mg/kg, respectively. Consequently, the treated igneous rocks (syenite and trachyte) could be directly used as potassic fertilizers that would also be a source of other nutrients.

Graphene-Induced Growth of Co3O4 Nanoplates with Modulable Oxygen Vacancies for Improved OER Properties

CrystEngComm ◽  
2021 ◽  
Author(s):  
Xinheng Li ◽  
Lei Qi ◽  
Mei Wang
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Hydrothermal Treatment ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Oxygen Vacancies ◽  
Transition Metal Oxide ◽  
Oxide Hydroxide

Transition metal oxide/ hydroxide is intensively studied for oxygen evolution reaction (OER). Herein, graphene-induced growth of Co3O4 nanoplates with modulable oxygen vacancies via hydrothermal treatment is reported. With the increase...

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