The use of Karelia’s finelyground mining waste and local clay for production of heatinsulating materials

NOVYE OGNEUPORY (NEW REFRACTORIES) ◽

10.17073/1683-4518-2021-6-3-9 ◽

2021 ◽

pp. 3-9

Author(s):

V. P. Ilyina ◽

T. P. Bubnova

Keyword(s):

Thermal Expansion ◽

New Mineral ◽

Local Clay ◽

Talcum Powder ◽

Insulating Materials ◽

Fine Grained ◽

Mining Companies ◽

Low Thermal Expansion ◽

Thermal Physical Properties ◽

Mineral Product

The results of the study of fine-grained feldspathic and talcchlorite waste from Republic of Karelia’s mining companies as a new mineral product for heat-insulating materials and stationary heat accumulators (fireplaces and furnaces) are reported. The physico-mechanical and thermal-physical properties of the materials, based on finely ground waste and local clay, are appraised. The materials produced from pegmatite waste are highly strong, and can be used for lining furnaces and fireplaces. Heat-insulating materials based on talc-chlorite waste have low thermal expansion at 20‒900 °C, their thermal resistance increases 9 times (at 980 °C, water) and their mechanical strength is 2,6 times higher than that of samples containing talcum powder.

Download Full-text

Some recent developments in high-strength glasses and ceramics

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1964.0212 ◽

1964 ◽

Vol 282 (1388) ◽

pp. 52-56

Keyword(s):

Thermal Expansion ◽

Bending Strength ◽

Glass Ceramics ◽

High Strength ◽

Fine Grained ◽

Thermal Expansion Coefficients ◽

Low Thermal Expansion ◽

Recent Developments ◽

Expansion Coefficients ◽

Mechanical Strengths

Two areas of development in the field of glasses and ceramics have produced new materials with unusual combinations of properties. Glass-ceramics are melted and formed as glasses by conventional glass-forming techniques, but by a subsequent heat treatment, they are converted to fine-grained crystalline structures with new and useful combinations of properties. Products with thermal expansion coefficients approaching zero and flexural strengths ranging from 10 000 to 50 000 Lb./in. 2 have been made though not all combinations of low thermal expansion coefficients and high mechanical strengths are possible. The second area of development is in so-called Chemcor glasses. Such glass products can be preferentially pre-stressed by chemical means so as to produce an outer layer with high compressive stress and a bending strength in the finished product up to 100 000 Lb/in. 2 .

Download Full-text

Synthesis and processing of nanocrystalline Ag–Fe–Ni for low thermal expansion–high conductivity thermal management applications

Journal of Materials Research ◽

10.1557/jmr.2001.0053 ◽

2001 ◽

Vol 16 (2) ◽

pp. 340-343 ◽

Cited By ~ 1

Author(s):

J. Stolk ◽

M. Gross ◽

D. Stolk ◽

A. Manthiram

Keyword(s):

Electrical Conductivity ◽

Thermal Expansion ◽

Metal Ion ◽

Coefficient Of Thermal Expansion ◽

Thermomechanical Analysis ◽

Nominal Composition ◽

Two Phase ◽

X Ray ◽

Fine Grained ◽

Low Thermal Expansion

Nanocrystalline Ag–Fe–Ni powders were produced by a reduction of the aqueous metal ion solutions with sodium borohydride and then converted to fine-grained silver–Invar alloys that offer attractive thermal, electrical, and mechanical properties. The samples were characterized by x-ray diffraction, scanning electron microscopy, wavelength dispersive x-ray spectrometry, thermomechanical analysis, microhardness measurements, and electrical conductivity measurements; thermal conductivity was estimated using the Wiedemann–Franz law. Sintering of a specimen with a nominal composition of 60 wt% Ag–25.6 wt% Fe–14.4 wt.% Ni led to the formation of a two-phase silver–Invar alloy with a grain size of approximately 2 μm, a hardness of 133 HK200g, coefficient of thermal expansion of 12.44 × 10−6 / °C, and electrical conductivity of 2.13 × 105 (Ω cm) −1.

Download Full-text

ZrW2O8-doped epoxy as low thermal expansion insulating materials for superconducting feeder system

Cryogenics ◽

10.1016/j.cryogenics.2012.04.016 ◽

2012 ◽

Vol 52 (12) ◽

pp. 638-641 ◽

Cited By ~ 7

Author(s):

Xinxin Chu ◽

Zhixiong Wu ◽

Chuanjun Huang ◽

Rongjin Huang ◽

Yuan Zhou ◽

...

Keyword(s):

Thermal Expansion ◽

Insulating Materials ◽

Low Thermal Expansion

Download Full-text

TEM/AEM characterization of fine-grained clay minerals in very-low-grade rocks: Evaluation of contamination by empa involving celadonite family minerals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100165938 ◽

1996 ◽

Vol 54 ◽

pp. 694-695

Author(s):

Gejing Li ◽

D. R. Peacor ◽

D. S. Coombs ◽

Y. Kawachi

Keyword(s):

Electron Microscopy ◽

Volcanic Rocks ◽

Analytical Electron Microscopy ◽

Metamorphic Rocks ◽

New Mineral ◽

Chemical Compositions ◽

Low Grade ◽

Fine Grained ◽

Depth Analysis ◽

Mineral Aggregates

Recent advances in transmission electron microscopy (TEM) and analytical electron microscopy (AEM) have led to many new insights into the structural and chemical characteristics of very finegrained, optically homogeneous mineral aggregates in sedimentary and very low-grade metamorphic rocks. Chemical compositions obtained by electron microprobe analysis (EMPA) on such materials have been shown by TEM/AEM to result from beam overlap on contaminant phases on a scale below resolution of EMPA, which in turn can lead to errors in interpretation and determination of formation conditions. Here we present an in-depth analysis of the relation between AEM and EMPA data, which leads also to the definition of new mineral phases, and demonstrate the resolution power of AEM relative to EMPA in investigations of very fine-grained mineral aggregates in sedimentary and very low-grade metamorphic rocks.Celadonite, having end-member composition KMgFe3+Si4O10(OH)2, and with minor substitution of Fe2+ for Mg and Al for Fe3+ on octahedral sites, is a fine-grained mica widespread in volcanic rocks and volcaniclastic sediments which have undergone low-temperature alteration in the oceanic crust and in burial metamorphic sequences.

Download Full-text