Results 231 to 240 of about 1,129,458 (281)

The triboelectric separation of quartz—calcite and quartz—apatite powders after chemical conditioning

Powder Technology, 1977
Abstract Quartz—calcite and quartz—apatite mixtures in their natural state cannot readily be separated by triboelectric means, since all three minerals acquire a negative charge after contact with common metals. Adsorption of oleate ions from aqueous solution lowers the surface work function of the minerals to such an extent that while the ...
M.J. Pearse, M.I. Pope
openaire   +1 more source

Synthesis of powder-like fine crystalline quartz

High Pressure Research, 2001
Abstract A method of preparation of monodisperse powder-like fine crystalline quartz as separate well-faceted crystals of fixed size was developed. The size and habit of crystals are controlled during the process of their synthesis. The process is performed in two stages.
V. S. Balitsky, T. M. Bublikova, E. A. Marina, L. V. Balitskaya, Zh. S. Chichagova, H. Iwasaki, F. Iwasaki   +6 more
openaire   +1 more source

Electrical conduction in quartz powder

Journal of Materials Science, 1980
Observations have been made on the direct current behaviour of crushed natural quartz at temperatures of the order of 1300 K in order to investigate the effect of applied electric fields on the impurities present in the samples. Migration of the alkaline impurities, leaving an alkali free layer adjacent to the anode, has been detected by analysis of ...
openaire   +1 more source

The use of limestone to replace physical filler of quartz powder in UHPFRC

Cement & Concrete Composites, 2018
One of the key features of ultra-high performance fiber-reinforced concrete (UHPFRC) is the inclusion of quartz powder (QP) as a filler to optimize granular packing.
Sung-Hoon Kang, Yeonung Jeong, K. Tan, Juhyuk Moon   +3 more
semanticscholar   +1 more source

Vacuum sintering of quartz powder and phase transformation of quartz

Vacuum, 1961
Abstract The process of the phase transformation of quartz to silica glass in the range of heating time 10–120 min at the pressure of 10 −5 Torr is as follows: At the heating temperature below about 1700°C Quartz→silica glass→cristobalite; At the heating temperature above about 1700°C Quartz→silica glass.
openaire   +1 more source

Thermal infrared directional emissivity of powdered quartz

Journal of Geophysical Research: Solid Earth, 1995
Thermal infrared directional emissivity of quartz was measured for several particle size ranges and packing fractions. The samples measured were (1) a polished quartz slab; (2) a 75–250 μm powdered quartz sample, cleansed of clinging fines; (3) a 0–75 μm powdered quartz sample, sifted into a fairy castle structure; and (4) the same sample compressed to
Andrew E. Wald, John W. Salisbury
openaire   +1 more source

Hydrothermal synthesis of mono-dispersed quartz powders

Journal of Materials Science, 2004
The hydrothermal method was first used for crystallization of quartz in the middle of 19th century, and has been developed to grow large single crystals of quartz industrially [1]. On the other hand, the hydrothermal method has been recognized as an excellent method to prepare ceramic powders [2].
K. Yanagisawa, Y. Zhu, A. Onda, K. Kajiyoshi   +3 more
openaire   +1 more source

The influence of particle size on the pozzolanic reactivity of quartz powder

Powder Technology, 1999
Abstract Materials with cement-based matrices represent a class of materials notable for their wide and plentiful use. Up to the present, component reactivity was closely linked to the material's vitreous characteristics. The question we wanted to find an answer to was: is the pozzolanic reaction one which is specific to vitreous materials? To tackle
J.C. Benezet, A. Benhassaine
openaire   +1 more source

Limiting density behavior of quartz powders

Powder Technology, 1969
Abstract An experimental study into the effects of varying particle characteristics on maximum and minimum bulk densities of dry quartz powders is presented. The characteristics which were varied are particle size, particle size distribution (or gradation), and particle shape.
openaire   +1 more source

Preparation of crystalline silica (quartz, cristobalite, and tridymite) and amorphous silica powder (one step)

Journal of Physics and Chemistry of Solids, 2018
Silica nanoparticles (SiO2 NPs) have found applications in many advanced areas. In this study, we report a powder technology route as a low cost, simple and safe method for the fabrication of SiO2 NPs.
M. Nabil, K. Mahmoud, A. El‑Shaer, Huda A. Nayber   +3 more
semanticscholar   +1 more source