scholarly journals TO THE QUESTION OF THE INFLUENCE OF COMPLEX BINDER ON THE PROPERTIES OF NON-AUTOCLAVE SILICATE COMPOSITES WITH THE USING NON-TRADITIONAL RAW MATERIALS

Author(s):  
A.A. Volodchenko ◽  
V.S. Lesovik
Keyword(s):  
Author(s):  
Т. Дмитриева ◽  
T. Dmitrieva ◽  
Н. Куцына ◽  
N. Kucyna ◽  
А. Безродных ◽  
...  

The paper discusses the main aspects of soil reinforcement in road construction by adding a binder component to them. The use of this technology allows to solve the problem of high-quality raw materials shortage while improving the physicomechanical characteristics or keeping them at the same level, as well as to increase labor productivity and reduce production costs. The technogenic raw materials for the production of soil concrete were studied, the main physicomechanical characteristics and requirements that must be taken into account when selecting the composition of the soil concrete mixture were analyzed. The paper compares the physicomechanical characteristics of the road composite, reveals the advantages and disadvantages of introducing binder components of various types: cement, cement with modifier and a complex binder. It has been established that the introduction of a complex binder or cement with modifier contributes to the improvement of the physicomechanical characteristics while reducing the consumption of cement in the composition of the soil-concrete mixture compared to traditional soil-concrete with cement.


2013 ◽  
Vol 833 ◽  
pp. 221-224 ◽  
Author(s):  
Bo Tan ◽  
Kai Chen ◽  
Zhao Hui Huang ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
...  

The non-sintering Ti (C,N)-Si3N4-SiC composite refractories were prepared using natural quartz, rutile and silicon carbide particles/powders as the raw materials, phenolic resin and urotropin as a complex binder and silicon powder as the additive. The influence of the binder amount on the density, flexural strength, volume shrinkage and the microstructure of the non-sintering Ti (C,N)-Si3N4-SiC composite refractories was studied in detail. The results showed that the amount of binder has significant effects on the properties of the non-sintering Ti (C,N)-Si3N4-SiC composite refractories. The bulk density decreased and the apparent porosity increased as the amount of binder increased, and the flexural strength increased and then decreased as the amount of binder increased, and the volume shrinkage increased with the increase of the amount of binder. The binder is propitious to the properties of the non-sintering Ti (C,N)-Si3N4-SiC composite refractories, but excessive binder will result in the degradation of properties of the as-fabricated composite refractories, the optimum amount of complex adhesive is 15%.


Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.


Author(s):  
Chung-kook Lee ◽  
Yolande Berta ◽  
Robert F. Speyer

Barium hexaferrite (BaFe12O19) is a promising candidate for high density magnetic recording media due to its superior magnetic properties. For particulate recording media, nano-sized single crystalline powders with a narrow size distribution are a primary application requirement. The glass-crystallization method is preferred because of the controllability of crystallization kinetics, hence, particle size and size distribution. A disadvantage of this method is the need to melt raw materials at high temperatures with non-reactive crucibles, e.g. platinum. However, in this work, we have shown that crystal growth of barium hexaferrite occurred during low temperature heat treatment of raw batches.


Author(s):  
O. Yu. Kichigina

At production of stainless steel expensive alloying elements, containing nickel, are used. To decrease the steel cost, substitution of nickel during steel alloying process by its oxides is an actual task. Results of analysis of thermodynamic and experimental studies of nickel reducing from its oxide presented, as well as methods of nickel oxide obtaining at manganese bearing complex raw materials enrichment and practice of its application during steel alloying. Technology of comprehensive processing of complex manganese-containing raw materials considered, including leaching and selective extraction out of the solution valuable components: manganese, nickel, iron, cobalt and copper. Based on theoretical and experiment studies, a possibility of substitution of metal nickel by concentrates, obtained as a result of hydrometallurgical enrichment, was confirmed. Optimal technological parameters, ensuring high degree of nickel recovery out of the initial raw materials were determined. It was established, that for direct steel alloying it is reasonable to add into the charge pellets, consisting of nickel concentrate and coke fines, that enables to reach the through nickel recovery at a level of 90%. The proposed method of alloying steel by nickel gives a possibility to decrease considerably steel cost at the expense of application of nickel concentrate, obtained out of tails of hydrometallurgical enrichment of manganese-bearing raw materials, which is much cheaper comparing with the metal nickel.


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