Papers by Keyword: Mercury Porosimetry

Abstract: The influence of the dispersion of the nickel slag additive on the strength of ceramic bricks based on low-melting clay of the Khalilovsky deposit in the Orenburg region and nickel slag from the dumps of OJSC "Combine Yuzhuralnickel" (Orenburg region) is considered. The study involves assessing the effect of the preparation method, the dispersion of the additive (nickel slag) on the microstructure of the finished samples. Using modern research methods with the involvement of high-tech equipment, the micro-and macrostructure of ceramic samples with the addition of slag in an amount of 5–60% is considered. The structure of the synthesized samples is studied by the method of mercury porosimetry depending on the percentage ratio of clay / slag and the fineness of grinding of the nickel slag additive. The data on the influence of the material composition of the clay / slag charge, the dispersity of the additive and the firing temperature on the strength of the prototypes are given, and an assessment is made of the technological feasibility of increasing the dispersion of the raw materials used. Intorduction

Abstract: In this study the effect of age, w/c ratio on mean distribution radius and dispersion of pores in Ordinary Portland Cement (OPC) sand mortar was determined through Mercury Intrusion Porosimetry (MIP) test. For this purpose the cement sand mortar specimens were prepared from two different types of OPC with varied w/c ratios such as 0.2, 0.3, 0.4, 0.5 and 0.6 and tested at different curing ages from 1 day to 90 days. Separate relationships relating the mix parameters such as w/c ratio and age with mean distribution radius (r_0.5) and coefficient (d) representing dispersion of pores, are developed for OPC sand mortars.

Abstract: Current wall constructions utilize cement mortars, the properties of which have been modified with introducing lime or plasticizers. The complex structure of these mortars as well as their very large inner area results in large differences in capillary moisture transport. Macroscopic studies do not allow to accurately predict the mortar behaviour in contact with water. Capillary rise as well as drying and freezing of water are dependent on the size and the layout of pores. The biggest adsorption capacity is featured by micropores. Moisture transport takes place in mesoporous material, and moisture adsorption takes place on the surface of such materials. Macropores mainly act as a transport medium and carry moisture to mesoporous material and micropores. In terms of mesoporous material and macropores mercury porosimetry is more suitable. Mortar structure plays an important role in the moisture transport. Mortar additives, that have been introduced in the form of lime and plasticizers, modify the distribution and size of pores. Porosimetric study results concerning selected mortars have been presented in this article. The structure changes resulting from the introduction additives to mortars have been analyzed and the impact on humidity of such mortars has been defined.

Abstract: Refractory castable specimens were prepared using industrial white fused alumina as aggregates, chromium oxide green and ultrafine alumina powder as matrix materials, solid aluminum dihydrogen phosphate (Al(H₂PO₄)₃) or liquid AlPO4 as binder materials. Effect of different binder additions on the properti_{Subscript text}es of high chromium oxide IGCC refractory castables, such as bulk density, apparent porosity, strength was evaluated and their microstructures were observed by SEM and mercury porosimetry.

Abstract: The powder compaction process is the most widely used forming technique for shaping ceramic products, since traditional ceramic as floors until advanced ceramics for technical applications. This process is characterized by high productivity but it has a serious problem, namely the density gradient originated during the die cavity filling and the subsequent compaction operation^[. Therefore, the process requires a high control of all parameters involved in order to guarantee to obtain samples with high homogeneity of the green density, which ensures a sintered body of high quality and low population of microstructural defects. Thus, it is extremely important to understand the variable that controls the compaction mechanisms and interfere in the homogeneity of the green density along the compacted body.