Study of quenching treatment after limonite ore reduction to decrease silica content

2020 ◽  
Author(s):  
Naufal Wirasyawal Luneto ◽  
Bagas Muhammad Syafa ◽  
Ahmad Maksum ◽  
Agus Budi Prasetyo ◽  
Reza Miftahul Ulum ◽  
...  
Keyword(s):  
Author(s):  
J. Drennan ◽  
R.H.J. Hannink ◽  
D.R. Clarke ◽  
T.M. Shaw

Magnesia partially stabilised zirconia (Mg-PSZ) ceramics are renowned for their excellent nechanical properties. These are effected by processing conditions and purity of starting materials. It has been previously shown that small additions of strontia (SrO) have the effect of removing the major contaminant, silica (SiO2).The mechanism by which this occurs is not fully understood but the strontia appears to form a very mobile liquid phase at the grain boundaries. As the sintering reaches the final stages the liquid phase is expelled to the surface of the ceramic. A series of experiments, to examine the behaviour of the liquid grain boundary phase, were designed to produce compositional gradients across the ceramic bodies. To achieve this, changes in both silica content and furnace atmosphere were implemented. Analytical electron microscope techniques were used to monitor the form and composition of the phases developed. This paper describes the results of our investigation and the presentation will discuss the work with reference to liquid phase sintering of ceramics in general.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
SHELLEY ACHARYA ◽  
ADITI DUTTA

The studies were mostly concentrated in Nine forest ranges of the WLS including the core areas. The soil of this region mostly is dry, red and with iron and silica content. Though the soil mites are prevalent in moist humid condition, we got a diversed population of 20 different species under 14 genera which is less than average probably due to the soil condition. Protoribates magnus is the dominant species in this study. The species with larger ranges were Scheloribates curvialatus.


Author(s):  
Yusup Hendronursito ◽  
Muhammad Amin ◽  
Slamet Sumardi ◽  
Roniyus Marjunus ◽  
Frista Clarasati ◽  
...  

This study was aimed to increase granite's silica content using the leaching process with HCl concentration variation. The granite used in this study came from Lematang, South Lampung. This study aims to determine the effect of variations in HCl concentration, particle size, and rotational speed on the crystalline phase and chemical elements formed in the silica product produced from granite. The HCl concentration variations were 6.0 M, 7.2 M, 8.4 M, and 9.6 M, the variation in particle size used was 270 and 400 mesh. Variations in rotational speed during leaching were 500 and 750 rpm. Granite powder was calcined at 1000 ºC for 2 hours. Characterization was performed using X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP- OES). The results showed that the silica content increased with increasing HCl concentration, the finer the particle size, and the higher the rotational speed. XRF analysis showed that the silica with the highest purity was leached with 9.6 HCl with a particle size of 400 mesh and a rotational speed of of 750 rpm, which was 73.49%. Based on the results above, by leaching using HCl, the Si content can increase from before. The XRD diffractogram showed that the granite powder formed the Quartz phase.


2015 ◽  
Vol 23 (1) ◽  
pp. 1-14
Author(s):  
Sudirman Sahid ◽  
◽  
Nor Shahida Kader Bashah ◽  
Salina Sabudin ◽  
◽  
...  

1999 ◽  
Vol 49 (4) ◽  
pp. 597-605 ◽  
Author(s):  
A.R. Norris ◽  
C.T. Hackney

2015 ◽  
Vol 46 (6) ◽  
pp. 2534-2552 ◽  
Author(s):  
Theresa Coetsee ◽  
Christian Reinke ◽  
Johannes Nell ◽  
Petrus Christiaan Pistorius

2012 ◽  
Vol 476-478 ◽  
pp. 1408-1411
Author(s):  
Xin Fan ◽  
Qiu Ju Qin ◽  
Xiu Fang Wen ◽  
Jiang Cheng ◽  
Zhuo Ru Yang

In this paper raspberry-like composite particles were prepared via cationic soap-free emulsion polymerization with silica sol as stabilizer and 2-(methacryloyl) ethyltrimethylammonium chloride (MTC) as cationic auxiliary monomer. According to the TGA and TEM results we could find that the electrostatic attraction supplied by MTC played a vital role in the adsorption of silica particles as well as the generation of raspberry-like morphology. The silica content and appearance of composite particles were found to be improved with the increasing amount of silica sol and MTC while varied little with changes of AIBA amount.


2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Abdullah Mohammed Ali Mohammed Altaweel ◽  
Jaya Madhu Raj ◽  
Malalvalli Nagarajaiah Chandrashekara ◽  
Puttegowda Ramya ◽  
Parthasarathy Sampathkumaran ◽  
...  

Abstract Polystyrene (PS) based composites respectively with cenosphere (CS) and calcium aluminosilicate (CAS) as fillers were studied using the positron lifetime technique to reveal the correlation between free volume, a microstructural property, and mechanical properties of the composites (tensile strength and tensile modulus). The thermal stability of the composites was determined using differential scanning calorimetry. The results showed that addition of CAS filler lead to a significant improvement in the mechanical properties of the composite, whereas addition of CS resulted in improvement in tensile modulus only. Both PS/CAS and PS/CS composites showed enhancement in thermal stability compared with that of the pure PS matrix. The positron results showed that the average free volume size for the PS/CAS composite (at 40 phr CAS) was reduced significantly compared with that of the pure PS. These results are understood in terms of the influence of silica content, filler-matrix interaction, and particle size.


2015 ◽  
Vol 51 (2) ◽  
pp. 269-272 ◽  
Author(s):  
Marlon T. Conato ◽  
Matthew D. Oleksiak ◽  
B. Peter McGrail ◽  
Radha K. Motkuri ◽  
Jeffrey D. Rimer

Zeolite HOU-2 (LTA type) is prepared with the highest silica content (Si/Al = 2.1) reported for organic-free syntheses.


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