Chemicals used for treatment of water intended for human consumption. Calcium carbonate, high-calcium lime and half-burnt dolomite. Test methods

2001 ◽  
TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.


Agropedology ◽  
2019 ◽  
Vol 28 (2) ◽  
Author(s):  
G. Tiwari ◽  
◽  
A. Jangir ◽  
R. P. Sharma ◽  
B. Dash ◽  
...  

Detailed soil survey (1:10000 scale) was carried out using base map prepared from satellite data (IRS-P6 LISS IV and Cartosat-1) and Digital Elevation Models (DEM) in conjunction with Survey of India (SOI) Toposheets of 1:50000 scale in Valia block, Bharuch district of Gujarat. On the basis of landform, slope, land use/land cover and ground truth, six landscape ecological Units (LEUs) were delineated and six soil series were identified in the block. Five soil series occur on alluvial plain (cover 66.16 %) and one soil series occupies pediplain 27.61 %. These series were mapped into ten soil mapping units as phases of soil series. The representative pedons of alluvial plain were moderately deep to very deep and their sand, silt and clay content ranged from 8.2 to 44.4, 9.8 to 40.2 and 43.8 to 55.6 per cent, respectively. These pedons were neutral to strongly alkaline (pH 6.8 - 9.7), non-saline with low to high organic carbon (0.18 – 1.2 %) content, low to high calcium carbonate (5.9 - 26.6 %) and high CEC [>35 cmol (p+) kg-1]. Exchangeable complex of these pedons were dominated by Ca2+ followed by Mg2+, Na+ and K+ cations with high base saturation (72.0 to 99. 4 %). Soils were classified as Vertic Haplustepts, Typic Haplusterts, Typic Calciustepts, Typic Haplustepts and Sodic Haplusterts. The representative pedon of pediplains was shallow, dark brown (7.5YR3/2), clayey, strongly alkaline (pH>8.5), non-saline (<2 dSm-1) and had moderate organic carbon (0.50-0.75 %) and calcium carbonate (5-15 %) with high CEC [>35 cmol (p+) kg-1] and classified as Lithic Haplustepts. The soils were evaluated for their suitability for commonly grown crops (cotton, pigeon pea, wheat and chick pea) and mapping unit 2 and 4 were highly suitable for cotton cultivation and other were moderately to marginal suitable for other crops.


2013 ◽  
Vol 575-576 ◽  
pp. 54-57 ◽  
Author(s):  
Xiu Hong Hao ◽  
Yan Min Wang ◽  
Ai Qin Zhang

Granite, due to the poor adhesiveness with asphalt, cannot be widely used as aggregate in asphalt pavement. In this study, nanoscaled calcium carbonate (CaCO3), was selected as modifier to modify asphalt. The adhesion of aggregate and asphalt was evaluated by Boiling test method and the Marshall Test and Immersion Marshall Test were conducted on asphalt concrete (AC-16) according to the Standard Test Methods of Bitumen and Bituminous Mixture for Highway Engineering (JTG E20-2011). The results showed that When the Doping content of CaCO3 (%) is 7%, the adhesion levels reached up to 5 grade and achieved the project requirements. The Immersion Marshall Stability (MS1) of AC-16 CaCO3 modified asphalt concrete can improve 27.6% than that the Matrix asphalt concrete.


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