scholarly journals Effect of Grain Size and Replacement Ratio on the Plastic Properties of Precipitated Calcium Carbonate Using Limestone as Raw Material

2014 ◽  
Vol 51 (2) ◽  
pp. 127-131
Author(s):  
Chul Seoung Baek ◽  
Kye Hong Cho ◽  
Ji-Whan Ahn
2015 ◽  
Vol 77 (3) ◽  
Author(s):  
Anuar Othman ◽  
Nasharuddin Isa ◽  
Rohaya Othman

Precipitated calcium carbonate (PCC) chemically can be synthesized in the laboratory. In this study, hydrated lime or calcium hydroxide was used as raw material with sucrose as additive to produce PCC. The process was compared with the one without additive. PCC produced was observed based on morphology, mineral composition and size by using Fesem-Edx and LPSA, respectively. PCC products without additive demonstrated fine and more uniform size of calcite PCC as compared to the one with additive. Nevertheless, the process with additive produced more PCC product than without additive.


2015 ◽  
Vol 827 ◽  
pp. 203-207 ◽  
Author(s):  
Mastuki ◽  
Malik Anjelh Baqiya ◽  
Darminto

Synthesis of Ca-Fe-O using solution mixing method employing CaCO3 and Fe2O3•H2O has been conducted. Extraction of limestone as the raw material of precipitated calcium carbonate (PCC) and iron sands as that of Fe2O3•H2O was prepared to explore various compound of C-Fe-O, where the CaFe4O7 phase is mainly expected. The PCC and Fe2O3•H2O each are dissolved in 1 M HNO3 and mixed to be most homogeneous. The results of the synthesis are characterized by DTA/GTA and then sintered at temperatures of 800°C, 900°C and 1000°C.The sintered samples were characterized by XRD, FTIR, and VSM. The sintering temperature at 800°C, 900°C and 1000°C gave result the phase content of CaFe4O7 being respectively 55.42%, 44.55% and 36.39%. Other major phases in the Ca-Fe-O samples consist of Ca2Fe9O13 and Ca4Fe14O25. The remanence value of the corresponding samples is 2.11, 1.28, and 1.74 emu/g respectively.


Author(s):  
Klaus Dölle ◽  
Bardhyl Bajrami

Paper manufacturing on a global scale is a highly competitive market which requires to constantly improve the manufacturing process to be competitive. To decrease production cost paper manufactures, add filler material prior to sheet forming to replace costly wood fiber based raw material. This research project investigates the use of in-situ precipitated calcium carbonate produced in the presence of eucalyptus fiber material at a 41.0% filler level prior to beating. The in-situ filler containing eucalyptus fiber suspension was used on a 12’ (304mm) wide Laboratory Fourdrinier Paper Machine together with non-filler containing eucalyptus fiber material, and a commercial precipitated calcium carbonate filler material. The manufactured in-situ fiber suspension resulted in a higher ash retention compared to the addition of the powdered commercial PCC filler material. In addition to commercial filler material retention is improved at higher filler addition above 30%. The increased ash retention is linked to the increased micro fibrillation fiber material of the in-situ filler-fiber suspension forming neckless like particles on the fibers microfibrils. Mechanical paper properties showed an improvement for in-situ precipitated filler material compared to commercial filler material addition. Optical properties could be improved in comparison to the eucalyptus fiber without filler addition for in-situ precipitated filler material and a combination of in-situ and commercial filler material.


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.


1976 ◽  
Vol 7 (5) ◽  
pp. 307-320 ◽  
Author(s):  
G. S. Bremmeng ◽  
A. E. Kloster

Transjøen, a lake in S.E. Norway investigated hydrographically from October 1969 to October 1971, consists of two basins, both of which are meromictic (lake with lower layer which does not participate in the periodic circulations). The lake has a large influx of groundwater of very varying chemical composition. The calcium content is high and precipitated calcium carbonate and electrolyte rich groundwater is assumed to be the main reason for the meromictic stability. The redox potentials of monimolimnion (the lower layer which does not participtate in the periodic circulation) are extremely low, but in spite of this fact the content of sulphate is high.


Sign in / Sign up

Export Citation Format

Share Document