Effects of bentonite binder dosage on the properties of green limestone pellets

Vladimir D. Jovanović, Dinko N. Knežević, Živko T. Sekulić, Milan M. Kragović, Jovica N. Stojanović, Slavica R. Mihajlović, Dragana D. Nišić, Dragana S. Radulović, Branislav B. Ivošević, Milan M. Petrov

Abstract


This paper presents the results of tests carried out to determine how the dosage of bentonite added as binder, affects the properties of green pellets made of the limestone fines that originate from Lithothamnium limestone processing. Bentonite was added to limestone in different mass fractions (1, 2.5, 5 and 10%), whereas all the other parameters of the pelletizing process remained constant. The aim of pelletizing was to consolidate limestone fines and form mechanically stable pellets, provided that all the other properties of limestone remain unchanged. The pellets formed in this way were analysed applying DTA/TG analysis and FTIR and SEM analyses. The results showed uniform distribution of bentonite in the pellets, demonstrated that the pellets are compact and there is no formation of new compounds. The pellets were tested for resistance to impact, compres­sive strength and abrasion resistance. Also disintegration tests were performed to deter­mine the time required for the pellet to disintegrate completely in water. These mech­anical properties are essential for transport, handling, storage and general use of pellets. The values of most of the parameters established for pellets with 5% bentonite, meet the standards required for use in agriculture for liming acid soils, however their application is limited because their impact resistance is unsatisfactory and the time required for their complete disintegration in water is extremely short. It should be noted that further increase of bentonite content (over 10%) will not improve the quality of green pellets. In view of the results obtained, it is necessary to introduce drying into the pelletizing process in order to bring the green pellets into solid state.


Keywords


lithothamnium limestone, bentonite, pelletizing, pelletizing plate, green pellet testing.

Full Text:

PDF (3,026 kB)

References


H.R. von Uexküll, E. Mutert, Global extent, development and economic impact of acid soils, S. Afr. J. Plant Soil 171 (1995) 1–15.

D. Vidojević, Report on the State Soil in Serbia, the Ministry of Environmental Protection and Spatial Planning, Belgrade, 2009 (in Serbian)

S. Milić, Fertility of Privately Owned Land in Different Crop Growing Regions of Vojvodina, 45. Agronomist Conference, Zlatibor, 2001, www.nsseme.com/about/ /inc/SAS/45SAS/2011-02-04/3%Milic.pdf

K.B. Albert, D. Langford, Pelletizing limestone fines, Mars Mineral, Mars, PA, 1998, pp. 12–29.

B.C. Nyle, The Nature and Properties of Soils, 10th ed., Macmillan Publisher, London, 2000, pp. 232–235.

Breaton stone, The Complete guide to agricultural lime, http://www.braenstone.com/wp-content/uploads/Ag–lime-Ebook-4.21.15

Č. Jevremović, Pelletizing of Fly Ash from Power Plants and Environmental Protection, Faculty of Mining and Geology, Tuzla, 1988.

P.C. Kapur, S.C.D. Arora, S.V.B. Subbarao, Water-bentonite interaction in balling of iron ores, Chem. Eng. Sci. (1973) 1535–1540.

T. Gluba, The effect of wetting conditions on the strength of granules, Physicochem. Probl. Miner. Process. 36 (2002) 233–242.

C. Schilling, J. S. Lee, B. Ghiasi, M. Tajilrou, M. Wöhler, C.J.Lim, X.T. Bi, A. Lau, S. Pelz, L. Tabil, S. Sokhansanj: Towards manufacturing the “ideal pellet”, CSBE/SCGAB, Annual Conference, Edmonton, Alberta, Canada, 2015, Paper No. CSBE15-XXX.

M. Petrović, Mineral Processing – Agglomeration Basics, Faculty of Mining, Geology and Civil Engineering, Tuzla, 2008, p. 288.

K.V.S. Sastry, D.W. Fuerstenau, Kinetics of green pellet growth by the layering mechanism. Transact. AIME 262 (1977) 43–47.

V.R. Sirisha K.K. Vijaya Sri, K. Suresh, G.K. Reddy, N. Devanna, A review of pellets and pelletization process - a multiparticulate drug delivery system, Int. J. Pharm. Sci. Res. 4 (2013) 2145–2158.

E. Murad, The characterization of soils, clays and clay firing products. Hyperfine Interact. 111 (1998) 251–259.

http://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447041&topicorder=9&maxto=10.




DOI: http://dx.doi.org/10.2298/HEMIND160210023J

Copyright (c) 2017 HEMIJSKA INDUSTRIJA

Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.