Variation of back-calculated breakage rate parameters in Bond-mill grinding

Hoşten, Çetin
Avsar, C
The variation of breakage rates with grinding environment is important in the analysis and simulation of various grinding processes. In particular, computer simulation of the labor-intensive experimental Bond grindability test requires reliable estimates of breakage rate and distribution parameters from a minimum amount of experimental work. This paper was aimed at studying the variation of breakage rate parameters in the Bond mill. Batch kinetic experiments with monosize feeds and standard locked-cycle Bond grindability tests with natural size feeds were carried out on cement clinker and trass samples. Using the cumulative-basis, size-discretized population balance model (PBM) of batch grinding and invariant breakage distribution parameters determined from monosize short-time grinding experiments, the breakage rate parameters were back-calculated by minimizing the sum of squares of relative deviations between the simulated and experimental product size distributions. The back-calculated rate parameters were found to be varying depending on either grinding time or the feed size distribution. No single set of parameters was found to be representative of the whole grinding path in the Bond grindability test, and therefore attempts to simulate the Bond test with 1 set of parameters resulted in incorrect computed work index values.


Effect of swaging on microstructure and tensile properties of W-Ni-Fe alloys
DURLU, NURİ; Caliskan, N. Kaan; Bor, Sakir (Elsevier BV, 2014-01-01)
The objective of this study was to investigate the effect of swaging on the microstructure and tensile properties of high density two phase alloys 90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe. Samples were liquid phase sintered under hydrogen and argon at 1480 degrees C for 30 min and then 15% cold rotary swaged. Measurement of microstructural parameters in the sintered and swaged samples showed that swaging slightly increased tungsten grain size in the longitudinal direction and slightly decreased tungsten grain size i...
Determining surface residual stress in steel sheets after deep drawing and bulging processes
Adıgüzel, Sinem; Gür, Cemil Hakan; Karadoğan, Celalettin; Department of Metallurgical and Materials Engineering (2011)
The aim of this thesis is to investigate the effects of bulging and deep drawing processes on St4 cold rolled steel by simulation and experimental characterization. In the simulations, commercial software programs MSC Marc and Simufact.forming were used. The experimental studies cover metallographic investigations, hardness measurements, and residual stress measurements. Residual stress measurements were carried out by different non- destructive characterization methods; X-ray diffraction and Magnetic Barkh...
Investigating the effects of water pretreatments on chromite liberation
Camalan, Mahmut (Informa UK Limited, 2020-01-18)
Many studies investigated the effects of grinding aids on mechanical and breakage properties of particles, as well as the flowability of ore-water slurries in wet grinding mills. Only recently, it was showed that grinding aids can promote grain-boundary fracturing. This paper aims to observe the effects of water pretreatment on chromite liberation, to underlie some reactions between water and chromite samples which promote the liberation of coarse chromite grains, i.e. the grain-boundary fracturing. For the...
Effects of fabrication method on initial powder characteristics and liquid phase sintering behaviour of tungsten
Erol, Mahmut; Erdogan, Metehan; Karakaya, İshak (Elsevier BV, 2018-12-01)
Direct electrochemical production of tungsten involves removal of oxygen in solid state from an important tungsten compound, calcium tungstate, in molten salts. A detailed experimental study was performed to characterize the liquid phase sintering behaviour of the tungsten powder (WE), which was produced by the direct electrochemical reduction technique. All of the tungsten heavy alloy (WHA) compositions covered in this study, contained four parts nickel, one part cobalt and over 90 wt% tungsten. The pellet...
Effect of ternary alloying elements addition on atomic ordering characteristics of Fe-Al intermetallics
Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (Elsevier BV, 1999-05-28)
The energetic and structural characteristics of atomic ordering processes in Fe-0.5(Al1-nXn)(0.5) intermetallics have been qualitatively analyzed based on the statistico-thermodynamical theory of ordering by means of a quasi-chemical method combined with electronic theory in the pseudopotential approximation. The effects of ternary impurities on order-disorder phase transformation temperature and the characteristics of atomic short-range order in Fe-Al type intermetallics have been calculated. Impurity elem...
Citation Formats
Ç. Hoşten and C. Avsar, “Variation of back-calculated breakage rate parameters in Bond-mill grinding,” SCANDINAVIAN JOURNAL OF METALLURGY, pp. 286–293, 2004, Accessed: 00, 2020. [Online]. Available: