Ball size distribution for the maximum production of a narrowly-sized mill product

2015 ◽  
Vol 284 ◽  
pp. 12-18 ◽  
Author(s):  
Ngonidzashe Chimwani ◽  
François K. Mulenga ◽  
Diane Hildebrandt
Keyword(s):  
Size Distribution ◽  
Mill Product ◽  
Maximum Production ◽  
Ball Size

scholarly journals Effects of Ball Milling Processing Conditions and Alloy Components on the Synthesis of Cu-Nb and Cu-Mo Alloys

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1224 ◽  
Author(s):  
Xuekun Shang ◽  
Xitao Wang ◽  
Silian Chen
Keyword(s):  
Size Distribution ◽  
Ball Milling ◽  
Oxidation Process ◽  
Processing Parameters ◽  
Processing Conditions ◽  
Cold Welding ◽  
Immiscible Alloys ◽  
Ball Size ◽  
Milling Method

The effects of processing parameters in ball milling and the different behaviors of Cu-Nb and Cu-Mo alloys during milling were investigated. High powder yields can be obtained by changing the BPR value and ball size distribution and no clear dependence of BPR value on powder yield can be found from the experiment results. The addition of oxygen can largely reduce the effect of excessive cold welding during ball milling. A “two-step” ball milling method was introduced to evaluate the different evolution processes and morphologies in different alloys. With 8 h pre-milling, this method considerably benefits the oxidation process of Mo and shows its promising potential in the synthesis of immiscible alloys. Based on the experiment results and analysis, we suggest that the different behaviors of Cu-Nb and Cu-Mo alloys are related to the shear modules and different tendencies to be oxidized.

scholarly journals Exploring the End-Liner Forces Using DEM Software

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1047
Author(s):  
Ngonidzashe Chimwani ◽  
Murray M. Bwalya
Keyword(s):  
Discrete Element Method ◽  
Size Distribution ◽  
Ball Milling ◽  
Discrete Element ◽  
Significant Cost ◽  
Cost Component ◽  
Dem Simulation ◽  
Ball Size ◽  
Ball Motion ◽  
Simulation Scheme

The main roles of liners are to protect the mill shell and promote effective ball motion for grinding. For this reason the liner profile is carefully selected to ensure that the productivity is maximized and due liner replacement is made when this objective is no longer met. These issues have been extensively studied on shell liners as mill relining is a significant cost component of ball milling. To date, not much has been written about end-liners and the kind of forces they are subjected to. A discrete element method (DEM) simulation scheme is conducted to look at how ball size distribution, mill filling, end-liner configuration and shape affect the distribution of forces acting on the liners that were assessed to understand end-liner wear and damage. The results showed how forces varied both radially and tangentially for the different sections of end-liner, with important insights drawn for end-liner manufactures.

scholarly journals Yield and size distribution of potatoes as influenced by seed rate.

1959 ◽  
Vol 7 (4) ◽  
pp. 257-268 ◽  
Author(s):  
A.J. Reestman ◽  
C.T. De Wit
Keyword(s):  
Linear Relationship ◽  
Size Distribution ◽  
Surface Area ◽  
Seed Size ◽  
Skin Surface ◽  
Seed Rate ◽  
Maximum Production ◽  
Seed Potatoes ◽  
Large Seed ◽  
Number Of Stems

Five spacing experiments were carried out in 1957 and '58 with seed potatoes, var. Alpha, measuring 25-28 mm, 35-45 mm and 45-60 mm, planted at 400, 600, 800, 1000 or 1200 tubers/ha in rows 60 cm apart and harvested on 7 dates between 29 July and 16 Oct. There was a positive correlation, within experiments, between the number of stems produced per tuber at wide spacings and the surface area of the skin of the tubers, both where whole tubers and cut setts were used. There was a linear relationship between the reciprocal of the yield and the reciprocal of the seed rate where both were expressed in m2 of skin surface/are. [See Fld Crop Abstr. 12: 1525 and 13: 777.] Where the reciprocal of the yield for each sett size was averaged for all 5 experiments and plotted against the reciprocal of the seed rate, it was shown that the use of large seed depressed yields; this was considered to be due to the less regular distribution of haulms in the row where the large seed was used. Seed size had little influence on grading. Rows 60 cm apart were considered too widely spaced for maximum production.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Comparison of alumina ball size distribution in two white cement grinding units using Swebrec function

DYNA ◽  
2019 ◽  
Vol 86 (209) ◽  
pp. 25-29
Author(s):  
Lina María Chica Osorio ◽  
Ismael Eduardo Rivera ◽  
Marlon Rincón Fulla ◽  
Adriana Marcela Osorio ◽  
Moisés Oswaldo Bustamante ◽  
...  
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Size Distribution ◽  
Distribution Model ◽  
Ball Size ◽  
White Cement ◽  
Swebrec Function ◽  
Cement Grinding ◽  
Alumina Ball

The results of characterizing the alumina ball size distribution in two mills of a crushing and grinding plant are shown. The mills were unloaded and the ball charge was screened in order to establish the ball size distribution. For both mills, the balls retained during the unloading were compared to the balls retained at the beginning of the process, and additionally, they were compared to the results obtained by the Swebrec adjusted distribution model. In both cases, the experimental data have had a good fit with this model. This practice is important in order to establish the best ball charge at the beginning of the operation and the ball recharge in the steady state.

scholarly journals A process mineralogy approach to study the efficiency of milling of molybdenite circuit processing

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ataallah Bahrami ◽  
Morteza Abdollahi ◽  
Mirsaleh Mirmohammadi ◽  
Fatemeh Kazemi ◽  
Abolfazl Danesh ◽  
...  
Keyword(s):  
Size Distribution ◽  
Open Circuit ◽  
Closed Circuit ◽  
Destructive Effect ◽  
Mill Product ◽  
Flotation Process ◽  
Comminution Process ◽  
Particles Size Distribution ◽  
Mineralogical Study ◽  
Mill Feed

AbstractThis study is conducted with the aim of investigating the efficiency of open and closed-circuit molybdenite ore comminution processes (primary and secondary mill, respectively), through mineralogical study of mills feed and product. For this purpose, particle size distribution, minerals distribution, degree of liberation and interlocking of minerals in mills feed and product were studied. According to the results, chalcopyrite, molybdenite, pyrite and covellite constitute the major part of the mineral composition of open-circuit mill feed. Minerals at the mill product, in the order of abundance include liberated molybdenite particles, liberated chalcopyrite and interlocked chalcopyrite with pyrite, liberated and interlocked pyrite particles, and associated silicate gangues. The d50 values of the feed and product particles of the open-circuit mill are equal to 13.80 and 13.40 microns, respectively. Degree of liberation of molybdenite for the feed and product of this mill is almost the same and is equal to 98.0%. Closed-circuit mill feed includes, in order of is abundance, liberated molybdenite particles in the form of blades and irregular polygonal shapes, liberated and interlocked chalcopyrite, and liberated and interlocked pyrite particles with gangue minerals. Molybdenite particles in the mill product are almost completely liberated, and the degree of liberation values of chalcopyrite and pyrite are 84.40% and 91.40%, respectively. According to particles size distribution of the feed (d50 equal to 25.03 microns) and the product (d50 equal to 24.24 microns) of closed-circuit mill, it can be stated that comminution is not well-operated in closed-circuit mill due to the low solid percentage of closed-circuit mill feed and the inefficiency of hydrocyclone. Examination of Mo, Cu, and Fe grade variations for 10 days in both off and on modes of mill shows that closed-circuit mill does not have an impact on comminution process. It can even be concluded that the mill has a destructive effect the flotation process by producing slimes.

scholarly journals Particle Size Distribution Models for Metallurgical Coke Grinding Products

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1288
Author(s):  
Laura Colorado-Arango ◽  
Juan M. Menéndez-Aguado ◽  
Adriana Osorio-Correa
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Ultrafine Particles ◽  
Goodness Of Fit ◽  
Metallurgical Coke ◽  
Ball Size ◽  
Grinding Conditions ◽  
Comparison Criteria ◽  
Grinding Time

Six different particle size distribution (Gates–Gaudin–Schuhmann (GGS), Rosin–Rammler (RR), Lognormal, Normal, Gamma, and Swebrec) models were compared under different metallurgical coke grinding conditions (ball size and grinding time). Adjusted R2, Akaike information criterion (AIC), and the root mean of square error (RMSE) were employed as comparison criteria. Swebrec and RR presented superior comparison criteria with the higher goodness-of-fit and the lower AIC and RMSE, containing the minimum variance values among data. The worst model fitting was GGS, with the poorest comparison criteria and a wider results variation. The undulation Swebrec parameter was ball size and grinding time-dependent, considering greater b values (b > 3) at longer grinding times. The RR α parameter does not exhibit a defined tendency related to grinding conditions, while the k parameter presents smaller values at longer grinding times. Both models depend on metallurgical coke grinding conditions and are hence an indication of the grinding behaviour. Finally, oversize and ultrafine particles are found with ball sizes of 4.0 cm according to grinding time. The ball size of 2.54 cm shows slight changes in particle median diameter over time, while 3.0 cm ball size requires more grinding time to reduce metallurgical coke particles.

Optimisation of the size distribution of ball mill product by modelling grinding variables using DX8 software

2018 ◽  
pp. 1-8
Author(s):  
Abolfazl Ebadnejad ◽  
Hamed Dehghani ◽  
Mina Hadizadeh ◽  
Karim Ghorbani ◽  
Maziyar Sanaie
Keyword(s):  
Size Distribution ◽  
Ball Mill ◽  
Mill Product

scholarly journals Experimental Study of Operational Parameters on Product Size Distribution of Tumbling Mill

2020 ◽  
Author(s):  
moslem mohammadi soleymani
Keyword(s):  
Size Distribution ◽  
Critical Speed ◽  
Operational Parameters ◽  
Copper Ore ◽  
Mill Product ◽  
Slurry Concentration ◽  
Pilot Model ◽  
Grinding Media ◽  
Grinding Mechanism ◽  
Mill Speed

Abstract To assess the effects of the mill operating parameters such as mill speed, ball filling, slurry concentration and slurry filling on grinding process and size distribution of mill product, it was endeavored to build a pilot model with smaller size than the mill. For this aim, a pilot mill with 1m × 0.5m was implemented. There are 15 lifters with 50mm height and face angle of 30˚. In the present work, the combination of the balls (40% of the balls with 60mm diameter, 40% of the balls with 40mm diameter and 20% of the balls with 25mm diameter) was used as grinding media with 10%, 15%, 20% and 25% of the total volume of the mill. The experiments were carried out at 60%, 70%, 80% and 90% of the critical speed. The feed of the mill is copper ore with the size smaller than 25.4 mm, which d80 and d50 of them are 12.7 and 8 mm, respectively and slurries with 40%, 50%, 60%, 70% and 80% of solid and the slurry filling between 0.5 and 2.5. The results showed that the best grinding and grading occurs at 70-80% of the critical speed and ball filling of 20-25%. Optimized grinding was observed when the slurry volume is 1-1.5 times of the ball bed voidage volume and the slurry concentration is between 60% and 70%. The mill grinding mechanism in this work is a combination of both impact and abrasion mechanisms.

scholarly journals The Effect of Grinding Media on Mineral Breakage Properties of Magnetite Ores

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Liang Si ◽  
Yijun Cao ◽  
Guixia Fan
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Production Capacity ◽  
Milling Process ◽  
Ball Size ◽  
Grinding Media ◽  
Grinding Conditions ◽  
Steel Balls ◽  
Different Diameters

The breakage and liberation of minerals are the key to fluidized mining for minerals. In the ball milling process, steel balls function as not only a grinding action implementer but also energy carrier to determine the breakage behavior of ores and the production capacity of the mill. When ground products present a much coarse or much fine particle size distribution, the separation process will suffer, resulting in inefficient recovery of useful minerals. Optimal control of the particle size distribution of the products is therefore essential, but the complexity and randomness of ball mill grinding make it difficult to determine the appropriate ball size. To solve the problem in the precise measurement of grinding ball diameters, this paper carried out magnetite grinding experiments with grinding balls of different diameters under the same grinding conditions to study the influence pattern of steel ball diameters on the particle break behavior, the particle size distribution of ground products, and the mineral liberation degree distribution. The research proposed on the matching relation between the ball size and the quality of ground products is essential for improving the ground product quality and reducing energy consumption.

Dry ball mixing and deagglomeration of alumina and zirconia composite fine powders using a bimodal ball size distribution

2014 ◽  
Vol 40 (9) ◽  
pp. 15293-15302 ◽  
Author(s):  
Jens Fruhstorfer ◽  
Stefan Schafföner ◽  
Christos G. Aneziris
Keyword(s):  
Size Distribution ◽  
Ball Size ◽  
Fine Powders
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