Rod Mill Product Control and Its Relation to Energy Consumption: A Case Study
Abstract
:1. Introduction
2. Materials and Methods
2.1. Materials and Particle Size Distribution Determination
2.2. Experimental Design
2.3. Mathematical Modeling for Optimization
3. Results
3.1. Particle Size Distribution and Energy Consumption Determination
3.2. Numerical Simulation
4. Discussion
5. Conclusions
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- It was shown that by varying the percentage of critical mill speed or grinding media charge, the impact on reducing energy consumption becomes noticeable.
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- This work will take on more significance when it is necessary to reach mineral liberation while preventing overgrinding phenomena. In this sense, varying the solid/water ratio may well control excessive fine particle generation. Without being the best action to reduce energy consumption, some improvement in this respect can be observed.
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- It was also demonstrated how it is possible to control the particle size of the product by varying the feed rate, and lifter and rod geometry, while keeping energy utilization constant. By applying one or a combination of these criteria, it is possible to achieve both objectives, to control grinding without excessive energy consumption.
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- In the overall process, considering comminution as the most expensive module, an improvement in energy consumption efficiency could lead to subsequent savings for companies. A 20% reduction in media charge could lead to a 12% reduction in energy bill, which would be a remarkable milestone. Modeling and prediction approaches can also be used to manage production and energy issues, as simulation could express the product size, considering the parameters that affect the milling process.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Parameter | Meaning |
---|---|
D10 | 10% of the particles are under this size |
D50 | 50% of the particles are under this size |
D80 | 80% of the particles are under this size |
F300 | Percentage of particles less than 300 μm |
C1050 | Percentage of particles larger than 1050 μm |
Feature | Value | Units |
---|---|---|
Internal diameter | 388 | mm |
Internal length | 506 | mm |
Rod media charge | 40, 33, 27, and 20 | % |
Rod diameter | 30 and 40 | mm |
Critical speed (Vc) | 71.2 | rpm |
Engine power | 4 | kW |
Tests | Vc | Media Charge | S/L |
---|---|---|---|
(%) | (%) | (%) | |
A | 50 | 40 | 50–55–60–65 |
B | 60 | 40 | 50–55–60–65 |
C | 70 | 40 | 50–55–60–65 |
D | 80 | 40 | 35–55–60–65 |
Test | Vc | Media Charge | S/L | Solid Feed Flow | Rod Dimensions | Lifter Dimensions |
---|---|---|---|---|---|---|
(%) | (%) | (%) | (g/min) | (mm) | (mm) | |
V1 | 50 | 40 | 60 | 3000 | 30 | 23 |
V2 | 60 | |||||
V3 | 70 | |||||
V4 | 80 | |||||
M1 | 60 | 40 | 60 | 3000 | 30 | 23 |
M2 | 33 | |||||
M3 | 27 | |||||
M4 | 20 | |||||
S1 | 60 | 40 | 30 | 3000 | 30 | 23 |
S2 | 55 | |||||
S3 | 60 | |||||
S4 | 70 | |||||
F1 | 60 | 40 | 60 | 1500 | 30 | 23 |
F2 | 3000 | |||||
R | 60 | 40 | 60 | 3000 | 40 | 23 |
L | 60 | 40 | 60 | 3000 | 40 | 35 |
Evaluated Parameter | Energy Consumption (kWh/t) | D50 (μm) | F300 (%) | C1050 (%) | |
---|---|---|---|---|---|
Critical rotational speed [%] | 50 | 8.0 | 395 | 31 | 9 |
60 | 10.7 | 360 | 35 | 5 | |
70 | 11.7 | 325 | 46 | 5 | |
80 | 13.3 | 320 | 47 | 5 | |
Media charge [%] | 20 | 7.8 | 645 | 24 | 21 |
27 | 8.7 | 500 | 31 | 13 | |
33 | 9.3 | 443 | 31 | 11 | |
40 | 10.6 | 377 | 40 | 6 | |
Solid/water rate S/L [%] | 30 | 9.0 | 315 | 47 | 5 |
55 | 9.4 | 350 | 40 | 5 | |
60 | 8.1 | 368 | 38 | 6 | |
70 | 9.3 | 643 | 20 | 24 | |
Feed flow [g/min] | 1500 | 9.1 | 205 | 66 | 1 |
3000 | 8.8 | 368 | 38 | 4 | |
Rod size [mm] | 30 | 8.1 | 368 | 33 | 6 |
40 | 9.8 | 390 | 32 | 4 | |
Lifter size [mm] | 23 | 9.8 | 390 | 32 | 4 |
35 | 9.1 | 405 | 31 | 5 |
Parameter | Value |
---|---|
k | 0.500 |
n1 | 1.022 |
n2 | 1.500 |
S1 | - |
α | 3.204 |
ω1 | 0.005 |
β1 | 2.970 |
ω2 | 0.005 |
β2 | 4.372 |
Experimental | Simulated | |||||
---|---|---|---|---|---|---|
Parameter | F300 (%) | C1050 (%) | D50 (μm) | F300 (%) | C1050 (%) | D50 (μm) |
Critical rotational speed | 31 | 9 | 395 | 34 | 8.5 | 410 |
35 | 5 | 360 | 39 | 5.0 | 365 | |
46 | 5 | 325 | 47 | 4.0 | 320 | |
47 | 5 | 320 | 46 | 4.0 | 325 | |
Media charge [%] | 40 | 6 | 377 | 41 | 4.0 | 340 |
30 | 11 | 443 | 31 | 9.0 | 420 | |
31 | 13 | 500 | 30 | 9.0 | 425 | |
24 | 21 | 645 | 21 | 17.0 | 580 | |
Solid/water Rate S/L [%] | 20 | 24 | 643 | 20 | 21.0 | 640 |
38 | 6 | 368 | 41 | 5.0 | 360 | |
40 | 5 | 350 | 49 | 3.0 | 340 | |
47 | 5 | 315 | 48 | 3.0 | 316 | |
Feed flow [g/min] | 66 | 1 | 205 | 72 | 1.0 | 210 |
38 | 4 | 368 | 40 | 4.5 | 355 | |
Rod size [mm] | 32 | 4 | 390 | 37 | 6.0 | 380 |
33 | 6 | 368 | 40 | 4.5 | 360 | |
Lifter size [mm] | 32 | 4 | 390 | 39 | 4.5 | 380 |
31 | 5 | 405 | 35 | 5.5 | 400 | |
RMSE | 4.1 | 1.9 | 26.6 |
% Media Charge | Energy (kWh/t) | Energy Red. (%) |
---|---|---|
40 | 10.6 | 0 |
33 | 9.3 | 12.1 |
27 | 8.7 | 18.1 |
20 | 7.8 | 26.8 |
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Anticoi, H.; Guasch, E.; Pérez-Álvarez, R.; de Luis-Ruiz, J.M.; Oliva, J.; Hoffman Sampaio, C. Rod Mill Product Control and Its Relation to Energy Consumption: A Case Study. Minerals 2022, 12, 183. https://doi.org/10.3390/min12020183
Anticoi H, Guasch E, Pérez-Álvarez R, de Luis-Ruiz JM, Oliva J, Hoffman Sampaio C. Rod Mill Product Control and Its Relation to Energy Consumption: A Case Study. Minerals. 2022; 12(2):183. https://doi.org/10.3390/min12020183
Chicago/Turabian StyleAnticoi, Hernan, Eduard Guasch, Rubén Pérez-Álvarez, Julio Manuel de Luis-Ruiz, Josep Oliva, and Carlos Hoffman Sampaio. 2022. "Rod Mill Product Control and Its Relation to Energy Consumption: A Case Study" Minerals 12, no. 2: 183. https://doi.org/10.3390/min12020183