Volume 2 • Issue 2 • 1000106
J Powder Metall Min
ISSN: 2168-9806 JPMM, an open access journal
Research Article Open Access
Veerendra Singh et al., J Powder Metall Min 2013, 2:2
http://dx.doi.org/10.4172/2168-9806.1000106
Research Article Open Access
Powder Metallurgy & Mining
Artificial Neural Network Modeling of Ball Mill Grinding Process
Veerendra Singh
1
*, P K Banerjee
1
, S K Tripathy
1
, V K Saxena
2
and R Venugopal
2
1
Research and Development, Tata Steel, Jamshedpur-831001, India
2
Indian School of Mines, Dhanbad, Jharkhand-826004, India
*Corresponding author: Veerendra Singh, Research and Development, Tata
Steel, Jamshedpur-831001, India, E-mail: veerendra.singh@tatasteel.com
Received December 27, 2012; Accepted February 15, 2013; Published February
21, 2013
Citation: Veerendra Singh, Banerjee PK, Tripathy SK, Saxena VK, Venugopal R
(2013) Artiicial Neural Network Modeling of Ball Mill Grinding Process. J Powder
Metall Min 2: 106. doi:10.4172/2168-9806.1000106
Copyright: © 2013 Veerendra Singh, et al. This is an open-access article
distributed under the terms of the Creative Commons Attribution License, which
permits unrestricted use, distribution, and reproduction in any medium, provided
the original author and source are credited.
Keywords: Milling; Ball mill; Particle size; Artiicial Neural Network;
Regression
Introduction
Milling is a vital unit operation in various material processing
operations and consumes around 2% of the energy produced in the
world [1,2]. It dictates the cost economics of mineral, cement, power,
pharmaceutical and ceramic industries. Grinding is an important unit
operation for chrome ore pelletisation process. Chromite ore along
with 5% coke is milled in the wet ball mill and iltered ore cake is mixed
with bentonite and used for production of green pellets. Pellet quality
and pelletisation subprocesses (iltering, pelletisation and sintering)
depend on the characteristics of the ball mill product size. Physical
properties of ores, especially hardness, friability and grindability play
a vital role in grinding to achieve the desired ineness for pelletisation
process [3,4]. Ore particle size, shape and roughness inluence the
particle packing and moisture required for green ball formation [5].
Improper particle size distribution results in poor pellet qualities and
reduced plant throughput as well. Ball mill operation is a complex
process and there is no unanimous mathematical relationship given
in the literature for all kind of materials. Various attempts have been
made to relate the milling parameters and particles ineness but most
of these models required a material constant for diferent materials.
Material constant vary signiicantly with change in ore properties and
it restricts the success of the models [6-10]. Artiicial neural network
is a faster and reliable tool to develop a mathematical model to predict
the process variability in such cases. It is not a new technique for
mineral processing and has already been explored for various mineral
processing operations in past [11,12].
Present study is focused to model the ball operation of a
pelletisation plant to predict the ball mill product size distribution with
changed operating conditions. he mathematical model developed
using artiicial neural network has been compared with various
conventional models and results are compared for actual and predicted
size distributions.
Problem Deinition
Problem statement
Performance ball milling depends on ore properties and process
variables. Ore properties depend on the geological and geographical
characteristics. It is not possible to develop a single mathematical model
for all kind of ores. Various mathematical models have been developed
using the material constants but a limited success has been achieved. It
is very diicult for a static model to consider the variation in the ores
characteristics along the vertical and horizontal location of ore block.
his problem becomes more critical when a blend of diferent kind of
materials grounded in a ball mill for pelletisation purposes. Artiicial
neural network can be a useful technological development which can
consider all the uncertainties to develop a dynamic model without
bothering about the material constants and geography of ore block. In
this study an Artiicial Neural Network (ANN) based neural network
model has been developed to predict the particle size distribution of a
ball mill product using the lab data. Developed model uses ball size,
ball-ore ratio, ball load and grinding time as the input variables and
particle size distribution (<75 µm, <38 µm) as an output measurements.
Data analysis
Experimental data were collected from lab to develop the
mathematical model. A statistical analysis has been carried out to see
the variable interdependence. Details are given in the table 1 and 2.
Experiments were carried out using a ball mill of 38 cm diameter×38
cm length and Chrome Ore (-3 mm), Coke Fine (-1 mm) and at a pulp
density of 70% solid and 50 rpm ball mill speed.
Material characterisation
he test work was carried out using the chromite ore samples
Abstract
Grinding consumes around 2% of the energy produced in the world but existing methods of milling are very
ineficient and use only 5% of the input energy for real size reduction rest is consumed by machine itself. Chrome
ores are comminute, iltered, pelletized and sintered to use into submerged arc furnace for ferrochrome production.
Variation in ore properties affects the particle size distribution during milling. Artiicial neural network based model
is developed to predict the particle size distribution of ball mill product using grinding data available for difference
in grindability of Sukinda chromite ores. Input variables for model were ball size, ball load, ball-ore ratio, grinding
time. Output was particle size distribution (+75 µm, -75 µm, +38 µm; -38 µm). Three different kinds of mathematical
models have been compared to predict the particle size distribution. Finally a neural network based model was found
most accurate. Dynamic artiicial neural network model does not require any material constant and optimizes the
mathematical correlation with better accuracy in a dynamic process. This methodology can be used to develop an
online system to predict the ball mill performance to improve the performance of grinding circuit in mineral, metal
and cement industry.