THE MINE TO MILL CONCEPT AND ITS APPLICATION IN OPEN PIT MINES
The optimization of open pit mines is an issue of paramount importance for the mine
and mill management. It aims to enhance the performance of the processes in order to
obtain the maximum profit from the whole operation.
The Mine to Mill concept is aunified approach that considers the components of the
mine-mill chain as a whole. It provides high productivity and maximum revenues by
increasing the efficiency of rock fragmentation and size reduction.
This paper discusses the potential benefits for the mining companies to embrace the
Mine to Mill philosophy. It starts with an introduction to the su bject, making a revision of
thedifferent tools it provides, followed by its methodology and its alternative approaches
such as the Mine to Mill blasting. Finally, real cases of successful application of this
holistic concept in open pit mines are presented and commented.
INTRODUCTION TO THE MINE TO MILL APPROACH
The main objective in any kind of business is to increase the profits in order to attain
the greatestpossible ratio of return on investment. In an attempt to achieve this, the
mining industry´s traditional approach has been based in two stages:
1) Mining, to remove the commodity from the ground. Includes drilling, blasting, loading
and hauling. Eventually, the individual optimization of each of these units is
emphasized, embracing the minimum cost per concept philosophy rather than the
2) Processing, to convert the commodity into a marketable end product , encompassing
crushing, grinding and classification.
As they are often considered as self governing
each process has a
determined budget and production capacity to fulfill, so efficiency is assessed
independently. The management of either Mine or Mill often focuses on maximizing
production andminimizing costs of each stage in a stand -alone manner, missing
potential economic benefits and energy saving opportunities. (Adel et al 2006)
Nevertheless, mining and processing of commodities are closely related. If the aim of
the operation is the overall profits optimizations, so an optimization model that takes into
account the entire system, from the blasting process to thecomminution circuit should
In this sense, the Mine to Mill concept provides an integrated model to increase the
global productivity of mine and plant operations through the enhancing of the overall
fragmentation system. Given that comminution comprises the most energy intensive
and costly set of unit operations at a mine/mill site, the aim is to lower energy costs in all
stages ofcomminution (blasting, crushing and grinding).
The Mine t o Mill model,
therefore, focuses on improving the particle size reduction at any the step of the
operation, resulting in significant energy savings and productivity increase.
The fundamentals of the Mine to Mill philosophy are the following:
Explosives are the lowest cost source of energy for fragmentation of most typesof rocks
A well fragmented
muckpile results in more effective loading and haulage
operations (lower loading times, operating costs, maintenance costs and
optimum bucket and truck fill factor).
Material with good blasting fragmentation entails lower crushing and grinding
Blasted material requires less comminution energy than material removed
without blasting.The Mine to Mill Philosophy was developed at the Julius Kruttschnitt Mineral Research
Centre (JKMRC) from the University of Queensland in Australia in 1998. Since then, it
has been applied with satisfactory results in gold, copper, lead, zinc and aggregates
operations throughout the world. Mine-to-Mill® is a registered trademark of JKTech, the
commercial division of JKRMC.