1496
Development of a Lab-Scale Test for
Pre‑Concentration Evaluation
Adrian Dance, Bob McCarthy
SRK Consulting (Canada) Inc.
Cameron Bruin
Base Metallurgical Laboratories Ltd.
ABSTRACT: Pre-concentration opportunities are available for most operations to improve the grade of their
mill feed and eliminate fine/soft contaminants or coarse/hard material.
For a greenfield project, pre-concentration is difficult to evaluate due to a lack of standardized testing methods
and sample top-size constraints. This is exacerbated by our current testing practices where sample preparation
involves stage-crushing down to a manageable size—destroying the opportunity to evaluate coarse beneficiation
methods. This paper covers recent progress by the authors to develop a standardized ranking test using half drill
core samples. The objective is to consider pre-concentration at an early study stage and quantify the impact on
project economics.
The laboratory test can be done on 10kg to 50kg of half core samples, measuring the metal deportment by
size at different levels of impact breakage, comparable to primary/secondary stage crushing. By incorporating
this test protocol with an established comminution test, it can be inserted into current metallurgical testwork
programs with minimal disruption. As well as estimating the grade by size response to crushing and screening,
coarse particles are tested for sensor response at this time, typically dual-energy XRT. SRK Consulting is col-
laborating with Base Metallurgical Labs in Kamloops BC to provide an independent evaluation of pre-concen-
tration at the laboratory scale before committing to the cost and sample mass requirements of manufacturer’s
performance tests.
BACKGROUND/CONTEXT
The mining industry is increasingly faced with “grade-
challenged” projects or deposits encumbered with poor
metallurgical performance and, at times, generate prod-
ucts with high impurities or difficult properties for down-
stream processing. The response from industry has been to
exploit economies of scale with larger and larger process
plant capacities matched with less selective, bulk mining
including mass underground mining methods. However,
the byproduct of this strategy is higher dilution, greater vol-
umes of waste and tailings to handle and of course, larger
tailings management facilities.
There are numerous definitions of pre-concentration or
coarse beneficiation. Pre-concentration is defined here as
physically separating different grade components of plant
feed, while it still is dry, coarse and conveyable. (In the case
Development of a Lab-Scale Test for
Pre‑Concentration Evaluation
Adrian Dance, Bob McCarthy
SRK Consulting (Canada) Inc.
Cameron Bruin
Base Metallurgical Laboratories Ltd.
ABSTRACT: Pre-concentration opportunities are available for most operations to improve the grade of their
mill feed and eliminate fine/soft contaminants or coarse/hard material.
For a greenfield project, pre-concentration is difficult to evaluate due to a lack of standardized testing methods
and sample top-size constraints. This is exacerbated by our current testing practices where sample preparation
involves stage-crushing down to a manageable size—destroying the opportunity to evaluate coarse beneficiation
methods. This paper covers recent progress by the authors to develop a standardized ranking test using half drill
core samples. The objective is to consider pre-concentration at an early study stage and quantify the impact on
project economics.
The laboratory test can be done on 10kg to 50kg of half core samples, measuring the metal deportment by
size at different levels of impact breakage, comparable to primary/secondary stage crushing. By incorporating
this test protocol with an established comminution test, it can be inserted into current metallurgical testwork
programs with minimal disruption. As well as estimating the grade by size response to crushing and screening,
coarse particles are tested for sensor response at this time, typically dual-energy XRT. SRK Consulting is col-
laborating with Base Metallurgical Labs in Kamloops BC to provide an independent evaluation of pre-concen-
tration at the laboratory scale before committing to the cost and sample mass requirements of manufacturer’s
performance tests.
BACKGROUND/CONTEXT
The mining industry is increasingly faced with “grade-
challenged” projects or deposits encumbered with poor
metallurgical performance and, at times, generate prod-
ucts with high impurities or difficult properties for down-
stream processing. The response from industry has been to
exploit economies of scale with larger and larger process
plant capacities matched with less selective, bulk mining
including mass underground mining methods. However,
the byproduct of this strategy is higher dilution, greater vol-
umes of waste and tailings to handle and of course, larger
tailings management facilities.
There are numerous definitions of pre-concentration or
coarse beneficiation. Pre-concentration is defined here as
physically separating different grade components of plant
feed, while it still is dry, coarse and conveyable. (In the case