138 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
If the first two decades of the twenty-first century have
taught us anything, it’s that uncertainty is chronic instabil-
ity is permanent disruption is common and that we can
neither predict nor govern events. There will be no new
normal there only be a continuous series of not normal
episodes that defy prediction and are unforeseen by most of
us until they happen. (Collins and Lazier 2020)
Tailings engineers seek to build robust tailings facilities
with the long-term goal of producing an environmentally
inert landform post-closure. The conundrum designers
face is the dependence on mineral processing technology
that uses water as a liberating, conveying, and distribut-
ing medium creating, at times, impounding structures
ripe for stability concerns. We are also now guided by an
industry standard that was structured around principles of
social responsibility (environmental, social, and governance
[ESG]) but is applied to structures that by their nature
have to adhere to Newtonian physics. How does all this
mesh together as coherent guidance? What works and what
doesn’t?
Society depends on skilled engineering resources for
safe day-to-day living, yet we live in a time when the avail-
able resources cannot meet an overwhelming demand.
Why is this? Is it possible that the civil engineering prac-
tice has been devalued and suffering the consequences of
society’s decisions to defocus engineering and science? Even
worse, could it be that resources have been driven from the
industry by environmental pundits who have vilified the
mining industry and created a toxic environment that the
younger generation does not wish to approach? The irony
is that environmental activism has produced consequences
never imagined and that is now embedded in the indus-
try for the next 10 to 20 years. The development of new
tailings management technologies, any future success of
the Global Industry Standard on Tailings Management
(GISTM) (ICMM et al. 2020), and the suffocating lack of
resources are discussed with consideration for the impacts
in the future.
OVERVIEW
History has shown that a single latent condition rarely
results in a catastrophic engineering failure, but the failure
is manifested by multiple interdependent contributing fac-
tors. Thus, a catastrophic failure in the context of this dis-
cussion always results in extensive environmental and social
consequences and many have associated loss of life.
Typically, a catastrophic failure is a result of 8 to 10
contributing factors that individually are constrained and
pose little threat. However, they create a brittle event-chain
ripe ready for initiation by a single trigger (Holtz 1990).
These contributing factors are unintentionally “baked” into
the operating system and can include a myriad of issues like
technical design flaws, construction errors and omissions,
poor quality assurance, and quality control, compromised
or lack of key interpersonal relationships, poorly defined or
executed governance, and political and social impacts. We
can see this unfortunate process in action for catastrophic
failures such as the Columbia Space Shuttle incident, the
flood protection dikes in Louisiana during Hurricane
Katrina, and the Stava Tailings Dam failure.
The Stava failure that occurred in 1985, as an example,
was the result of static liquefaction that produced a cascad-
ing dam failure, accelerating tailings downstream at near
highway speeds and wreaking a path of destruction, kill-
ing 268 people. The contributing factors included unfavor-
able foundation conditions, accumulation of water in the
foundation soils due to an unseasonably wet year, lack of
design elements that provide for stability and foundation
drainage, completion of a repair that had ancillary impacts
on the decant structure (dewatering system) within the
facility, lack of proper governance by both the owner and
the regulator and in action to engineering recommenda-
tions provided by the design engineer (engineer of record
[EOR]). Elimination of many of these contributing factors
could have likely prevented a failure. However, with poor
oversight, design construction, and governance, the neces-
sary event chain was created.
Our job as engineers and designers of tailings storage
facilities is to eliminate or mitigate the potential contribut-
ing factors so that the risk (likelihood and consequences) of
a failure has been appropriately reduced to some nominal
value. The challenges of tailings engineering are identifying
new technologies that produce stable landforms, establish-
ing robust governance (i.e., the GISTM), and maintaining
sustainable engineering resources throughout the dam life
(potentially multigenerational) that are both technically
sound and practically trained.
TRADITIONAL AND EMERGING
TAILINGS MANAGEMENT
TECHNOLOGIES
Tailings facilities are unique structures with the beach
being uniquely different regardless of location and proxim-
ity to other sister dams. Water dam designers are burdened
with selecting ideal sites with favorable foundation condi-
tions either at initial construction or with the appropriate
modification. They can design and construct homogeneous
embankments with protective filters or even zoned struc-
tural embankments with the entire facility able to reach
“steady state loading” upon first filling.
If the first two decades of the twenty-first century have
taught us anything, it’s that uncertainty is chronic instabil-
ity is permanent disruption is common and that we can
neither predict nor govern events. There will be no new
normal there only be a continuous series of not normal
episodes that defy prediction and are unforeseen by most of
us until they happen. (Collins and Lazier 2020)
Tailings engineers seek to build robust tailings facilities
with the long-term goal of producing an environmentally
inert landform post-closure. The conundrum designers
face is the dependence on mineral processing technology
that uses water as a liberating, conveying, and distribut-
ing medium creating, at times, impounding structures
ripe for stability concerns. We are also now guided by an
industry standard that was structured around principles of
social responsibility (environmental, social, and governance
[ESG]) but is applied to structures that by their nature
have to adhere to Newtonian physics. How does all this
mesh together as coherent guidance? What works and what
doesn’t?
Society depends on skilled engineering resources for
safe day-to-day living, yet we live in a time when the avail-
able resources cannot meet an overwhelming demand.
Why is this? Is it possible that the civil engineering prac-
tice has been devalued and suffering the consequences of
society’s decisions to defocus engineering and science? Even
worse, could it be that resources have been driven from the
industry by environmental pundits who have vilified the
mining industry and created a toxic environment that the
younger generation does not wish to approach? The irony
is that environmental activism has produced consequences
never imagined and that is now embedded in the indus-
try for the next 10 to 20 years. The development of new
tailings management technologies, any future success of
the Global Industry Standard on Tailings Management
(GISTM) (ICMM et al. 2020), and the suffocating lack of
resources are discussed with consideration for the impacts
in the future.
OVERVIEW
History has shown that a single latent condition rarely
results in a catastrophic engineering failure, but the failure
is manifested by multiple interdependent contributing fac-
tors. Thus, a catastrophic failure in the context of this dis-
cussion always results in extensive environmental and social
consequences and many have associated loss of life.
Typically, a catastrophic failure is a result of 8 to 10
contributing factors that individually are constrained and
pose little threat. However, they create a brittle event-chain
ripe ready for initiation by a single trigger (Holtz 1990).
These contributing factors are unintentionally “baked” into
the operating system and can include a myriad of issues like
technical design flaws, construction errors and omissions,
poor quality assurance, and quality control, compromised
or lack of key interpersonal relationships, poorly defined or
executed governance, and political and social impacts. We
can see this unfortunate process in action for catastrophic
failures such as the Columbia Space Shuttle incident, the
flood protection dikes in Louisiana during Hurricane
Katrina, and the Stava Tailings Dam failure.
The Stava failure that occurred in 1985, as an example,
was the result of static liquefaction that produced a cascad-
ing dam failure, accelerating tailings downstream at near
highway speeds and wreaking a path of destruction, kill-
ing 268 people. The contributing factors included unfavor-
able foundation conditions, accumulation of water in the
foundation soils due to an unseasonably wet year, lack of
design elements that provide for stability and foundation
drainage, completion of a repair that had ancillary impacts
on the decant structure (dewatering system) within the
facility, lack of proper governance by both the owner and
the regulator and in action to engineering recommenda-
tions provided by the design engineer (engineer of record
[EOR]). Elimination of many of these contributing factors
could have likely prevented a failure. However, with poor
oversight, design construction, and governance, the neces-
sary event chain was created.
Our job as engineers and designers of tailings storage
facilities is to eliminate or mitigate the potential contribut-
ing factors so that the risk (likelihood and consequences) of
a failure has been appropriately reduced to some nominal
value. The challenges of tailings engineering are identifying
new technologies that produce stable landforms, establish-
ing robust governance (i.e., the GISTM), and maintaining
sustainable engineering resources throughout the dam life
(potentially multigenerational) that are both technically
sound and practically trained.
TRADITIONAL AND EMERGING
TAILINGS MANAGEMENT
TECHNOLOGIES
Tailings facilities are unique structures with the beach
being uniquely different regardless of location and proxim-
ity to other sister dams. Water dam designers are burdened
with selecting ideal sites with favorable foundation condi-
tions either at initial construction or with the appropriate
modification. They can design and construct homogeneous
embankments with protective filters or even zoned struc-
tural embankments with the entire facility able to reach
“steady state loading” upon first filling.