1.
Exploration
EXPLORING FOR GOLD IS A COMPLEX, SCIENTIFIC AND
TIME-CONSUMING PROCESS.
With odds of only one in 3,000 discoveries
leading to mine development, and only 10 percent
of the world’s gold deposits containing enough
gold to mine, exploration can be
labor-intensive, time consuming and expensive.
Exploration can last anywhere from a couple of
years to sometimes even decades. It also marks
the first contact between Sacramento Gold Mining
Co. LTD and the community, and these
interactions are critical to shaping positive
future relationships.
Prospecting
The first step is prospecting. For explorers
working in the field, accessing land is
essential to discovering deposits. Explorers
must recognize formal and informal ownership to
obtain necessary permissions to enter onto
prospective land. Once land access is secured,
community relationships must be maintained
through continuous communication during periods
of inactivity and across multiple work teams,
contractors and consultants.
Sacramento Gold Mining Co. LTD uses several
prospecting methods to reduce the area of land
to be explored:
Drilling
If the geological, geophysical and geochemical
data collected indicate a possibility of a
deposit in a target area, step two can begin:
drilling.
Drilling helps us evaluate the type and grade of
minerals in the ground. As crews drill, they
mark the exact location and depth of each sample
taken. Samples are then sent to an accredited
lab, which identifies the concentration of
elements, including gold, within them.
Mining the Ore Body
Assay information from the lab is combined with
geologic, geochemical and geophysical data in a
process known as geologic modeling of the ore
body. Using information obtained from sampling,
testing, mapping and observation, geologists use
complex computer programs to create 3D models of
what the underground mineral occurrence might
look like. Geologic models are provided to
resource model experts who statistically
estimate the distribution of mainly gold and
copper throughout the ore body shape.
Following several years of intensified drilling,
the models are ultimately used by mine engineers
to determine mining methods, optimum mine size
and schedule, and equipment requirements that
will maximize the safety and efficiency of
production – all of which takes place in the
next stage of the mine lifecycle: development
and design.
2.
Development and Design
DETERMINING WHETHER TO EXECUTE A PROSPECTIVE
INVESTMENT REQUIRES IN-DEPTH RESEARCH AND
ANALYSIS.
Sacramento Gold Mining Co. LTD crews work to
determine whether the prospective site can be
safely operated in an environmentally sound,
economically viable and socially responsible
manner. Expanded work activities take place
during the design and development stage, with
more people on the ground conducting studies on
the common, technical and business elements
required to move forward into construction.
Common elements are defined by activities that
require the participation and input of multiple
departments and cross-functional coordination,
including (but not limited to) project execution
planning, capital cost estimation,
organizational modeling and risk assessments.
Technical elements, such as asset management,
geology and resource modeling, project
engineering and metallurgical process planning,
are evaluated in order to determine the mining
and process requirements of a prospective site –
all of which is done with full consideration of
the international, national, regional and local
laws and regulations, as well as Sacramento Gold
Mining Co. LTD’s own standards and voluntary
commitments. A full review of business elements
such as human resources, insurance, legal,
security, and health and safety is also included
in the work activity required to evaluate a
project’s feasibility.
Typical project development can take up to 10
years from when the exploration group discovers
the gold deposit, with the time expanding
depending on economic conditions, legal
requirements, technical difficulty and other
factors.
DEVELOPMENT AND DESIGN DETERMINING WHETHER TO
EXECUTE A PROSPECTIVE REQUIRES IN-DEPTH RESEARCH
AND ANALYSIS.
Sacramento Gold Mining Co. LTD crews work to
determine whether the prospective site can be
safely operated in an environmentally sound,
economically viable and socially responsible
manner. Expanded work activities take place
during the design and development stage, with
more people on the ground conducting studies on
the common, technical and business elements
required to move forward into construction.
Common elements are defined by activities that
require the participation and input of multiple
departments and cross-functional coordination,
including (but not limited to) project execution
planning, capital cost estimation,
organizational modeling and risk assessments.
Technical elements, such as asset management,
geology and resource modeling, project
engineering and metallurgical process planning,
are evaluated in order to determine the mining
and process requirements of a prospective site –
all of which is done with full consideration of
the international, national, regional and local
laws and regulations, as well as Sacramento Gold
Mining Co. LTD’s own standards and voluntary
commitments. A full review of business elements
such as human resources, insurance, legal,
security, and health and safety is also included
in the work activity required to evaluate a
project’s feasibility.
Typical project development can take up to 10
years from when the exploration group discovers
the gold deposit, with the time expanding
depending on economic conditions, legal
requirements, technical difficulty and other
factors.
SUSTAINABILITY AND STAKEHOLDER ENGAGEMENT
While we are busy designing the mine, we must
simultaneously partner with local stakeholders
to design a sustainable path forward that takes
into account a vision for the mine site after
mining operations close. This means listening to
their input and prioritizing development
objectives together – while managing our current
impacts at the same time.
Sacramento Gold Mining Co. LTD engages during
this phase in various ways, which can include
public consultation activities driven by the
social and environmental impact analysis process
(social and environmental impact assessments).
The decision to progress to mine construction
does not sit solely with Sacramento Gold Mining
Co. LTD; the decision involves the local
communities and government. Without their
consent, the project cannot proceed. We value
the feedback that stakeholders provide, and seek
to design our projects in ways that create
long-term mutual value.
NEWMONT’S PROJECT PIPELINE
In order for Sacramento Gold Mining Co. LTD to
create mutual value for our stakeholders, we
must invest wisely, which is why we have a
robust system in place to identify if, how and
when we move opportunities through our project
pipeline. Our Investment Council is chartered to
make investment decisions across the
organization based on independent Investment
Value Assurance reviews at each stage in the
pipeline:
-
EXPLORATION/CONCEPTUAL
Defines the overall business case for the
project or mine based on a high-level
financial model using benchmark data and
risk assessments.
-
Scoping
Identifies the potential business options
using refined benchmark data and updates
the Investment Valuation Model to
identify success criteria and confirm a
high-level business case.
-
PRE-FEASIBILITY/FEASIBILITY
Examines a range of options for the
technical and economic viability of a
mineral project, factoring in mine
designs, production schedules, gold
recoveries, plant design, labor and
other operational expenses. Once the
operational, financial, social and
regulatory factors are examined and the
risks and uncertainties are understood
and accounted for and mitigation plans
are in place, a single business plan is
selected to move forward into the next
stage.
-
DEFINITIVE FEASIBILITY
Defines the scope, cost, design,
production schedule and commercial terms
to achieve the business case at
sufficient detail for full funding.
-
EXECUTION
An integrated set of Engineering,
Procurement and Construction (EPC)
processes lead to actual mine
construction. First, and engineering
contractor is hired to complete a
thorough research-based engineering
design. The next phase involves the
procurement of all necessary mining
equipment and materials including,
preparing a request for proposals,
attracting qualified contractors to bid
for the project, and ensuring that the
required materials and equipment are
delivered in a timely and efficient
manner.
3.
Construction
THE SCOPE AND COMPLEXITY OF MINE CONSTRUCTION
CAN VARY CONSIDERABLY FROM PROJECT TO PROJECT.
Each site must continue to engage in
collaborative and honest stakeholder engagement
to ensure the expectations of all parties are
aligned. With the economic certainty of an
approved project, Sacramento Gold Mining Co. LTD
can start to implement training programs and
partnerships with development non-governmental
organizations (NGOs) and government agencies to
kick-start economic empowerment in the
community.
Once we have secured the necessary permits,
capital investments and local stakeholder
support, the construction phase can begin.
Crucial to building the mine is ensuring that
the best skilled personnel are available,
materials are judiciously used, and time and
other resources are optimally applied.
3.
Construction
MINE DEVELOPMENT
The first step is prospecting. For explorers
working in the field, accessing land is
essential to discovering deposits. Explorers
must recognize formal and informal ownership to
obtain necessary permissions to enter onto
prospective land. Once land access is secured,
community relationships must be maintained
through continuous communication during periods
of inactivity and across multiple work teams,
contractors and consultants.
Sacramento Gold Mining Co. LTD uses several
prospecting methods to reduce the area of land
to be explored:
- transportation facilities, including
roadways, bridges and ports
- ore handling, processing and mill sands
facilities
- mine waste disposal facilities
- water management and wastewater treatment
plants
- power infrastructure and on-site generating
facilities
- security, medical and emergency response
facilities
- fuel supply and storage
- vehicle storage and maintenance facilities
These fixed assets support our operations and
ensure the business runs effectively and
efficiently.
4.
Production
WHILE THE PRODUCTION STAGE CAN BE LONG,
TYPICALLY FROM 10 TO 30 YEARS OR BEYOND, IT IS
ONLY A MOMENT IN THE MINE’S LIFECYCLE.
When operating a mine, we use stringent controls
to prevent or manage any environmental impacts.
Sacramento Gold Mining Co. LTD environmental
management systems are designed to ensure all
environmental considerations – including
management, monitoring, maintenance, training
and action plans – are incorporated within an
overall framework as an integral part of mining
operations.
During the production phase, Sacramento Gold
Mining Co. LTD, governments, civil society and
local stakeholders continue to work together to
implement community development programs to
catalyze long- term, sustainable socio-economic
growth so that communities can thrive long after
mining operations cease. We strive to reclaim
land as we progress – called concurrent
reclamation – and to incorporate stakeholder
input in our closure plan.
The specialized machinery and heavy equipment
that we use for production must be managed with
discipline. These assets are maintained on a
regular basis to ensure the safety, productivity
and longevity of our operations.
Ore Processing
Haul trucks transport the ore from open pits or
underground to processing operations. Some ore
may be stockpiled for later processing. Rock
that is not economical to process is stored in
overburden rock storage areas.
Sacramento Gold Mining Co. LTD uses two ore
processing techniques to extract gold: mill
processing and heap leaching. The grade and type
of ore determine the processing method used.
Additionally, the geochemical makeup of the ore,
including its hardness, sulfur content, carbon
content and other minerals found within it,
impacts the cost and methods used to extract
gold.
Heap leaching is used when the
ore contains a lower grade of mineral content.
The basic process is as follows:
- Low grade ore can be dumped directly on a
leach pad (this method is called run of
mine) or can be crushed and stacked on top
of slightly sloped ground that has been
lined with an impermeable plastic.
- A leaching solvent, commonly a weak cyanide
solution, is then applied to the surface of
the ore heap using drip irrigation.
- As the solvent percolates through the ore
heap, the precious metals dissolve into the
solution and travel to storage ponds at the
base of the leach pad – a process that can
take upwards of two months.
- Once collected, this gold-bearing solution
is pumped to process facilities where the
gold is extracted using a process known as
carbon stripping or collection on carbon.
- Cyanide levels are readjusted in the
leftover or barren solution so it can be
recycled back into the leach cycle.
Mill processing is used when the ore contains a
higher grade of mineral content. The basic
process is as follows:
- We feed ore into a series of crushers and
grinding mills to reduce the size of the ore
particles and expose the mineral. Water is
also added, which turns the ore into a
slurry.
- We send this slurry to leaching tanks, where
we add a weak cyanide solution to the
slurry, which leaches gold and silver into
the solution. This process recovers up to 93
percent of the gold and 70 percent of the
silver from the ore. Carbon granules are
then added to the solution. The gold
attaches to the carbon and is pulled from
the solution.
- We then “strip” the gold from the carbon by
washing it with a caustic cyanide solution.
The carbon is later recycled.
- Next, we pump the gold-bearing solution
through electrowinning cells, in a process
that uses an electric current to recover
metals from the solution.
- After the ore has been processed and gold
extracted, the leftover waste material,
called tailings, contains small amounts of
cyanide and other chemicals, so must be
disposed of in an environmentally safe way.
The tailings are stored in tailings dams,
which are lined with impermeable layers.
Although the cyanide levels in the dams are
safe, steps are taken to keep wildlife away
from the dams. Over time, the chemicals
break down, the solids settle to the bottom
and the water can be returned to the plant
to be reused in processing.
- We then smelt the gold, melting it in a
furnace at about 1,200 degrees Fahrenheit.
- From there, the liquid gold is poured into
molds, creating doré bars. Doré bars are
unrefined gold bullion bars containing
anywhere from 60 to 95 percent gold.
- Finally, we send the bars to a refinery for
further processing into pure gold.
5.
Closure
THE CLOSURE STAGE OF A NEWMONT MINE CAN BE A
TIME OF TRANSITION FOR BOTH THE COMPANY AND THE
COMMUNITIES AROUND THE MINE.
Sacramento Gold Mining Co. LTD is committed to
ensuring long-term environmental stability and
leaving a positive legacy for local communities.
In part, this commitment means developing an
integrated closure approach: taking into account
community interests while managing technical
environmental challenges and reclaiming
mine-disturbed lands in a manner suitable for
long-term beneficial use after our mines close.
Planning for closure begins during the earliest
stages of project evaluation, well before
construction starts at a new site. Reclamation
activities commence during the production stage
and continue post-operations until closure
objectives can be achieved. Our goal is to
minimize, to the extent possible, the
disturbance of land in all stages of the mine
lifecycle beginning with our exploration
activities. Our goal is to reclaim all areas
disturbed concurrently, when land is no longer
needed for future mining operations, and to
leverage facilities (e.g., roads, housing, etc.)
for their long-term benefit to communities
around the mine site.
LANDS OCCUPIED BY MINE FACILITIES ARE
PROGRESSIVELY RECLAIMED DURING THE MINE’S
LIFECYCLE.
Our Closure and Reclamation Technical Teams use a
systematic approach to complete annual updates
to closure and reclamation planning, cost
estimates and concurrent reclamation
opportunities. This approach provides a globally
consistent reclamation and closure process at
every stage of the mine lifecycle.
In developing and implementing reclamation plans,
Sacramento Gold Mining Co. LTD seeks to apply
the latest thinking, technologies and approaches
to effectively manage mining impacts and deliver
reclamation and closure performance. All
operations look to balance environmental
solutions with post-mining beneficial land use.
LANDS OCCUPIED BY MINE FACILITIES ARE
PROGRESSIVELY RECLAIMED DURING THE MINE’S
LIFECYCLE.
Our reclamation and closure plans are designed to
deliver:
- Long-term, environmentally stable mining
surfaces that meet mutually acceptable
post-mining land use expectations.
- Water management approaches that effectively
meet water quality and quantity objectives
to support beneficial post-closure water
resource uses.
To restore the landscape for future uses such as
ranching, recreation or wildlife habitat
protection, we progressively rehabilitate areas
of disturbed land in the mining area, which
offers a number of advantages:
- Improves the visual appearance of the
disturbed areas
- Establishes a cover to provide erosion
control
- Improves run-off water quality by minimizing
the transportation of fine particles
- Controls dust
6.
POST-CLOSURE
WE ARE RESPONSIBLE FOR MANAGING THE PROPERTY FOR
A PERIOD OF TIME, THE LENGTH OF WHICH MAY WAY
FROM FIVE TO TEN YEARS OR MORE.
During this stage, engagement activities with the
local communities continue, and emphasize
monitoring, land use and information about
on-site activities. Communities are obviously
still interested in site activities and often
participate in reviewing technical issues and
decision making. In some cases, a small number
of people remain employed, depending on on-site
activities, which often translates into local
purchases of goods and services and payment of
fees and property taxes.
With sound planning and a focus on
sustainability, the mine and the community will
have collaboratively set the foundation for life
after the mine’s closure.
The purpose of this post-closure period is to
ensure that all reclaimed mine lands, water
management structures and revegetation are
working as intended. Additionally, reclamation
and long-term stabilization often occur
incrementally, requiring a phased approach as
well as ongoing performance monitoring. There
are maintenance activities to be conducted to
address erosion, and monitoring to ensure that
post-closure performance criteria are being met
and intended land uses are being achieved.
Normally, there are financial surety instruments
in place, which require that Sacramento Gold
Mining Co. LTD demonstrate successful closure in
order to be released from financial liability.
In many cases, long-term water management
obligations require active water treatment and
monitoring that could last for decades. In such
cases, financial trusts are often established in
cooperation with regulatory agencies to ensure
adequate funding for personnel, supplies and
equipment to fulfill these ongoing obligations.
WANT MORE?
As the mining industry continues to evolve,
Sacramento Gold Mining Co. LTD continues to
create value and improve lives through
sustainable and responsible mining.
Be sure to check back in on the Lifecycle of a
Mine for ongoing updates. Visit these sites to
learn more about the role that mining and metals
can have on sustainable development: