Anderson Engineering

Environmental Remediation: What are the types of mines in Utah and the US?

Environmental remediation in Utah occurs on a daily basis at active, closed, and abandoned mine sites.To understand the importance of environmental reclamation, it is also important to understand mining in Utah. This article provides a brief overview of the main types of mining in Utah, other types of mines, and the importance of mining to the Utah economy. Future articles discuss the specific types of mine waste found in Utah requiring site remediation.

Mining in Utah

Utah’s mining production totaled $3.7 billion in 2018.
Metals accounted for 2.1 billion, with $1.8 billion coming from Rio Tinto Kennecott alone), industrial minerals accounted for $1.2 billion, and coal for $450 million.
Utah is actively engaged searching for new metals including beryllium, magnesium and potash. Potential new metals include uranium, vanadium, and lithium.

Types of Mines in Utah and the United States

Open Pit Mining

Open pit mining removes surface rock and uses deep vertical holes to create the mine.

Dredging

Dredging excavates metals from a watercourse via a device that loosens and lifts the material.

Underground Mining

Underground mining is a classic approach that creates shafts or ramps to access the orebody.

In Situ Solution Mining

In situ mining injects a soluble substance into the ore and extracts the resulting solution.

Open pit mining

Open pit mining is the primary method by which major metallic ores are extracted. Open pit mining is the method of choice for low grade ores. With the larger ore bodies common to metal mining the ore body is mined in benches with blasting used to free overburden and continue downward mining. Waste from open pit mining include overburden, mine water, and waste rock.

In the video above you see an example of the type of blasting operations carried out at different open pit mines. At Anderson, we provide engineering field services to mining companies by working with blasting crews to provide field sampling for data collection of ore quality. This data is then used for future mine planning and excavation.

Dredging

Dredging is another type of surface mining that is used to mine heavy metallic minerals that deposit as sediment at the bottom of waterways. Dredging involves using a variety of devices to loosen, extract, and remove the desired deposit from the riverbed or ocean floor. Dredging is not common in the US for metallic mineral mining anymore with most operations ceasing in the 1990’s.

Underground Mining

Underground mining involves the creation of shafts or ramps into a body of rock to gain access to the ore. Underground mining has a significant smaller footprint and surface disturbance as compared to open pit mining. Underground mining also typically has less waste and overburden material as the ore body is generally of higher quality. Underground mining has been decreasing in use in the United States with a mild uptick during the 1990’s as an additional to open pit mining to pursue additional underground resources.

The EPA has a great summary of coal mining and coal mining operations.

In Utah, the majority of underground mining is associated with coal mining. In 2018, five Utah coal operators produced 13.8 million short tons of coal valued at $454 million from seven underground mines and one surface mine. The largest producers of coal in short tons in Utah are:

Mine	Company	Production 18	Forecast 19
Dugout Canyon	Canyon Fuel Company	557	900
Skyline #3	Wolverine Fuels LLC	3614	4200
Emery	Bronco Utah Operations, LLC	442	700

Each year the Utah Department of Natural Resources publishes the Utah Mining Report. The report provides an in-depth analysis and report on the mining and mineral industry in Utah.

In Situ Solution Mining

In situ solution mining involves the sequential drilling of holes into the orebody and the subsequent introduction of a solvent that allows mineral deposits to be extracted via the resulting solution. This method is rarely used but has been used in the past to extract uranium and copper deposits in suitable conditions. However, this moethod can have significant risk to groundwater.