- AustraliaNorth AmericaWorld
Investing News NetworkYour trusted source for investing success
- Lithium Outlook
- Oil and Gas Outlook
- Gold Outlook Report
- Uranium Outlook
- Rare Earths Outlook
- All Outlook Reports
- Top Generative AI Stocks
- Top EV Stocks
- Biggest AI Companies
- Biggest Blockchain Stocks
- Biggest Cryptocurrency-mining Stocks
- Biggest Cybersecurity Companies
- Biggest Robotics Companies
- Biggest Social Media Companies
- Biggest Technology ETFs
- Artificial Intellgience ETFs
- Robotics ETFs
- Canadian Cryptocurrency ETFs
- Artificial Intelligence Outlook
- EV Outlook
- Cleantech Outlook
- Crypto Outlook
- Tech Outlook
- All Market Outlook Reports
- Cannabis Weekly Round-Up
- Top Alzheimer's Treatment Stocks
- Top Biotech Stocks
- Top Plant-based Food Stocks
- Biggest Cannabis Stocks
- Biggest Pharma Stocks
- Longevity Stocks to Watch
- Psychedelics Stocks to Watch
- Top Cobalt Stocks
- Small Biotech ETFs to Watch
- Top Life Science ETFs
- Biggest Pharmaceutical ETFs
- Life Science Outlook
- Biotech Outlook
- Cannabis Outlook
- Pharma Outlook
- Psychedelics Outlook
- All Market Outlook Reports
Stripping Ratios: What are They and Why are They Important?
Stripping ratios aren’t often discussed, but they can be an early and important indicator for mining projects. Here’s what investors should know about them.
A strip ratio, or stripping ratio, is an important measurement related to the open-pit mining process.
Put simply, it represents the amount of waste material, also known as overburden, that must be moved in order to extract a given amount of ore. That said, stripping ratios are not only about the volume of unwanted material present at a site; they also take into account the types of material that must be removed to reach the ore. After all, moving lightweight material like sand or dirt is simpler than moving hard rock.
Ore quality is another consideration in stripping ratios. That’s because if a deposit contains low-quality ore, more of it must be mined in order to achieve a return on investment.
How to calculate stripping ratios?
At their most basic, strip ratios can be calculated by dividing overburden thickness by ore thickness. For example, an overburden thickness of 100 meters and an ore thickness of 50 meters would yield a strip ratio of 2:1. That means mining 1 cubic meter of ore would require mining 3 cubic meters of overburden.
The stripping ratio of a deposit may be used, in part, to gauge how profitable it may be. The lower the strip ratio the better, since a low strip ratio translates into lower mining costs and good prospects for profitability.
Conversely, a project with a very high strip ratio likely will not be profitable. In this case, the unwanted material is much greater than the amount of ore that can potentially be extracted, making it too expensive to mine.
It should be noted that every deposit is different, and a project that benefits from another factor — for example, having high grades — can potentially support a higher strip ratio. Generally speaking, there is an inverse relationship between reserve grade and strip ratio.
With all of this in mind, mining companies calculate strip ratios for open-pit projects well before they enter development and production, and tend to seek out projects with relatively low strip ratios. Even so, given all the factors involved in calculating a strip ratio, it’s difficult to determine an overall ideal figure. In the case of a "typical" large, low-grade copper porphyry deposit, a strip ratio below 3:1 is generally considered good.
What are some examples of stripping ratios?
Mines with good strip ratios include Lundin Mining’s (TSX:LUN,OTC Pink:LUNMF) Candelaria copper-gold-silver mine in Chile at 2.1:1, and Copper Mountain Mining’s (TSX:CMMC,OTC Pink:CPPMF) copper mine in Canada at 2.2:1.
Western Copper and Gold (TSX:WRN,NYSEAMERICAN:WRN) has emphasized that its Casino copper-gold project in Canada's Yukon has a “truly impressive” life-of-mine strip ratio of 0.43:1.
It is also not unusual to see a high-grade volcanic massive sulfide deposit support a strip ratio greater than 5:1.
For example, the high-grade Bisha copper mine in Eritrea posted a strip ratio of 5.4:1 in 2014. Similarly, the high-grade New Liberty gold mine in Liberia had a strip ratio of 15.5:1.
This is an updated version of an article originally published by the Investing News Network in 2014.
Don’t forget to follow us @INN_Resource for real-time news updates!
Securities Disclosure: I, Melissa Pistilli, hold no direct investment interest in any company mentioned in this article.
Editorial Disclosure: Western Copper and Gold is a client of the Investing News Network. This article is not paid-for content.
- Top 10 Copper-producing Companies (Updated 2023) ›
- How to Invest in Copper (Updated 2023) ›
- When Will Copper Go Up? (Updated 2023) ›
- Top 10 Copper Producers by Country (Updated 2023) ›
- The Red-Hot Case for Copper as an Inflation Hedge (Updated 2023) ›
Melissa Pistilli has been reporting on the markets and educating investors since 2006. She has covered a wide variety of industries in the investment space including mining, cannabis, tech and pharmaceuticals. She helps to educate investors about opportunities in a variety of growth markets. Melissa holds a bachelor's degree in English education as well as a master's degree in the teaching of writing, both from Humboldt State University, California.
How to Invest in Copper:
Copper Reserves: Top 5 Countries (Updated 2024)
Top 10 Copper Producers by Country (Updated 2024)
The Red-Hot Case for Copper as an Inflation Hedge (Updated 2024)
What Was the Highest Price for Copper? (Updated 2024)
Top 10 Copper-producing Companies (Updated 2024)
How to Invest in Copper
When Will Copper Go Up?
Is the World Running Out of Copper?
Economics of the Copper Scrap Market
A Look at Historical Copper Prices
7 Basic Copper Facts for Investors
Types of Copper Deposits in the World
What are Copper Futures?
LME Copper vs. COMEX Copper
5 Major Copper Uses
Outlook Reports
Featured Copper Investing Stocks
Browse Companies
MARKETS
COMMODITIES
Commodities | |||
---|---|---|---|
Gold | 2194.68 | +3.71 | |
Silver | 24.52 | -0.04 | |
Copper | 4.01 | +0.01 | |
Oil | 81.74 | +0.39 | |
Heating Oil | 2.60 | 0.00 | |
Natural Gas | 1.70 | -0.01 |
Investing News Network websites or approved third-party tools use cookies. Please refer to the cookie policy for collected data, privacy and GDPR compliance. By continuing to browse the site, you agree to our use of cookies.
Melissa Pistilli has been reporting on the markets and educating investors since 2006. She has covered a wide variety of industries in the investment space including mining, cannabis, tech and pharmaceuticals. She helps to educate investors about opportunities in a variety of growth markets. Melissa holds a bachelor's degree in English education as well as a master's degree in the teaching of writing, both from Humboldt State University, California.
Learn about our editorial policies.