Mining waste
Lake depositMining waste deposits, also known as mine tailings or mining waste piles, are the residual materials left after valuable minerals or metals have been extracted from ore. These deposits vary in form, including tailings ponds, waste rock piles, and slag heaps, depending on the mining and processing methods used.
The Knaben molybdenum mines in Norway, operational from 1885 to 1973, left behind significant mining waste deposits, primarily consisting of tailings and waste rock. One of the most prominent remnants is a sand landfill covering approximately 120 acres and reaching up to 20 meters thick, located beneath the former processing plant. This deposit contains elevated levels of metals, including molybdenum, copper, and zinc.
Originally, mine waste was deposited into two lakes—Lille Knabetjødn and Store Knabetjødn—with Lille Knabetjødn now completely filled and Store Knabetjødn partially filled. Over time, infilling between the lakes led to the formation of the extensive sand deposit seen today.
The heavy metal content in these tailings poses environmental risks, primarily leaching into water sources and affecting local ecosystems. The Norwegian Geotechnical Institute (NGI) has conducted assessments and mitigation studies to evaluate the stability of the landfill and recommend measures to reduce contamination and rehabilitate the area.
Knaben’s mining waste remains a complex environmental issue, requiring continuous monitoring, remediation strategies, and resource recovery considerations to mitigate long-term ecological impacts.
Industrial steel
MetalIndustrial steel is a broad category of steel alloys used in heavy industries, construction, and manufacturing. It is primarily composed of iron and carbon, with varying amounts of alloying elements like manganese, chromium, nickel, and molybdenum to enhance properties such as strength, durability, and resistance to corrosion, heat, and wear.
Industrial steel plays a vital role in modern infrastructure, manufacturing, and technology. Its versatility, recyclability, and strength make it an essential material in sectors such as transportation, aerospace, energy production, and heavy machinery.
Molybdenite
MineralMolybdenite is a soft, silvery-gray mineral composed of molybdenum disulfide (MoS₂). It is the primary ore of molybdenum, a metal used to strengthen steel and in high-temperature applications. Molybdenite has a greasy feel and a hexagonal crystal structure, similar to graphite, allowing it to function as a dry lubricant. It commonly forms in hydrothermal veins and porphyry deposits.
Molybdenum
Chemical elementMolybdenum (42Mo) is a chemical element that was first isolated from molybdenite (MoS₂), a naturally occurring mineral. Historically, molybdenite was often confused with lead ores, which led to its name being derived from the Greek word molybdos (μόλυβδος), meaning lead. Although molybdenum shares some physical properties with graphite, such as a metallic luster and layered crystal structure, it is generally harder and produces a cold black pigment, while graphite is typically dark grey and softer.
Molybdenum is notable for its exceptionally high melting point of 2,623°C, making it one of the most heat-resistant metals. This property made it highly valuable in military applications during both World Wars, particularly in artillery, tank armor, and armor-piercing shells. Molybdenum strengthens steel alloys, enhancing their durability, hardness, and resistance to heat, which led to it being dubbed the "war metal."
During World War II, Germany’s access to American molybdenum supplies was cut off due to Allied trade restrictions, forcing them to seek alternative sources in Europe. This led to the occupation of regions rich in molybdenum, such as Knaben in Norway, which was strategically important due to being the only active European molybdenum mine.
Today, molybdenum is primarily used in stainless steel production, where it improves corrosion resistance, and in lubricants (molybdenum disulfide grease), which are valued for their ability to withstand extreme temperatures and pressures. Once considered rare and strategically significant, molybdenum has become a commodity metal, and its extraction in Norway has been deemed economically unviable due to market conditions and profitability concerns.
Stainless-steel
MetalStainless steel is a corrosion-resistant alloy primarily composed of iron, carbon, and a minimum of 10.5% chromium, which forms a passive oxide layer that protects it from rust and staining. Depending on its grade and intended use, stainless steel may also contain elements such as nickel, molybdenum, titanium, and manganese to enhance its strength, heat resistance, and durability.
This versatile material is widely used in industries such as construction, automotive, aerospace, medical, and food processing due to its strength, hygiene, and resistance to extreme temperatures and chemical exposure. Stainless steel is commonly found in kitchenware, surgical instruments, industrial equipment, and architectural structures, making it a fundamental material in modern engineering and design.