Questions You Should Know about Tailings Pipeline

01 Sep.,2025

 

Tailings Pipelines Corrosion Prevention Techniques

A pipeline plays a crucial role in mining operations by transporting waste slurry from processing plants to tailings storage facilities. These pipelines are essential for the safe and efficient disposal of tailings, which consist of a mixture of water, fine-grained rock, and processing chemicals. However, due to their exposure to extreme environmental conditions, including high temperatures, salinity, and abrasive slurry compositions, these pipelines are highly susceptible to wear and corrosion. Without proper tailings pipeline design, these challenges can lead to operational inefficiencies, increased costs, and environmental hazards.

Corrosion occurs when the pipeline material degrades due to chemical, electrochemical, or mechanical interactions with its environment. This deterioration weakens the structure, leading to leaks, ruptures, and reduced pipeline lifespan. The highly abrasive nature of the slurry, combined with variations in pH levels, accelerates corrosion, making maintenance and prevention strategies a top priority for mining companies. Implementing effective tailings pipeline design strategies, including selecting durable materials like HDPE tailings pipe, is essential to mitigate these risks and enhance operational efficiency.

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The Impact of Corrosion on Tailings Pipelines

Corrosion in a tailings pipeline can have severe consequences, significantly affecting operational reliability and increasing costs. The primary impacts include:

  • Shortened Lifespan: Corrosion rapidly weakens pipeline materials, requiring frequent replacements, leading to higher capital and maintenance costs. Investing in durable materials, such as HDPE tailings pipes, can help extend pipeline longevity and reduce these expenses.
  • Environmental and Regulatory Risks: Pipeline failures due to corrosion can result in leaks, contaminating nearby water sources and ecosystems. This can lead to hefty regulatory fines and potential shutdowns, affecting the sustainability of mining operations.
  • Production Disruptions: A failing tailings pipeline can cause operational delays, which can impact overall productivity and profitability. The need for unplanned repairs and downtime can also significantly disrupt mining efficiency.

Given these challenges, implementing corrosion prevention techniques is critical for ensuring long-term sustainability and cost-effectiveness in tailings pipeline operations. By integrating robust tailings pipeline design methods, selecting corrosion-resistant materials, and adopting proactive maintenance strategies, mining companies can significantly reduce corrosion-related risks and enhance overall pipeline performance.

Understanding Corrosion in Tailings Pipelines

A. What is Corrosion?

Corrosion is a natural process that causes materials, particularly metals, to deteriorate due to chemical and electrochemical reactions with their environment. In mining operations, pipeline design plays a crucial role in mitigating corrosion risks by ensuring that pipelines can withstand the harsh conditions associated with transporting tailings.

Corrosion in a pipeline occurs when the material comes into contact with water, oxygen, or the chemical composition of the transported slurry. Over time, these interactions weaken the structure, causing thinning walls, leaks, and, in severe cases, complete system failure. To minimize these risks, effective pipeline design must account for factors such as material selection, protective coatings, and optimized flow rates.

One of the most effective solutions for corrosion resistance is using HDPE tailings pipe. Unlike metal pipes, HDPE tailings pipe does not corrode when exposed to water, chemicals, or oxygen, making it a durable and low-maintenance option for transporting tailings in harsh mining environments.

B. Types of Corrosion Affecting Tailings Pipelines

Several types of corrosion can impact the integrity of a pipeline:

  • Uniform Corrosion – A gradual and consistent material loss across the pipeline surface due to prolonged exposure to corrosive conditions.
  • Pitting Corrosion – A localized form of corrosion that creates small holes or pits in the pipeline material, leading to weak points and potential perforation.
  • Galvanic Corrosion – Occurs when two dissimilar metals come into contact in the presence of an electrolyte, leading to the accelerated corrosion of the less noble metal.
  • Erosion-Corrosion – A combination of mechanical wear and chemical attack, commonly found in pipelines transporting highly abrasive tailings slurry.
  • Crevice Corrosion – Occurs in stagnant areas such as gaskets, welds, and joints, where trapped moisture and chemicals promote localized corrosion.
  • Microbiologically Influenced Corrosion (MIC) – Caused by bacteria that generate acidic byproducts, leading to localized corrosion damage and material degradation.

Implementing a well-planned tailings pipeline design that includes corrosion-resistant materials, coatings, and maintenance strategies is essential to preventing these forms of corrosion.

C. Key Factors Contributing to Corrosion in Tailings Pipelines

Several environmental and operational factors accelerate the corrosion process in pipelines used for tailings transport:

  • Abrasive Nature of Tailings Slurry – The high solid content in tailings causes mechanical wear, leading to faster material degradation. The use of HDPE tailings pipe helps minimize abrasion-related damage due to its smooth internal surface, which reduces wear.
  • Acidic or Alkaline pH Conditions—Residual process chemicals can create highly acidic or alkaline environments, increasing corrosion rates. To reduce the impact of chemical exposure, an optimized tailings pipeline design should incorporate pH control strategies.
  • Presence of Oxygen and Moisture—Exposure to oxygen and water leads to oxidation, which is a leading cause of rust and material weakening in metal pipelines.
  • Temperature Extremes – Large temperature fluctuations cause thermal expansion and contraction, which can induce stress and accelerate material fatigue.
  • Flow Velocity and Turbulence – High flow speeds, especially in bends and joints, increase erosion-corrosion risks, leading to premature wear and potential leaks.

By integrating robust tailings pipeline design strategies, mining operations can significantly reduce corrosion-related failures, extend the service life of their pipelines, and lower long-term maintenance costs.

Corrosion Prevention Techniques for Tailings Pipelines

A. Material Selection for Corrosion Resistance

Selecting the right pipeline material is the first and most crucial step in preventing corrosion in a tailings pipeline. Different materials offer varying levels of durability and resistance to chemical, mechanical, and environmental damage. Common options include:

  • HDPE (High-Density Polyethylene) – Non-corrosive and flexible, making it a preferred choice for modern tailings pipeline design. However, HDPE tailings pipes can be vulnerable to mechanical wear in highly abrasive environments.
  • Stainless Steel – Provides excellent resistance to chemical corrosion but is costly, making it less viable for extensive pipeline networks.
  • High-Alloy Steels – Duplex stainless steels offer enhanced durability, particularly in acidic tailings environments, making them an excellent option for long-term reliability.
  • Rubber-lined and Ceramic-Lined Pipes – Designed to withstand extreme abrasion and chemical attack, significantly extending pipeline service life.

Choosing the right material depends on the chemical composition of the tailings slurry, environmental factors, and the specific operational requirements of the tailings pipeline.

B. Protective Coatings and Linings

Applying protective coatings and linings is another effective method of preventing corrosion. These create a barrier between the pipeline material and corrosive elements in the transported slurry. Common options include:

  • Epoxy-Based Coatings – Provide excellent resistance to moisture and chemical attack.
  • Polyurethane Coatings – Offer flexibility and impact resistance, making them ideal for areas subject to mechanical stress.
  • Fusion-Bonded Coatings – Suitable for high-temperature applications, offering a strong protective layer.
  • Rubber and Ceramic Linings – Widely used in high-wear areas due to their superior abrasion resistance.

Integrating these protective measures into tailings pipeline design helps to reduce material degradation and extend pipeline longevity.

C. Cathodic Protection Systems

Cathodic protection (CP) is an electrochemical technique that prevents corrosion by altering the electrical charge of the pipeline. There are two primary types of CP:

  • Sacrificial Anode Systems – Utilizes metals such as zinc, magnesium, or aluminum, which corrode instead of the pipeline material.
  • Impressed Current Cathodic Protection (ICCP) Systems – Uses an external power source to apply a protective current, preventing corrosion in submerged or underground pipelines.

Cathodic protection is particularly beneficial for metal pipelines exposed to high-corrosion environments, offering a long-term solution for corrosion mitigation.

D. Proper Pipeline Design and Installation

A well-optimized tailings pipeline design can significantly reduce corrosion risks. Key strategies include:

  • Optimizing Routing – Avoiding areas with high mechanical wear or exposure to corrosive elements.
  • Increasing Wall Thickness – Using thicker-walled pipes in high-impact sections to prolong service life.
  • Joint and Fitting Protection – Employing corrosion-resistant welding techniques and lined fittings to prevent crevice corrosion.

By carefully planning the installation of the tailings pipeline, mining operations can mitigate the risks associated with corrosion and enhance its overall efficiency.

E. Routine Monitoring and Maintenance Strategies

Regular monitoring and maintenance play a crucial role in preventing costly pipeline failures. Key strategies include:

  • Ultrasonic Thickness Measurements – Detects early signs of pipeline thinning due to corrosion.
  • Smart Pigging and Inline Inspection Tools – Identifies weak points and areas vulnerable to corrosion.
  • Corrosion Sensors and Real-Time Monitoring – Provides continuous data on pipeline conditions, enabling predictive maintenance.
  • Cleaning and Flushing Procedures – Removes accumulated deposits that can accelerate corrosion and impact flow efficiency.

Routine maintenance ensures early detection of corrosion issues, reducing the likelihood of unexpected failures.

F. Environmental and Chemical Controls

Managing the chemical properties of the tailings slurry is another effective method of preventing corrosion. Techniques include:

  • pH Adjustment – Neutralizing excessively acidic or alkaline tailings to reduce their corrosive effects.
  • Use of Corrosion Inhibitors – Adding chemical compounds that slow down corrosion reactions.
  • Flow Rate Optimization – Preventing excessive turbulence and stagnation to minimize erosion-corrosion risks.

Mining operations can significantly enhance the durability and performance of their pipeline infrastructure by integrating these strategies and utilizing durable materials such as HDPE tailings pipe.

Future Innovations in Corrosion Prevention

As mining operations continue to expand, new technological advancements are emerging to enhance corrosion prevention in tailings pipelines. These innovations aim to increase durability, reduce maintenance costs, and improve efficiency. By incorporating cutting-edge materials and smart monitoring solutions, the industry is moving toward more sustainable and long-lasting infrastructure.

Nanotechnology-Based Coatings

One of the most promising advancements in tailings pipeline design is the use of nanotechnology-based coatings. These coatings provide superior protection by forming ultra-thin barriers that resist chemical attack and moisture infiltration. Some nanocoatings even possess self-healing properties, meaning they can repair minor surface damage before it leads to more significant corrosion. This technology greatly extends pipeline lifespan and reduces maintenance frequency.

IoT-Enabled Smart Monitoring Systems

The integration of IoT (Internet of Things) technology in pipeline maintenance allows for real-time monitoring of pipeline conditions. Smart sensors installed along the pipeline can detect temperature fluctuations, pressure changes, and early signs of corrosion. This real-time data collection enables predictive maintenance, preventing unexpected failures and ensuring continuous operation. By optimizing pipeline design with IoT-based monitoring, mining companies can significantly improve efficiency and reduce operational risks.

Self-Healing Materials

Advanced materials are being developed to enhance pipeline resilience, with self-healing coatings being a breakthrough in corrosion prevention. These coatings contain microcapsules filled with protective agents that are released when the pipeline surface is compromised. This self-repair mechanism prevents corrosion from spreading and extends the durability of pipelines, including HDPE tailings pipes, which are already known for their resistance to chemical and environmental damage.

By integrating these cutting-edge technologies, mining operations can significantly enhance the reliability of their pipelines, ensuring that HDPE tailings pipe and other materials maintain long-term integrity in harsh environments.

Conclusion

Corrosion is one of the biggest challenges facing mining operations, and taking a proactive approach to corrosion prevention is essential for ensuring the longevity and efficiency of a pipeline. By implementing a combination of material selection, protective coatings, cathodic protection, optimized tailings pipeline design, and routine maintenance, mining companies can significantly extend the lifespan of their infrastructure.

Recap of Key Corrosion Prevention Strategies

  • Material Selection: Choosing the right materials for a pipeline, such as stainless steel, high-alloy steel, or HDPE tailings pipe, based on environmental conditions.
  • Protective Coatings and Linings: Epoxy, polyurethane, rubber, or ceramic linings are applied to act as barriers against corrosive elements.
  • Cathodic Protection: Utilizing sacrificial anodes or impressed current systems to prevent electrochemical corrosion.
  • Proper Design and Installation: The tailings pipeline must be optimized to reduce stress points, turbulence, and erosion-related damage.
  • Routine Monitoring and Maintenance: Conducting predictive inspections, smart monitoring, and regular cleaning to prevent corrosion before it leads to failures.

Long-Term Benefits of Proactive Corrosion Prevention

  • Cost Savings: Extending the lifespan of a tailings pipeline reduces replacement and maintenance expenses.
  • Environmental Compliance: Reducing the risk of leaks ensures adherence to environmental regulations and prevents contamination.
  • Enhanced Operational Efficiency: A well-maintained pipeline ensures continuous operation, minimizing downtime and maximizing productivity.

Investing in corrosion prevention strategies, including the use of HDPE tailings pipe for increased durability, helps mining companies build safer, more reliable, and cost-effective pipeline systems, ensuring sustainable and efficient tailings transport.

Tailings dams: an explainer - London Mining Network

The who, the what and the why of mining waste dams

Introduction

With nearly every mining operation comes a mining waste dam, or tailings dam. The first were built two centuries ago and now there are ongoing studies trying to estimate how many of them exist in the world. Most people only hear about them if they fail, and even then, the headlines fall in and out of mainstream news fairly rapidly. Anyone wanting to know more about mining should know about them as they are an integral part of the industry.

One of the most deadly mining waste disasters was recorded almost a year ago, on 25th January in the town of Brumadinho, Minas Gerais, Brazil. Marcela Nayara Rodrigues, from Brumadinho and member of Movement of Water and Mountains, reported during a recent visit to the UK that 272 people were killed by the massive wave of toxic sludge, with 14 still missing. Owned by Brazilian mining giant Vale, many of those affected by this collapse don’t call what happened a tragedy, but a corporate crime.

London Mining Network (LMN) is working on this issue with affected communities and groups supporting affected communities at this critical time.

Cutting through the jargon, we explain below what tailing dams are and the consequences of their failure.

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What are mine tailings?

Tailings are the waste products from mining – mining waste. During mining, machinery and chemicals are used to grind up rock into a fine sand to extract minerals and metals from the rock, along with large amounts of water, often in countries prone to drought. Everything that isn’t useful at the end of this process is waste. This includes finely ground rock particles, chemicals, minerals and water. Depending on the type of mining, tailings can be liquid, solid or a bit of both.

Many substances found in tailings are lethal, others are radioactive. It’s not uncommon to find large amounts of cyanide, mercury and arsenic, thereby creating toxic sludge.

What are tailings dams?

Before tailings dams, all mining companies used to dump their waste into the nearest water source. Tailings dams reduce this but there are still notable cases of companies still disposing their tailings in rivers and the sea, such as PT Inalum, the Indonesian company which owns Grasberg gold mine in West Papua. Birds and animals drink from and bathe in these contaminated waters, whether designated tailings dams or not. And toxic substances from tailings dams regularly leak into nearby rivers and streams, devastating local ecosystems.

Tailings dams can be huge lakes, with embankments reaching hundreds of metres high. Mining waste is piped into or dumped into the dam. One of the reasons dams fail is due to a lack of monitoring and poor or inadequate maintenance. Companies should be compelled to monitor their dams, draining excess water if necessary and checking that the dam is strong enough to contain the mining waste.

What are the different types of tailings dams?

Tailings dams are different to those built for reservoirs or hydroelectric projects which are usually made from reinforced concrete or stone. There are four different types:

Upstream dams

These dams use a cheaper, higher risk method of construction which is therefore more dangerous. The mine tailings is used to create a barrier. The dam gets higher as more tailings are stored behind them, increasing the risk of collapse. Upstream dams can become unstable and leak if the mine waste behind the dam gets too wet. This will damage the dam and may cause it to collapse. It is no coincidence that most of the dams which have collapsed around the world have been upstream dams.

Upstream tailings dams are finally beginning to be made illegal in some countries, including in Brazil and Chile. The devastating Brumadinho dam disaster has been the catalyst for some governments, some mining companies and some investors to make changes – but none of this is compulsory. There is no international independent or impartial body regulating tailings dams, or in fact, any of the mining industry.

Centreline dams

Centreline dams are in between upstream and downstream dams in terms of expense and stability. The barriers are made out of earth or rock to form a barrage rather than mining waste.

Downstream dams

Downstream dams are also constructed with earth or rock. They are more stable than the two dams above because they don’t store wet mining waste underneath the barriers. They are also more expensive because they take up more space and more material. However, this form of construction is by no means safe from failure or free from negative consequences. For example, a downstream dam at British multinational Anglo American’s Minas Rio operation is regularly leaking toxic waste, local residents told LMN during a visit to the area, in Minas Gerais, Brazil, in August .

Dry tailings 

In this method, water is removed so that the dry tailings can be stored with less risk to nearby water sources, ecosystems, workers and communities. So far it is not a popular choice due to it being more expensive and time-consuming. Like all tailings dam types, dry tailings is not free from risk or possible negative impacts. For example, the water removed from dry tailings is likely to remain toxic, making reusing or disposing of it still problematic.

What are the consequences of collapse?

Seven dams collapsed in , in Brazil, Peru, India, Myanmar and Russia. The latter, which collapsed on 17th October, was apparently an illegally built dam which violated safety regulations and was part of a gold mine operation in Siberia. 15 people were killed, 13 others are missing. The first of these was the dam failure at Brumadinho, in the Brazilian state of Minas Gerais on 25th January. An upstream tailings dam, owned by the Brazilian mining giant Vale, burst near to the town of Brumadinho, owned by Brazilian mining giant Vale. Vale employees and external experts had previously warned the company that the dam was unstable. The collapse destroyed or damaged people’s homes and devastated the local environment. A country hotel nearby was destroyed, killing those inside. The company is still clearing the toxic sludge, the dust of which still covers buildings nearby.

In , just 50 miles away and also in Minas Gerais, the Fundao tailings dam collapsed in the town of Mariana. Twenty people were killed and it was Brazil’s worst environmental disaster to date; some 33 million cubic metres of iron ore tailings were released into the vital water source, the river Doce. A million people along the river were affected and the waste travelled over 500km to the mouth of the river in the Atlantic Ocean. This mine operation was owned by Samarco – a joint venture of Vale and British-Australian mining company BHP..

Over four years on and Samarco has not yet completed one single house for the affected communities. The ecosystems and fish which support communities alongside the river may never recover.

In August , Canadian mining company Imperial Metals’ Mount Polley copper-gold mine dam collapsed releasing 25 million cubic metres of wastewater and tailings into nearby water systems and lakes. A year before it failed, the company reported that the dam contained 84,831 kilograms of arsenic, 38,218 kg of lead and 562kg of mercury along with other minerals and waste products.

Dodgy dams we know about

Several factors are used to classify a dam’s risk, including its height, slope, terrain and nearby seismology. The risk classifications were reported by the companies, though there is not yet an independent global standard.

Risk indicates how a dam rupture could affect the nearby environment, not a dam’s potential for rupture. A dam is considered “high risk” if it would cause extreme or catastrophic danger to nearby communities, including mass fatalities.

Some 687 tailings dams are at high risk of failure, according to recent research carried out by investors. Most of the 262 high-risk upstream dams are in South Africa. Back in , tailings dam expert Lindsay Newland Bowker wrote that all 144 of Brazil’s large tailings dams should be considered at significant risk of failure.

In June , British multinational companies such as Glencore and BHP reported that five of its tailings dams were at ‘extreme’ risk of causing damage and loss of life. Glencore admitted that 17 of its dams were at extreme risk of failing.

Spanish mining company Atalaya is listed on London’s Alternative Investment Market – a less regulated market (for smaller companies) than the London Stock Exchange. The company’s Riotinto Mine [formerly associated with Rio Tinto mining company but not now] is an opencast copper mine in the province of Huelva, Andalusia, southern Spain. The mine currently processes 9.5 million metric tons of copper ore per year with plans to expand to 15 million metric tons per year.

In May , Spanish environmental organisation Ecologistas en Acción published a video which was picked up on social media showing one of the sections of the Riotinto dam leaking and piping/bubbling, indicating problems with the dam’s retaining walls.

The ratio of liquid to solid in the dam is 70 percent liquid to 30 percent solid. Violating the environmental conditions of which the company holds its license to operate, Atalaya Mining has not built the necessary concentration plant to thicken the tailings to the 50 percent solids required. Despite warnings by Ecologistas en Accion and expert Dr Steve Emerman in his report for LMN, published in June , and recently in LMN’s summary report, that the dams have exceeded their capacity and one is proposed to be raised in a potentially dangerous way, and both.are at extreme risk of collapsing, nothing has been done.

Are there alternatives to tailings dams?

Yes, no, kind of! Rather than calling for the use of a different type of tailings dam, LMN calls for independent monitoring of tailings dams and that mining companies are accountable for their dams during and post-operation. We also urge shareholders to hold these companies to account. We advocate for a justice transition to post-extractivism, in other words, we agree there needs to be less fossil fuel mining to decrease carbon emissions, but we shouldn’t replace this with metals mining – we need to reduce all types of mining. This approach would necessarily reduce the number of tailings dams.

Is the mining industry doing anything?

Governments that grant mining licenses to companies need to implement stricter environmental legislation for them to abide by, the UK government needs to increase penalties for mining companies operating overseas which violate UK law, and international binding regulations need to be implemented by an independent body. Currently companies are invited to sign up to voluntary standards rather than binding ones.

The International Council on Mining and Metals (ICMM) has formed an independent committee to set global standards for tailings dams, but as long as its members include British-linked multinationals Glencore, BHP, Rio Tinto and other large mining companies, it’s difficult to see how it could be truly independent.

Since Brumadinho, major mining industry investors such as the Church of England pensions board along with other investors are developing an Investor Mining and Tailings Safety Initiative on tailings dams to record data from around the world. Some mining corporations are responding to requests for data and others are not. It is important to remember that this initiative relies on self-reporting, and as many companies have failed to report back on some or all of the questions asked, the database is far from complete. Diligence is needed to ensure that companies do not use the database to greenwash the harmful practices they are continuing elsewhere, while improving their reputation with regards to the appearance of increased tailings dam safety.

What work is LMN doing on tailings dams?

London Mining Network supports communities harmed by companies listed on the London Stock Exchange and the Alternative Investment Market (AIM), so our work on tailings dams focuses on multinationals BHP, Rio Tinto, AngloAmerican and Glencore. We continue to monitor these companies activities, as well as many other UK-connected mining companies operating around the world.

We are also looking into Vale – a New York Stock Exchange registered company – because some of its current and former investors are British, and work being done in the aftermath of Brumadinho such as the Investor Initiative will, we hope, place effective pressure on the mining industry as a whole.

We have been involved in advocacy on Brazil’s Samarco disaster for a number of years, and hosting representatives to the UK to attend the company’s annual general meetings (AGMs) so they can ask the BHP board what they plan to do for those affected, in terms of house-building to broader reparations and accountability. We continue this work and advocacy throughout the year.

We have recently published a detailed report and a report summary on Atalaya Mining’s RioTinto tailings dams in Spain, which are at real risk of collapse. This report has already been used in legal proceedings against the company.