Erik Groves is the Executive Vice President for TK Mining Services out of Delta, Colorado and Vice President of Business Development for Napier Ventures out of Vancouver, Canada. ____________
Q: What is the general attitude of the mining industry in terms of corrosion awareness?
A: In the past, mining has usually held a short-term replacement mentality. Wear and tear from abrasion was accepted as a given, but not much consideration given to corrosion as a life-limiting factor for mine structure or equipment. As the commodity prices have remained low and regulation increased, mines that want to survive have needed to transition to a more sustainable, maintenance based approach. This means an increased awareness and understanding of corrosion risk to assets and its associated consequences. As compared to other industries, mining is behind the times in terms of corrosion prevention, with corrosion control measures generally limited to maintenance painting or coating. In the domestic coal industry alone for example, for every 1 billion mt of coal produced, between $62 million and $124 million was spent on maintenance painting or coating for corrosion control. In a market defined by bankruptcies and diminishing demand, these are costs that need to be reduced as they directly hit the bottom line.
Q: Due to lower resource prices, the industry in general has been cautious about spending and the budget area that is often first to be reduced is Maintenance. From a corrosion viewpoint, operations may not feel repercussions in the short term, but as time goes on, usually 12 - 18 months, the number of corrosion related failures begin to increase. What should Operations & Maintenance Team keep in mind when developing strategies to prevent future failures under tightening budget constraints?
A: The problem in making substantial progress in developing effective and efficient corrosion control protocols is a typical right hand not talking to the left hand. At most mines, production is not coordinating with maintenance, and visa versa. The industry cannot afford to have these two sides of the house living in a bubble. Production managers must be aware of the cost of replacement and downtime for repairs. Maintenance managers need to look at alternate approaches to corrosion control and get away from the “That is the way we have always done it” mentality. If a mine wants to have a life of a decade or more, then the production and maintenance teams need to develop integrated plans now to utilize best practices now to assure viability. Corrosion control will be a major part of that integrated plan.
The mining industry tends to rely heavily on past experience and the knowledge of equipment suppliers to resolve any corrosion issues so that production is not interrupted. Engineers with corrosion knowledge and expertise are generally hired by project and not as general staff. Because each mine faces its own particular chemical and biological brew of corrosion “triggers”, whenever possible, a corrosion consultant making individualized assessments can quickly becomes a very valuable investment.
Q: What area or areas are most obviously or severely impacted by corrosion?
A: The area most commonly impacted by corrosion is infrastructure in the form of not just buildings and conveyors, but also wire rope, critical chains, roof bolts, pumps, electronics, pipes, well screens, dams, bridges and water intakes damaged by environmental factors such as acid mine drainage. Every experienced mine manager knows the pains of equipment downtime and how it can bring an operating mine to a halt. Corrosion treatment of equipment components by manufacturers is an untapped industry. Breakage of a corroded hose can bring a CM down for multiple shifts, but for a small price, that hose could be coated and the lifetime use extended by a factor of ten-fold. At the end of the day, keeping that equipment in operation helps the bottom line.
Q: I keep hearing about microbially influenced corrosion (MIC). Can you briefly explain the phenomenon?
A: The harsh and aggressive conditions in certain mining operations enhance corrosion activity and the use of saline bore water loaded with bacterial life for process water create a naturally inoculated microbially mixed environment. Many sites are experience microbially influenced corrosion (MIC) after less than 12 months. MIC is not usually a single process, but an association and interaction of various microbial types leading to corrosion. MIC can involve a plethora of organisms and mechanisms. Deterioration of materials by living organisms is commonly referred to as biodeterioration, and this phenomenon can encompass both metallic and non-metallic materials (including concrete). MIC is a caused by different microbial types in association with each other and with suitable physical, chemical and electrochemical parameters at or in the metal surface, including sulfate reducing bacteria and bacteria that trap heavy metals such as copper and cadmium within their extracellular polymeric substance, resulting in the formation of ionic concentration cells. Bacteria also produce byproducts that can be corrosive to metals, including inorganic acids, organic acids, sulfides and ammonia.
The mechanisms involved with MIC can been seen in other types of corrosion. For example, MIC corrosion can rapidly attack metal, and cause pitting corrosion in excess of 5 mm/yr. Microorganisms attack protective metallic and organic coatings exposing the underlying material to corrosion. MIC can also corrode metal due to differential aeration or galvanic corrosion if the protective coating itself is a metal. In addition MIC may alter the composition of corrosion inhibitors, making corrosion control by covering a surface problematic at best.
Case studies implicate MIC in many corrosion failures of critical mine site assets including tankage, the deterioration of large rubber lined process equipment, the deterioration of process cooling towers and the premature failure of stainless steel reverse osmosis water lines.
Q: MIC Research on MIC on iron and carbon steel had been proposed as early as 1910 and the first theory for MIC mechanisms was suggested during the 1930's (von Wolzogen Kurh & van der Vlugt 1934). MIC has been a demonstrated and identifiable problem for a very long time. What approaches have been developed to address MIC?
A: Some of the first theories on MIC were developed in the 1930’s. Fungi, aerobic bacteria and organic biocides, biofilm monitoring, electroflotation, organic additives, and barrier plastics have been tried, with varying levels of success. Unfortunately, in all these cases, researchers have a tough time balancing the benefits with a new set of problems each suggested solution has created. I borrow the term “contraindication” from the medical field to describe this. Contraindication is where the procedure designed to fix a problem results in more problems than it was designed to fix in the first place.
Knowing how long this problem has been known about and not fully resolved was why we were so excited to start working with CleanWirx. CleanWirx is the most practical advance in technology for dealing with MIC. Not only is it effective and ecologically responsible, but it is easy to integrate into industry-wide accepted best practices.
Q: How does CleanWirx fit into corrosion control and prevention strategies in terms of combatting MIC and other forms of corrosion while making the best of tight budgets?
A:While there have been amazing advances in corrosion resistant coatings, we learned that many of the problems were being caused underneath the coating. With almost all steel being 2nd and 3rd generation recycled steel, it contained microcontaminants, macrocontaminants and reactive sites even before being exposed to the elements. CleanWirx effectively removes all these contaminants and prevents flash rusting on surfaces. After the CleanWirx treatment, the surface is fully prepared for coating. Think of it as a surgeon cleaning up the surgery site before beginning an incision. CleanWirx also makes coatings adhere better so they can do an even better job of protecting surfaces. Because CleanWirx is coating neutral, it can be used with virtually any coating system to maximize surface protection surfaces from corrosive elements outside the substrate. CleanWirx does not soften or degrade coatings and has no detrimental effect on even galvanization, inorganic zinc coating or thermal spray metal coatings. Applying a water repellent, high-performance coating that has high resistance to chemicals, biological agents and abrasion, such as Ionyx Molecular coatings, over CleanWirx treated surfaces will prevent corrosion from occurring above and below the substrate for decades.
Q: For someone who has never used CleanWirx before, explain how the Cleanwirx system is applied?
A: The application of CleanWirx is actually quite simple and only requires a few pieces of specialized equipment. First, if there is visible debris or rust, the surface needs to be blasted. Second, the CleanWirx system is a gel-like that is applied either manually or by pressure spray. Removal of CleanWirx is done via a specialized pressure washer. CleanWirx requires no acid washing, so that saves a step. CleanWirx does its job so well, surfaces can be left uncoated for days, which means surfaces do not need to be blasted (or reblasted) in increments, and maintenance teams don’t need to alternate back and forth between blasting and priming/coating. Prep and coating can be performed in single, uninterrupted stages. Moreover, use of corrosion inhibitors and/or dehumidification is unnecessary when using the CleanWirx system, saving significant time and money in surface preparation.
Surfaces pass inspection prior to coating – the first time. For example, an entire tank can be blasted, treated with CleanWirx and then coated, regardless of its size. This saves time, effort and money, and allows companies to return assets back into service faster. CleanWirx (step 1) Gel has a dwell time of a mere 30 minutes. Pressure wash the surface with CleanWirx (step 2) Rinse to remove gel and contaminants. Wait 30 minutes or so for surfaces to dry. At that point, coatings may be applied, but – and this is the great thing – coatings do not HAVE to be applied right away. In one specific case, a refinery’s tank was treated with CleanWirx, but it rained for multiple days so the contractor was unable to coat during that time. All that was required when the rain finally stopped was to rinse the surface and let it dry prior to coating – with absolutely no reblasting needed. Without CleanWirx, the flash rusting would have been horrible, but with the CleanWirx, it looked like it was blasted five minutes earlier.
Q: Besides budget constraints and the problem of dealing with the myriad facets of MIC, you spoke of a third concern: environmental regulations (and by association corporate stewardship). Can Cleanwirx help in this regard?
A: Yes. CleanWirx is non-toxic and biodegradable. It reduces the use of environmentally harmful impact blasting. The chemicals used in CleanWirx are not corrosive to skin and have low to zero VOC (less than 1%), and it requires no “hazmat” shipping. What is more amazing is that CleanWirx is a product that is far more effective than any product on the market, but also the meets the most meticulous “green” standard. That is even before you take into consideration the lower safety and liability risks from coating failures that are eliminated as coatings adhere better to a surface treated with CleanWirx. Preventing catastrophic coating failure and employing environmentally safer products will help bring costs down while keeping even the most scrutinizing environmental critics happy.
Q: Where has this system been implemented, and what have been the results?
A: The result were spectacular. Implementation of CleanWirx on pipelines, offshore platforms, and refinery tanks alone have resulted in huge savings. To briefly illustrate, in one of the very first pilot test using CleanWirx involved wastewater pipes and drums. One area was treated with CleanWirx, while two similar sites were prepared using conventional methods, then coated using standard epoxy coating. During the eleven-year period of testing (thus far), the CleanWirx site needed zero maintenance and evidenced no sign of corrosion. The other two sites required remedial maintenance four times due to corrosion issues. So, it has been eleven years and no issues, as the product already exceeded conventional treatments multiple times over, who knows, maybe it has eleven more years left. CleanWirx manufacturer recommends retreatment every 20 years.
Q: What sorts of contributions do you expect new “anti-corrosion” technologies like CleanWirx to make to the mining industry in terms of immediate benefit and over the next ten years?
A: There has been quite a bit of interest in coatings in mining. I think mining companies and equipment manufacturers want to duplicate the success seen in other industries. While the move towards anti-corrosion coatings has been progress, prevention of corrosion from under coating surfaces is key to facilitating seamless coating protection. Secondly, coatings that adhere better to surfaces suffer fewer failures. These are two areas where CleanWirx technology lessens the detrimental impact of corrosion damage and asset loss on the industry, making it more profitable and safe. If the industry wants to maximize the value of their coating treatments, a move toward CleanWirx seems to be the way things are heading. Seeing that trend and being involved early on was why I was so eager to be one of the first adopters of using the CleanWirx system. Of course, being able to get a “green” notch on the belt at the same time makes it even better.
In a highly competitive mining environment, operations proactively tackle the costs of corrosion rather than reactively dealing with the effects of corrosion will be have an inherent advantage in the market. In a world where one failed weld can cost hundreds of thousands, the improved performance of CleanWirx is not hard to appreciate.
In terms of other technologies, it is important to remember that corrosion within the mining industry is corrosion enhanced by abrasion. What makes corrosion control difficult and corrosion prevention more advantageous is that mine atmospheres and waters are unique and vary widely; each mine experiences relatively different corrosion-related problems, including aerobic and anaerobic microorganisms (producing sulfuric acid and hydrogen sulfide, respectively) that make a harsh environment also an extremely corrosive environment. It is probably one of the most difficult environments to deploy a corrosion prevention protocol but also arguably the industry that stands the most to gain from doing so.
Technologically advanced high-performance coatings, like the previously mentioned Ionyx Molecular coatings, are engineered to resist a wide range of possible corrosion factors. Implementing such coatings along with enhanced monitoring technologies benefits the industry by lowering risk and liability, reducing equipment and infrastructure damage requiring repair or replacement, affording leaner operations (with significantly less budget needing to be allocated for coatings maintenance and redundant equipment), and increasing the industry’s ability to prevent corrosion-related failures that negatively impact both the environment and public opinion of the industry.
Erik Groves is the Executive Vice President for TK Mining Services out of Delta, Colorado and Vice President of Business Development for Napier Ventures out of Vancouver, Canada.