Waste Heat Recovery Boilers

On-Site HVTS Cladding Mitigates Waste Heat Recovery Boiler Corrosion

IGS HVTS cladding has been successfully used over the past decade to provide protection for heat recovery boilers in the mining and mineral processing industries. Our cladding successfully minimizes failures and repairs caused by corrosion-erosion metal wastage of heat recovery boilers and ducts in zinc and copper smelters.

IGS High Velocity Thermal Sprayed (HVTS) cladding is ideal for protecting against the high-temperature corrosion and erosion environment in the Smelting processes. We have developed our IGS HVTS alloy cladding for protection in combustion environments with aggressive sulfidation conditions up to 1800°F (980°C). It is highly protective against under deposit corrosion when Sulfur together with Sodium, Potassium and Vanadium oxides form low melting temperature eutectic pyro-salts. The high Chromium alloy, together with unique structurally densifying chemistry, provides a practically impermeable inert alloy cladding, with high bond strength. The material also has good erosion resistance due to effective hard-phase integration in a ductile binder.

IGS HVTS cladding eliminates metal wastage, limiting production losses due to unplanned downtime. The composite system is also effective in inhibiting heavy slag adhesion.

Our Experience Protecting Waste Heat Boilers

IGS is the pioneer in the use of Thermal Spray claddings in the Mining & Mineral Processing Industry. We have completed dozens of applications for heat recovery steam generators over the past decade. We use our knowledge and experience to successfully support WHB users with proven solutions for their most critical assets.  IGS has considerable experience applying High Velocity Thermal Spray and Weld Overlay surface protection solutions to copper and zinc smelter waste heat recovery boilers. Our principal services have included fireside protection with corrosion-erosion resistant proprietary high alloy, high temperature, metal coatings on waste heat boiler and furnace tubes, off-gas ducting, and automated cladding on cooler plates.


IGS Automated Cladding for Furnace Copper Cooler Plates

Given the increase in the smelting intensity planned for PGM furnaces at higher power, water-cooled plate coolers are installed in the sidewalls in the slag zone. Transition coolers in furnaces freeze any slag splashes and thus prevent slag leaks. IGS utilizes a synergic pulsed GMAW process in semi-automatic or automatic modes. The main modes of metal transfer to the base metal, in order of increasing current density, globular transfer, spray transfer, and rotating transfer. The strong magnetic field from rapid high current pulsing initiates rotary spray transfer with a droplet size much less than the electrode diameter. The higher peak but lower background current results in less heat, less distortion and less dilution, providing a reduced heat-affected zone with better cladding chemistry.

Because automated cladding is often suited for a part, but not all, of our customers’ wastage problems, IGS provides turnkey High Velocity Thermal Spray, automated and manual weld overlay, mechanical services and project management. IGS maintains an “R” stamp through the NBIC. All work we undertake complies strictly with ASME Sections VIII and IX, the IGS Quality Control Plan, and customer-specific requirements.


Corrosion-Erosion of Furnace Tubes

Many Smelting facilities are focused on the reduction of SO2 emissions. A specific drive to reduce these emissions has led to the building of Acid Converter Plants. The process conditions in these furnaces contribute to wall corrosion with the generation of both Sulphur and other corrosive Halide salt species. The presence of H2S may lead to cracking, especially in the roof and freeboard panel sections. These are typically protected by monolithic refractory, but the remainder of the tubes are exposed to the high-temperature conditions inside the furnace.

Corrosion-Erosion of Off-Gas Ducting

IGS HVTS is a strong protection system that may protect tubes from acid dew point corrosion, high-temperature sulfidation, oxidation and erosion, caused by the sulfur and water environment. HVTS cladding systems act as a barrier that prevents the gaseous sulfur and chloride components from contacting the base metal, thereby preventing high-temperature corrosion.

Optimized Solutions for Mining and Mineral Processing Equipment Protection

Over the past decade, we have leveraged our experience and knowledge to develop unique materials and methods. We did it to provide reliable and predictable protective barriers in the most challenging mining and mineral processing environments.  We have learned that:

  • HVTS cladding reduces risk in Risk-Based Inspection (RBI) programs, extending inspection intervals and freeing up inspection resources for other tasks, providing end-users time to focus on additional maintenance concerns affecting productivity and output. This provides significant cost savings for maintenance over the lifetime of heat recovery boilers and furnace ducts.
  • We build the success of our coatings upon the essential building blocks of advanced know-how, developed and proven materials, process technologies and experienced application personnel.
  • IGS HVTS cladding is a manageable surface protection solution as it is easily repaired, so in the event that an area is compromised for whatever reason, it can be locally restored without any need to remove additional material, creating value for equipment owners and operators by ensuring reliability and proactive maintenance solutions for asset management.

We have over 10-years experience in the Metal and Mining industry. Call us to get your equipment protected.

Mitigate Heat Recovery Boiler Corrosion

Get in touch with your local subject matter expert

Contact Us