Hastelloy C Chemical Pumps for Metal Refining Processes

Hastelloy C Chemical Pump: Engineered for Metal Refining

The Hastelloy C chemical pump is a heavy-duty, horizontal, single-stage centrifugal pump specifically designed for the extreme demands of metal refining operations. Built in a back pull-out construction, foot mounted, with end suction and top centerline discharge, this pump conforms to DIN 24256 / ISO 2858 standards and generally meets API 610 requirements. The entire wetted surface is fabricated from Hastelloy C276, a nickel-chromium-molybdenum alloy that delivers outstanding resistance to pitting, crevice corrosion, and stress-corrosion cracking in hot, aggressive chemical environments. Its robust design ensures reliable performance when transferring corrosive acids, leaching solutions, electrolytes, and high-temperature process fluids that rapidly attack lesser metals. By integrating a back pull-out configuration, maintenance teams can remove the rotating assembly without disturbing the casing or piping, dramatically reducing downtime in critical metal refining circuits.

HIS Pumps and Systems offers this Hastelloy C pump in a wide range of sizes from 32 mm to 200 mm discharge, covering flows up to 400 m³/h and heads up to 140 meters. Operating speeds of 960, 1450, and 2900 rpm allow precise matching to system curves, while fluid temperatures from -10 °C to +250 °C are handled effortlessly. The pump can be configured with gland packing, moulded graphite rings (Grafoil), or single and double mechanical seal arrangements to suit the specific fugitive emission and reliability requirements of each metal refining installation. Every component is precision machined and inspected, ensuring the Hastelloy C chemical pump becomes the long-lasting workhorse of your hydrometallurgical, electrorefining, or acid regeneration processes.

• Hastelloy C276 Wetted Parts: The casing, impeller, shaft sleeve, and wear rings are cast or machined from solid Hastelloy C276, providing uniform corrosion resistance across all surfaces exposed to the process fluid. This eliminates galvanic couples and ensures the pump survives aggressive acid blends commonly used in metal dissolution and purification.
• Back Pull-Out Design: The complete bearing bracket, shaft, and impeller assembly can be withdrawn rearward without disconnecting suction and discharge flanges. This feature reduces maintenance time by up to 60% compared to conventional designs, a critical advantage in continuous metal refining lines where every hour of downtime can cost thousands of dollars in lost production.
• Top Centerline Discharge: The discharge flange is positioned on the centerline of the pump, minimizing piping loads and simplifying installation. This self-venting configuration is also beneficial when handling liquids that may release gases, such as acidic leaching solutions containing dissolved oxygen or hydrogen.
• Flexible Sealing Options: Choose from braided gland packing (with or without asbestos), Grafoil high-temperature packing, or advanced single and double mechanical seals. For hazardous or highly corrosive media, double mechanical seals with an external flush plan offer zero emissions and extended seal life, crucial for metal refining plants aiming to meet stringent environmental regulations.
• Wide Operating Envelope: With 32 mm to 200 mm pump sizes and capacities reaching 400 m³/h, this single pump family can cover multiple process duties within a metal refinery – from small metering flows of additives to large circulation loops in solvent extraction and electrowinning circuits – reducing spare parts inventory and simplifying training.
• High-Temperature Capability: The pump can continuously handle fluids from -10 °C up to 250 °C, enabling its use in heated leach circuits, autoclave discharge, and acid regeneration systems where temperatures must be maintained to optimize reaction kinetics while preserving pump hydraulic stability.

Why the Metal Refining Industry Demands Hastelloy C Pumps

Metal refining environments are among the most corrosive in the industrial world. Processes such as acid leaching, solvent extraction, and electrowinning routinely expose pumps to concentrated sulfuric acid, hydrochloric acid, nitric acid, and mixed acid solutions at elevated temperatures. Standard stainless steels like 304 or 316 quickly succumb to localized attack, leading to premature failures, leaks, and unplanned shutdowns. Hastelloy C276, a wrought nickel-chromium-molybdenum alloy, was developed precisely to withstand these harsh conditions. Its high nickel content provides excellent resistance to reducing acids, while chromium imparts passivity in oxidizing media; molybdenum and tungsten further enhance resistance to pitting and crevice corrosion, especially in the presence of chlorides and aggressive metal ions typically found in pregnant leach solutions and electrolytes.

Metal refineries also deal with highly oxidizing and fluctuating process conditions. For example, during nickel or cobalt hydrometallurgy, the slurry may contain fine abrasives and high redox potentials that can initiate stress-corrosion cracking in inferior alloys. Hastelloy C276’s unique chemistry effectively resists both uniform and localized corrosion forms, while maintaining mechanical strength at temperatures up to 250 °C. Moreover, in magnetic drive pump configurations, the non-magnetic nature of Hastelloy reduces eddy current losses, improving efficiency – a hidden benefit that further justifies the investment. By selecting a Hastelloy C chemical pump, metal refining plants achieve a dramatic reduction in maintenance frequency, lower lifecycle costs, and compliance with environmental and safety standards that demand leak-free operation.

• Resistance to Mixed Acids: Metal refining uses a combination of sulfuric, hydrochloric, and nitric acids at varying concentrations. Hastelloy C276 exhibits exceptional compatibility across this spectrum, resisting both reducing and oxidizing attack – a feat impossible for conventional alloys, thereby eliminating catastrophic corrosion that would otherwise contaminate the refined metal product.
• Chloride Pitting Immunity: Many leach liquors contain chlorides that induce severe pitting in 316SS. The high molybdenum and tungsten content in Hastelloy C276 raises the critical pitting temperature well above process temperatures, preventing pinhole leaks that could halt production and cause safety incidents in enclosed tank houses.
• Stress-Corrosion Cracking Resistance: Refinery processes often involve cyclic thermal and pressure loads. Austenitic stainless steels are prone to chloride stress-corrosion cracking, but Hastelloy C276’s nickel-rich matrix nearly eliminates this risk, ensuring structural integrity of the pump casing and impeller over decades of operation.
• Hot Acid Handling: The ability to pump acids at up to 250 °C without degradation allows metal refineries to integrate the pump directly after autoclaves or heated reactors, avoiding the need for expensive heat exchangers or intermediate cooling steps, preserving heat budget and reducing energy consumption. By eliminating intermediate cooling, the plant footprint shrinks and process heat is retained for downstream unit operations, maximizing overall energy efficiency.
• Erosion-Corrosion Resistance: In hydrometallurgical circuits, suspended solid particles such as fine ore, gypsum, or precipitated salts can scour pump surfaces. Hastelloy C276 maintains a hard, passive surface film that resists both mechanical erosion and chemical dissolution, ensuring impeller vanes and volute walls stay smooth and efficient over thousands of operating hours.
• Extended Mean Time Between Repairs (MTBR): A refinery pump failure can result in severe environmental and safety consequences. Hastelloy C pumps consistently exceed the MTBR of titanium, duplex, or 316SS pumps in identical service by a factor of three to five, translating into drastically lower maintenance labor and spare parts costs.
• Resistance to Oxidizing Metal Ions: Pregnant leach solutions contain high concentrations of ferric, cupric, or cobaltic ions that accelerate corrosion in standard alloys. The chromium and molybdenum in Hastelloy C276 form a stable passive layer in the presence of these oxidizing species, preventing metal dissolution that could contaminate the final refined product.
• Seamless Integration with Refinery Safety Systems: Because Hastelloy C pumps maintain leak-tight integrity even under thermal cycling, they support closed-loop circulation systems that minimize worker exposure to toxic or acidic mists. This aligns with ISO 14001 and OHSAS 18001 standards, reducing insurance premiums and regulatory risk.

Critical Applications in Metal Refining

The Hastelloy C chemical pump is deployed across the entire metal refining flowsheet, from raw ore leaching to final electrowinning. In acid leaching circuits for copper, nickel, cobalt, zinc, and rare earth elements, the pump handles heated sulfuric or hydrochloric acid solutions laden with metal ions, aggressively attacking any wetted component. Its ability to operate reliably under these conditions makes it the standard choice for pregnant leach solution transfer, raffinate recirculation, and barren liquor return. The pump’s high head capability also allows it to feed autoclaves and pressure oxidation vessels, where reliable sealing and material integrity are paramount for safety and yield. In addition, the Hastelloy C pump excels in solvent extraction (SX) circuits, moving loaded organic and aqueous phases without introducing metallic contamination that could degrade the extractant or lower phase disengagement efficiency.

In electrowinning tankhouses, the pump circulates electrolyte containing high concentrations of sulfuric acid and dissolved metals at elevated temperatures. The alloy’s immunity to localized attack ensures that cathode quality remains uncompromised, directly improving the purity of the final metal product. Other specialized uses include acid regeneration plants where spent pickle liquor or waste acid is concentrated and recycled, and the transfer of corrosive reagents such as ferric chloride, cupric chloride, and ammonium sulfate solutions. Magnetic drive variants of this pump are frequently applied in zero-emission scenarios, handling hazardous or high-value solutions where even a single drop leakage is unacceptable. From pilot plants to full-scale refineries, the Hastelloy C pump delivers consistent performance that translates directly into higher throughput and lower total cost of ownership.

• Pregnant Leach Solution (PLS) Transfer: After heap leaching or agitated leaching, the PLS containing dissolved copper, nickel, or zinc must be pumped to solvent extraction or cementation. Hastelloy C pumps resist the combined attack of acid, chloride, and high metal ion concentrations, ensuring uninterrupted flow without corrosion-induced failures that could stop the entire refining operation.
• Electrolyte Circulation in Electrowinning: The pump maintains a continuous flow of hot, acidic electrolyte through the cells, preventing stratification and ensuring uniform metal deposition. The smooth, corrosion-free surfaces of the Hastelloy C wet end avoid introducing particulates that could cause dendritic growth and short circuits on cathodes.
• Solvent Extraction Mixer-Settler Feed: The pump accurately transfers aqueous and organic phases to the mixing chamber. Hastelloy C276 construction prevents catalytic degradation of the organic extractant by corrosion by-products, preserving the extraction efficiency and phase separation characteristics critical to high recovery rates.
• Acid Regeneration and Concentration: In pyrohydrolysis or fluidized bed acid regeneration plants, the pump handles concentrated hydrochloric or sulfuric acid at temperatures approaching 200 °C. Hastelloy C’s resistance to hot acid attack ensures long-term reliability while recovering valuable acid and reducing waste disposal volumes.
• High-Pressure Autoclave Feed: Before pressure oxidation or pressure acid leaching, the slurry must be pressurized to 20–40 bar. Hastelloy C pumps equipped with high-strength shafts and robust casing designs handle these severe conditions, resisting the erosive and corrosive synergy found in autoclave feed streams containing sulfuric acid and abrasive sulfide minerals.
• Raffinate Recycle: The barren aqueous phase leaving solvent extraction is acidic and contains residual organics. Hastelloy C pumps reliably recycle this stream back to leaching, preventing corrosion that would otherwise accumulate metals in the raffinate and upset the process balance.
• Reagent Dosing and Transfer: Corrosive additives such as cobalt sulfate, sulfuric acid, or hydrochloric acid are stored in day tanks and precisely transferred to process vessels. The Hastelloy C pump’s low NPSHr and steady flow characteristics allow accurate chemical metering, essential for maintaining refining bath chemistry within tight tolerances.
• Spent Electrolyte Treatment: Following electrowinning, the depleted electrolyte contains a mixture of acid and metal ions. Hastelloy C pumps transfer this corrosive stream to treatment and neutralization circuits, where any leakage would create severe occupational and environmental hazards. The pump’s double mechanical seal option provides guaranteed zero leakage.

Request a Quote

Do not let pump corrosion dictate your metal refining productivity. Connect with our team to receive a customized proposal for a Hastelloy C chemical pump configured to your exact process conditions. We will review your flow, head, temperature, and chemical compatibility requirements to specify the ideal pump with the right mechanical seal arrangement and motor drive. Get a competitive quote today and ensure uninterrupted, high-purity metal output.

Key Features of the Hastelloy C Chemical Pump

Every engineering decision in this pump focuses on maximizing reliability and ease of maintenance in metal refining. The back pull-out monoblock construction allows the entire rotor assembly - including shaft, impeller, bearing housing, and seal - to be removed from the rear without disturbing the suction or discharge piping. This design is a productivity multiplier, enabling a single mechanic to perform a seal change or impeller inspection in under an hour, compared to half a day on traditional horizontally split pumps. The centerline discharge and foot-mounted volute casing are internally smoothed and precision-cast in Hastelloy C276 to minimize turbulence and maximize hydraulic efficiency. By carefully matching the pump's specific speed to the application, HIS ensures stable operation even at low flows, preventing recirculation damage that often plagues general-purpose pumps in aggressive media.

The shaft, while isolated from the process fluid by a Hastelloy C276 sleeve, is manufactured from high-tensile alloy steel and supported by heavy-duty, grease-lubricated antifriction bearings. An optional cooling jacket on the bearing housing allows for safe operation when pumping hot liquids up to 250 °C, protecting bearing life. The mechanical seal chamber is generously sized to ANSI/API dimensions to accept a wide range of cartridge seals. For the most critical metal refining applications, HIS can supply a Plan 53B pressurized double seal system with a barrier fluid tank, ensuring zero process leakage into the atmosphere. The combination of rugged mechanical design and corrosion-proof materials makes this pump the definitive solution for long-term, trouble-free operation in the world's most demanding refineries.

• Hastelloy C276 Volute and Impeller: The casing and closed impeller are investment-cast from virgin Hastelloy C276, ensuring uniform wall thickness and dimensional accuracy. This eliminates casting defects that could become initiation sites for corrosion, providing a service life that frequently exceeds 15 years in continuous sulfuric acid service at 100 °C, outperforming titanium and Alloy 20 alternatives that suffer from hydride embrittlement or localized attack.
• Cartridge Mechanical Seal Ready: The seal housing accepts cartridge-type single and double mechanical seals without modification. Cartridge seals are pre-assembled and preset, eliminating installation errors and reducing pump commissioning time. For autoclave feed or tankhouse electrolyte, a double pressurized seal with a clean buffer fluid ensures zero emissions and protects the environment from toxic acid mists.
• Reinforced Bearing Frame: A rigid cast iron bearing bracket, isolated from the process fluid, supports the shaft with a pair of deep-groove ball bearings and an angular contact thrust bearing. This configuration absorbs both radial and axial hydraulic loads, extending bearing life beyond 25,000 hours even under variable duty cycles commonly seen in metal refinery campaigns.
• Optimized Hydraulic Performance: The impeller design uses a three-dimensional curved vane profile that reduces NPSH required by up to 20% compared to standard designs. This is particularly important when pumping hot, near-boiling acids or solutions with high vapor pressure, preventing cavitation damage that would instantly erode inferior materials and degrade metal purity.
• Low-Life Cycle Sealing Cost: Even when using single mechanical seals, the combination of Hastelloy C rotating faces with a silicon carbide stationary face and FFKM elastomers can achieve over three years of uninterrupted service. The elimination of frequent seal changes reduces hazardous maintenance activities and process interruptions, delivering a total cost of ownership 40% lower than competitive pumps in identical service.
• Dual Flange Connection Standardization: The pump is supplied with flanges drilled to ANSI B16.5 class 150 or 300, or DIN PN16/PN40, making it interchangeable with existing metal refinery piping systems. Raised-face and flat-face options are available, simplifying replacement of legacy pumps without costly pipe modifications.
• Thermal Insulation Jacket Option: For processes requiring precise temperature control, the casing can be fitted with a steam or hot oil jacket to maintain the fluid temperature above its crystallization point. This is essential when pumping concentrated sulfuric acid or nickel sulfate solutions that can form damaging crystals upon cooling and block the impeller.
• Field Adjustable Impeller Clearance: An external axial adjustment mechanism allows the impeller clearance to be restored without disassembling the pump, compensating for any gradual erosion and restoring original capacity and efficiency. This feature extends the time between full overhauls by months, keeping the refinery's nameplate capacity intact.

Technical Specifications of the Hastelloy C Chemical Pump

The Hastelloy C chemical pump is manufactured to exacting dimensional and performance standards, ensuring compatibility and interchangeability with global pumping infrastructure. The hydraulic coverage spans from small 32 mm discharge pumps delivering 5 m³/h up to 200 mm pumps moving 400 m³/h, with differential heads reaching 140 meters on a single stage. All wetted components including casing, impeller, shaft sleeve, wear ring, and seal chamber are fabricated from Hastelloy C276 (UNS N10276). The pump shaft is made from AISI 4140 high-strength alloy steel, protected from the process fluid by the Hastelloy C sleeve, while the bearing frame is cast iron ASTM A48 Class 35. The pump’s design pressure permits operation up to 20 bar at 250 °C, and the hydraulics are tested to ISO 9906 Grade 1 efficiency standards.

Sealing flexibility is a cornerstone of this pump’s design. The stuffing box accepts 8 mm to 16 mm square braided packing rings in depths from 60 mm to 120 mm, with a lantern ring for external flush when required. For mechanical seals, the seal chamber conforms to ISO 3069 dimensions and can accommodate single cartridge seals to EN 12756, or dual seals following API 682 Plan 53/54 configurations. A choice of elastomers including Viton, EPDM, and Kalrez is available to handle specific chemical attacks. The pump can be driven by a standard TEFC squirrel cage induction motor via a flexible coupling, mounted on a common baseplate. All units undergo hydrostatic testing and performance curve verification before shipment, assuring refinery operators of immediate, reliable startup and sustained performance.

• Discharge Range & Performance: Available in 32, 40, 50, 65, 80, 100, 125, 150, and 200 mm nominal discharge sizes. At 2900 rpm and 200 mm size, the pump delivers 400 m³/h at 140 m head, capable of filling a standard tankhouse circulation line with a single unit, while the 32 mm model precisely meters 5 m³/h into small extraction mixer-settlers, demonstrating a 80:1 turndown ratio across the product family.
• Material Specifications: Wetted components: Hastelloy C276 (UNS N10276) – chemical composition: 57% Ni, 16% Cr, 16% Mo, 5% Fe, 4% W, with trace Mn and V. This precise chemistry yields a pitting resistance equivalent (PREN) value exceeding 65, far surpassing 316SS (PREN 25) and duplex 2205 (PREN 35), guaranteeing immunity in process streams that contain high chloride and low pH.
• Impeller & Casing Machining Tolerances: Both the impeller and casing are investment cast and then CNC machined to ISO 2768-mK tolerances. The balance of the impeller is verified to G 6.3 per ISO 1940, ensuring vibration levels below 2.5 mm/s at operating speed, even when the pump handles dense, high-specific-gravity electrolytes up to 1.4 SG, maintaining process stability and extending bearing life.
• Bearing and Lubrication System: Heavy-duty, permanently sealed deep-groove and angular contact bearings are factory-filled with a high-temperature, corrosion-resistant grease. The bearing housing is split horizontally for inspection without pump disassembly. An optional oil bath lubrication system with sight glass and constant-level oiler can be fitted for continuous 24/7 operation in remote, unmanned refinery installations.
• Testing and Certification: Each pump undergoes hydrostatic testing at 1.5 times its design pressure and a full performance curve test at BEP (best efficiency point). Material certificates to EN 10204 3.1 for all Hastelloy C276 parts are provided, giving metal refineries full traceability and confidence that no material substitution has occurred, which is crucial for safety-critical acid circuits.
• Variable Speed Drive Compatibility: The pump can be directly coupled with a VFD to precisely modulate flow for varying refinery loads. Hastelloy C's stable corrosion properties across a range of temperatures and velocities mean that even at reduced speeds, there is no risk of localized corrosion that could occur on a stainless steel impeller under stagnant or low-flow conditions.
• Noise and Vibration Limits: Designed to meet ISO 10816 vibration standards, the pump and motor set operate at sound levels below 85 dBA at full load. This is a significant advantage in enclosed tankhouses or solvent extraction buildings where multiple pumps run simultaneously, improving the workplace environment and reducing worker fatigue without requiring acoustic enclosures.

Why Choose HIS Pumps and Systems

HIS Pumps and Systems has built a reputation as the premier supplier of corrosion-resistant process pumps for India's demanding chemical and metal refining sectors. With decades of in-house engineering experience, we understand the specific challenges that metal refineries face – from hot, concentrated acids to high-pressure autoclave feeds. Our Hastelloy C chemical pumps are not off-the-shelf products; they are carefully engineered solutions tailored to your exact process specifications. We maintain comprehensive inventory of Hastelloy C276 castings, forgings, and bar stock, enabling us to offer delivery times that are 30-50% shorter than European or American manufacturers while maintaining identical quality standards. Every pump is assembled in our state-of-the-art facility and tested against its specific performance curve, ensuring it meets the hydraulic and mechanical requirements of your unique refining circuit.

Beyond the pump itself, HIS provides a lifetime of support. Our application engineers work closely with your operations team to select the optimal seal arrangement, material combinations, and motor starter configuration. We offer field commissioning, vibration analysis, and performance troubleshooting to guarantee your pump achieves years of trouble-free operation. Our spare parts program ensures you have critical components on your shelf before you need them, and our 24/7 WhatsApp support line connects you directly to a knowledgeable engineer who can guide you through any emergency. Choosing HIS means you are not just buying a pump; you are investing in a partnership that keeps your metal refinery producing high-purity metal without interruption.

• Decades of Hastelloy Expertise: HIS has designed, manufactured, and serviced hundreds of Hastelloy C pumps for Indian and global metal refineries. Our metallurgical engineers ensure each casting meets the strictest chemical composition and corrosion testing requirements, so you receive a pump that will withstand your specific acid blend, temperature, and pressure for decades, not months.
• Shorter Lead Times on Hastelloy C Pumps: By maintaining a strategic inventory of pre-machined Hastelloy C276 components, HIS can assemble and deliver a standard Hastelloy C chemical pump in as little as 8-10 weeks, compared to 16-24 weeks from overseas suppliers. This rapid availability minimizes plant downtime when an existing pump fails unexpectedly.
• In-House Performance Testing: Each pump is tested on a dedicated test loop that simulates actual refinery fluid properties using water with viscosity modifiers. We provide you with a certified test curve showing flow, head, power consumption, and efficiency at five points from shut-off to run-out, giving you the data needed to optimize your P&ID and control strategy.
• Tailored Mechanical Seal Solutions: HIS partners with leading seal OEMs to deliver complete pre-assembled cartridge seal systems that match the exact pressure, temperature, and chemical conditions of your refinery. Whether you need a simple single seal with a Plan 11 flush or a pressurized dual seal with a Plan 53B barrier system, we deliver a fully integrated, leak-tight assembly.
• On-Site Commissioning Assistance: Our field engineers travel to your site to supervise installation, alignment, and initial start-up. They ensure the pump is operating within its best efficiency range and not subject to harmful cavitation or vibration, protecting your investment from day one and training your maintenance staff on best practices.
• Lifecycle Spare Parts Management: HIS provides a comprehensive recommended spare parts list tailored to your pump’s service and operating conditions. We stock critical Hastelloy C276 spare parts such as wear rings, shaft sleeves, and impellers for immediate shipment, ensuring you are never more than 48 hours away from a critical component in an emergency.
• 24/7 Technical Hotline: Refineries operate around the clock, and so does our support. Through our dedicated WhatsApp number, your operators can send photos, vibration data, or process readings at any hour, and receive immediate diagnostic guidance from a senior HIS engineer who understands corrosion-resistant pumps inside and out.

Talk to Our Pump Experts

Navigating the material and configuration options for a metal refining pump can be complex. Our application specialists are ready to listen to your process requirements and recommend the precise Hastelloy C chemical pump model, seal plan, and motor spec that will maximize your plant's uptime and metal purity. Initiate a conversation now and get answers within minutes, not days.

Material Compatibility of Hastelloy C in Refining Chemicals

Hastelloy C276 is universally recognized as the most versatile corrosion-resistant alloy available for the metal refining industry. Its unique combination of nickel, chromium, molybdenum, and tungsten provides exceptional resistance to a broad range of aggressive chemicals that are routinely encountered in hydrometallurgical and pyrometallurgical flowsheets. In sulfuric acid, the dominant acid in copper and nickel leaching, Hastelloy C276 maintains a corrosion rate of less than 0.1 mm/year even at concentrations up to 98% and temperatures approaching 100 °C. This is a stark contrast to stainless steel 316, which fails rapidly above 10% concentration, or Alloy 20, which struggles in the presence of oxidizing contaminants. The alloy’s resistance extends to hydrochloric acid, where it tolerates all concentrations at room temperature and diluted hot solutions, making it ideal for chloride-based leaching of laterite ores or the regeneration of ion exchange resins.

The presence of ferric and cupric ions, common in pregnant leach solutions, actually enhances the passivity of Hastelloy C276, whereas these same oxidizing agents dramatically accelerate the corrosion of lower-grade alloys. In nitric acid, Hastelloy C276 shows useful resistance up to about 20% concentration at moderate temperatures, though for pure nitric service it is not the optimum choice; however, in the mixed acid scenarios typical of metal refineries, it excels. The alloy also resists phosphoric acid, wet chlorine gas, and sulfur dioxide, all of which may be present in refining off-gas treatment or acid plant feed systems. Understanding this compatibility allows refinery process engineers to specify the pump with confidence, knowing that it will not degrade or contaminate the process stream, preserving both equipment integrity and final metal purity.

• Sulfuric Acid Resistance: In metal refining, sulfuric acid concentrations range from dilute (10%) in heap leaching to concentrated (93-98%) in acid plants. Hastelloy C276 exhibits outstanding resistance across this spectrum, with corrosion rates typically below 0.05 mm/year at 50 °C and 0.1 mm/year at 100 °C. This allows the pump to handle both weak acid leach solutions and concentrated acid circulation without any material degradation or iron contamination of the product.
• Hydrochloric Acid Compatibility: Laterite nickel and rare earth refineries frequently employ hydrochloric acid leaching. Hastelloy C276 resists all concentrations of HCl at ambient temperature, and its high molybdenum content provides immunity to the pitting and crevice corrosion that rapidly destroys 316SS when chlorides are present, even at elevated temperatures around 70-80 °C typical of atmospheric leach circuits.
• Mixed Acid Performance: Real refinery streams rarely contain a single acid. A typical pregnant leach solution may contain sulfuric acid, a small amount of hydrochloric acid, and dissolved ferric sulfate. Hastelloy C276's balanced composition handles these synergies where stainless steels and even duplex grades suffer catastrophic failure. The alloy's passive film remains stable, preventing the metal contamination that would interfere with subsequent solvent extraction selectivity.
• Oxidizing Salt Solutions: Ferric chloride and cupric chloride etchants used in printed circuit board recycling and specialty metal recovery are extremely aggressive. Hastelloy C276 exhibits negligible corrosion in these environments, whereas titanium is attacked by the free acidity, and stainless steel suffers rapid pitting. The pump's inertness ensures safe transfer of these high-value, corrosive reagents.
• Wet Chlorine and Hypochlorite: In gold refining and certain leaching processes, wet chlorine gas or sodium hypochlorite is generated. Hastelloy C276 resists these strong oxidizing environments without the risk of stress-corrosion cracking, unlike many austenitic stainless steels. This allows the pump to be used in chlorination circuits and cyanide destruction systems safely and reliably.
• Phosphoric Acid and Phosphate Slurries: In the production of lithium iron phosphate (LFP) battery materials or the refining of phosphate ores, phosphoric acid containing fluoride impurities is encountered. Hastelloy C276 outperforms Alloy 20 and 316SS in resisting the combined corrosion of phosphoric acid and fluoride ions, extending pump life in these emerging applications critical to the energy transition.
• High-Temperature Water and Steam: In autoclave feed and blowdown services, the pump may handle high-temperature aqueous solutions containing dissolved gases. Hastelloy C276 maintains its corrosion resistance and mechanical properties up to 250 °C, resisting the accelerated oxidation that would embrittle or scale lower alloys in these demanding conditions.

Selection Guide for Your Hastelloy C Chemical Pump

Selecting the correct Hastelloy C chemical pump for a metal refining application involves a systematic evaluation of process conditions and mechanical requirements. Begin by defining the hydraulic duty: flow rate in m³/h, differential head in meters, available NPSH, and the fluid's specific gravity and viscosity at pumping temperature. Using these parameters, HIS engineers will select the optimal pump size and impeller trim to operate as close to best efficiency point (BEP) as possible, minimizing shaft deflection, vibration, and recirculation damage. It is crucial to also record the fluid composition – not just the major acid concentration but also any trace chloride, fluoride, or metal ions that influence corrosion behavior. A complete chemical assay of the process stream allows our metallurgists to verify that Hastelloy C276 is the correct alloy and to specify compatible elastomers, gaskets, and seal face materials for the application.

The selection of the shaft sealing system is equally critical. For relatively benign, cool liquids, a simple single mechanical seal with a Plan 11 flush from the discharge may suffice. For hot, hazardous, or crystallizing fluids, a double mechanical seal with a pressurized barrier fluid (API Plan 53B) is recommended to prevent leakage and ensure seal faces remain clean and lubricated. If the pump will handle liquids near their boiling point, a cooling jacket on the seal chamber or bearing housing may be required. Consideration must also be given to the motor enclosure, baseplate material, and coupling guard. HIS provides a comprehensive data sheet that captures all these variables, and our technical team will review it with you to finalize a pump configuration that meets your performance, reliability, and budget goals. By following this selection methodology, metal refineries can ensure they receive a Hastelloy C pump that is truly fit for purpose, rather than a generic pump that may fail prematurely.

• Define the Hydraulic Duty: Provide accurate flow rate at normal and maximum conditions, total dynamic head, suction pressure, and fluid temperature. This information determines the pump size, rpm, and impeller diameter. Undersizing leads to cavitation; oversizing causes low-flow recirculation. Precise hydraulic data ensures the pump operates in its most efficient and reliable range, saving energy and reducing lifecycle costs.
• Complete Chemical Analysis: Share a detailed breakdown of your process fluid, including all acids, bases, salts, and solid particle concentration and size distribution. This analysis confirms material compatibility beyond the major components, identifying any trace constituents that might attack elastomeric seals, gaskets, or the Hastelloy C276 alloy itself. A pH measurement alone is insufficient for proper alloy selection.
• Select Seal Type and Flush Plan: Based on the fluid's hazard level, temperature, and tendency to crystallize or polymerize, choose between single or double mechanical seals and appropriate API flush plans. For example, a hot copper electrolyte requires a Plan 23 seal flush for cooling, while a dirty leach solution might use a Plan 32 external clean flush to keep solids away from the seal faces.
• Consider Installation and Piping: Evaluate the suction piping layout for adequate straight run and submergence to prevent air entrainment and vortexing. The pump's NPSH required must be less than the available NPSH by a safe margin. HIS engineers can model the suction system and recommend modifications to avoid cavitation, which is the most common cause of damage even in corrosion-resistant pumps.
• Motor and Drive Selection: Specify the power supply voltage, frequency, and enclosure type (TEFC, explosion-proof, etc.). Consider a variable frequency drive if the refinery's production rate varies significantly. A VFD with a Hastelloy C pump provides tur ndown flexibility, enabling you to adjust flow without sacrificing the pump's corrosion resistance or mechanical stability. A VFD also provides soft-start capability, reducing inrush current and mechanical stress on the pump and piping during startup.
• Plan for Maintenance and Spares: During the selection phase, discuss with HIS the recommended spare parts list for a two-year operational period. This includes a spare mechanical seal cartridge, a set of bearings, gaskets, and a wear ring set. Having these on-site reduces mean time to repair and allows the refinery maintenance team to perform a complete pump overhaul within a single shift, ensuring process continuity.
• Documentation and Performance Curves: Ensure you receive a complete set of documentation, including the certified performance test curve, material certificates, general arrangement drawing, and installation/operation manual. This data is essential for integrating the pump into the plant's DCS and for training operators. HIS provides comprehensive digital and physical documentation packages that expedite commissioning and regulatory compliance checks.