Industrial Mixer Reliability and Longevity – A Case Study

One of Dynamix’s business pillars is to produce quality products that are reliable and have longevity. We consistently see repeat customer orders for products that have been in service for 12-30 years, or more. One such customer has reordered an Industrial Agitator that has served them for over 15 years. This one came in for a rebuild in perfect working order.

Application: Germanium Releach Reduction 

Model: NMX-7-23-30 30HP @ 79rpm, Single 48” P4 impeller mounted on a 4” Sch 40 pipe shaft 152” long  

Application Details: Application: Germanium Slurry, 

• Viscosity: 100cps S.G. 1.6 S 
• Solid size  9.2um 
• Solid Conc: 40% 

This industrial mixer is meant to be used when mining coking coal. This type of coal was generally shipped to smelters to be used to make steel, and by our client, would clean or concentrate the coal from thermal coal (anthracite) in their coal washing plant in BC interior. These two grades of coal have different specific gravities and they use magnetite to float and concentrate the lighter coking coal before shipping. The Dynamix mixer was used in the slurry to help float and concentrate the lighter coking coal. In simple terms, coal particles had to be suspended in water with magnetite and fine metals. The mixer met our client’s product suspension and separation challenges so this type of coal could be transported to smelters and steel plants around the world.

Having trust in Dynamix’s product and application experience is something our clients appreciate, and cases such as the situation here is a testament to this. Engineering an industrial mixer solution for the client and their challenging environment is what our application engineers love. A subsequent newer model for their processing was again ordered for their needs moving forward.

The coal washing plant in BC was just one of many locations that Dynamix provided mixers for. Numerous industrial mixers were also installed in other mining facilities of this client including the Zinc mines in northern BC. These mixers were used in their leaching process in Autoclaves, Reagent Mixing Tanks, and Flotation Cells/Tanks for Zinc or Copper.

The mixers were mainly used in their phosphoric acid reactor and to extract lead and exotic metals. Much like the process of using mixers at various stages of the leaching process of copper, zinc is processed in the similar fashion at the Trail facilities. An option added to the impeller was the wetted parts. The impellers were manufactured with rubber coating to as to endure the acidic environment when mixing.

Mixing Challenges for High-Solids Slurries

As solids loading increases, slurries can stop behaving like a uniform fluid and more like a moving bed of particles. Settling, compaction, and dead zones all become more common, making consistent suspension harder to maintain, especially near the bottom and around internal obstructions.

These conditions raise mechanical demands on the mixing system as well. Higher density and abrasive solids increase torque requirements, amplifying radial and thrust loads. Wetted components and sealing interfaces all face higher wear. Reliable performance relies on maintaining uniform solids suspension and avoiding repeat settle-out and restart events.

What Mixing Parameters Help Prevent Settle-Out and Abrasion in High-Solids Slurries?

Slurry suspension is often approached using the just-suspended speed; the impeller speed at which no particles remain motionless on the tank bottom. Operating near the required suspension threshold helps avoid dead zones, re-entrainment, and wear.

Preventing repeated settle-out cycles supports more than just process quality. Abrasives accelerate wear, so matching impeller type, clearance, and speed to suspension needs helps reduce abrasive contact that shortens seal lifespan. 

The large NMX mixer was used in these facilities. 

The NMX Series Mixer is ideally configured for Heavy Industry. While the efficiency of this mixer is extremely high, its capacity to scale into the most demanding applications is what makes this our premium mixer line.

This mixer line is applied to your process to balance robust design with a very high efficiency.  

Drives: 

Standard motor options include high efficiency, severe duty, and washdown. Options include high altitude, low temperature, high temperatures, explosion proof, and more.

Quality is Assured at Dynamix. All drives are designed and manufactured to worldwide standards: 

• Quality Management – ISO 9001 
• CSA Certified for Class 4228-01 Class I, Group C, D, Class II, Groups E, F and G 
• UL Certification for Motors for Use in Hazardous Locations: Class I, Group C and D; Class II Group E, F and G 
• USA Premium efficiency certificate of compliance (CC 092B) 
• Canada Premium efficiency CSA C390-10 
• Gear Certificate as per DIN 3990 
• NMX 8-12 torque ratings and speeds according to ISO 6336 
• NMX 8-12 sound pressure levels according to ISO 8579-1 

NMX Series Agitators – available in both parallel helical and bevel helical gear configurations 

• High efficiency mixer design – configured to optimize power consumption 
• High efficiency components – high efficiency motor and gearbox 
• Power Range: 1 – 200hp  
• Hp Efficiency:  97% (2-stage) / 95.5 % (3-stage)  
• Torque Range: 1000-2.5klb-in  
• Ratio Range: 4.26:1-268:1 

• VFD Compatible (VFD Control Optional)

Heavy Duty Output Bearings increase the external load carrying capacity of the speed reducer. Increased capacity in overhung (radial) and/or thrust (axial) loading ensures that premature bearing failure will not occur due to high stresses in the bearing elements. The increased bearing capacity optimizes the gearbox for mixing application.  

• Case-hardened, high-quality gearing (Rockwell 60 C typical / up to AGMA Class 13)  
• Oil-safe seal system  
• Auto breather regulates internal pressure and keeps contaminants out  

• Solid Gear Case housing to minimize torsion
• Spread bearings optimize shaft designs
• Mount designs to suit your tank: Flange, Plate, other
• Sealing technology to suit your operation and budget; Double or Quadruple Lip Seals, Packing, Mechanical Seals to suit your application or brand requirement
• Stainless steel (316) protective paint coating – USDA/H1 compliant with protective features and options for severe duty and washdown environments

Shaft Design: 

• Hollow shaft designs are a technology that needs attention. This capability is critical to understand proper shaft design and optimization 

• Increased critical speeds mean more mixing and shaft stability 

• Shaft Design is one of the most technical parts of the mixer design. In order to optimize our mixer, we can select from 3 or 4 standard bearing spreads that utilize heavy duty tapered roller bearing to handle high overhung thrust loads, for longer service life. With proper shaft design, steady bearings and bump rings should be avoided. These are often used when the shaft design is not controlled or understood properly.
• From here, we can optimize overhung load (OHL) and critical speeds.  

Impellers: 

Full line of Impeller options: Pitch, Radial and our unique Dynaflow High-Efficiency Impeller.

Our innovation in split-hub design enables superior performance in larger applications, and an ease of installation and removal that’s impossible with other impeller designs.  

Our modular design approach provides you with the ability to optimize your energy usage, as well as your process and application performance. Thousands of configurations of mixers have been manufactured with our approach.  

Popular Options: 

Dry Well and Dry Cavity designs are available to assure oil-safe operation. These are used as a redundancy to the seal from the oil-sump. This prevents oil leakage through the output flange.

Drywell seal designs are available for food and water treatment applications where oil contamination is not acceptable.

These options are also available with vapor lip seals, stuffing glands, and both single and double mechanical seal designs. 

Features: 

• Drop Flange – easily remove drive for maintenance without removing shaft from tank 
• High Efficiency Design – Configured to optimize power consumption 
• High Efficiency Components – High-Efficiency Motor and Gearbox Designs 
• Available in special alloys to suit your application 
• Available with special coatings and polishes to suit your application 
• Sight tube or optional oil proximity indicator is available

Many companies have relied on Dynamix products for quality and longevity. Here more examples of  returning customers:

1. City of Anamosa Water Treatment Plant: Officials at the City of Anamosa have come back to us for more mixers for their municipal water treatment process.
2. Bitumar: This client has come back for an even bigger mixer for their asphalt manufacturing.

We are proud to service these customers in their varied industries with our quality industrial mixers. We look forward to servicing more mining companies as clients and helping them with their mixing needs. If your team needs robust mixing solutions tailored to your specific mining industry processes, talk with the engineers at Dynamix to ensure that you get the right equipment for the job.