How the right sealing solution can increase slurry pump reliability

ALEXANDRA EASTWOOD

By paying close attention to the sealing solution used in the gland area of slurry pumps, mining operators can increase productivity.

By paying close attention to the sealing solution used in the gland area of slurry pumps, mining operators can increase productivity – and profitability.

Slurry pumps are the workhorses of mining operations, helping to efficiently transport ore in the form of slurry throughout the site. Unfortunately, they are also often one of the more trouble-prone parts of many plants, with the abrasive nature of mining slurries taking a high toll on pump components.

A particular stress point is the gland area, where mechanical seals or packing are used to prevent leakage. Sealing solutions that are of poor quality or that are ill-suited to the application at hand can greatly increase maintenance demands, and lead to unplanned stoppages and excessive water use.

Mining operators looking to increase the efficiency of their slurry pumps – and in turn the whole operation – should spend time analysing their slurry and choose a tailored sealing solution that can cope with the inherent stresses.

Some of the factors to consider when analysing the slurry include the hardness and abrasiveness of the slurry; the amount and weight of solids being carried; and the salinity, chemical composition and temperature of the slurry. These can all impact heavily on component wear.

Armed with this information, operators can make a more informed choice about what kind of features are required from a sealing solution, be it a mechanical seal or packing. While uptake of mechanical seals is varied across mining settings, they have the potential to extend time between maintenance intervals by up to four times compared to packing. However, a slightly higher level of training is required among maintenance staff.

How to choose the right seal and packing

So, what factors should be considered when choosing a mechanical seal?

A good seal should have a stationary sprung design with non-clogging springs and micro-polished dynamic O-ring surfaces. It should also have the flexibility to add erosion protection features, like polyurethane in applications where the slurry is extremely abrasive.

Additionally, a good mechanical seal should also be flexible enough to add support features to prolong operating life, such as quench/drain and flush. It should have line-to-line seal faces, and be designed with generous cross sections and a robust drive mechanism that can mount on hardened pump sleeves.

For packing, the yarn needs to be sufficiently strong to prevent the slurry from penetrating into the fibre. It should be woven in a manner that creates a torturous leak path.

The packing needs to be low friction for low energy consumption and to reduce any damage to the rotating shaft, despite the presence of slurry. It should also be flexible enough to transfer the axial energy into radial load and maintain a positive seal for prolonged periods. Thereby reducing the amount of follower adjustments required during the life of the packing.

In conclusion, slurry pumps play a crucial role in mining operations. By examining operating conditions and requirements and choosing an appropriate sealing solution, pump uptime can be increased, water consumption reduced, and high productivity maintained.

Want to know more?

To find out how to choose the best pump sealing solution for mining slurry operations, download the white paper.

Introducing the latest in slurry seal design

ALEXANDRA EASTWOOD

Lance Brett, national product manager at Seal Innovations, is excited to bring the new Heavy Duty Slurry Seals onto the market.

Lance Brett has been working in mechanical seals for over 35 years. Now a national product manager at Seal Innovations, he is excited to bring the new Heavy Duty Slurry Seals onto the market for Australian customers.

“We’re really pleased with the quality of these seals and how they stand up in terms of wear life and reliability,” he said.

“It perfectly complements the rest of our product range and offers new potential for our involvement in the mining and quarrying sectors.”

The role of a sealing application cannot be overlooked, especially in resources where they act to secure valuable materials while they are being processed. Slurry is formed when water combines with ferrous and non-ferrous raw material, such as rock and soil between 1mm and 25mm thick. In mining, there are several types of pumps used in the transport of large volumes of slurry to mineral processing plants, where it then undergoes a separation process.

The solids within slurry can often prove highly abrasive, contributing to the accelerated wear life of critical parts, including seals. This problem can be amplified in a hyper saline environment, which may cause crystallisation of material around the surface.

The new Heavy Duty Slurry Pump Seal from Seal Innovations can withstand the harshest operating environments, providing maximum seal life in mining, quarrying and dewatering applications. The abrasion resistant metal components, along with silicone carbide faces, create an open design which reduces flush water and product dilution.

“This seal unit has been specifically designed for handling slurry concentration of up to 40 per cent solids by weight,” Brett said.

“It is an incredibly robust construct mechanical seal which is best suited to rugged mining and quarrying environments. Differently to standard O-ring designs, it is a rotating assembly, offering accurate installation with no special tools required.”

What’s more, the smooth, elastomer-coated cone spring increases the product’s reliability with an even spring load to the seal’s faces. This ensures minimal wear or clogging, in operating pressures up to 300 psig (20.7 bar).

“We have introduced this product to fill a prominent need in the market for mining-suited slurry pump parts,” Brett said.

“It’s a really exciting addition to our portfolio of industry leading seal products, and we’re already taking it to some of our most valued customers as an upgrade solution on troublesome equipment.”

He adds that, in addition to a comprehensive catalogue of sealing products, the business also provides aftermarket engineering and repair services from some of their centrally located branches.

“We can repair and overhaul slurry pump units as well as seals from our workshop in Brisbane, and we can repair any type of slurry seal from our Melbourne workshop,” Brett said.

“Everything is repaired back to manufacturer specification, and thoroughly tested for performance before re-entering the field.”

Technicians from Seal Innovations regularly visit customer sites, utilising their comprehensive knowledge of seal engineering to carry out audits, training and installation services. In line with its motto – “keep industry moving” – the company strives to meet each customer’s unique requirements and offer a one-stop-shop for all sealing needs.

Features of the new Heavy Duty Slurry Seal

  • Line-on-line seal face design
  • Fully sintered, interchangeable silicon carbide faces
  • Clamp collar
  • Anti-jamming drive washers
  • Smooth, elastomer coated anti-clogging cone spring
  • All static secondary gaskets
  • Quench Containment Device (QCD) for a water or Syntheic Lub Device (SLD).

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