Flotation cell and leach tank linings: rubber, polyurethane or epoxy?

In a flotation cell or a leach tank, the lining must resist slurry abrasion and process chemistry at the same time. Sheet rubber remains the reference solution when fine-particle abrasion dominates, polyurethane suits impact and high-turbulence zones, and filled epoxy or novolac is used for local rebuilds and chemical splash. The final choice is confirmed against the actual solution chemistry, the temperature and the manufacturer's data sheet.

Concentrators and hydrometallurgical plants in Quebec and Ontario run cells and tanks around the clock between shutdowns. When the lining fails, the steel wears quickly and the next shutdown gets longer. This guide is for maintenance managers and project managers who must select, install or inspect these linings. It complements our rubber lining page and our reference page on protective coatings.

Why do slurry and leach solution destroy bare steel?

Because they combine two mechanisms that feed each other: abrasion strips the layer of corrosion products, and the solution immediately attacks the exposed metal. This is erosion-corrosion, much faster than either mechanism on its own.

Wear is never uniform in a cell or a tank. The most exposed zones are well known and should guide the lining choice:

• Rotor and stator zone. Turbulence peaks there and particles strike the wall at high velocity.
• Feed box and slurry inlet. Direct impact of the flow, often with coarser particles.
• Overflow launders and froth channels. Fast flow, splashing and wet-dry cycles.
• Floor and corners. Settled solids, sliding abrasion and under-deposit corrosion.
• Liquid line. Alternating immersion and exposure to air, often more corrosive than the submerged section.

In a leach tank, chemistry often dominates: acidic solution, alkaline solution or oxidizers, sometimes at elevated temperature. In a flotation cell, abrasion dominates, but reagents can attack some elastomers. One circuit can therefore need several linings depending on the zone.

Which lining for which abrasion and chemistry?

Start from the dominant mechanism in each zone, then confirm chemical and thermal compatibility on the data sheet. The table below summarizes generally recognized trends; it does not replace the manufacturer's advice or an immersion test in the actual solution.

Our rubber vs ceramic vs polyurethane comparison covers the choice for pure wear. For a vessel where chemistry dominates, our industrial tank lining selection guide and our vinyl ester vs novolac epoxy comparison help decide among non-elastomeric systems.

Which rubber for a process cell or tank?

Soft natural rubber is the most common choice against fine slurry abrasion; synthetic rubbers (butyl, bromobutyl, chloroprene) are chosen when chemistry, oils or reagents require it. The exact compound, hardness and thickness come from the manufacturer's data sheet and the project specification.

Three decisions shape a rubber lining:

• The compound. Natural rubber absorbs particle energy and resists wet abrasion well, but it tolerates some oxidizers and hydrocarbons poorly. Butyl and bromobutyl compounds are selected for several acidic solutions; chloroprene handles oils better.
• The cure. Removable parts can be lined in the shop and autoclave-cured. In an installed tank, pre-cured sheets are cold-bonded, or sheets cure in place by steam, hot air or self-vulcanization, depending on the system.
• The seams. Sheets are joined with skived overlaps. Seam orientation follows the flow direction so the slurry does not lift the edges.

NACE SP0298 covers sheet rubber linings for abrasion and corrosion service. Hardness is measured with a durometer per ASTM D2240, which lets you track rubber ageing from one shutdown to the next.

Where are polyurethane and filled epoxy the better fit?

Polyurethane fits where impact and turbulence exceed what rubber can absorb, and filled epoxy is mainly used to rebuild a worn wall or protect a sliding-wear zone. They often complement rubber rather than replace it.

• Cast polyurethane. For flotation mechanism parts, nozzles and impact zones, moulded to precise shapes.
• Sprayed polyurethane. For lining large surfaces with complex shapes. Its resistance to hot water and strong acids must be checked on the data sheet, as some polyurethanes hydrolyze.
• Ceramic-filled epoxy. For rebuilding a thinned wall, filling pits before a new lining or protecting a launder floor. The film is rigid, so it is a poor fit for heavy-impact zones.
• Novolac epoxy. For acid splash zones, sumps and containment areas around tanks.

For the pumps on the same circuit, our article on slurry pump wear coatings applies the same logic to casings and impellers.

What preparation does a process tank need before lining?

An immersion lining only holds on steel that has been designed, repaired and blast-cleaned for it. Continuous welds, rounded edges and the absence of crevices are settled before blasting; cleanliness and profile are settled during it.

• Design and repairs. NACE SP0178 describes design and weld-finish details for vessels to be lined for immersion service: continuous, ground welds, no stitch welding, rounded corners and edges.
• Decontamination. Process residues and soluble salts left in pits compromise adhesion. Washing and a salt check (for example per ISO 8502-6 and ISO 8502-9) come before final blasting.
• Blasting. Abrasive blasting reaches the cleanliness grade and profile required by the system data sheet; lining follows before any recontamination.
• Ambient conditions. Surface temperature stays above the dew point by the margin set in the specification, which often calls for dehumidification inside a closed tank.

How do you inspect a cell or tank lining during a shutdown?

Inspect against a fixed checklist and compare each reading with the previous one: the trend is what lets you decide between repair and replacement. Inspection is prepared before the shutdown, with confined space entry, lockout, cleaning and lighting.

The high-voltage holiday test is set according to lining type and thickness: excessive voltage can damage rubber. Our article on tank lining shutdown planning shows how to fit inspection and repairs into the schedule.

A local repair is enough when wear remains concentrated and the surrounding bond is sound. When disbonding spreads or the steel underneath is attacked, a complete new lining becomes safer than repeated patching.

Frequently asked questions

Can rubber be installed in a tank without dismantling it?

Yes. Pre-cured cold-bond sheets or sheets that cure in place are used. Preparation, ventilation and control of ambient conditions then become the critical points.

Does polyurethane replace rubber in a flotation cell?

Not everywhere. Polyurethane resists impact better and suits mechanism parts, but soft rubber is often still superior against fine slurry abrasion. The two are frequently combined in the same cell.

How do you know whether a lining will resist the leach solution?

Give the manufacturer the composition, concentration, temperature and any oxidizers, then check the chemical resistance chart. For an unusual solution, an immersion test on a sample settles it.

When should a cell or tank lining be inspected?

At every planned shutdown that allows draining, using a consistent checklist. Frequency is set from the wear found at previous inspections and the site's shutdown schedule.

How do you get a quote for a cell or tank lining?

Our crews and qualified subcontractors install, repair and inspect linings in cells, vessels and process tanks, alongside mining equipment painting, including in Abitibi-Témiscamingue, the Côte-Nord and Ontario. Send photos, dimensions, solution composition and temperature, the nature of the slurry and the length of your next shutdown through the request a quote form: pricing on consultation, reply within 24 business hours.