Mining - Aggregates

Problem

The flotation cells at the customer’s mines were being damaged by the materials processed in these tanks. Flotation cells are contained units that are used to perform froth flotation on a slurry to extract valuable minerals. The slurry within a flotation cell at a mine is typically very abrasive. As it circulates throughout the cell chamber, the suspended particles abrade the walls and floors, exposing bare metal, which results in the corrosion of the expensive steel structure. Chemical wear is also a problem for flotation cells because harsh chemicals are often added to the slurry to help separate fine solids out of the mixture. These chemicals often accelerate the corrosive process.

The company first attempted to line their cells with urethane-lined steel plates by welding them to the bottom of their flotation cells. The problem caused by these urethane-lined steel plates was that the abrasive material gradually worked its way around the back of the plates and corroded the steel welds. The slurry then made its way under the steel plates and began corroding the cell structure, rendering the steel plates useless. Because of the substantial capital expense to replace a flotation cell, and the resulting operational downtime that cell replacement entails, a solution to protect these tanks from further wear was sought by the company.

Solution

It was clear that in order to protect the cell from abrasion and corrosion, the company would require an impermeable monolithic protective layer. The company investigated several industrial paints and epoxy coatings, but decided that a thin coating could require several re-coatings per year and would not withstand the types of abrasion that would occur within a flotation cell. With this in mind they contacted their local Rhino Linings® applicator for a solution that was substantial, seamless, and required minimal downtime. The applicator selected Rhino Linings HardLine 21-55 for its unique blend of attributes including abrasion resistance and durability against corrosion and chemical wear. The interior metal surface was blasted to a 2 mil profile, primed, and the lining was applied at 1/8” (.32 cm) on the bottom and 3/8” (.95 cm) thickness on the sides of the cell.

Results

HardLine 21-55 eliminated damage from abrasion, impact and corrosion in the company’s flotation cell. As a result of the positive return on investment through reduced maintenance costs, the company made a decision to line other flotation cells throughout their operations.