Flotation Froth Management Upgrade

Optimize cell froth carry rates, properties, and stability while achieving thicker froth beds with a custom-designed froth recovery set-up from Metso.

There are limitations to the volume of material the froth phase can support and transport to the flotation cell’s launder lip in any given period. This is known as the froth carry rate (FCR), and is expressed as t/m²h, or the amount of material that 1 m² of froth can carry to the launder lip in an hour. In addition, lip loading (LL, t/mh), which is the quantity of concentrate pouring into the launder per meter of lip, is an important factor for launder design.

Too much or too little froth crowding leads to a non-optimal FCR. Problems with the level of froth crowding typically arise for one or more of the following reasons:

• Insufficient data is available during the design phase to calculate the correct FCR down a bank of cells
• The safety margin calculated by the design engineer is too wide
• A change in feed grade or capacity, leading to a larger or smaller amount of froth flowing to the concentrate. This directly affects the FCR and can result in the froth area being too large for the cell duty

Launders are an essential part of any flotation cell, and using a launder with the correct design and orientation for your specific application helps to ensure optimal metallurgical performance. Installing the wrong type of launder will make it difficult or even impossible to achieve your grade and recovery targets. Frothing problems can often occur when froth dries on top of a cell or when an insufficient amount of froth is formed. These problems are often a result of non-optimal lip length, froth area, or transport distance.