Flotation Equipment

Choosing flotation equipment based mostly on how long it stays in the water has been taught in undergraduate university courses for a long time now. Interpreting kinetic flotation curves for the minerals you want to get can help you figure out how long they stay in the water. This is usually done in a lab or on a small scale.

It’s essential to know how long the flotation cells need to stay to figure out how big and how many they should be. There are other factors that should also be taken into account to develop a more sophisticated solution. When you choose a flotation machine, there are many important points to consider. This article will discuss these points and their importance. 

Equipment design options

Tank type

For a long time, tanks for flotation cells have been square, like a hog-trough. These tanks, also called “conventional” flotation cells, have been used for many years. In a bank of conventional cells, the slurry comes in at the front of the bank and passes through each cell in turn. There are usually two to eight cells in a bank like this. Cell models used in the past had a lot of material that went around the mixing mechanism because there were either small or no bulkheads between each cell, or the mixing wasn’t perfect. 

These days, modern conventional cell designs are much more efficient than their predecessors, and they’re still being used and sold in many parts of the world.

Tank lining

It’s common for flotation tanks to be made of mild steel that needs to be protected from corrosion by process fluids. The surface protection (lining) of the tank, in turn, increases the operational life of the equipment by a lot. The size of the solid particles, the abrasive index of the ore, how long the plants will live, and the reagents that will be used all play a role in which lining is chosen.

Self aspirated versus forced air

A mechanical flotation cell can be broken down into two main groups based on how air is brought into the cell. When you use a self-aspirating flotation cell, the air is brought into the slurry by the vacuum that is created by the rotor. The atmosphere in a forced-air flotation cell comes from a low-pressure blower outside the cell. It is then pumped through a shaft inside and to the rotor of the flotation cell.

Blower selection for forced air machines

Forced air flotation machines need a low-pressure air blower to get the air they need to work. A blower is chosen based on how much air it can move at a specific pressure. The cell froth surface area is multiplied by the appropriate superficial gas velocity (or range of rates) for the flotation plant’s targeted mineral type. 

This determines how much air is needed in the flotation plant to get the mineral. It’s essential to know how high up the flotation tanks are, the density of the slurry, how much air is lost between the blower manifold and where the slurry is thrown out of the flotation cells.

Belt drive versus Gearbox

When you choose a flotation cell, think about how the power gets to the rotor and how it gets there. A basic belt drive system is used in most small flotation cells. The motor’s rotational speed is slowed down by adjusting the ratio of drive to driven pulleys. This allows the rotor to move in the right place. 

This method of power transmission can also be used for more giant cells. Still, there is a practical design limitation because the driven pulley size needed for these tanks makes this method not very practical to use. It also gets more extensive and more expensive as these systems get bigger. The drive rack that holds the pulleys and motors grows and costs more as these systems get bigger. 

When installing pulleys and belts, it is essential to ensure they are correctly aligned and tensioned because improper installation and maintenance practices can waste energy and make the straps and rollers wear out more quickly.

Slurry level control

In flotation cell selection, the type of level control valve is essential because the amount and quality of the product recovered from each cell significantly impact how well the process works. Dart valves and pinch valves are the two main types of valves that can be used to keep the slurry level in a flotation cell from getting too high.

Instrumentation and control

It is essential to ensure that high-quality instruments and valves are used in forced air flotation machines that can control how much air is added. The air mass flow metre determines how much air is coming into the flotation cell. This is the first thing you’ll need. 

Most of the time, these instruments use the difference in temperature between a heated electrode and a cold electrode to figure out how much gas is passing by. These instruments need to be durable and withstand a lot of heat and weather for a long time. Some commercial models have become well-known as reliable manufacturers for mineral processing applications because of their durability.

Conclusion

To make sure that the performance of a new mineral processing plant meets expectations, it is essential to choose the right flotation equipment. Selecting a piece of equipment only based on how long you’ll be using it is a simple way to choose. Other factors that should also be taken into account before making a choice are:

• The rate at which you can carry froth.
• This is when the lip is loaded.
• The amount of energy it takes to run things.
• Need for maintenance.

Consider these above factors and choose the right equipment. This will not only lead to the best choice to meet performance expectations, but it will often go above and beyond them.