Principle of Dense Machine Operation
Using the force of gravity inherent in solid particles, the slurry is separated into clear liquid and a high-concentration sediment, a process known as concentration.
During the concentration process, the mineral particles suspended in the pulp settle downward due to their own gravity. In the instant of beginning to settle, the particles accelerate downward under the influence of gravity. Subsequently, as the settling speed of the particles increases, the water resistance also increases, causing the acceleration to gradually decrease. Until the water resistance becomes equal to the gravity of the particles, the acceleration of the particles' descent reduces to zero. Consequently, the particles settle at a constant speed, which is known as the settling terminal velocity.
Concentrated slurry, if the concentration is low, the particle collisions and interference during sedimentation can be neglected, and this type of sedimentation is known as free sedimentation. However, if the slurry concentration is high, the particles interfere with each other during sedimentation, resulting in greater mechanical resistance due to collisions and friction. In this case, the sedimentation is referred to as interference sedimentation. Since there is an additional mechanical resistance between the particles, aside from the resistance of water, the terminal sedimentation velocity of interference sedimentation is smaller than that of free sedimentation. This explains why particles sediment more quickly in low-concentration slurry and more slowly in high-concentration slurry.
In the continuous operating concentration equipment, the sedimentation concentration process is divided into clarification zone, sedimentation zone, compression zone, and extrusion zone.
If we can control the input and output of ore quantities to make them exactly equal, then the positions of each partition can be correspondingly fixed at a certain height and remain in a state of dynamic equilibrium. At this point, the interfaces of each partition seem to be stationary and unchanging.
This is not easy to achieve in production practice. Due to changes in the feed and discharge volumes, the dynamic balance is disrupted, and the heights of each section also change accordingly. To ensure the smooth progress of the concentration process, the requirements for the heights of each section are: the clarification section should not be less than 0.2 to 0.3 meters, and the sedimentation section should not be less than 0.3 to 0.5 meters.

Thickener Classification
Thickener machines are mainly categorized into three types based on their transmission methods, with the first two being more common.
1. Central drive type. Such thickeners usually have a smaller diameter, with most being less than 24 meters.
2. Periphery Roller Drive Type. A commonly used medium to large thickener. Named for its use of a driving carriage for transmission. The diameter is typically around 53 meters, with some reaching up to 100 meters.
3. Periphery rack and pinion drive. This type has a basic diameter over 53 meters, but is now used less frequently.