★Natural dehydration is an operation that uses the self-gravity of the moisture on the surface of material particles to separate. This operation is usually performed on a screen, a homogenizer or a Dewatering Screen machine, such as a coal slime dehydration screen, a clean coal dehydration screen, and a AURY vibrating dehydration screen.
★Concentration is a method that relies on the settling of fine-grained materials in a liquid under the action of gravity or centrifugal force. Concentrators, AURY hydrocyclones, decanter centrifuges, concentration funnels and pyramidal sedimentation tanks are instruments and machines that work based on this principle.
★Filtration is an operation method that uses porous partitions to separate solid particles and liquids. Under the action of gravity or centrifugal force, or under pressure and decompression, the liquid passes through the partition and becomes filtrate; the solid particles adhere to the filter partition to form a filter residue layer. Machines used in this operation include vacuum filters, filter presses and AURY filter centrifuges.
★Drying is a method of dehydrating materials based on the principle of water evaporation. Drying operations usually use various dryers. The choice of dehydration method depends on many factors such as the distribution characteristics and content of moisture in the material and the size of the material particles.
★Properties of water in concentrates
Generally, there are four main types of moisture contained in concentrates, which are divided into gravity moisture, capillary moisture, membrane moisture and hygroscopic moisture.
Gravity water: Gravity water refers to the part of the gaps between solid particles that can flow freely under the action of gravity. It is the easiest moisture to remove from materials.
Capillary moisture: There will be relatively small gaps between the solid particles of the concentrate, and capillary action can occur between these gaps. The water in these small gaps is capillary water.
Membrane moisture: Membrane moisture refers to the formation of a hydrated film on the surface of solid particles due to the dipolar effect of water molecules, which is called membrane moisture. Compared with other water, this part of water is more difficult to remove.
Hygroscopic adsorption: Adsorption exists on the surface of concentrated solid particles, adsorbing water molecules on the surface, and reaching the inside of the solid particles through osmosis. The water attached to the surface of solid particles is called adsorbed water; the water that penetrates into the interior of solid particles is called adsorbed water; the two together are called hygroscopic water. This water is also difficult to remove.
★Mineral dehydration methods
According to different process requirements, a variety of dehydration methods can be used, which can be roughly divided into the following categories:
✬The gravity dehydration
Gravity dehydration refers to the use of gravity to dehydrate. It can be divided into the following two forms.
Natural gravity dehydration: that is, the natural gravity of water on the surface of solid particles is used for dehydration.
Gravity concentration and dehydration: that is, dehydration that uses the gravity of solid particles to settle in the liquid to achieve solid-liquid separation. The dehydration principle of the concentrator is this method.
✬The Mechanical dehydration
Mechanical dehydration refers to the separation of solid particles from water through mechanical force. It can be divided into the following three forms.
Centrifugal dehydration means. Use centrifugal force to separate solid from liquid, such as centrifugal dehydrator.
Screening dehydration refers to Dewatering Screen based on the inertia force generated when the material and the AURY vibrating screen surface move relative to each other, such as AURY horizontal vibrating screen
Filtration and dehydration refers to a method of passing the solid-liquid mixture through fine plant fiber fabrics or wire mesh to accelerate solid-liquid separation through vacuum or pressure, and is used in vacuum filters.
✬The thermal dehydration
Thermal dehydration refers to dehydration achieved by using heat energy to vaporize and evaporate the moisture in the material, such as thermal drying, sunlight exposure, etc.
✬The Magnetic dehydration
Magnetic dehydration refers to the use of a strong magnetic field to generate magnetic force on magnetic minerals to achieve solid-liquid separation.
★The role of concentrate dehydration
The main uses of concentrate dehydration in the mineral processing plant are as follows:
✬Reduce the moisture content of the concentrate and improve the quality of the concentrate. Because the moisture content of the concentrate is one of the important criteria for measuring the quality of the concentrate, if the moisture content is too high, the concentrate will not have much value.
✬Save water. A large amount of water is used in the ore sorting process, which can be recycled during the concentrate dehydration process to avoid waste.
✬Convenient shipping and reduced shipping costs. The higher the moisture content of the product, the higher the transportation cost. Dehydrating the product also reduces the transportation cost.
