Explanation of beneficiation terms 1 Filtration 2 Filtration speed

Introduction to the principle of filtration in mineral processing technology.

Filtration is the process of separating solid particles from fluids, the basic principle is: the mixture of liquid and solid phases is given to the surface of the medium with multiple voids (that is, the filter medium, generally with filter cloth, etc.), under the action of pressure difference, the liquid passes through the medium, and the solid particles remain on the medium, which is called filter cake; The liquid passes through the cake layer and the media layer to become a clear filtrate. A filter that uses filtrate as a product is generally easier to operate than a filter that uses a filter cake as a product.

For further dewatering of fine-grained materials that have undergone initial dewatering, filtration is currently the most commonly used method. Compared to other separation methods, filtration consumes less energy.

1. Filtration method.

The methods of industrial application filtration can be divided into four types according to the different filtration powers.

1) Gravity filtration. This type of filtration is a type of deep-bed filtration (i.e., thick filtration layer) characterized by the deposition of solid particles within a thicker, granular media bed. The particle diameter in the suspension is smaller than the diameter of the bed pores and adheres to the filter media as the particles follow the fluid through the zigzag pores within the bed.

This type of filtration is suitable for applications where the particles in suspension are very small and the content is very small. For example, in waterworks, a layer of quartz sand is used as a filter medium to purify water.

2) Vacuum filtration. The vacuum pump is used to cause a certain pressure difference between the two sides of the filter medium, and under the action of this driving force, the liquid of the suspension passes through the filter cloth, and the solid particles are deposited on the upstream side of the filter cloth in the form of cake layers. This method is generally suitable for handling suspensions with small liquid-solid ratio and fine particles.

3) Pressurized filtration. Using high-pressure air 785 kPa (8 kg cm2) or high-pressure water 883-1569 kPa (9-166 kg cm2) to fill the diaphragm installed on one or both sides of the filter chamber, with the help of diaphragm expansion and uniform pressing of the filter cake, the filter cake with very low water content can be obtained. It is generally suitable for handling fine-grained sticky materials that are difficult to filter.

In recent years, combined pressure-vacuum filtration has been developed.

4) Centrifugal filtration. Using centrifugal force, the liquid in the suspension is thrown out, and the particles are intercepted on the surface of the filter cloth, and the centrifugal force field can provide a stronger filtration driving force than the specific gravity force field, with high separation speed and good effect. Suitable for handling slurries containing fine solid particles.

Filtration is the process of reducing the moisture of the slurry to a certain extent, of course, in addition to the drying method, the process of using the equipment of a filter, vacuum filter or water ring filter to reduce the moisture.

The filtration speed is the speed and length of the process of reducing the moisture.

Very popular.