Fine sieve selection

Fine screening refers to screening equipment with a mesh opening of less than 1 mm. The main purpose of a fine sieve beneficiation plant: First, to improve the efficiency of classification for the purpose of grading equipment as grinding circuit and other operations; the second is to improve concentrate grade for the purpose for sorting circuit. As a grading device, the classification efficiency of the fine sieve is higher than that of the spiral classifier and the force division cyclone, and it can overcome the shortcomings of the useful classification of the useful minerals in the grit in the classification process of the spiral classifier and the hydrocyclone, which is beneficial to Improve grinding efficiency and reduce over-grinding.

There are many kinds of fine sieves, and there are fixed fine sieves, linear vibration fine sieves, high-frequency vibration fine sieves and other types of fine sieves which are applied industrially or have achieved good results through industrial tests. The treatment of fine screening is generally based on actual production, industrial tests or equipment samples.

Fixed fine screen

Fixed fine screening (also called hit vibrating fine mesh nylon or nylon-like castor fine mesh) are widely used in iron ore concentrator magnetic sorting circuit (coarse to fine screen to concentrate, undersize products as concentrates, the oversize product return Grinding again). The fixed fine screen is composed of a feeding device, a nylon braided screen surface and a tapping device. According to the treatment of ore and equipment configuration requirements, each set of fixed fine screen can be made into a different number of joints (1 to 25 joints) of sieve surface, each joint screen size is generally 400mm × 1200mm, the size of the sieve hole is generally 0.15mm, Several kinds of 0.20mm and 0.30mm. The processing capacity of the fixed fine sieve is generally 8~16t/(m ² ·h).

In recent years, China has also developed classification equipments such as linear vibrating fine screening, high-frequency fine screening, vertical cylindrical sieve and swirling fine screening. Industrial tests have achieved good results, and some have been applied in industry. The technical performance and related data are listed in Table 1 to Table 6, respectively.

Table 1 Main technical performance of KZS1632 linear vibrating fine screen

project	unit	Numerical value
Processing capacity	t/h	65
Unit throughput	t/(m 2 ·h)	15~18
Sieve width	Mm	0.4±0.1
Screen strip (width × height)	Mm	2.5×4
Screen elevation angle	(°)	7
Sieve low elevation angle	(°)	0
Working amplitude (maximum)	Mm	4.3
Vibration frequency	Times / min	960
Sieve plate (length × width)	Mm	1600×450
Screen surface (length × width)	Mm	3150×1600
Excitation angle	(°)	30
Vibration motor power	kW	4

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Table 2 GPS900-3 high frequency vibration fine screen technology performance

Table 3 DGS ₂ electromagnetic vibration high frequency fine screen technology performance

model	DGS 2 -4	DGS 2 -6	DGS 2 -8
Screen size / mm	400×1200 (1560)×4	400×1200 (1560)×6	400×1200 (1560)×8
Screen size / mm	0.5, 0.3, 0.2, 0.15
Separation size / mm	0.3~0.074
Screen angle (°)	45~60
Double amplitude / mm	0.2~1.0
Vibration frequency / time · min -1	3000
Power / kW	0.45	0.65	1.5
Unit throughput t·h -1	20~35	30~50	40~60

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1 means the amount of each processing.

Table 4 GPS800×1600 high frequency vibration fine screen technology performance

Table 5 Ñ„2m vertical cylinder screen technical performance

Table 6 Technical performance of Ñ„150m swirl fine screen