Entering the 21st century, with the ultra -fine processing of non -metal minerals in my country, ultra -fine crushing classification technology has become one of the most important deep processing technologies and is of great significance to the development of modern high -tech industries.
Set up production line of ball mill and graded machine refers to the continuous working system that uses dry methods to crush and re -grade; The selection of grinding media and lining plate is flexible, the high -purity processing pollution of the material is small, the overall operation of the equipment is reliable, the product quality is stable, and the particle size distribution is controllable. It is especially suitable for the ultra -fine processing of silicon microfim. The product is high, good in shape, stable quality indicators, and strong granular distribution regulation. However, because the functions and focus of the rating machine and classifiers are different, the cooperation problems in the production system are particularly important. If it is properly cooperated, it can exert its own characteristics, complementary advantages, high efficiency, poor cooperation, form function constraints, more energy consumption, consume more energy consumption, consume more energy consumption, consumes more energy consumption, consumes more energy consumption, consumes more energy consumption. ,low efficiency.
Its process flow is generally
Because ball mills and classifiers are usually produced by two companies, there are often differences in the concepts of yield. The output of the ball mill is given the fineness of the material, the effective diameter, the long diameter ratio, the speed of the ball mill, the selection of the ball mill, the amount of filling, the effective length of the grinding body, the amount of the material, the amount of the material, the amount of the grinding medium, and the size of the material. influences.
The output of the classifier is affected by the various conditions such as powder concentration, turbine classifier speed, air volume and wind pressure, grading efficiency, particle size distribution, product fineness, etc. The two devices should have the following relationships: [123 123 ]
The output of the classifier \u003d the processing volume of the classifier \u0026 mdash; the rough material quantity after classificationThe yield of the ball mill \u003d raw material amount of material+rough material return after classification
Holocated The processing volume of the machine \u003d the yield of the ball mill
Therefore, the matching of the two must be considered in the equipment selection and design.
1. The impact of various factors of the ball mill on the output and quality of silicon micro -powder
1.1 The effective diameter, long diameter ratio, and ball mill speed after the ball mill is adopted
The ball mill adopted In general, there are two types of aluminum lining and ball lining. The ball milling medium is mostly two types: alumina jet and ball stones. Regardless of which lining and lining, the effective diameter of the ball mill will be reduced. In the case of the speed of the grinding machine, the smaller the effective diameter, the worse the grinding effect, and the lower the output. Therefore, when selecting the diameter of the grinding machine, the effective diameter of the decrease in the lining plate should be fully taken into account to prevent the material from the decrease in the parabolic line in the grinding, which is not conducive to material grinding.
Under the condition of production capacity requirements, the long diameter ratio selection and classifier of the ball mill is a key factor, which is directly related to investment, energy consumption and product quality.Increase the whiteness, but the investment is slightly higher, and the regulation of the granularity distribution mainly depends on the combined combination of the ball mill long diameter ratio and the hierarchical machine.
1.2 The choice of grinding medium and lining plate
The choice of grinding media and lining board is also a very important factor restricting the quality and yield of silicon microfim. The advantage of the use of aluminum lining and jersey is that the aluminum aluminum lining plate is thin, the effective diameter of the grinding cavity is large, and the proportion of the availability is large, which is conducive to the crushing and grinding of the material. The corresponding production is higher than the output of the ball lining and the availability. Its disadvantage is to increase the percentage of Al2O3 in the quality index of silicon microfan. Due to the abrasion of the aluminum aluminum lining plate and the junior ball, the service life is limited, so it increases costs. And during grinding, the degree of fever is higher than the temperature of the ball lining plate and the availability. It is easy to reduce the whiteness of silicon microflower due to the increase of the grinding temperature, which affects the quality of the product of silicon micro powder.
The use of the ball lining and the jet ball, because the thickness of the lining plate is large, the effective diameter of the ball mill is reduced by more than 20 cm, and the contact between the various balls medium is very irregular, and even some are some of them. The contact between the face and the surface is not conducive to the crushing and grinding of the material, affecting the output of silicon microfim. Because the jersey and lining are used in the ball stone, the service life is generally worn by 30㎏ per ton of ball stone, so the medium ball stone is added to the ball mill at a time, but the wear can be converted into silicon microfan products, so there is basically no cost. cost. Because the main component of the ball stone itself is SIO2, it will not cause changes in the quality indicators of the material, and the heating rate is lower than the aluminum oxide lining and the junior ball, which will not affect the quality of silicon microfan. In addition, the price of ball stones is low and low investment.
1.3 Grade and fill rate of grinding media
The grade and fill rate of the grinding medium of the ball mill can also affect the output of silicon microfim. The level and fill rate should be generally in the following range. (Taking the ball stone as an example)
\u0026 phi; 80mm 25
5 15 25 35 45 (%)
45
35
\u0026 pHI; 90mm
25
15
]
(%) 5
75
77
78
79
80
81
82
83
5
15
25 \u0026 phi; 70mm
35
45
74
75
76 [76 [76 [76 []123]
7778
79
80
8182
73 [123
]
7475
76
78
80
72
73
75
76
77
123] 7879
80
72
73
74
] 75
77
78
70
71
72
] 70
71
72
73
7475
76
77
68
69
70
7172
73
74123]
7273
74
45 35 25 5 (%)
\u0026 phi; 60mm; 60mmFigure 4 of the grinding body of the ball mill
%
90 10% 80 66 20
70 64 65 30
60 63 64 40
50 61 62 63 50 \u0026 phi; 70mm
\u0026 phi; 80mm 40 59 60 61 62 60
30 56 57 59 60 61 70
20 54 56 57 59 60 80
10 53 54 55 56 57 58 59 90
90 80 70 60 50 40 30 10%
\u0026 pHI; 60mm
The grinding body of the ball grinding machine three grades
H
The fill rate of the ball mill filling machine:
H/D \u003d 0.63 0.62 0.61
￠ \u003d 35.8 36.2 37.8 38.8
D: Effectively Diameter
￠: Filling rate (%)
Two H
grinding body loading calculation:
g \u003d 0.785d2l ￠ p
] G: grinding body loading caps T
L: The effective length of the ball mill
P: grinding body volume density
According to the size of the medium ball stone
p Average \u003d 2.7k (k is spatial coefficient k \u0026 asymp; 0.7)
P average \u003d 2.7 \u0026 times; 0.7 \u0026 asymp; 1.89
Average ball diameter:
D1G1+D2G2+D3G3 +\u0026 hellip;D ball \u003d g1+g2+g3+\u0026 hellip;
D1-3 Different diameter media ball
G1-3 Each media ball quality
2. The impact of various factors on the output and quality of silicon micro -powder
1.1 The main regulatory parameters of the classifier
The turbine grading device of the classifier forms a stable centrifugal force by rotating field, By adjusting the number of impelios of the classifier, the speed of the leaf wheels, the wind pressure of the infiltration fan, the air volume, and the size of the secondary wind grided washing device, the product's particle size and output. The production decreases and the number of leaves and wheels is too small, it is easy to form a high speed, which is not conducive to grading, and the quality of the product is reduced; the secondary wind grid pottery is too small, and the fine powder mixed in the coarse material is not clean, which will affect the grading efficiency Essence
1.2 Dordrop resistance of classifier
Due to the high hardness of quartz, severe wear of equipment and pollution products, we must carry out wear -resistant protection of equipment For several PPM requirements for impurities, the protection method of equipment is very critical.
All cavity and pipelines such as ceramics or organic wear -resistant materials are very effective and reliable. However, due to its high -speed rotation, the grading rotor is complicated, the most severe wear, and the protection is more difficult. At present, the rotor of the vertical grading machine is difficult to overall ceramics due to the large volume; the balance after paste the porcelain is decreased, the porcelain sheets are easy to fall off at high speed, the operation life is shortened, and the reliability is reduced. The size of the rotor of the horizontal classifier is small, and the overall ceramic wheel or alloy wheel is usually used. However, due to its relatively high speed, the wear is still heavier, it still has certain metal pollution to the product, and the impeller is expensive, especially the multi -rotor structure. As a result, the replacement cost is large and the operating cost is high. In addition, the limit speed of the ceramic wheel is affected by its strength, which limits the peak cutting and sorting fineness of the graded machine.
Qingdao Youming Ke Fan Fan Technology Equipment Co., Ltd. uses special polymer wear -resistant materials to make graded impeller. Its good balances allowed to wear the limit under its good balance and The cost of alloy impeller and ceramic impeller is greatly reduced, which is greatly improved than the surface spray impeller and plastic impeller, which greatly reduces operating costs and has a high cost performance for zero metal pollution for materials. At present, it has been widely used in Anhui, Jiangsu, Shandong, Hebei, Shaanxi, Liaoning and other places, and has been updated and transformed for several users of the original classifiers. Through the long -term operation comparison, taking crystalline silicon microfilling as an example, the maintenance of 10,000 tons of 320 mesh products is about 3,000 yuan, which is only one -tenth of other impeller, and the continuous service life is more than two years.
3. The cooperation between the ball mill and the classifier
In the dry method super fine crushing classification production system composed of the ball mill and the grading unit, the production of the ball mill is large and the powder concentration is high. The powder depends on the negative pressure suction, and the centrifugal field hierarchical zone formed by the rotation of the classification leaves is graded; and the grinding products that have been grinded in the ball grinding machine cavity should be discharged in time, so the air consumption is large and the pressure loss increases. When choosing an induced fan, the wind pressure indicators should be fully considered to form a stable air volume required. Qingdao Youming Ke Fan Main Technology Equipment Co., Ltd. is for Anhui Fengcheng Powder Material Factory and Fengyang Lida powderIn the dry ultra -fine crushing classified silicon microfiflower production lines of a number of ball mills and grinding machines such as material factories and other airflow classifiers, the pulse bag collector with a large filtration area is used, and the impeller rotor with special materials is used. The output quality of silicon micro -powder. Adjust the air volume and wind pressure of the entire system correctly, so that the qualified products in the grinding machine can be removed in time, improving the grinding efficiency of the ball mill, high product grading efficiency, and large output. Continuous production and processing of 1,000 tons of system stability and obvious effect.
4. The correct connection method can improve the work efficiency and stability of the system
Because the ball mill is always in a high concentration discharge when working continuously, the ball mill is running.中，磨腔内一直处于半负压状态，因此分级机在与排料管连接时多采用\u0026ldquo;三通式直联\u0026rdquo;，留下一个二次进风口，并加风量调整阀，以调整The air volume pressure in the grinding machine; and the material in the material in the material pipe dispersed. (As shown in the figure)
In short, in the dry ultra -fine crushing classification production system composed of ball mills and grades, the correct cooperation and coordination of the two are particularly important. Constitution, high energy consumption and low efficiency. If it is properly cooperated, it can give full play to their respective advantages, make the entire system advantage complement each other, less effort, and high efficiency. If the adjustment valve is too small, it is easy to cause the air volume in the ball mill is too large, forming \u0026 ldquo; wind sweeping \u0026 rdquo; affecting the grinding effect in the ball mill; it is not conducive to the graded machine transport material, which is easy to form blocking materials. If the opening is too large, it is easy to cause the material in the grinding machine to grind and reduce the output.