Do these things well, let your silica sand ball mill reduce consumption and increase production

The function of silica sand ball mill in beneficiation is to dissociate the useful mineral components after crushing to the state of monomer dissociation, so as to provide suitable pulp with suitable size and concentration for beneficiation operation. The final beneficiation index depends mainly on the quality of grinding products. Therefore, the grinding quality of the silica sand ball mill is particularly important. It must meet the concentration required by the separation operation. In order to meet the requirements, the operators of the ball mill not only need to know the routine operation and maintenance process of the ball mill, but also need to master the following knowledge.

Silica sand ball mill

Controlling feed size of silica sand ball mill

The size of grinding particle of silica sand ball mill has a great influence on the productivity and energy consumption of ball mill. Generally, under the specified grinding fineness, the finer the feed particle size, the higher the production capacity of silica sand ball mill and the lower the energy consumption.

The relationship between feed size and ball mill capacity is as follows:

K=Q2/Q1=(d1/d2)l/4

Among them, K means "yield increase coefficient"

D1, D2 denotes "grinder feed size, mm"

Q1, Q2 means "mill output, t/h"

For example, the grinding particle size of ball mill is reduced from 20 mm to 15 mm. The calculation is as follows: k=(20/15)l/4=1.075.

The results show that the output of the ball mill has increased by 7.5%. Therefore, in the production of the ball mill, materials with finer grinding fineness should be provided as far as possible.

In actual production, the feed material of silica sand ball mill is the final product of crusher. Therefore, the total crushing ratio of crushing operation can be added to the crushing process to achieve more crushing and less grinding.

The main reason for more crushing and less grinding is that the crushing energy consumption is small, the grinding energy consumption is high, and the crushing efficiency is higher than that of grinding. Therefore, the crushing effect can be fully exerted when production conditions permit, and fine materials can be provided to grinding as far as possible to improve grinding processing capacity. The suitable size of feeds for different concentrators is shown in the table below.

Concentrator scale (t/d)	Grinding particle size (mm)
500	10～15
1000	6～12
2500	5～10
4000	4～8

Table 1: Silica sand ball mill feed size table

Adjusting grinding concentration and fineness of silica sand ball mill

Grinding concentration refers to the pulp concentration (the ratio of minerals to water) in the silica sand ball mill, and the content of the specified grade in the discharges of the silica sand ball mill with grinding fineness, which are interrelated and interacted with each other.

In open-circuit grinding, the grinding concentration is mainly affected by the nature of the ore, the amount of ore and the water, and the grinding fineness is mainly affected by the size composition of the ore, the grinding concentration and the ball-adding system. When the properties of raw ore change, such as the increase of coarse particle size and the constant feed volume, the grinding fineness can be ensured by reducing feed water and increasing grinding concentration. If the fine particle size increases, the feed water should be increased and the feed quantity should be increased appropriately to reduce overcomminution.

In short, no matter the grinding size, the grinding concentration can be adjusted by adjusting the feed water to control the grinding fineness.

Generally, the situation will become more complex when closed-circuit grinding, which mainly increases the factors of sand return. If the feed water is fixed, the amount of raw ore and sand return will increase, the grinding concentration will be increased, and vice versa.

In closed-circuit grinding, grinding fineness is affected not only by the amount of sand returned, but also by the classification efficiency. If the amount of sand returned is large, the grain size composition of the whole feed will change, and the grinding speed will increase with the increase of fine grain size. At this time, the grinding concentration can be reduced appropriately, and the discharge speed can be increased to reduce overcomminution. If the amount of sand returned is reduced and the raw ore is coarse, the feed water can be reduced to increase the grinding concentration.

Master ball loading quantity of silica sand ball mill

For newly installed or overhauled ball mills, there will be the problem of how many balls are loaded. The ball loading quantity and size of ball mills can be determined by experiments. The theoretical data indicate that when the size and speed of ball mill are fixed, the production capacity of ball mill will increase with the increase of filling rate in the range of filling rate ()<50%. (The filling rate of ball mill is 40-50%, the lattice ball mill is high, and the overflow type is low.)

The filling rate of ball mill refers to the ratio of the volume of medium in ball mill (V ball) (including pore) to the effective volume of ball mill (V machine).

The calculation formula is as follows:

_ = V ball/V machine X 100%

V sphere =W/ Delta

W= V machine_ &= pi/4 D2L_&

W = the total mass of the medium added to the grinder, t

V ball = volume of medium, M3

Delta = bulk density of medium, t/m3

D = effective inner diameter of grinder, M

L = effective length of grinder, M

Master the ball loading size of silica sand ball mill

Usually, the size of ball-loading diameter of ball mill depends on the size, hardness, density of the abrasive, the diameter, speed of ball mill, ball-milling confidentiality, pulp concentration and other factors. In actual production, it is mainly determined by the particle size composition of the material in the ball mill.

The feeding size of ball mill is different. When dealing with hard or coarse materials, it needs larger impact force, so it needs to add large size steel balls. When dealing with soft or fine size materials, it needs to grind mainly, and small size steel balls should be added.

Control of discharge concentration of silica sand ball mill

Drainage concentration, also known as grinding concentration, directly affects the fluidity of pulp and the ability to transport mineral particles in the barrel. In addition, it also affects the role of grinding media. In general, the normal grinding concentration is between 60% and 83%. In rough grinding, the grinding concentration is slightly higher, which can be controlled between 75% and 83%. In fine grinding, the grinding concentration can be adjusted between 65% and 75%.

In addition, the grinding concentration varies with the density of the ore. For the ore with higher density, the grinding concentration can be adjusted higher, and for the ore with smaller density, the grinding density can be adjusted lower (the specific density value depends on the results of beneficiation test).

Granularity of feeding ore, grinding concentration, fineness, ball loading, size and discharge concentration are the key factors to determine the grinding quality of ball mill, as well as the key to directly affect the final technical and economic indicators. Its importance can be imagined. Therefore, in production, it is suggested that ball mill maintenance personnel understand the relevant knowledge of ball mill grinding.