What is the difference between a dry ball mill and a wet ball mill in production?

Product introduction :https://www.cementepc.net/grinding/Cement-ball-mill.html

Jiangsu LVSSN company core cement epc

Ball mill is a common equipment in grinding equipment, but also the material after the crushing and screening operation, the key equipment for grinding.According to the classification of grinding, the ball mill can be divided into dry ball mill and wet ball mill.What are the differences between a dry ball mill and a wet ball mill?

1. How it works

When the dry ball mill is running, the material enters the first bin of the mill uniformly through the feeding device through the feeding hollow shaft screw, and the bin is equipped with stepped lining board or corrugated lining board, which is equipped with steel balls of different specifications.The centrifugal force generated by the rotation of the ball mill barrel will bring the steel ball to a certain height and then it will fall down.

After the material is roughened in the first warehouse, it enters the second warehouse through the single layer compartment plate, which is equipped with flat lining plate and steel balls of different specifications to further grind the material.Finally, qualified materials are discharged through the discharge grates to complete the grinding operation.

The working principle of wet ball mill is similar to that of dry ball mill, but different.Wet ball mill needs to add appropriate amount of water or anhydrous ethanol in the grinding process, which means that the grinding concentration has certain requirements.The amount of water is determined by the nature of the material.Qualified materials are discharged out of the cylinder through the discharge part, and the unqualified materials are returned to the wet ball mill for further grinding.
 

2. Structural construction

Dry ball mill and wet ball mill both include feeding part, feeding part, rotating part, transmission part (reducer, small transmission gear, motor, electric control) and other major parts.

The difference is that the structure structure of the dry ball mill is relatively more complicated than the wet ball mill, and its discharge mouth is straight cylinder shape, and it is equipped with air device, dust pipe and dust collector, which is determined by its working principle.The structure of wet ball mill is simple, no need to add too many auxiliary accessories, discharge mouth is like a horn, built-in screw device to facilitate discharging.

3. Scope of application of ball mill

In general, the dry ball mill is suitable for all kinds of metal ore, non-metal ore, including water will react with materials, such as cement, marble and other building stone, or require powder form to store and sell products.In addition, if the plant is located in a dry area, water resources are scarce, for the sake of water conservation, can use dry ball mill.

Wet ball mill is applicable to a wide range of metal ore, non-metal ore, including gold ore, silver ore, copper ore, iron ore, molybdenum ore, phosphate ore, feldspar, fluorite and so on.Wet ball mills can be used as long as the material meets water and does not affect the quality of the final product.

It should be noted that when wet ball mill is used, the proportion of steel ball, material and water should be determined through ore dressing test to ensure the ideal grinding effect.As for the choice of what kind of grinding equipment, or depends on the ball mill follow-up operations, product nature and production costs.

Only by finding out the suitable grinding mode of the material, can the ball mill run efficiently and well, the two grinding equipment have their own advantages, we are still in the nature of the material, characteristics and the requirements of the product, working environment and other aspects of the rational choice.

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How can ability judge ball mill load

Product introduction :https://www.lvssn.com/mill/Cement-ball-mill.html

Jiangsu LVSSN company core cement epc

Ball mill load is the sum of ball load, material load and water amount in the mill.What are the methods of measuring ball mill load?
 

1. The sound method

Industrial production practice shows that the sound of the ball mill has a certain relationship with the material load. The essence of this method is to determine the material load in the ball mill according to the difference in the noise produced by the ball mill.When the material load in the ball mill increases, the noise intensity of the ball mill decreases.On the contrary, the noise intensity of the ball mill increases, that is, there is a relationship between the noise intensity of the ball mill and the material load in the ball mill.Therefore, the noise intensity of the ball mill can be used to evaluate the material load in the ball mill.

 

2. Active power method

The working characteristics of a wet ball mill can be directly described by the useful power consumed.When the mill and its rotating speed are fixed, the theoretical calculation and actual test results show that there is a certain relationship between the active power of the ball mill motor and the load of the ball mill.With the increase of the ball mill load, the active power of the ball mill motor rises obviously at the beginning, and after reaching a certain extreme value, the active power decreases instead with the increase of the ball mill load. This extreme value can be considered as the optimal point of the ball mill load.Therefore, the useful power is directly related to the load of the ball mill.
 

3. The vibration method

When the ball mill is running, the grinding body and the material are on the side of the mill, and the grinding material and the rotating part of the mill are in a serious unbalance state, which causes the unbalance centrifugal force and makes the mill system vibrate.When the speed of the mill is unchanged, the vibration intensity of the mill is related to the amount of the grinded material.
 

4. Pressure sensor method

A load sensor is installed under the bearing of the feeding end and discharging end of the ball mill to continuously weigh the mill, so as to determine the total amount of ball medium, ore and water in the ball mill and determine the load of the mill.Its advantage is simple, the disadvantage is the detection accuracy is not high, can not accurately detect the ball mill medium, ore and water in the respective amount.In addition, the wear of ball mill lining plate, the change of ore property, the change of steel ball weight before and after adding will have a great impact on the test results.

 

5. Differential electromagnetic sensor method

It only measures the useful part of the vibration signal of the mill shell and eliminates the general interference signal.The sensor can be mounted at a distance of 71 ~ 80mm from the shell of the ball mill.The sensor has high reliability and sensitivity and low signal transmission delay.But this kind of detection system can't detect the concrete value of the ball mill's medium filling rate, material ball ratio and grinding concentration.
 

6.Hall power transmitter method

In the closed circuit grinding system of a ball mill with a double screw classifier, the load of the ball mill is indirectly reflected by measuring the amount of sand returned by the classifier.In the grinding production process, when the load of the ball mill exceeds the normal value, the coarse particle composition of the ball mill will increase, which will definitely increase the amount of returned sand; otherwise, the amount of returned sand will decrease.Therefore, it is feasible to measure the load of the ball mill indirectly by measuring the amount of returned sand. The hall power transmitter is used to measure the electric power of the classifier.At the same time, the absolute value of power is not required to be measured in this measurement, so only the single-phase power variation value of the three-phase motor with internal rotation of the double helix classifier is measured, so as to reflect the relative change of the returned sand amount and realize the automatic control of the ball mill load.

The single factor detection method introduced above is unable to judge the medium filling rate, material ball ratio and grinding concentration of the ball mill, so it is more important to choose the appropriate method according to the actual situation of the site.

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There are two reasons for jaw crusher shaking

Product introduction :https://www.lvssn.com/crusher/Jaw-crusher.html

Jiangsu LVSSN company core cement epc

Types of mining equipment such as jaw crusher, at work, because of the bad environment, so the fault cannot be avoided in production, the influence of some fault for production is large, there are some fault for production is small, the influence of rock is one of the fault, the influence of this phenomenon for production is also cannot be ignored, so we need to promptly solve the problem, to solve this problem, first have to find the reasons, there are two reasons for jaw crusher shaking

 

1. Loosen or break the screw

For the fixed jaw crusher equipment, the need to install before production, installation of time needs to be fixed on the ground, when I was a fixed screw need to use this part, if in production, appeared on one side of the screw loosening or fracture, then the machine will appear slightly shaking phenomenon, if not timely processed at this time, so the late shaking will be more serious, long-term working process will cause the screw fracture phenomenon, which makes the machine is in intense shaking,The solution to this phenomenon is to timely tighten or replace the loose or broken screws, so that the jaw crusher firmly fixed on the foundation, and then the stable crushing work;

 

2. The flywheel deviates from its original position

Fly Geneva wheel is one of the important parts of jaw crusher, which at the time of installation, the position is fixed inside the equipment, but the installation if staff in the installation error, will cause the part deviation from the original position, make the machine centre of gravity is imbalance, and then, the phenomenon of the rock, the phenomenon of the solution is to fly Geneva wheel to adjust the installation location;

Jaw crusher shaking of the two reasons, one is related to the screw, one is related to the position of the slot wheel, for these two phenomena of the solution, if you have a better way, also can communicate with us

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What are the problems with the shaft of the jaw crusher?

Product introduction :https://www.cementepc.net/crusher/Jaw-crusher.html

Jiangsu LVSSN company core cement epc

For jaw crusher, can complete the processing requirements, mainly depends on its performance are in good condition, and its performance are in good condition and their internal many parts are in good condition, in general, the parts is worn, the potential problems with the production going on, wear phenomenon gradually increase, the performance of the equipment also gradually decline, if worn parts will fail, then the device will stop the production, for internal of jaw crusher parts, some parts wear relatively quickly, these parts belong to wear parts, has an important influence for the work of equipment, the shaft is one of them,What are the problems with the shaft of the jaw crusher?

1. Shaft neck wear

The rotation shaft in use, wear conditions are different, need to take the repair program is different, when the jaw crusher rotation shaft wear is not big, can be plated on the shaft neck a layer of chrome, grinding to the required size;If wear is more, can be on the shaft neck surfacing welding, and then to the lathe cutting polishing;For serious wear condition, turn 2-3mm on the shaft neck, then turn a sleeve, cover on the shaft neck while it is hot, and then turn to the required size;

2. Shaft bending

Jaw crusher shaft bending phenomenon, will also cause the production is difficult to carry out, the repair method and the degree of bending has a great relationship, when the shaft bending is not big, can be repaired by grinding the shaft neck, slip ring method;When the bending exceeds 0.2mm, the rotating shaft can be placed under the press, and the bending part can be corrected under pressure. The surface of the corrected shaft can be polished by lathe cutting.When the bending is too large, a new shaft is needed.

Shaft neck wear and shaft bending phenomenon, for the repair of these two phenomena, jaw crusher shaft no matter which kind of fault, wear or bending degree of different, the need for repair methods are different, only to solve the wear or bending phenomenon, to ensure the smooth working process of jaw crusher.

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Roll crusher roller cracking how to do?

Product introduction:https://www.cementepc.net/crusher/Roll-crusher.html

Jiangsu LVSSN company core cement epc

The roller crusher, as its name implies, its crushing principle is to use the roller of material extrusion to complete the crushing operation, therefore, the roller to roller crusher is an important part.So, the problem came, in the process of operation, on the roller crusher roller cracking how to do?

Under normal conditions of roller crusher roller wear, the appearance of the roller is not cylindrical, forming two big, small center concave outline, then the larger mud block or mud ball can be worn through the concave, play no role in breaking, so it is necessary to repair the roller.There are two methods commonly used in roller repair: local cutting (grinding) machining repair and local surfacing repair.

1. Local surfacing welding

Local surfacing welding is to weld and fill the worn groove of roller crusher.This kind of method is brief and useful, do not affect the production, and surfacing the hardness and wear resistance are better, the defect is only suitable for good weldability roller (such as cast steel roller).
 

2. Local cutting (grinding) method

Local cutting (grinding) method of operation is: on the roller crusher frame, a special tool rack, its moving track should be parallel to the roller axis.Repair start to roll crusher, with manual feed organization (conditional can also choose active feed organization) on the roller cutting.

(1) the running track of the tool rest is parallel to the axis of the roller, preventing the taper after cutting and affecting the crushing effect.

(2) control the roller speed of the crusher.Roller appearance of the linear speed should not exceed the cutting tool allowed cutting speed, otherwise should be adopted to reduce the speed to prevent damage to the tool.

(3) about the high hardness roller, cutting can not be processed, at this time can choose to grinding a head according to the cutting method for grinding processing.

3. Disassembly and repair

The repair method after disassembly is to disassemble the roller with the shaft together and apply it to the machine after repair by turning.This method has large workload, long downtime, but easy and thorough repair.

Roller crusher is a kind of crushing equipment, its feed particle size is relatively small, fine discharge particle size, mainly used in stone production line of secondary crushing, we only ensure the normal operation of roller crusher, to ensure the profit of the enterprise.

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