What factors depend on the particle size of the ultra-fine jet mill

There are two basic methods for obtaining ultra-fine powders, one is physical method, the other is chemical synthesis, and the other is a hybrid method based on these two methods. And nanomaterials are generally prepared by a hybrid method. The main equipment for preparing ultra-fine powder by physical method is grinder, classifier and collection equipment of various principles. The ultra-fine jet mill is an important way to obtain ultra-fine powder by dry processing.

The ultra-fine jet mill is the shearing of the material by the high-pressure airflow, the impact between the particles of the material itself, the impact and friction between the material and other parts of the equipment, and the material is smashed. The ultra-fine jet mill can be operated in an aseptic state. The average particle size of the material after airflow pulverization is fine, the particle size distribution is narrow, the particle shape is regular, the surface is smooth, and it has the characteristics of high purity, high activity, and good dispersibility. Moreover, it does not generate heat during pulverization, and is suitable for pulverizing low-melting and heat-sensitive substances. Therefore, the ultra-fine jet mill is very suitable for the ultra-fine preparation of drugs. According to statistics, about 25% of ultrafine jet mills in the world are used in the pharmaceutical industry.

The control of the particle size of the product by the ultra-fine jet mill mainly depends on the size of the raw material, the crushing pressure, the feeding pressure, and the feeding speed. The specific logical relationship between the ultra-fine jet mill and these parameters is: the smaller the particle size of the raw material, the higher the crushing efficiency; on the contrary, the larger the particle size of the raw material, the relatively low crushing effect. When the crushing pressure and the feed pressure are constant, the product will be finer when the feed rate is reduced, and the product will become coarser when the feed rate is increased. In the case of a certain feed rate, the particle size of the product will be finer when the crushing pressure is increased, and the product will become coarser when the crushing pressure is reduced. Therefore, particle size control is achieved by adjusting the parameters of the ultra-fine jet mill during the crushing process to achieve different crushing fineness. Before crushing, it is necessary to determine the relationship between the feed rate and the pressure and then determine the appropriate crushing parameters to achieve the customer's Granularity requirements. The particle size of the product needs to use a particle size detector to check the fineness and distribution range. In addition, if the electron microscope is used for measurement, it can be more accurate. Of course, you can also compare the detection results with the internationally famous particle size detector.

The ultra-fine jet mill is a relatively precise machine. In the daily use and maintenance process, some details still need to be paid attention to by the operator. In order to improve the crushing efficiency of the ultra-fine jet mill, it is necessary to check whether the raw materials meet the requirements before production. It is strictly forbidden to mix foreign objects in the raw materials. During production, a certain amount of materials must be kept in the grinding cavity of the ultra-fine jet mill. Under the condition of constant pulverizing gas flow, there are more materials in the grinding cavity, and the classifier current is large; there are few materials in the grinding cavity, and the classifier current is small. In addition, the feeding speed must be uniform and stable, not too fast or too slow. If the feeding speed is too fast, the equipment will be overloaded.

The equipment should be maintained regularly, and the air supply pressure should be checked frequently to see if it has reached the pressure required for crushing, as well as the grading motor of the ultra-fine jet mill. After 3000 hours of operation of the equipment, or long-term shutdown and long-term storage before reusing it, please promptly Clean up the materials adhering to the nozzle of the ultra-fine jet mill, the inner wall of the mill cavity and the grading part to prevent the impact of the ultra-fine jet mill's smashing effect.

by ALPA Powder

Significance of ultrafine powder classification

Ultrafine powder is not only the basis for the preparation of structural materials, but also a material with special functions. It is widely used in fine ceramics, electronic components, bioengineering treatments, new printing materials, high-quality refractory materials, and materials related to fine chemicals. And many other fields. With the more and more widespread application of ultrafine powder in modern industry, the status of powder classification technology in powder processing is becoming more and more important.

In the crushing process, only part of the powder meets the particle size requirements. If the products that have reached the requirements are not separated in time, and the products that do not meet the particle size requirements are pulverized together, it will cause energy waste and over-crushing of some products. .

In addition, after the particles are refined to a certain degree, the phenomenon of crushing and agglomeration occurs, and the crushing process is even worse due to the agglomeration of the particles. For this reason, products should be classified during the preparation of ultra-fine powders. On the one hand, the particle size of the product should be controlled within the required distribution range, and on the other hand, the products with the required particle size in the mixture can be separated in time to return the coarse particles. Re-pulverization to improve the pulverization efficiency and reduce energy consumption.

With the increase in the fineness of the powder required and the increase in output, the difficulty of grading technology is getting higher and higher. The problem of powder grading has become the key to restricting the development of powder technology, and it is one of the most important basic technologies in powder technology. one. Therefore, it is necessary to study the technology and equipment of ultrafine powder classification.

by ALPA Powder

Jet mill is more suitable for crushing materials with high added value and good brittleness

The development of ultra-fine pulverization technology is becoming more and more rapid, thanks to the market demand for jet mill equipment. Jet mill, cyclone separator, dust collector, and induced draft fan constitute a complete pulverization system. The pulverization mechanism determines the scope of application of the pulverizer. The characteristics of wide and high fineness of the finished product. Typical applicable materials are: superhard diamond, silicon carbide, metal powder, etc.

The ultrafine pulverizer enters the cylindrical pulverizing chamber through the feed port, and the grinding wheel that moves in a circular motion along the grinding rail performs pulverization and shearing. The crushed materials are brought out of the crushing chamber by the negative pressure airflow generated by the fan and enter the material collection system. After filtering through the filter bag, the air is discharged, the materials and dust are collected, and the crushing is completed. By changing the ordinary air of the gas source into inert gas, such as nitrogen and carbon dioxide, the pulverizer can be used as an inert gas protection device. It broke the bottleneck of the crushing industry and brought the crushing industry to a new level.

The jet mill adopts supersonic jet grinding and cold plasma pulverization, which is completely different from the existing pure mechanical pulverization method. There is no local overheating in the crushing process, even if it is crushed at low temperature, it can be completed immediately, so as to maximize the retention of the biological activity of the powder components, thereby producing the required high-quality products. Due to the supersonic jet grinding, the feed force distribution is relatively uniform, avoiding excessive crushing, and the obtained ultrafine powder has a uniform particle size distribution, which greatly increases the powder's adsorption, solubility, and specific surface area.

The ultra-fine powder jet mill adopts a closed system, which not only avoids polluting the surrounding environment, but also prevents the product from being polluted by dust in the air. It is widely used in the ultra-fine grinding of food and health products. In the crushing process, the microbial content and dust pollution are controlled, and products with ultra-narrow particle size distribution are produced. The collection rate of the conventional jet mill is more than doubled. The automatic control is realized, the operation is simple, the operation is stable, and the equipment is intelligent.

by ALPA Powder

How to deal with the abnormality of the superfine pulverizer to reduce the loss

The superfine pulverizer has powerful functions and is widely used. However, abnormalities will inevitably occur during the use of the equipment, which may affect the production situation, or cause the production line to stop, and the loss is immeasurable. Therefore, when encountering some exceptions, we should master certain handling methods.

The parts of the shredder are damaged or fall off, or if hard objects such as rocks or iron enter the machine, there will be abnormal noises. The inspection should be stopped immediately, and the damaged parts should be replaced or the hard objects should be removed. The main reasons for low production efficiency are insufficient motor power, improper pulley preparation, belt slippage, severe hammer wear, uneven feeding or excessive moisture content of raw materials. If the above situation occurs, you can take corresponding measures to solve the problem, or replace the motor or pulley to increase the speed, but it must not exceed the rated working speed; or adjust the belt tightness, or replace the belt, or replace the hammer. In operation, the feed should be uniformly added in small amounts and quickly to maintain continuous uniformity; over-wet raw materials should be dried and then crushed for processing.

For the operation and use of the ultrafine pulverizer, after unpacking, first carefully check whether the equipment is damaged during transportation, and then put the electrical control devices of the high-speed machine and auxiliary machines in place, and then connect them to the pipelines of the main and auxiliary machines. When the flange of each nozzle is assembled, ensure the sealing of the pipeline. At the same time, a ground connection is adopted between each single unit and the pipe flange to avoid dust explosion caused by static sparks. Before trial operation of each stand-alone machine, check whether there are metal objects in the machine, and remove it if there is any. In addition, check whether the bolts are firm, the tightness of the belt, the reliability of the guard, and so on. The motor starts steadily. After five minutes of no-load operation, the operator should carefully observe the various instruments on the control cabinet and wait for the no-load current to stabilize before feeding.

What should I do if the bearing of the superfine grinder is overheated? When the bearing is poorly lubricated, damaged, or the main shaft is bent, the rotor is severely unbalanced, and the belt is too tight, the bearing will overheat. The bearings can be restored to normal state by adding or replacing lubricating oil, replacing bearings, spindles, balancing rotors, and adjusting belt tightness. The following reasons may cause the crusher to vibrate strongly: the hammers are installed incorrectly, the weight deviation of the corresponding two sets of hammers is too large, the bearing is damaged or the main shaft is bent, and the foot connecting screw is loose. If the hammers are arranged incorrectly, they should be rearranged according to the instructions; if the weight deviation of the corresponding two sets of hammers is too large, the weight should be balanced so that the weight difference does not exceed 5 grams; if the bearing is damaged or the spindle is bent, it should be replaced in time ; If the foot connecting screws are loose, they should be tightened.

by ALPA Powder

The difference between talcum powder and calcium carbonate as plastic filling

Generally, most of the plastic masterbatch is added calcium carbonate, but it must be calcite crystal ore. Both talcum powder and calcium carbonate can be added to plastics. In terms of cost, calcium carbonate is lower than talcum powder. In terms of production process, calcium carbonate is easier to process than talc powder. The polypropylene pellets used for strapping should be added with talcum powder and calcium carbonate, the ratio of which is: polypropylene: talcum powder: calcium carbonate = 70:25:5. For woven bags, calcium carbonate should be used, and the addition amount can reach more than 30%. Note the temperature during processing.

1. Both talcum powder and calcium carbonate are used for filling. The main purposes are:

• Increase dimensional stability (that is, reduce shrinkage)
• Increase the stiffness of the material,
• Increase the heat resistance of the material,
• Reduce material costs and other aspects.

But it also has its shortcomings:

• Density increases,
• If it is not used well, the impact toughness will decrease.
• The luster of the material has decreased.

2. Talcum powder has the same particle size distinction as calcium carbonate, generally 300 mesh, 600 mesh, 800 mesh, 1250 mesh and 2500 mesh. Of course, there are finer ones, and generally used in plastics, 800 mesh and 1250 can be selected. Target these two, so that the performance and price ratio can be the highest.
3. The price of talcum powder fluctuates. Generally speaking, it is not a big problem to set the price according to the number of meshes. For example, the general price of 800 mesh is between 700 and 850 yuan, and the price of 1250 mesh is between 1000 and 1000. Between 1280 yuan. The price is too high or too low is not normal.

About the difference between talcum powder and calcium carbonate:

• The shape of talcum powder is flake, so it has higher rigidity, dimensional stability and heat resistance temperature, and it has good reinforcement effect.
• Calcium carbonate is generally granular, so its stiffness and other aspects are not as good as talc, but its price is lower, and its whiteness is high, and it has little impact on plastic impact toughness.
• Talc has a nucleation effect on polypropylene, while calcium carbonate has no obvious effect in this respect.
• Calcium carbonate can generally be divided into light calcium carbonate and heavy calcium carbonate, but talc powder does not have this distinction, talc powder is ground from natural minerals.

Calcium carbonate/talc powder composite reinforced PP, its properties are as follows:

by ALPA Powder

Introduction of six advantages of jet mill

Since the advent of jet pulverization and classification equipment in the 1930s, various types have been continuously updated and the structure has been continuously improved, such as flat jet mills, circulating jet mills, impingement jet mills, jet mills, target jet mills and fluidized bed (jet) jet mills Wait.

Fluidized bed jet mill has the characteristics of low energy consumption, light wear, low pollution, low noise, fine particle size, uniform distribution, etc. It is widely used in synthetic resins, phenolic resins, polyvinyl chloride, pigments and dyes, powder coatings, colorants, and medicine , Cosmetics, advanced ceramics, magnetic powder, abrasives, metal powder, food, flavor, stearic acid, fat, wax, mineral powder, pesticide and wettable powder production.

The main advantages are as follows:

(1) The linear impact crushing and surface impact crushing of the traditional jet mill are transformed into three-dimensional impact crushing. The high-speed airflow generated by the jet impact is fully utilized in the material flow of the crushing chamber to generate gas-solid crushing and classified circulating flow in the crushing zone. Similar to the effect of fluidization, the efficiency of impact crushing and the comprehensive utilization of energy are improved. Compared with other traditional methods, energy consumption is reduced by 30%.

(2) The impact crushing zone and the gas-solid flow zone are placed in the middle space of the crushing chamber to avoid the impact erosion of the material driven by the high-speed airflow on the crushing chamber wall, and improve the most serious wear problem during the jet impact crushing process. Reduce the possibility of material contamination.

(3) Using high-purity nitrogen, argon and other protective gases as the working medium to prevent oxidation, the closed-loop operating gas consumption is small and the cost is low.

(4) In the process of fully closed loop operation, there is no dust flying, no pollution to the environment, and no harm to the human body.

(5) After jet mill pulverization, the activity of the powder is improved. The energy of the high-speed jet in the jet milling and classification process not only breaks the particles, but also changes the internal structure of the particles, especially the surface state to a certain extent. Gas flow can remove several atoms or ions from the particle lattice, resulting in mechanical loss of the crystal structure. In this way, with the ultrafine grinding of the powder material, the surface energy or internal energy of the particles increases, and the activity of the particles increases. The increase in particle activity is not only conducive to the progress of the chemical reaction, but also conducive to the adsorption and coating of the particles.

(6) The product has fine particle size, large output, suitable for large-scale production, high particle size classification accuracy, narrow product particle size distribution, and easy adjustment of product particle size.

by ALPA Powder

Advantages of jet mill in medicinal grinding

With the rapid economic development, higher requirements are put forward for the fineness and purity of various powders (including pharmaceutical powders) and their grinding equipment; ultra-fine grinding is very important for medicines and can affect its efficacy. And absorption in the body; the current market demand for micronized solid drugs is increasing year by year. At present, a jet mill is usually used for ultrafine grinding of drugs.

Micropowder crystallization is obtained by controlling the crystallization process conditions to obtain ultrafine particle crystals, which are then filtered, scrubbed, drained, and dried. Micropowder crystallization is obtained by ultrafine grinding of crystal particles. The defects of micro-powder crystallization are that it is difficult to filter, wash, drain, and dry, and it is easy to cause crystal leakage during the filtering and washing process, resulting in low yield and daily output, and the final product has low purity, many impurities, and adverse drug reactions. It is aggravated, so it is generally less used in production. At present, the ultra-fine grinding process is more widely used.

The airflow grinder accelerates the compressed air or inert gas through the nozzle, and uses the energy of high-speed elastic fluid (300~500m/s) or superheated steam (300~400℃) to make particles between particles, gas and particles, and particles With the wall and other parts, there are fierce impacts, shears, collisions, frictions and other effects. At the same time, under the effect of the centrifugal force of the airflow or the combined effect of the classifier, the coarse and fine particles are classified to achieve ultra-fine grinding. . The jet mill is a common preparation method for pharmaceutical powder, and is suitable for the grinding of antibiotics, enzymes, low melting point and other heat-sensitive drugs.

The advantages of jet mills in medicine are as follows:

• The range of particle size distribution is narrow, and the average particle size is fine;
• Good powder appearance and high product purity;
• Suitable for low melting point and heat sensitive drugs;
• Good airtightness and no pollution;
• Easy to operate;
• Grinding-mixing-drying on-line operation.

by ALPA Powder

Features and development direction of air classifier

Airflow classifier is a kind of equipment that uses centrifugal force of impeller rotation and drag force generated by airflow to classify materials. It is widely used in the classification and purification process of quartz, feldspar, mica, kaolin, and magnesium oxide. It has the characteristics of high classification accuracy, energy saving and high efficiency, and low production cost.

The air classifier includes a drive motor, a grading wheel, a fine powder outlet, a secondary air inlet, a raw material inlet, and a coarse powder outlet. Airflow classifier is a kind of airflow classification equipment. The classifier and cyclone separator, dust collector and induced draft fan form a set of classification system.

Under the action of the fan, the material moves to the classification area at high speed from the lower inlet of the classifier with the updraft; under the action of the strong centrifugal force generated by the high-speed rotating classification turbine, the coarse and fine materials are separated; the fine particles that meet the particle size requirements pass through The gap between the grading wheel blades enters the cyclone separator or dust collector to collect; the coarse particles entrained by the part of the fine particles hit the wall and the speed disappears, descends along the cylinder wall to the secondary air outlet, and the strong elutriation of the secondary air separates the coarse and fine particles; The fine particles rise to the classification zone for secondary classification, and the coarse particles fall to the discharge port for discharge.

Performance characteristics of air classifier

It is suitable for the fine classification of dry micron products. It can classify spherical, flake and irregularly shaped particles, and can also classify particles of different densities. The particle size of the classified product can reach D97:3~150μm, the product particle size is steplessly adjustable, and the variety is extremely convenient to change.

The classification efficiency (extraction rate) is 60%~90%. The classification efficiency is related to the nature of the material and the particle content that meets the particle size. The fluidity of the material is good, and the particle content that meets the particle size requirement is high, the efficiency is high, and vice versa. The speed of the grading wheel is high, and the apex is cut accurately. Multi-stage classifiers can be used in series to produce products of multiple particle sizes at the same time.

It can be used in series with ball mills, vibration mills, Raymond mills and other grinding equipment to form a closed loop. The control system adopts program control, the running status is displayed in real time, and the operation is simple and convenient.

The system runs under negative pressure, and the dust emission exceeds 40mg/m³. After adopting the noise reduction measures, the equipment operation noise is not higher than 75dB (A).

Application field

Minerals, chemicals, metallurgy, abrasives, ceramics, refractories, medicines, pesticides, food, new materials, etc., especially suitable for the classification of non-mineral products such as calcium carbonate, kaolin, quartz, talc, and mica.

The development direction of air classifier

• Large-scale and refined

With the continuous expansion of the ultra-fine powder market and the expansion of production scale, the demand for large-scale ultra-fine crushing and fine classification equipment will continue to grow. The use of large-scale equipment can reduce the energy consumption per unit product, simplify the process, reduce the area occupied, and reduce the equipment investment and production cost of the unit product.

• Vortex air classifier gradually dominates the market

The vortex air classifier is simple in structure, adjustable in particle size, and has a wide range of adaptability. It is widely used in construction, mineral processing, fine chemicals, special ceramics and other industrial fields.

• Automatic control

Industrial control automation technology is developing towards intelligence, networking and integration. The automatic control of airflow classification can improve production efficiency, reduce labor intensity of workers, and improve the overall automation level of the powder processing industry and the core competitiveness of the enterprise.

by ALPA Powder

Grinding machine fault treatment and daily maintenance

The grinding of materials is an indispensable process in the production of products in many industries (such as metallurgy, mining, building materials, chemicals, ceramics, etc.). Due to the difference in the physical properties and structure of the materials, the selection of the grinder should also be analyzed in detail.

There are many grinding equipments on the market. Choosing a suitable grinding equipment can not only reduce the grinding time and reduce the waste of materials, but also help the wear of the grinding equipment.

Factors to be considered when selecting

• Material type and hardness

Material type and hardness is an important principle for choosing a grinder. The hardness of different materials is not the same. Usually Mohs hardness is used to indicate the hardness of the material. The Mohs hardness is divided into 10 levels. The greater the Mohs hardness number, the harder the ore and the more difficult it is to grind, and vice versa.

• Material moisture content

The water content of the material will also affect the choice of the grinder. When the water content is too large, the fine-grained material will agglomerate or stick to the coarse-grained material due to the increase in humidity, thereby increasing the viscosity of the material, reducing the discharge speed and increasing the productivity. Decline.

• The degree of dissolution of the ore

The degree of dissolution of the ore also directly affects the productivity of the grinder. When the ore is ground, it is easy to break along the cleavage surface. Therefore, the productivity of the grinder is correspondingly higher than that of the ore with a dense structure. .

• Incoming and discharging granularity

The granularity of incoming and outgoing materials is used to judge the type and level of grinding equipment required. If the content of coarse particles (large dry discharge port size) in the grinding material is high or the ratio of the largest ore supply to the width of the ore supply is large, the grinding ratio that the grinder needs to achieve (the particle size of the material before grinding is compared with that after grinding) The ratio of the particle size of the material) is large, so the productivity is reduced; when the content of fine particles of grinding material (close to or smaller than the size of the discharge port) is large or the ratio of the largest block of the ore to the width of the ore is small, the grinding ratio to be achieved is small , So its productivity is increased accordingly.

• Construction Site

The size of the construction site is also one of the factors that people consider when choosing a grinder. In addition, the location of the grinding equipment also affects the choice of the grinding machine.

• Yield

The output is also an important indicator that determines the selection of grinding equipment. The conventional understanding is that the higher the output requirement, the larger the specifications of the grinding equipment required, and the corresponding input and output will increase.

Common faults and treatment methods of grinding machines

• Worn spindle bearing

cause

1) Problems with bearing lubrication, heating or damage to the bearing, increase the transmission torque of the mating surface of the bearing inner ring and the shaft, produce relative movement, and cause the wear of the bearing position;

2) For long-term use, the metal material itself will produce normal metal fatigue, resulting in the generation of its fit clearance, which will cause the wear of the bearing position.

Fault judgment

1) Check the vibration of the pulley and observe the overall vibration and noise of the equipment when the equipment is running normally;

2) Use temperature measuring equipment to check the temperature of the bearing part;

3) Use testing equipment to check the vibration and relative displacement of the bearing part.

• The main shaft keyway, the wear of the key, the shaft and the pulley hole

cause

1) During long-term use, normal metal fatigue wear occurs on the mating surface of the pulley and the shaft, and the fit gap increases, causing the relative impact of the key and the keyway, leading to the wear of the keyway, and then increasing the wear of the shaft and the pulley hole.

2) The mating method of the key connection, the mating surface of the key and the keyway is the main transmission torque. In the actual operation process, the mating surface of the key and the keyway is most prone to metal fatigue wear, resulting in the operation process between the pulley shaft hole and the shaft Relative movement occurs, which in turn causes the wear of each mating surface in this part.

Fault judgment

1) Observe the swing degree of the pulley during the operation of the equipment;

2) Measure the temperature change of the mating surface of the pulley and the shaft;

3) Observe the overall noise and vibration during the normal operation of the equipment.

• Bearing heating damage

cause

1) During the installation process, the bearing clearance is too small or too large, which may cause heat, ablation, seizure, etc. during the operation of the bearing;

2) During normal operation, the bearing failed to add lubricating oil in time;

3) The service life of the bearing is too long, which leads to fatigue and wear of various parts of the bearing itself, and various index parameters cannot meet the requirements of normal use.

Fault judgment

1) Check the vibration of the pulley and observe the overall vibration and noise of the equipment when the equipment is running normally;

2) Use temperature measuring equipment to check the temperature of the bearing part;

3) Use testing equipment to check the vibration and relative displacement of the bearing part.

• Wear or fall off of the liner

cause

1) During use of the wear-resistant liner, it is normal for the liner to wear due to high-speed impact and erosion;

2) Damage to the fixing bolts of the liner may cause the liner to fall off.

Fault judgment

1) Loose or fall off of the liner will cause abnormal vibration and abnormal noise of the equipment;

2) The particle size increases.

• Increased overall equipment vibration

cause

1) Shaft wear, key editing, bearing damage, keyway damage, belt pulley shaft hole wear, liner looseness or fall off, and anchor bolt looseness will all cause the overall vibration of the equipment to increase. Check according to the specific conditions;

2) The rotor wears unevenly, and the dynamic balance fails.

Fault judgment

The overall vibration of the equipment has increased, and it is necessary to check all parts of the equipment as a whole to determine the source of the vibration.

• Belt tumbling

cause

1) The belt quality is not good;

2) Improper assembly.

Fault judgment

1) Choose a belt with qualified quality;

2) Install according to a reasonable method, and adjust the pulley on the same plane.

Maintenance of the grinder

As the core equipment for ore production, how to reduce the wear of the machine, extend the service life of the equipment, and convert economic benefits more efficiently in the daily use process, the following will share some methods of daily maintenance and maintenance of grinding.

• Check the machine regularly

1) When any grinding equipment is switched on and off, it should be paid attention to regularly shut down the machine and check the internal wear and tear of the machine.

2) During the inspection of the grinder, the machine must be completely stopped before the inspection can be carried out, so as to avoid a series of dangers. When overhauling the machine, be sure to check the wearing parts. The wearing parts must be replaced in time after they reach the maximum degree of wear resistance.

• Regularly check the condition of accessories

1) The conveyor belt is indispensable in the stone production line, and the driving of the machine is the contribution of the conveyor belt. Regularly adjust the tightness of the conveyor belt to ensure uniform force on the conveyor belt.

2) The bearing wears a lot in use. Frequent oiling can increase the service life of the bearing. Add 50-70% of the total amount in the bearing. The usual method is to pull the bearing and eccentric shaft out of the bearing cavity for processing.

• Do a good job of lubricating parts

1) Always pay attention to timely lubrication of the friction surface, which can ensure the normal operation of the machine and prolong the service life.

2) The grease used should be determined according to the conditions of use, temperature and other conditions. The grease added to the bearing seat is 50-70% of its volume, and must be replaced every three months; clean gasoline or kerosene must be used to clean the bearing and the dirt in the bearing seat when changing the oil.

Daily maintenance of grinder

Turn off the power switch, clean the materials scattered around the crusher, and check whether the screws are loose at the docking part of the motor and the reducer.

Lubricate the bearing parts regularly. The bearing parts are easily damaged parts. Only regular oiling can prolong the service life of the bearing.

by ALPA Powder

How to improve the use value of barite?

Barite is an important barium-containing mineral, with high specific gravity (4.3-4.7), low hardness (3-3.5), stable chemical properties, insoluble in water and acid, barite can be used as a white pigment (commonly known as Lith Powder), can also be used in the chemical industry, papermaking, textile fillers and other industrial sectors. In the glass production, it can act as a flux and increase the brightness of the glass, of which 80%-90% is used as a mud weighting agent in oil drilling.

The fineness of barite powder determines its use and value. Take oilfields as an example. Oilfields have strict requirements on the fineness of barite powder, which can neither be too coarse nor too fine. Improper fineness will cause changes in the rheological properties of the heavy mud itself, which will lead to serious Of drilling accidents occurred, so how to effectively control the fineness?

1.   The purpose of barite is to subdivide it according to the different fineness of barite after being crushed by a pulverizer. It is used as a mud weighting agent for drilling, with a fineness of more than 325 mesh. To prepare lithopone pigment, the fineness of barite powder is required to be at least 1250 mesh. Used as paint filler, barite powder requires more than 2000 mesh. The fineness of barite used in textiles is even finer.

2.  Selection of barite grinder

Which mill is used for 325 mesh barite powder, 1250 mesh barite powder and 2000 mesh barite powder?

The hierarchical impact mill can effectively control the fineness and output of barite, and the same equipment can crush different finenesses, and the fineness can be adjusted arbitrarily between 1-75 microns. Its characteristics are as follows:

1) Low energy consumption: It integrates centrifugal grinding, impact grinding, and extrusion grinding, which can save energy by 40-50% compared with other types of mechanical grinding machines.

2) High fineness: Equipped with self-diverting grading system, product fineness ≥2500 mesh.

3) Large feeding range: feeding particle size ≤50mm, the material only needs to pass through the first-level coarse crushing equipment.

4) Low wear: The crushing parts are made of new composite wear-resistant materials, with long service life, and no pollution when processing materials with Mohs hardness ≤5.

5) Strong mechanical stability: it can produce without stopping for 24 hours for a long time.

6) Full functions:

• It can grind needle-shaped materials to achieve the aspect ratio of the finished product to 15:1;
• There is no temperature rise during the grinding process, which is suitable for the grinding of heat-sensitive materials;
• The sintered agglomerated ultra-fine materials can be broken up, and the particle size recovery rate can reach 100%;
• With particle shaping function, it can effectively increase the bulk density.
• Materials that can grind fibrous tissue;
• It can grind materials with high moisture content and has a drying function;
•  

  It can grind strong viscous materials.

7) Negative pressure production, no dust pollution, excellent environment.

8) High degree of automation, strong stability and easy operation.

9) The entire system adopts automatic control, which can realize one-button start and stop, and the operation is simple and convenient. The connection with the central control can realize remote control.

Scope of application:

1.  Typical materials of non-metallic minerals include: hard kaolin, talc, graphite, calcite, gypsum, diatomaceous earth, wollastonite, barite, pyrophyllite, aluminum hydroxide and other materials ultrafine grinding and nano calcium carbonate, oxidation Superfine grinding and breaking up of cerium and other materials.

2.  Typical heat-sensitive materials include: lactose, wax, resin, fat, bone meal, plants, etc.

3.  The typical materials for ultra-fine processing of Chinese herbal medicines and raw materials are: pollen, hawthorn, shiitake mushrooms, pearl powder, stomach medicine, nimodipine, antibiotics, Ganoderma lucidum, gallnut, fleece-flower root, andrographis, mint, houttuynia, fern root, Pueraria lobata, Radix isatidis, etc.

by ALPA Powder