Dry powder briquetting machines are generally used for the compression molding of dry powdery materials, and most other types of briquetting machines generally require the addition of binders, additives, etc. for the assistance of pressing into balls. However, the dry powder briquetting machine can be directly pressed without additives and adhesives. It can not only be cold-pressed without adhesives, but also can be hot-pressed according to the requirements of the performance and purpose of the finished ball. Speaking of raw materials, must the dry powder not contain any moisture? Let’s talk about what kind of materials are not suitable for dry powder briquetting machine?

The answer is actually very simple. Since it is a dry powder briquetting machine, we can tell from the name of the briquetting machine. At this time, it is distinguished according to the material being pressed. Since it is a dry powder, if the user’s material contains moisture, it is recommended that you do not choose a dry powder briquetting machine. You should choose the most suitable briquetting machine according to the specific conditions of the material. And some of the special requirements for the refined oil of the press ball must be pressed with a dry powder briquetting machine.

Testing-briquette-machine

Dry powder briquetting machine molding technology characteristics can be molded without adhesives

The technical feature of dry powder briquetting machine molding is that it can be molded without adhesives. Generally speaking, the briquetting machine requires the use of adhesives to complete the entire compaction of the material, but the dry powder briquetting machine is not the case. The characteristic of his molding technology is that no adhesive is used in the reproduction process. , Only relying on strong molding pressure can achieve batch molding of materials.

The binder-free molding method is widely used in the processing of dry powder. Although there is no external binder, it still uses the cohesive component of the dry powder itself to complete the molding work. In addition, some dry powder factories use hot pressing to make the dry powder produce a certain degree of plasticity, and then press it into a dry powder briquetting machine, a powerful briquetting machine and other equipment, and the rollers are rotated at a constant speed to compress the material. The pressure changes from small to large, and the molding pressure reaches the maximum at the center of the pair of rollers. After the material passes the line, the molding pressure decreases rapidly, and finally the material enters the ball-off state.

Metal-briquette-machine

We mentioned above that the forming feature of the dry powder briquetting machine is that it can be pressed without additives and binders. In addition to using the adhesive properties contained in the dry powder raw material itself, more importantly, the dry powder briquetting machine has a strong pressure, through which the pressing can be completed more easily.

In summary, the technical characteristics of the dry powder briquetting machine that can be directly pressed without using adhesives are also closely related to the strong pressure of the dry powder briquetting machine itself. Moreover, some of the more special raw materials will have some chemical reactions after adding binders or additives, which will affect the properties of the powder and the characteristics of the finished product, so a dry powder briquetting machine is required to complete the pressing work.

With the development of industrial mechanization technology, briquette briquetting machines have also entered a white-hot state, and various types of briquette briquetting machines have caused hot sales in the market. The reason why briquette briquetting machine is recognized by many users is because of its performance and the economic benefits it creates. In the production process of the briquette machine, it is necessary to control the particle size, moisture, adhesive, etc., to have a good mixture of materials, and install the proportion to add auxiliary materials, so that the briquette briquette can be efficiently and safely produced. As for the issue of output, comprehensive consideration should be made. It is not the briquette briquetting machine that has a large output. It depends on the performance of the briquette briquetting machine and ensuring efficient and trouble-free operation. These factors are all briquette briquetting. The key factor for the high output of the machine.

Especially for the briquette production line, the correct selection of various supporting equipment is also the key. For example, the selection of supporting equipment such as vertical crushers, vertical dryers, and double-shaft mixers should also be based on the entire briquette production line. . In addition, the correct installation method and skilled operation equipment are the key to the output of briquette briquetting machine. Generally speaking, there are many factors that affect the high-efficiency production of ball presses. Users should not just screen out the model, but find out the reasons and eliminate them one by one, so that more benefits can be obtained. The briquetting machine manufacturers have summarized the following factors that will have an important impact on the pulverized coal forming process. Let’s take a closer look.

1. The forming characteristics of coal

The forming characteristics of coal is the most critical internal factor affecting the forming process of pulverized coal, especially the influence of the elasticity and plasticity of coal is more prominent. The higher the plasticity of the coal, the better the forming characteristics of its pulverized coal.

Young coals such as peat and lignite are rich in asphaltenes and humic acid substances with high plasticity, so they have good formability and ideal forming effects, and they can even be formed without binders. As the degree of coalification increases, the plasticity of coal decreases rapidly, and its forming properties gradually deteriorate. For coal with a high degree of coalification, it is generally necessary to add a binder to increase the plasticity of the coal before it can be formed.

briquette

2. Forming pressure

When the forming force is less than the crushing force, the mechanical strength of the briquette increases with the increase of the forming pressure. Different coal types have different crushing power. The forming pressure is closely related to factors such as coal type, material moisture and particle size composition, and binder type and quantity.

3. Material moisture

The main functions of the moisture in the material in the molding process are:

The presence of an appropriate amount of water can act as a lubricant, reduce the internal friction of the molding system, and improve the mechanical strength of the briquette. If there is too much water, the water layer on the surface of the particles will become thicker, which will affect the sufficient density of the particles, and will reduce the mechanical strength of the briquette. In addition, excessive moisture will easily cause cracks when the briquette is dried, which makes the briquette easy to break;

If a hydrophilic binder is used to make the brew, an appropriate amount of water will pre-wet the surface of the particles, which will help the particles to bond to each other. If the water is too much, the effect of the binder will be worse. The more suitable molding moisture is generally 10%~15%;

If the hydrophobic binder is used for molding, the moisture will reduce the effect of the binder, so the moisture of the material is generally controlled below 4% at this time.

In short, material moisture should be flexibly controlled according to the actual situation and controlled within a range.

fine ore after crushing

4. Material particle size and particle size composition

When determining the particle size and composition of the material, the following principles should be followed:

(1) Ensure that the arrangement of the material particles and shaped blocks is the closest to improve the mechanical strength of the coal. Practice has proved that smaller material particle size is conducive to the close arrangement of particles;

(2) When the binder molding process is adopted, the total gap between particles is minimized, so as to reduce the amount of binder and reduce the cost of briquette.

5. Dosage of bonding agent

Since most coal types have poor molding properties, the molding process using binders is more common. At this time, the amount of binder is not only a key influencing factor of briquette strength, but also has a very important impact on the production cost of briquette.

From the perspective of binder consolidation, increasing the amount of binder is beneficial to increase the strength of the briquette; from the perspective of the palladium formation process, increasing the amount of binder is not conducive to increasing the molding pressure and the strength of the briquette: In terms of mold stability, increasing the amount of binder is also not conducive to improving the strength of briquette. Therefore, it is generally necessary to determine a binder amount through experiments.

The main mixing objects of horizontal strong continuous mixer are: the mixing of a variety of solid materials and powders, and the high-precision mixing of these materials after adding a binder. It is widely used in metallurgy, building materials, refractory materials, ceramics, glass, plastics, compound fertilizers and other solids. At the same time, the horizontal strong continuous mixer is also particularly suitable for mixing viscous materials. However, the purpose of high-precision mixing is inseparable from its structure. .

Advantages of horizontal strong continuous mixer:

The horizontal strong continuous mixer consists of a frame, a barrel, a mixing tool, a rake tooth, a composite rubber lining, a transmission system and a control system. The transmission system is composed of a hydraulic coupling, a V-belt, a torque sensor, an explosion-proof motor, and a hydraulic Motor and other components.

The single-axis multi-cavity design is adopted, and the teeth are arranged in different geometric shapes. The materials are put into the front and rear movable curtains of the horizontal strong continuous mixer body to achieve cross and mixing between the materials. This horizontal strong continuous mixer is particularly suitable for mixing powder and powder, as well as mixing and mixing between powder and a small amount of liquid (binder), or mixing between materials with a large specific gravity.

Horizontal Strong Continuous Mixer

Structure principle:

The U-shaped long cylinder structure of the horizontal strong continuous mixer ensures that the mixture in the cylinder moves with less resistance. The positive and negative screws of the horizontal strong continuous mixer are installed on the same horizontal axis, resulting in low power and high efficiency. In a stirred environment, the horizontal strong continuous mixer usually consists of two or three layers. The outer spiral collects material from both sides to the center. The inner spiral transports the material from the center to the side, so that the material forms more eddy currents in the flow, thereby accelerating the mixing speed of the horizontal strong continuous mixer and improving the mixing uniformity.

When working, through the mixing tools arranged in the middle of the equipment, and 13 or 26 mixing rakes in different directions on the mixing tools, the materials entering the mixing equipment will be sprayed, sheared, scattered, and scattered strongly in the form of convection. Exchange, etc., so that the materials are fully blended in the barrel of the mixer and move to the discharge end of the mixing equipment. In this way of mixing, the materials to be mixed are not easy to agglomerate and agglomerate in the mixing equipment.

In the process of mechanical mixing and mixing of materials, there are mainly the following five methods:

(1) Shearing and mixing form shearing surfaces in the materials, so that the materials will be mixed.

(2) Convective mixing of many agglomerated material particles move from one part of the mixer to another for relative flow.

(3) Diffusion of the particles of the mixed mixture, moving around with a single particle as a unit, similar to the molecular diffusion process in gas and liquid. It is irregular movement, especially when the particulate material (dust) is vibrated or fluidized, the diffusion effect is extremely obvious.

Double-Shaft Mixer

(4) The impact mixing causes the individual material particles to disperse under the impact of the material and the wall shell.

(5) Deformation and crushing of particles of the crushed mixture.

Five mixing methods exist simultaneously in each mixing process, but the first three play a major role. Taking batch mixer as an example, the mixing process can be divided into three stages.

First, the particles in agglomerates from one part of the material in a layered form to penetrate and slip to another part, and convective mixing occurs.

Secondly, the particles of different ingredients gradually disperse across the newly formed interface and diffuse and mix.

Finally, under the action of its own weight and centrifugal force, particles of similar shape, size and density will gather in different parts of the mixer, which is called particle aggregation.

The first two effects are helpful for mixing, and the latter is a separation effect that hinders the uniform distribution of particles. These three stages happen at the same time in the mixer, but in different mixing time, the effect is different.

This video shows the operating status of the briquetting machine used on site one year after Russian users purchased our briquetting machine.

Work site of Mongolia briquetting machineWork site of Mongolia briquetting machine

Recently, our company’s briquetting machine has been exported to Mongolia, and users with deep product quality have been acclaimed. The picture above shows the working site of the Mongolian briquetting machine.

Advantages of Zhongyuan Briquetting Machine

1. Chinese first high-pressure briquetting machine (GY750-300) was successfully manufactured in 1989.

2.Fully product range with roller diameter of 520-1200mm could be provided.

3.High line specific pressure of 11T/CM is forced to design on pre-pressing. .

4.The material has a good extrusion effect with high pelletizing ratio and high density briquettes.

5.Super wear-resistant roller surface is made by special bearing steel.This kind of roller surface has a good using effect and long working life.

6.Adopting dua l-output shaft reducer structure to improve the accuracy of the double rollers.

7. Completely-sealed gearbox is used with low noise and without oil leakage.

8. Fully using ball groove alignment structure of high-pressure briquetting machine for more convenient adjustment.

9. Adopting hard-tooth-surface gears to greatly improve using performance and life.

10.Adjustable-speed motor is used for preforming press.All wear parts are overlaid with wear-resistant alloy to improve service life.

11.The stand-alone hydraulic station can adjust pressure and have the special function of overpressure protection.

12.Finished briquettes forming lab is ready for customers to provide professional testing with specific datas.

The common crushing process in the crushing operation is the three-stage closed-circuit crusher process of coarse, medium and fine crushing plus screening operations, but there are also two-stage open-circuit or closed-circuit crushing processes. At present, the widely used crusher equipment is still two major types of equipment: coarse crushing and fine crushing.

The first stage in the crushing process is coarse crushing, which generally uses jaw crushers or gyratory crushers; the second stage, fine crushing, mostly uses cone crushers and reverse impact crusher.

Let’s talk about the difference between cone crusher and impact crusher in fine crushing operation.

The obvious difference between counter-breaking and cone crushing is the different crushing principle and appearance structure, which is easy to distinguish. The impact crushing principle is used for impact crushing. The material is repeatedly impacted and crushed between the plate hammer and the impact plate. The cone crusher uses laminated crushing. The rolling mortar wall continuously moves to the crushing wall, squeezing the material sandwiched between the two to make It’s shattered.

In addition, there are many differences between the two in actual production, as follows:

Impact Crusher

1. Different scope of application

Both impact crusher and cone crusher can act as secondary crushing equipment, but the hardness of the materials crushed by the two is different. Generally speaking, cone crushers mainly crush materials with higher hardness, such as granite, basalt, river pebble, etc., while impact crushers are used to crush materials with lower hardness, such as limestone, limestone, etc. In short, the impact crusher is suitable for crushing medium-hardness and lower toughness and brittle materials, and the cone crusher is suitable for crushing hard materials.

2. Different discharge sizes

The discharging granularity of the materials crushed by the two types of crushers is different. Generally speaking, cone crusher crushes finer materials than impact crusher. In actual production, more cone crushers are used in ore dressing, and more impact crushers are used in building materials and construction projects.

3. Different processing capacity

Compared with the impact crusher, the cone crusher has the characteristics of low energy consumption, heavy output and stable production. Therefore, the cone crusher is often used in large-scale and high-yield production lines.

4. Different input costs

The price of the cone crusher is more expensive than the impact crusher, but its wearing parts have a longer life, avoiding the trouble of frequent replacement of parts. The initial purchase cost of the impact crusher is low, and the later maintenance cost is higher; the cone crusher The early stage cost is high, and the later stage input cost is lower. From a long-term perspective, cone crushers are more cost-effective than counterattack crushers.

5. Different pollution levels

The impact crusher has large noise pollution and dust pollution; while the cone crusher has less pollution.

To sum up, it is a detailed introduction about the difference between impact crusher and cone crusher. Because the materials crushed by the two are different, there is also a big difference in use. It is recommended that you choose the appropriate crusher according to the crushed material.

Activated carbon is a kind of carbon with multiple pores. It has a very rich pore structure and good adsorption characteristics. Its adsorption is formed by physical and chemical absorption, and its appearance is colored. In addition to the main carbon, its composition also contains a small amount of hydrogen, nitrogen, and oxygen. Its structure looks like a hexagon. Due to the irregular hexagonal structure, it is determined that it is mostly body and high surface area. Characteristic, every gram of activated carbon has a specific surface equivalent to 1000 square meters.

Activated carbon is mainly made of materials with higher carbon content, such as wood, coal, fruit shell bones, and petroleum residues. With coconut shell as the most commonly used raw material, under the same conditions, the active quality and special characteristics of coconut shell activity are the best, because it has the largest specific surface area.

Activated carbon can be divided into physical steam method and chemical method according to the production method. Here, we will focus on the production of physical steam method. Generally, production is divided into two processes.

briquette

In the first step, carbonization, the raw materials are dried at a temperature of 170 to 600, and 80% of the organic tissue is carbonized in the same amount.

The second step is activation. The carbonized material that has been carbonized in the first step is fed into the reaction furnace to react with the activator and steam to complete the activation process and make a finished product. In the process of endothermic reaction, CO and H2 combined gas are mainly generated, which is used to heat the carbonized material to an appropriate temperature (800 to 1000 degrees), remove all its decomposable substances, and produce a rich pore structure and a huge specific surface area. The activated carbon has a strong adsorption capacity.

Activated carbon produced from different raw materials has different pore diameters. Among them, the pore diameter of coconut shell is the smallest, the pore diameter of wood activated carbon is generally larger, and the pore diameter of coal-based activated carbon is between the two.

The pore size of activated carbon is generally divided into three categories:

Large hole: 1000-1000000A

Transition hole: 20-1000A

Micropore: 20A

According to the above characteristics, it can be seen that for different adsorption objects, the corresponding activated carbon needs to be selected to achieve the best cost performance. Therefore, in liquid phase adsorption, activated carbon with more transition pores and larger average pores should be used.

Charcoal and briquettes, although both are activated carbon, both have great effects and are suitable for different professional fields. But their functions are different. Let me introduce them below.

Charcoal is an activated carbon product made from residues such as sawdust and nut shells. Briquettes are activated carbon products made from coal. Due to the different raw materials, there are differences in the production process, technical characteristics, and product characteristics of wooden activated carbon and briquettes, which affect the application fields relatively differently.

briquettes

1. In the field of liquid phase adsorption

Coal contains heavy metals and ash, and the purity of the product is low. Since the pores are mainly produced by physical methods, the pores are mainly micropores, which are suitable for small molecule adsorption and have a relatively narrow application range. Generally used in industrial fields, such as petrochemical, metallurgy, printing and dyeing, and liquid phase adsorption in sewage treatment; charcoal has low ash content, few impurities, and is easy to purify. Its pore distribution structure is easy to adjust, and the micropores and mesopores are developed and widely used, especially in fields that require higher adsorption performance and higher product safety requirements, such as food and beverage, medicine, and coal cannot be replaced.

2. In the field of gas phase adsorption

Coal has high strength and is easy to recycle, and is often used for gas phase adsorption; charcoal has low strength and is not traditionally used for gas phase adsorption. However, with the advancement of technology and production, with the advancement of technology, the application of charcoal has also been extended to some emerging gas phase adsorption fields, such as oil and gas recovery, household air purification, etc., and with the development of people. Pay more attention to health and environmental protection, and their application space in the field of gas adsorption will be further developed.

3. From the perspective of long-term trends

During the production process, raw coal resources are not renewable, coal-based activated carbon resources are limited, and carbon dioxide emissions increase. Therefore, product prices are driven by raw materials and environmental protection costs. The main reason for charcoal is that the “three residues” of forest products are renewable, and due to technological advances, the price is expected to decrease relatively. Therefore, the long-term competitive advantage of wood activated carbon is higher than that of briquettes.

Wood activated carbon and briquettes are different in many aspects such as production process, technical characteristics, and product characteristics. From an industrial perspective, the two belong to different industrial fields. The former belongs to the forestry chemical industry and the latter belongs to the coal chemical industry. At the same time, due to the different downstream application fields of briquettes and charcoal, the downstream customers of charcoal and briquettes are also different. The downstream users of wood activated carbon are mainly concentrated in food, beverage, medicine and other fields, and the manufacturers’ customers are mainly concentrated in the chemical, printing and dyeing, sewage treatment and other industrial fields. Competition between wood activated carbon and briquettes manufacturers.

The briquetting machine is composed of a pressing shaft assembly, a frame, a pre-press, a hydraulic system, a coupling, a reducer, and a motor. According to the function of each part, it can be divided into three parts: feeding, transmission, and forming. Each of the different parts has a vital influence on the forming of the briquetting machine. Zhongyuan Mine is a high-pressure briquetting machine, The manufacturer of ultra-high pressure briquetting machine has many years of experience in the structural design of briquetting machine, and will explain in detail the composition of these three parts and the operating principle of the briquetting machine.

Composition of briquetting machine

1. The feeding part is mainly to realize quantitative feeding to ensure that the material evenly enters the roller room. The screw feeding device is driven by a speed-regulating motor, and is rotated by a belt pulley and a worm reducer to force the pressed material into the main feed inlet. Due to the constant moment of the speed-regulating motor, when the pressure amount of the screw feeder is equal to the amount of material required by the host, a constant feeding pressure can be maintained to stabilize the pellet quality. If the feeding amount is too large, the electric power of the feeding device will be overloaded; if the feeding amount is too small, the ball will not be formed. Therefore, skilled operation techniques are an important condition to ensure the normal work of the pressure ball.

High pressure briquetting machine

2. In the transmission part, the main transmission system is: motor-coupling-synchronous reducer-roller. The main engine is powered by a speed-regulating motor, which is transmitted to two pressure rollers via a synchronous reducer. A hydraulic device is installed behind the movable bearing seat. The hydraulic protection device uses a hydraulic pump to drive high-pressure oil into the hydraulic cylinder, causing the piston to produce axial displacement. The front joint of the piston rod rests on the bearing seat to meet the production pressure requirements.

3. The forming part mainly refers to the main machine part, and the core part is the pressing roller. When there is too much feed between the two pressure rollers or metal blocks, the piston rod of the hydraulic cylinder is overloaded, the hydraulic pump will stop, the accumulator will buffer the pressure change, the overflow valve will open to return oil, and the piston rod will shift Enlarge the gap between the pressure rollers so that the hard objects can pass through the pressure roller, and the system pressure will return to normal, which can protect the pressure roller from damage. This machine can adjust the pressure according to the requirements of the pressure ball density, and the production is flexible and flexible.

Working principle of briquetting machine

In order to make the material into a ball under high pressure, a pre-compression screw is used to force the material to be formed into the middle of the counter roller. Due to the constant speed and reverse rotation, the material is compressed and formed. The unit pressure is from small to large until the centerline of the counter roller is “0-0”. At this point, the molding unit pressure reaches the maximum value. As the counter roller continues to rotate, the molding pressure continues to decrease, and it enters the ball-off state until the ball is off.

Among them, the main engine is powered by an electromagnetic speed regulating motor, which is transmitted to the driving shaft through a rod-pin coupling through a belt pulley, a cylindrical gear reducer. The driving shaft and the driven shaft are ensured to run synchronously through open gears. A hydraulic device is installed behind the passive bearing seat. The screw feeding device is driven by an electromagnetic speed-regulating motor, and is rotated by a belt pulley and a worm reducer to force the pressed material into the main feed inlet.

Medium-Pressure-Briquette-Machine

Due to the constant torque characteristic of the electromagnetic speed-regulating motor, when the pressure of the screw feeder is equal to the amount of material required by the host, a constant supply pressure can be maintained to stabilize the pellet quality. If the feeding amount is too large, the feeding device will be overloaded; if the feeding amount is too small, the ball will not be formed. Therefore, skilled operation techniques are an important condition to ensure the normal operation of the energy-saving briquetting machine.

The hydraulic protection device uses a hydraulic pump to drive high-pressure oil into the hydraulic cylinder, causing the piston to produce axial displacement. The front joint of the piston rod rests on the bearing seat to meet the production pressure requirements. When there is too much feed between the two pressure rollers or metal blocks, the piston rod of the hydraulic cylinder is overloaded, the hydraulic pump will stop, the accumulator will buffer the pressure change, the overflow valve will open to return oil, and the piston rod will shift Enlarge the gap between the pressure rollers so that the hard objects can pass through the pressure roller, and the system pressure will return to normal, which can protect the pressure roller from damage. Kaizheng environmental protection machine can adjust the pressure according to the requirements of the pressure ball density, and the production is flexible and flexible.

Analysis of working principle of briquetting machine

It can be seen from the working principle that the quality of the pressed ball blank is directly related to the spiral shape, speed, pre-pressure, etc., when the host-to-roller speed is fixed, so the pre-compression screw speed must be adjustable, and at the same time, it is related to the nature of the powder. The particle size and pelletizing process (dry and wet method) have a greater impact. Generally speaking, wet molding is easy. For dry molding, due to the large compression ratio of raw materials, it takes many times to press molding. Therefore, when dry molding is used, new The pressing process of feeding and returning the material can continuously and stably produce and ensure the quality of pellets.

Testing-briquette-machine

How does the briquetting machine work

1. The material enters the forming machine hopper evenly from the storage bin through the quantitative equipment, and is adjusted by the adjusting gate on the hopper to make the material evenly enter the middle of the roller.

2. The unit molding pressure of the material that is compressed by the rollers with the constant speed and reverse rotation is changed from small to large, and the molding pressure reaches a large value at the center line of the pair of rollers. After the material passes the line, the molding pressure decreases rapidly so that the material enters The state of the ball.

The above is all about the working principle of the briquetting machine. Only by understanding its working principle in detail can the briquetting machine be operated more efficiently and safely.

Briquette is made of pulverized coal as the main raw material, and is molded by mechanical processing according to the proportion, mechanical strength, and shape required by the specific application. The coal products with a certain strength, size and shape, common coal products include Briquettes, briquettes, coal sticks, briquettes, etc.

As a kind of clean coal production technology, briquette production has the advantages of simple operation, mature technology, low cost, obvious energy saving and efficiency, and reduced exhaust gas emissions. The production process is divided into binder-free molding, binder molding, and thermal Three kinds of compression molding. There are many types of forming machines, such as stamping forming machines, roll forming machines, screw extruders and honeycomb coal machines.

There are many types of briquette. The briquette can be pulverized coal, coal noodles, coal slime, respectively pressed into spherical or other shapes. It is also possible to mix pulverized coal and slime into spherical and other shapes. Used for boiler combustion and gas production.

Application of briquette

The powdered coal or pulverized coal is press-formed by a mechanical method, and the coal product has a certain shape or particle size. Common ones are briquettes, briquettes and briquettes. Briquette can improve combustion efficiency, reduce environmental pollution, expand the application range of lean coal, gas coal, long flame coal and lignite and other high volatile and weak caking coal, and rationally utilize coal resources.

There are two types of briquette for industrial use and civil use. Industrial briquette includes chemical briquette, which is used for chemical fertilizer production, steam locomotive briquette, and metallurgical briquette (also called briquette). Civil briquette, also known as domestic coal, is used for cooking and heating, mainly briquettes.

Chromium ore powder

Industrial briquette

①The briquette used in chemical industry is generally 35-50mm briquettes, which can be formed with anthracite less than 3mm or powdered lignite with a tar yield greater than 10%. It is mainly used for producing gas from chemical fertilizers, producing semi-coke, liquid or gas fuel and producing chemical products such as methanol and acetic acid.

②The briquette used as fuel for steam locomotives has several shapes such as oval shape and drip shape. The coal for locomotives developed in China can save coal by more than 8%. The development of power briquette needs to solve the key technical issues such as using temperature control to master thermal deformation characteristics during the combustion process, using batching technology to improve coal quality, and increasing the ash melting point of briquette. For example, for coal with high sulfur content, catalytic reverse equilibrium should be used to increase the sulfur conversion rate to reduce pollution.

③Formed coke is formed by forming weakly cohesive pulverized coal and coking in a continuous coking oven, or using high-speed thermal analysis to extract colloids to achieve hot pressing into coke. The development of coke can expand coking raw materials and improve the efficiency of coke ovens. China uses low-pressure binder molding to produce industrial briquette. The binder is mostly lime, petroleum pitch, tar pitch or paper pulp waste liquid. The amount depends on the agglomeration of coal, generally 5-10%.

Civil briquette

In addition to ordinary briquettes and briquettes, in recent years, the development of combustible briquettes for heating and upper-ignition briquettes for household cooking has begun. The structure and raw material formula of this briquette are more complicated. Generally consists of three parts: ignition layer, ignition layer and coal body. The ingredients of each layer are different in formula.

①The ignition layer is mostly mixed with oxidizer or paraffin wax, carbon, semi-coke powder and other combustible substances mixed with binder.

②The ignition point of the transition layer is slightly higher than that of the ignition layer, which can ignite fire. Therefore, the raw material coal is required to have a large calorific value of 6000kcal/kg and a suitable particle size.

③The coal body can adopt anthracite, bituminous coal, lignite, peat or flotation tailings according to local conditions. When the briquette made of bituminous coal burns, the volatile matter and the free carbon produced by pyrolysis are not fully burned and fumes. Therefore, the volatile matter of the ingredients must be controlled within the range of 20-25%, and an appropriate amount of coke and coke must be added. lime. Make the inside of the coal body have a good microporous structure, creating conditions for the uniform precipitation of combustible gas; it is also necessary to improve the stove to ensure sufficient oxygen supply to achieve complete combustion and smoke suppression. The briquettes with anthracite as the main body should be appropriately added with high volatile bituminous coal to enhance the flame temperature, height and ignition speed. If the ingredients are appropriate, the gas after the ignition of the briquettes can generally meet the environmental protection requirements, but the cost is slightly higher.

Advantages of briquette

lime

(1) Improve combustion efficiency and reduce energy waste

As the main body of civil briquette, briquette is equipped with advanced stoves, and its thermal efficiency is twice as high as that of burnt coal. Among various clean coal technologies, industrial coal has the highest energy conversion rate, reaching 97.5%, which is far greater than other technologies. Boiler briquette products have a large particle size, which can ensure the required gaps during combustion, and the combustion efficiency is high. At the same time, the amount of exposed coal is small. Compared with burning raw coal, it saves 15% to 20% of coal.

(2) Reduce environmental pollution

Boiler burning coal can greatly reduce air pollution. Compared with burning raw coal, SO2 emissions are reduced by about 40% to 60%, NO2 emissions are reduced by about 40%, soot emissions are reduced by about 60%, and strong carcinogens (Bap) are reduced by more than 50%, which has obvious environmental protection effects. The addition of sulfur-fixing agents and binders during the processing of briquette can reduce SO2 emissions by 40% to 50%, and at the same time can reduce solid dust emissions. In addition, briquette can use industrial waste and agricultural waste as a binder, turning waste into treasure, reducing the emissions of the three wastes.

(3) Change the performance defects of a single coal type

In the process of briquette processing and manufacturing, through the use of additives, coals with different properties are combined and blended to obtain indicators such as cohesiveness index, ignition point, ash content, ash melting point, sulfur content, fixed carbon, volatile content, and calorific value The improvement has increased the reactivity, flammability and thermal stability of coal, increased the ash melting point, and produced high-quality products with various indicators meeting customer requirements. For example, through coal blending, non-coking coal can be made into molded coke as a substitute for metallurgical coke; bituminous coal can be made into anthracite briquette to replace gas-making anthracite lump coal, thereby expanding the utilization of coal.

(4) Reduce demand for lump coal

A considerable part of China’s industrial boilers and kilns are layer-fired and require lump coal; the production of synthetic gas and fuel gas in China’s chemical fertilizer industry requires lump coal. The development of industrial briquette can alleviate the shortage of lump coal in short supply, and at the same time open up a technical way for the rational and effective use of fine coal.

Problems existing in burning industrial briquette in existing industrial boilers:

1. It is difficult to ignite the flame.

2. Stop the furnace to extinguish the fire.

3. The furnace temperature is low, the briquette burning time is long, the burning is not clean, and the carbon content in the ash is high.

Metallurgical industry materials

Industrial briquette needs requirements:

1. It has sufficient cold mechanical strength;

2. Have sufficient thermal stability;

3. It has strong moisture resistance and waterproof performance;

4. It has strong frost resistance;

5. With natural fast curing performance;

6. Save energy;

7. Reduce environmental pollution;

8. Low cost and high quality.

When evaluating the quality of industrial briquette, in addition to industrial analysis and element analysis of briquette, the following characteristic indicators should be considered:

1. Mechanical strength: including cold (hot) mechanical strength, drop strength, drum strength, etc. At present, there is no unified national quality standard for industrial coal, only the national quality standard for gasification and boiler coal. In the early 1980s, the main assessment indicators for “industrial coal development” were: cold compressive strength 350~500N/ball, drop strength greater than 75%, and drum strength greater than 70%. In addition, the mechanical strength requirements recognized by most domestic coal briquette experts for gasification briquette are: cold compressive strength greater than 400/N ball, thermal compressive strength greater than 200N/ball, thermal stability greater than 75%, and drop strength greater than 80% , The quality requirements for fuel briquette such as boilers can also be relaxed.

2. Ash melting property: the ash melting property ST of coal briquette for gasification is greater than 1250℃.

3. Sulfur fixation performance: the sulfur fixation rate of industrial coal with added sulfur fixation agent should be greater than 45%.

4. Water resistance: evaluate the performance of briquette after being immersed in water.

In addition to industrial analysis and element analysis, civil briquette also includes:

1. Calorific value: It should be greater than 16.6~20.8MJ/kg, which varies in different regions.

2. Compressive strength of honeycomb coal end face: Ф102mm, greater than 600N/block; Ф127mm, greater than 700N/block.

3. Thermal stability: no furnace collapse, no plugging, no slagging, no bursting during combustion.

4. Heating speed: more than 1℃/min.

5. Firepower: greater than 15/min.

6. Thermal efficiency: greater than 40%.

7. Ash melting: greater than 1100℃.

In the production and processing of most powdery or granular materials, in order to transport and use them more efficiently, it is necessary to use briquetting equipment to press these materials into pellets, but some materials are special because of their special characteristics. The physical characteristics and production process of the product can not be pressed into a shape at one time, so it is necessary to choose the second briquetting process of the briquetting machine to compress the material.

First, equipment required for briquetting

High pressure briquetting machine

Under normal circumstances, when the material cannot be added with any binder and requires a large ball-forming pressure, either high-pressure and ultra-high pressure briquetting machines (such as the high-pressure briquetting machine produced by Zhongyuan Mining Machinery) are used for material compression, or Change the material briquetting process, that is, cooperate with other equipment for secondary briquetting, so in addition to the briquetting machine, the equipment required for the secondary briquetting is as follows:

1. Belt conveyor: the conveying equipment that transports the material powder to the bucket elevator. Through a reasonable site layout, it can simultaneously carry the material after the initial briquetting of the briquetting machine and send it to the bucket elevator at the same time machine.

2. Bucket elevator: convey the material conveyed by the belt conveyor to the conveyor of the grinding and crushing system.

3. Material screening machine: Different granular materials are distinguished through the screen and sent to the grinding and crushing equipment or the supply bin.

4. Distributing chute: the qualified and unqualified balls are distinguished by vibration through the second compression.

5. Grinding and crushing equipment: It can crush and grind large particles and materials that cannot be formed at one time.

6. Screw conveyor: feed the materials from the supply bin to the briquetting machine after proportioning and metering.

Two, briquetting process

Mineral powder ball machine

1. Firstly, the ground material in the supply bin is sent to the briquetting machine through the screw conveyor for the first briquetting, and the material after the first pressing is sent to the sieving machine through the elevator for vibrating screening;

2. The screened material is sent to the grinding and crushing equipment for processing and then discharged into the intermediate bin as the aggregate for the secondary briquetting;

3. The screened material enters the fine powder silo, and then the fine powder and the aggregate in the intermediate silo are sent to the briquetting machine through a screw conveyor to perform secondary briquetting according to a certain ratio;

4. After the secondary compaction, the pellets will enter the distribution chute through the elevator. Under normal circumstances, the pellets will be vibrated and screened by the distribution chute. The finished pellets will go directly to the next processing stage, and the non-finished pellets will be sent to crush again The machine is crushed and then ground, and then returned to the supply bin of the briquetting machine, as the ratio of aggregate and fine powder for secondary briquetting.

Three, precautions for briquetting

1. In order to ensure sufficient material supply to the briquetting machine, in the case of a large amount of material being fed by the feeder, an overflow material outlet should be set at the screw feeding device, and the overflow material should be returned to the briquetting machine supply bin through a lifter.

2. The distribution chute should also be equipped with an overflow. When the distribution chute is full, the ball will flow out from the overflow to the vibrating screening machine, and the sieved material will enter the green ball circulation bin for storage. When the system fails, the balls in the green ball circulation bin are lifted by the elevator to the distribution chute and circulate again.

3. Before proceeding with formal processing, pay attention to adjust the ball-forming pressure of each briquetting machine and the symmetry of the press roller to avoid secondary briquetting and mold sticking caused by equipment problems.

4. Pay attention to the feeding route of each conveying equipment and screening equipment, and avoid the mixed storage of primary processing and reprocessing materials in the site design and process, so as to ensure that the material ratio of the secondary briquetting is more accurate.

The above content is a detailed introduction to the briquetting process. Basically, for materials that cannot be formed at one time, the ratio of fine powder and aggregate is used for secondary briquetting, which can greatly increase the spheroidization rate and the volume of the pellets. Density to ensure the quality of the ball.