The principle of Grate Dischargegrinding is nearly universally adapted in the cement grinding industry. Grate Discharge Ball Mills are the rule rather than the exception. Rod Mills for raw and finish grinding begin to enter the picture. Larger and larger diameter mills become common. Lengths tend to shorten. Cementgrinding using Grate Discharge principles developed in the ore milling industry applied to the cement industry. This experience plus the years of manufacturing know how unquestionably qualify Grate Discharge grindingfor the Cement Industry.
This phase of grinding may be either the wet or dry process, the end product going to a kiln. Material ground consists of limestone, cement rock, marl or marine shells along with secondary materials usually shale or clay. A typical raw mix consists of 75-85% limestone, 12-25% shale, the balance consisting of silica or quartzite and iron oxide. Exact proportioning is dependent upon their chemical properties before and after calcining to cement clinker. For good kiln practice the grind required is 88-92% 200 mesh for standard cement, 99%-200 mesh for high early. Uniform kiln feed size helps reduce tendency to form kiln rings.
Wet grinding is generally more efficient and permits a balanced feed direct to the grinding mill since a thorough mixing takes place during comminution. Since dust is not prevalent this hazard is eliminated and a cleaner plant results. More efficient classification is possible although due to high dilutions thickeners are required to provide about 65% solids for kiln feed. Where low cost fuel is available, the extra heat required during calcining, to drive off water, is actually less costly than resorting to less efficient dry grinding.
Improvements in air separators and more efficient dust collecting systems have minimised some of these problems to a point where present day costs become closely parallel. Only close economic study can determine which process should be used.
Clinker, the discharge product from the kiln, is partially cooled and broken or crushed to about 1 as feed to finish mills. Fineness of grind is dependent upon the type of cement to be produced. Since fineness of grind falls below standard screen size accuracy, fineness of grind is determined by use of a Wagner Turbidometer. Desired grind then is expressed for example as 1750 Wagner. Another determination is by air permeability surface area method termed Blaine. For close approximation and comparison the two have the following arbitrary relation Wagner = Blaine 1.75. An indication of Wagner in terms of mesh sizes is provided in the following table:
cement ball mill - jxsc machine
The cement ball mill is mainly used for grinding the finished products and raw materials of cement plants, and is also suitable for grinding various ore and other grindable materials in industrial and mining enterprises such as metallurgy, chemical industry, and electric power. Cement grinding is the last process of cement production, it is to mix cement clinker and a small amount of gypsum, and then grind the mixture to a certain fineness, that is cement. You may also interest in the ball mill product price, lime ball mill, quartz ball mill. Cement grinder types Cement ball mills can be divided according to discharge method: grate ball mills and overflow mills, and can be divided into wet mills and dry mills according to their processing conditions.
The main working part of the cement grinding mill is a rotary cylinder mounted on two large bearings and placed horizontally. The cylinder is divided into several chambers by a partition plate, and a certain shape and size of grinding bodies are installed in each chamber. The grinding bodies are generally steel balls, steel forgings, steel rods, pebbles, gravel, and porcelain balls. In order to prevent the cylinder from being worn, a liner is installed on the inner wall of the cylinder. When the cement grinding machine rotates, the grinding media adheres to the lining surface of the inner wall of the cylinder under the action of centrifugal force and frictional force with the lining surface of the inner surface of the cylinder, and rotates with the cylinder and is brought to a certain height. Under the action of gravity, it falls freely. When falling, the grinding media acts as a projectile and impacts the material at the bottom to crush the material. The cyclic motion of the abrasive body rising and falling is repeated. In addition, during the rotation of the mill, the grinding body also slides and rolls, so the grinding action occurs between the grinding body, the liner and the material, making the material fine. As new materials are continuously fed at the feed end, there is a material level difference between the feed and discharge end materials to force the material to flow, and the axial thrust of the impact material when the grinding body falls also breaks the material flow. Air movement also helps material flow. Therefore, although the mill barrel is placed horizontally, the material can slowly flow from the feed end to the discharge end to complete the grinding operation.
Ball mill liner The liner of cement dry-type ball mill can be divided into ceramic, granite, rubber, high manganese, magnetic liner and other materials. The function of liner is mainly to protect the cylinder from the direct impact of materials and steel balls and extend the service life. At the same time, the liner plate can also adjust the running track of materials. Generally, the head grinding bin is equipped with hard liner plate, which can enhance the impact force of materials and accelerate grinding. The liner plate of the fine grinding bin is corrugated liner plate or flat liner plate, which can enhance the grinding effect of materials.
Ball mill grinding medium The grinding medium of cement dry ball mill includes steel ball, steel rod, steel pipe, stone, porcelain ball, etc. the steel ball is divided into cast iron, bearing steel, carbon steel and other materials, and the diameter of steel ball varies from 15mm to 125mm. The steel bar is short cylindrical or conical, which has line surface contact with the material and strong grinding effect.
Cement ball mill advantages 1. It has strong adaptability to materials, continuous production and large processing capacity. The equipment has stable performance, is convenient for large-scale production, and meets the needs of large-scale production of modern enterprises. 2. The crushing ratio is large, the feeding size can reach 50 mm, the discharging particle size can be controlled, and the particle quality is good. 3. Cement dry-type ball mill is mainly used for grinding raw materials and clinker (finished products and raw materials) in cement plant, and also for grinding various ores and other grindable materials in metallurgy, chemical industry, electric power and other industrial and mining enterprises. It can be used for open flow grinding and circular flow grinding composed of powder concentrator. 4. The structure is reasonable, firm and can be operated under negative pressure. Cement dry ball mill has good sealing performance, environmental protection, simple maintenance, safe and reliable operation. Disadvantages But at present, the overall efficiency of cement dry-type ball mill grinding is low and energy consumption is large. Although the rolling bearing transmission mode is used now, the cement mill process is still the most power consuming part of the enterprise. Moreover, the cement dry-type ball mill is generally medium and long grinding, with large investment and high cost.
The application of ball mill in cement industry dates back more than 100 years. The ball mill for cement grinding plant is mainly of high fineness, dry grinding method, and the process is mainly of open circuit process and closed circuit process. The equipment of ball mill used in cement plant includes vertical cement mill, roller press and ball mill, etc.
The cement ball mill in cement plant is usually divided into 2-4 silos, the most representative of which are the new type of high fineness cement ball mill and open flow high fineness cement ball mill. There are three cement processing circuits. 1. Open circuit grinding The ball mill in the cement plant for open circuit grinding consists of grinding bin, dust collector and ball mill. Advantages: the cement plant process is the simplest, with less investment and simple operation and maintenance. Disadvantages: serious over grinding in the mill, low efficiency, difficulty in fineness adjustment of finished products, high power consumption.
2. Closed circuit grinding Closed-circuit grinding is widely used in cement mills all over the world. Cement grinding unit is widely used in the United States, Germany, France, Japan and other developed countries. For example, 95% of cement in Japan comes from closed-circuit grinding. The cement plant machinery of closed-circuit grinding consists of feeding system, finished product bin, powder concentrator and dust collection equipment. The process is relatively complete. The disadvantages are a large investment, many equipment and complex operation.
According to many years of practical production experience, JXSC summarizes that cement producers with a production capacity of fewer than 30 tons per hour are suitable for open circuit grinding, and closed-circuit grinding for large-scale production can be more economical.
Matters need attention 1. Cement has corrosion, which affects the service life of steel ball and increases the production cost. 2. Different wear-resistant microelements in different materials of wear-resistant steel balls will be damaged, which will cause poor wear-resistant effect and serious waste of clinker grinding mill. 3. During cement grinding, the material temperature may be higher than 100 , leading to dehydration of most gypsum or complete dehydration, causing coagulate of cement, which requires corresponding cooling measures, including mill ventilation, cylinder water cooling, etc. 4. After each clinker grinding, clean the cement grinding system, so as to avoid inconvenience to the next start-up due to slag material deposition.
Cement mill price Cement ball mill specially used for grinding cement clinker and other materials in building materials, cement production, metallurgical ceramics, electric power and petrochemical industry. JXSC can design and manufacture special cement ball mill equipment according to the output and fineness requirements of users. Contact us for machine selection and a price quotation.
china wet mill, wet mill manufacturers, suppliers, price
China manufacturing industries are full of strong and consistent exporters. We are here to bring together China factories that supply manufacturing systems and machinery that are used by processing industries including but not limited to: grinding machine, milling machine, ball mill. Here we are going to show you some of the process equipments for sale that featured by our reliable suppliers and manufacturers, such as Wet Mill. We will do everything we can just to keep every buyer updated with this highly competitive industry & factory and its latest trends. Whether you are for group or individual sourcing, we will provide you with the latest technology and the comprehensive data of Chinese suppliers like Wet Mill factory list to enhance your sourcing performance in the business line of manufacturing & processing machinery.
wet grid ball mill
Grid ball mill is widely used in smashing all kinds of ores and other materials, ore dressing and national economic departments like building and chemical industries etc. The size of ore shall not exceed 65mm and the best feed size is under 6mm. The effect in this job is better than coarse grinding. Grid ball mill consists of the shell, feeding part, discharging part, main bearing, lubricating system, driving system and other parts. There is wearing a liner inside the shell, and both ends of the shell are provided with a flange. The end cover of the mill is connected with the flange plate. The feeding part consists of the head, trunnion and feeding device. The discharge part includes the grid plate, head, and discharge trunnion.
Wet Grid ball mill is mainly used for mixing and grinding materials in two types: dry grinding and wet grinding .It has advantages of fineness uniformity and power saving. The machine uses different types of liner to meet different customer needs. The grinding fineness of material can be controlled by grinding time. The electro-hydraulic machine is auto-coupled and decompressed to reduce the starting current, and its structure is divided into integral type and independent type.
Compared with similar products,Wet Grid ball mill has the characteristics of low investment, low energy consumption, novel structure, simple operation, stable and reliable performance. It is suitable for mixing and grinding ordinary and special materials. The users can choose the right type, liner and medium type by considering the specific gravity, hardness, yield and other factors. The grinding medium is Wet Grid ball.
1.The ball mill is composed of a horizontal cylinder, a hollow shaft for feeding and discharging, and a grinding head. The main body is a long cylinder made of steel. The cylinder is provided with an abrasive body, and the steel lining plate is fixed to the cylinder body. The grinding body is generally a steel ball and is loaded into the cylinder according to different diameters and a certain proportion, and the grinding body can also be used with a steel section.
2.According to the particle size of the grinding material, the material is loaded into the cylinder by the hollow shaft of the wet grid ball mill feeding end. When the ball mill cylinder rotates, the grinding body acts on the cylinder liner due to the action of inertia and centrifugal force and friction. It is carried away by the cylinder. When it is brought to a certain height, it is thrown off due to its own gravity. The falling abrasive body crushes the material in the cylinder like a projectile.
3.The material is uniformly fed into the first chamber of the mill by the feeding device through the hollow shaft of the feeding material. The chamber has a step liner or a corrugated liner, and various steel balls are loaded therein. The rotation of the cylinder generates centrifugal force to bring the steel ball to a certain extent. The height drops and then hits and grinds the material. After the material reaches the rough grinding in the first bin, it enters the second bin through the single-layer partition plate. The bin is embedded with a flat liner with steel balls inside to further grind the material. The powder is discharged through the discharge raft to complete the grinding operation.
The main function of the steel ball in the ball mill is to impact crush the material and also play a certain grinding effect. Therefore, the purpose of grading steel balls is to meet the requirements of these two aspects. The quality of the crushing effect directly affects the grinding efficiency, and ultimately affects the output of the ball mill. Whether the crushing requirement can be achieved depends on whether the grading of the steel ball is reasonable, mainly including the size of the steel ball, the number of ball diameters, and the ball of various specifications. Proportion and so on.
The ball mill is composed of the main part such as a feeding part, a discharging part, a turning part, a transmission part (a reduction gear, a small transmission gear, a motor, and electric control). The hollow shaft is made of cast steel, the inner lining can be replaced, the rotary large gear is processed by casting hobbing, and the barrel is embedded with wear-resistant lining, which has good wear resistance. The machine runs smoothly and works reliably.