Our EXAMPLE Grinding and Classification Circuit is designed to grind 500 tonnes of ore per day, operating 24 hours per day, with an availability of 95%. This circuit will grind -5/8 material from the Crushing Plant, classify the slurry in one of two cyclones, and pass 70% of the minus 200 mesh material to the mill feed Thickener Circuit at a rate of 22 mtph. This section is intended to be read in conjunction with the Flowsheet and Piping and Instrument Diagrams.
Detailed Process Description and Control:Crushed ore in the fine ore bin flows througha slot feeder onto a 30 variable speed belt feeder. The bin low level alarm on the mill control panelannunciator will inform the mill that there is a shortage of feed material. The belt feeder has level and pullcord switches identical to the other three conveyors. In addition, the belt feeder is equipped with two speed switches; one at each pulley, in order to measure and alarm the difference in pulley speeds as a low speed may be normal for this drive. A belt weigh scale under the conveyor measures the weight of material passing over the idlers and coupled with the belt speed measures the total weight passing on the belt. The ball mill feed rate is set via the weight controller at the mill control panel which adjusts the speed of the belt. A digital counter or totalizer displays the results as total tonnes of ore passed and a recorder maintains a permanent record of ball mill feed.
Ore from the belt feeder enters a 10-6dia. x 13-0 ball mill, which grinds the -5/8 ore to 70% minus 200 mesh. Barren solution is added to the ball mill to produce a slurry of 60% solids. The solids content of the ball mill discharge is controlled by a ratio control loop, whereby barren solution addition is proportional to the ball mill feed. The set point of the controller is the percent solids desired in the ball mill. An orifice plate measures the barren solution flow rate and the controller calculates how much barren solution is required to make the desired slurry, based on the weight of material coming through, and modulates a motorized butterfly flow control valve in the barren solution line accordingly.
The ball mill is an overflow type discharge mill, and is designed for a 45% ball charge. Balls should be added on a regular basis as they are consumed in the mill. The balls are added with a one ton ball bucket, lifted by an overhead crane, and discharged into the ball mill feed chute. The ball charge is self-limiting a greater than 45% ball charge will cause the excess balls to discharge over the trommel screen and out of the mill.
Ground ore passes through the trommel screen onto a chute and is fed to a distributor box above the cyclone feed pumpbox. The pumpbox has two distinct compartments, each equipped with its own 30 HP cyclone feed pumpat its discharge. Normal operation requires the use of only one compartment at a time. Air cylinder valves on the distributor box are manually operated depending on which pumpbox compartment is being used. On changing compartments the distributor valves and cyclone feed pumps must be manually switched over, and the now unused pumpbox compartment must be pumped dry. Gland seal water to the pumps must also be switched over with their associated valves.
Barren solution is used as gland seal water for the two cyclone feed pumps. Each gland seal water line to the pumps is equipped with a sight flow glass; to ensure gland water is flowing to each pump, a dole valve; to control the flowrate of gland water to each pump; and a common pressure gauge; to ensure that sufficient gland seal water pressure is applied to the pump seals.
Although the cyclone feed pumps will self-regulate flow according to the level in the pumpbox, high and low level switches in each compartment will alarm at the control panel annunciator should a problem occur. The 10 HP 2 grinding area sump pump and the crushing area sump pump discharge into the distribution box, along with barren solution. A control loop regulates the flow of barren solution to the cyclone feed pumpbox.
The discharge of each cyclone feed pump is piped separately to its own 15 diameter cyclone, at a normal rate of 122 cubic meters per hour and 52% solids. Should both pumps shut down simultaneously, or the ball mill clutch be disengaged, the feed conveyor will be shut down. The cyclones separate the slurry particles by size; the coarse particles flow through the cyclone underflow to an underflow collection launder, and are then fed back to the ball mill for regrinding. Cyclone overflow (70% minus 200 mesh) is collected in an overflow collection launder, and flow by gravity to a 16 meter diameter thickener. The pH level in the overflow collection launder is monitored, and an indicating transmitter sends an alarm signal to the mill control panel annunciator if the pH level drops below 10.5 (basic).
In order for the cyclones to separate the particles by size effectively, the density of the cyclone feed slurry must be consistent, approximately 52% solids. This is controlled by measuring the slurry density in either cyclone feed line and controlling the amount of barren solution to the cyclone feed pumpbox. The density measurement is achieved using a nuclear source and detector/transmitter, saddle mounted to each pipe. Each transmitter feeds its signal to the controller, which decides which signal to use depending on which pump is running. The output of the controller modulates a butterfly control valve, in the barren solution line, adjusting the barren flowaccordingly. The cyclone feed density is recorded on a recorder which also records the thickener underflow density. Adjustment of the cyclone apex, utilizing air operated pinch valves, will also shift the particle size separation point coarser or finer.
The 15 HP 2 grinding area sump pump is designed to pump 35 cubic meters per hour, and in AUTO regulates its sump level with high and low float level switches. This pump can feed material to the cyclone feed pump-box or to the tailings box.
Max Feeding size <25mm Discharge size0.075-0.4mm Typesoverflow ball mills, grate discharge ball mills Service 24hrs quotation, custom made parts, processing flow design & optimization, one year warranty, on-site installation.
Ball mill, also known as ball grinding machine, a well-known ore grinding machine, widely used in the mining, construction, aggregate application. JXSC start the ball mill business since 1985, supply globally service includes design, manufacturing, installation, and free operation training. Type according to the discharge type, overflow ball mill, grate discharge ball mill; according to the grinding conditions, wet milling, dry grinding; according to the ball mill media. Wet grinding gold, chrome, tin, coltan, tantalite, silica sand, lead, pebble, and the like mining application. Dry grinding cement, building stone, power, etc. Grinding media ball steel ball, manganese, chrome, ceramic ball, etc. Common steel ball sizes 40mm, 60mm, 80mm, 100mm, 120mm. Ball mill liner Natural rubber plate, manganese steel plate, 50-130mm custom thickness. Features 1. Effective grinding technology for diverse applications 2. Long life and minimum maintenance 3. Automatization 4. Working Continuously 5. Quality guarantee, safe operation, energy-saving. The ball grinding mill machine usually coordinates with other rock crusher machines, like jaw crusher, cone crusher, to reduce the ore particle into fine and superfine size. Ball mills grinding tasks can be done under dry or wet conditions. Get to know more details of rock crushers, ore grinders, contact us!
Ball mill parts feed, discharge, barrel, gear, motor, reducer, bearing, bearing seat, frame, liner plate, steel ball, etc. Contact our overseas office for buying ball mill components, wear parts, and your mine site visits. Ball mill working principle High energy ball milling is a type of powder grinding mill used to grind ores and other materials to 25 mesh or extremely fine powders, mainly used in the mineral processing industry, both in open or closed circuits. Ball milling is a grinding method that reduces the product into a controlled final grind and a uniform size, usually, the manganese, iron, steel balls or ceramic are used in the collision container. The ball milling process prepared by rod mill, sag mill (autogenous / semi autogenous grinding mill), jaw crusher, cone crusher, and other single or multistage crushing and screening. Ball mill manufacturer With more than 35 years of experience in grinding balls mill technology, JXSC design and produce heavy-duty scientific ball mill with long life minimum maintenance among industrial use, laboratory use. Besides, portable ball mills are designed for the mobile mineral processing plant. How much the ball mill, and how much invest a crushing plant? contact us today! Find more ball mill diagram at ball mill PDF ServiceBall mill design, Testing of the material, grinding circuit design, on site installation. The ball grinding mill machine usually coordinates with other rock crusher machines, like jaw crusher, cone crusher, get to know more details of rock crushers, ore grinders, contact us! sag mill vs ball mill, rod mill vs ball mill
How many types of ball mill 1. Based on the axial orientation a. Horizontal ball mill. It is the most common type supplied from ball mill manufacturers in China. Although the capacity, specification, and structure may vary from every supplier, they are basically shaped like a cylinder with a drum inside its chamber. As the name implies, it comes in a longer and thinner shape form that vertical ball mills. Most horizontal ball mills have timers that shut down automatically when the material is fully processed. b. Vertical ball mills are not very commonly used in industries owing to its capacity limitation and specific structure. Vertical roller mill comes in the form of an erect cylinder rather than a horizontal type like a detachable drum, that is the vertical grinding mill only produced base on custom requirements by vertical ball mill manufacturers. 2. Base on the loading capacity Ball mill manufacturers in China design different ball mill sizes to meet the customers from various sectors of the public administration, such as colleges and universities, metallurgical institutes, and mines. a. Industrial ball mills. They are applied in the manufacturing factories, where they need them to grind a huge amount of material into specific particles, and alway interlink with other equipment like feeder, vibrating screen. Such as ball mill for mining, ceramic industry, cement grinding. b. Planetary Ball Mills, small ball mill. They are intended for usage in the testing laboratory, usually come in the form of vertical structure, has a small chamber and small loading capacity. Ball mill for sale In all the ore mining beneficiation and concentrating processes, including gravity separation, chemical, froth flotation, the working principle is to prepare fine size ores by crushing and grinding often with rock crushers, rod mill, and ball mils for the subsequent treatment. Over a period of many years development, the fine grinding fineness have been reduced many times, and the ball mill machine has become the widest used grinding machine in various applications due to solid structure, and low operation cost. The ball miller machine is a tumbling mill that uses steel milling balls as the grinding media, applied in either primary grinding or secondary grinding applications. The feed can be dry or wet, as for dry materials process, the shell dustproof to minimize the dust pollution. Gear drive mill barrel tumbles iron or steel balls with the ore at a speed. Usually, the balls filling rate about 40%, the mill balls size are initially 3080 cm diameter but gradually wore away as the ore was ground. In general, ball mill grinder can be fed either wet or dry, the ball mill machine is classed by electric power rather than diameter and capacity. JXSC ball mill manufacturer has industrial ball mill and small ball mill for sale, power range 18.5-800KW. During the production process, the ball grinding machine may be called cement mill, limestone ball mill, sand mill, coal mill, pebble mill, rotary ball mill, wet grinding mill, etc. JXSC ball mills are designed for high capacity long service, good quality match Metso ball mill. Grinding media Grinding balls for mining usually adopt wet grinding ball mills, mostly manganese, steel, lead balls. Ceramic balls for ball mill often seen in the laboratory. Types of ball mill: wet grinding ball mill, dry grinding ball mill, horizontal ball mill, vibration mill, large ball mill, coal mill, stone mill grinder, tumbling ball mill, etc. The ball mill barrel is filled with powder and milling media, the powder can reduce the balls falling impact, but if the power too much that may cause balls to stick to the container side. Along with the rotational force, the crushing action mill the power, so, it is essential to ensure that there is enough space for media to tumble effectively. How does ball mill work The material fed into the drum through the hopper, motor drive cylinder rotates, causing grinding balls rises and falls follow the drum rotation direction, the grinding media be lifted to a certain height and then fall back into the cylinder and onto the material to be ground. The rotation speed is a key point related to the ball mill efficiency, rotation speed too great or too small, neither bring good grinding result. Based on experience, the rotat
ion is usually set between 4-20/minute, if the speed too great, may create centrifuge force thus the grinding balls stay with the mill perimeter and dont fall. In summary, it depends on the mill diameter, the larger the diameter, the slower the rotation (the suitable rotation speed adjusted before delivery). What is critical speed of ball mill? The critical speed of the ball mill is the speed at which the centrifugal force is equal to the gravity on the inner surface of the mill so that no ball falls from its position onto the mill shell. Ball mill machines usually operates at 65-75% of critical speed. What is the ball mill price? There are many factors affects the ball mill cost, for quicker quotations, kindly let me know the following basic information. (1) Application, what is the grinding material? (2) required capacity, feeding and discharge size (3) dry or wet grinding (4) single machine or complete processing plant, etc.
Applications: It is mainly used in cement, silicate, new building materials, refractory materials, fertilizers, glass ceramics and other industries, as well as the grinding of various ores and other hard materials.
Grate ball mill (grate discharge ball mill) is aball milling machineused to grind various ores and other materials. Grate type ball mill is a traditional ball milling equipment for forced ore discharge by ore discharge grate.
Its basic structure and grinding process are basically the same as theoverflow type ball mill, but the structure of the ore discharge part is different. The discharge end of the grate discharge ball mill is equipped with a grate liner, and the material is discharged through the grate liner.
The characteristic of its discharge method is forced discharge, so the production capacity is higher. Grate discharge type ball mill has a higher processing capacity, but the product size is relatively coarse (0.2-0.3mm), suitable for the first stage of grinding operations.
The grinding steel ball inside the barrel of the grate ball mill is filled in accordance with different sizes and proportions. When the grinding ball is lifted to a certain height during the operation of the mill, the drop difference with the pulp surface is larger. Therefore, the impact of the steel ball on the material is strong, the crushing effect of the material is large, the grinding effect is better.
After the grate type ball mill starts, the material is fed into the barrel through the feed end, and the barrel then rotates around the horizontal axis according to a certain speed. At the same time, under the action of centrifugal force and friction force, the material is brought to a higher place, and then free-falling and throwing motion are carried out. Finally, the material is crushed under the combined action of grinding medium and cylinder.
The ground product is discharged through the discharging part. The discharging end of the grate ball mill is provided with a grate liner, on which there are many small holes for discharging. After the grinding operation is completed, the ore pulp is lifted to a higher level than the ore discharge opening through the grate liner and the fan-shaped chamber leading to the ore discharge opening, so that the ore pulp is discharged from the grate ball mill.
As a ball mills supplier with 22 years of experience in the grinding industry, we can provide customers with types of ball mill, vertical mill, rod mill and AG/SAG mill for grinding in a variety of industries and materials.Get in Touch with Mechanic