SAG mills are the opposite, they generally have a larger diameter than their length. This gives them an inherent higher capacity for a given length. Rods are also generally more expensive than balls and harder to handle. This means a rod mill equal in capacity to a ball or SAG mill would take up more plant floor area requiring a larger building.
WhatsApp: +86 18203695377The finesse of the material milled by the ball mill is, only except for the two small ball mills that have a wider range of However, the rod mill fine grinding fineness is about In terms of the fineness of the ground material, the ball mill has a finer handling ability.
WhatsApp: +86 18203695377The reason why rod mill is called rod mill is that its grinding medium is steel rod, while the grinding medium of ball grinding mill is steel ball. Because the shape of the grinding media is different, the working mode has its own characteristics. When the steel rod is in motion, the gap between the rods is a regular long strip, which plays a ...
WhatsApp: +86 18203695377The simplest grinding circuit consists of a ball or rod mill in closed circuit with a classifier; the flow sheet is shown in Fig. 25 and the actual layout in Fig. 9. ... Difference between open circuit and closed circuit grinding. Singlestage grinding is generally to be recommended for small plants on account of its simplicity. Variations in ...
WhatsApp: +86 18203695377Ball Mill PINION SHAFT BEARINGS. Pinion shaft bearings are of the SKF antifriction type mounted in a common twin bearing assembly. Bearings are fixed in place so that the pinion shaft of the mill is always in alignment with the drive components. Vbelt driven mills are furnished with an outboard bearing of similar construction.
WhatsApp: +86 18203695377The ball mill operates on the principle of impact and attrition . Impact is between rapidly moving balls and the powder material. mounted on a rotor and the powder material. The balls roll over each other and show rubbing action, hence attrition force is also responsible for size reduction.
WhatsApp: +86 18203695377Abstract. This paper describes a method for assessing the downstream milling energy requirements for high pressure grinding rolls (HPGR) products based on a Bond mill test procedure. Multiple tradeoff studies have reported the performance of HPGR versus SAG milling with energy savings of between 11 and 32 per cent.
WhatsApp: +86 18203695377The reason is illustrated in Figure 1, with the nonparallel nature of the SAG and ball mill products being clear. The more appropriate use of the size specific energy (SSE), the energy to produce ...
WhatsApp: +86 18203695377The purpose of the primary crusher is to reduce the ROM ore to a size amenable for feeding the secondary crusher or the SAG mill grinding circuit. The ratio of reduction through a primary crusher can be up to about 8:1. Feed: ROM up to m. Product: 300mm (for transport) to 200mm (for SAG mill) Feed Rate:
WhatsApp: +86 18203695377the AG/SAG mill (because there is no recycle), but loads the ball mills instead. Often an existing plant that observes their SAG mill is limiting throughput, but the ball mills are underloaded can opencircuit the primary mill to better balance the grinding load with the secondary mill. The coarse transfer size to the ball mill makes this circuit
WhatsApp: +86 18203695377Rods in place weigh approximately 400 pounds per cu. ft. and balls in place approximately 300 pounds per cu. ft.. Thus, quantitatively, less material can progress through the voids in the rod mill grinding media than in the ball mill, and the path of the material is more confined. This grinding action restricts the volume of feed which passes ...
WhatsApp: +86 18203695377Grinding media: SAG mills use steel balls as the grinding media, while AG mills use the ore itself as the grinding media. Size: SAG mills are larger in diameter and shorter in length than AG mills. They are also usually fed with a larger size of ore than AG mills.
WhatsApp: +86 18203695377Principle of SAG Mill operation. SAG is an acronym for semiautogenous grinding. SAG mills are autogenous mills that also use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%.[6][7] The largest SAG mill is 42′ () in diameter, powered by a 28 MW (38,000 HP ...
WhatsApp: +86 18203695377In a SAG mill the dimensions of the mill were m × m and the specific gravities of the mineral and that of the balls charged were and respectively. The mill was rotated at 75% of its critical speed when 8 % of the mill volume was charged with grinding balls. Estimate: 1. The mill power drawn, 2.
WhatsApp: +86 18203695377The power the mill consumes is a function of the ore and/or ball charge geometry and the mill speed. The motor only supplies the amount of power (or torque really) that the mill demands, and we add some extra power to the motor to deal with 'upset' conditions like a change in ore density or a surge in ore level inside the mill.
WhatsApp: +86 18203695377In this example, the OWi of the SAG mill was found to be 30% higher than the ball mill, thus suggesting that the SAG mill was less efficient than the ball mill. The apparent inefficiency of SAG mills when using Bond analysis is widely understood to be due to the difference in the slopes of the size distributions. In contrast, when the SSE75 was ...
WhatsApp: +86 18203695377What is the difference between a SAG mill and a ball mill? A SAG mill uses larger rocks or ore fragments as grinding media, while a ball mill uses smaller grinding media such as steel balls. Additionally, a SAG mill uses a minimal ball charge of 6 to 15%, while a ball mill requires a higher ball charge of 20 to 40%.
WhatsApp: +86 18203695377If a ball mill uses little or no water during grinding, it is a 'dry' mill. If a ball mill uses water during grinding, it is a 'wet' mill. A typical ball mill will have a drum length that is 1 or times the drum diameter. Ball mills with a drum length to diameter ratio greater than are referred to as tube mills.
WhatsApp: +86 18203695377In order to improve the processing capacity of the AG mill and reduce power consumption, a small number of steel balls can be added to form a semiautogenous mill (SAG mill). This article introduces the differences between ball mills, rod mills and SAG mills. Grinding Media Comparison
WhatsApp: +86 18203695377ρ b = ball density (t/m 3) AG/SAG Mill Power. In designing crushinggrinding flow sheets, correct estimations of mill power draw are important as it serves as one of the deciding factors for selecting an option between AG/SAG mills. In most cases, the circuit with the least or optimal power consumption is the preferred choice.
WhatsApp: +86 18203695377The final plan was to increase the ball charge in the SAG and ball mill to 10% v / v and 27% v / v, respectively; set the upper limit of the operating power in the ball mill to 5800 kW; use a TC Series crusher (without a power/feed ratecontrolling device, but with a feed bin) to crush pebbles for recirculation back to the SAG mill feed ...
WhatsApp: +86 18203695377One of the advantages of a rod mill is that it can handle a higher capacity than a ball mill of the same size. Additionally, the grinding medium in a rod mill is more uniform than that in a ball mill, and this can be beneficial for certain materials. Rod mills are also relatively lowmaintenance, making them a costeffective option for many ...
WhatsApp: +86 18203695377The Bond ball mill work index (Wi BM, or BWi) conducted from a feed size of approximately 2 mm to a product size on the order of 100 µm. The Bond rod mill work index (Wi RM, or RWi) conducted from a feed size of approximately 10 mm to a product size on the order of 1 mm. The Bond crushing (impact) work index (Wi C, CWi, LEIT or IWi) conducted ...
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