AG/SAG mill feed, trommel screen undersize product (-5.00 +0.00 mm), ball mill discharge and cyclone feed, overflow and underflow have been conducted in order to characterize the particle size distribution in the products and to carry out mass balancing of grinding circuits. Furthermore, an
WhatsAppGet PriceGet A QuoteThe biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1 mm. The calculation shows that the crushing ratio can reach 3000 ~ 4000, while the ball mill’s
WhatsAppGet PriceGet A QuoteDepending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size.
WhatsAppGet PriceGet A QuoteAmong the different grinding processes, Autogenous (AG) and Semi-Autogenous (SAG) mills are widely used for ore size reduction. The main difference between these two mills is the use of steel balls as grinding media, typically in the order of 6–12% in volume (Sbarbaro et al., 2005), in the SAG mills.
WhatsAppGet PriceGet A QuoteIf the mill feed setpoint is changed, then the actual feed rate needs to stabilise at the new target in a short period of time. The feed rate setpoint can then be tied into a SAG mill power optimisation strategy. SAG mill discharge control is quite involved due to few interactive variables, such as mill discharge sump level, classification
WhatsAppGet PriceGet A QuoteCurrent operational results show that the SAG mill is operating at 5% ball charge level by volume and is delivering a K80 800 micron product as predicted. Power drawn at the pinion is 448 kW, 13.617 kWh/tonne (SAG mill) and 570 kW, 17.325 kWh/tonne (ball mill) when processing 32.9 mtph, for a total of 30.942 kWh/tonne or 14.6% above the
WhatsAppGet PriceGet A QuoteThe performance of tumbling mills is sensitive to the volumetric mill filling which influences grinding media wear rates, throughput, power draw, and product grind size from the circuit. Each of these performance parameters peaks at different filling values. In order to contin-uously optimize mill operation, it is vital to
WhatsAppGet PriceGet A QuoteControl of -SemiAutogenous Grinding(SAG) mill weight is an example of an important process that exhibits many of these aspects. Maintaining the SAG mill weight at the optimum value is critical for achieving maximum grind rate efficiency and mill production (Powell, M.S., van der Westhuizen, A.P., & Mainza, A.N. 2009).
WhatsAppGet PriceGet A QuoteToor targeted the throughput, energy consumption and product size of the SAG mill, optimized the liner structure, and quantified the benefit of using shorter life liners. The results presented indicated that liners with a reduced mass and shorter life outperform their longer life counter parts in all key production parameters of throughput
WhatsAppGet PriceGet A QuoteSAG MILL BALL MILLS MILL DESIGN DATA. These projects involved SAG mills from 26 to 36 ft in diameter, with installed power in the range 9.7 to 16.8 MW using single, twin pinion, and gearless technology for drives over 16 MW. The ball mills used varied from 13.5 to 25 ft in diameter, with installed power in the range 1.85
WhatsAppGet PriceGet A QuoteThe performance of tumbling mills is sensitive to the volumetric mill filling which influences grinding media wear rates, throughput, power draw, and product grind size from the circuit. Each of these performance parameters peaks at different filling values. In order to contin-uously optimize mill operation, it is vital to
WhatsAppGet PriceGet A QuoteDownload scientific diagram | Configuration and performance of the SABC circuit (on the case of maximum theoretical processing capacity) from publication: New developments and optimization of Wu
WhatsAppGet PriceGet A QuoteAG/SAG mill feed, trommel screen undersize product (-5.00 +0.00 mm), ball mill discharge and cyclone feed, overflow and underflow have been conducted in order to characterize the particle size distribution in the products and to carry out mass balancing of grinding circuits. Furthermore, an
WhatsAppGet PriceGet A QuoteFurther optimization is achieved through the use of a sepol ® separator, which separates the finished product from the ground material. The grits separated out by the separator are fed back into the mill as recirculating material; this prevents overgrinding of the finished product in the ball mill discharge.
WhatsAppGet PriceGet A Quoteoptimize the milling performance by investigating this signature’s relation to mill product size, mill throughput, make-up ball size, mill speed, liner profile and ball addition rates. At the same time, it can also be used to design balls and liner systems that can survive longer in the mill. The technological advances made in electronics
WhatsAppGet PriceGet A QuoteThe mill product can either be finished size ready for processing, or an intermediate size ready for final grinding in a rod mill, ball mill or pebble mill. AG/SAG mills can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill, and some or all of the work of a ball mill. Because of the range of
WhatsAppGet PriceGet A QuoteThe crushed pebbles fall directly onto the SAG mill feed belt and return to the SAG mill. SAG mill product feeds two parallel ball mills of 6.6 m×11.1 m (internal diameter×length), each with a 9.7 MW twin pinion drive. The ball mills are operated at a ball charge volume of 30–32% and 78.5% critical speed.
WhatsAppGet PriceGet A QuoteIn the mining sector, these losses can be quite substantial. For example, a trained professional crew may require up to 120 hours to replace the worn liner of a SAG mill with each hour costing tens or even hundreds of thousands of dollars, depending on the size of the mill and the plant in which it operates.
WhatsAppGet PriceGet A QuoteThe analysis of the influence of ball sizes in SAG grinding hasn''t been developed in detail by considering the effect on process parameters inside the mill, grinding efficiency or internal classification. Historically a conventional grinding reference has been made on the empirical procedure developed by Azzaroni (1980).
WhatsAppGet PriceGet A Quotethe required SAG comminution of test ore material. Specific energy consumption (SEC) measured in kWh/t is a ratio of the mill drive power to the milling circuit output, without regard to circulating load. At the constant size of the cycle feed and discharge, SEC is a prime characteristic of material grindability in a certain ore pretreatment
WhatsAppGet PriceGet A Quotethroughput and final product size. This could be achieved through closer monitoring of the primary crusher performance and proper control of the ratios for the SAG mill feeders drawing the ore from the stockpile. The ball mill grinding efficiency was poor and could be indicated by the fraction < 125 µm of only 5-9 % or x. P, 80
WhatsAppGet PriceGet A QuoteThis work is aimed at optimizing the SAG mills feed size distribution as this is an important parameter that affects milling performance after ore competency. A lot of operations have recognized the optimization opportunity that can be taken advantage of by manipulating the feed size distribution to improve SAG milling efficiency.
WhatsAppGet PriceGet A QuoteThe modeling and simulation of semiautogenous (SAG) mills have been widely used in the design and optimization of mill performance in terms of its power draw, processing capacity and product size
WhatsAppGet PriceGet A QuoteThe SGI equation uses a transfer size between a SAG and ball mill; it is proposed that a synthetic transfer size of 2100 µm be used to model single-stage SAG mills. 5.9ˇ √˙˝ ˛ . ˚ 0.96 0.985˜ !"# ˝ $ ˝ √˙˝ %&’() (2) where: SGI is the SAG Grindability Index, minutes, P80 is the SAG hydrocyclone overflow 80% passing size, µm
WhatsAppGet PriceGet A QuoteThe operation of AG/SAG mills is sensitive to mill filling, therefore developing grindcurves to relate mill filling to performance indicators such as throughput, power draw, and product size can assist in achieving optimal mill operations. The throughput, power draw, and product size have been shown to peak at different mill filling levels.
WhatsAppGet PriceGet A QuoteEnd and shell liner design in these mills is much the same as for SAG mills. The effect of liner design on performance is equally as important. For instance, in an iron ore operation using 6.4 m (21 ft.) mills, mill throughput was increased by 15 percent and power consumption reduced by 13 percent by liner redesign alone.
WhatsAppGet PriceGet A Quoteby conventional ball mills, this optimization strategy involves maximizing SAG mill fresh feed tonnage while respecting the ability and limitations of the downstream ball mill – classification circuit to produce the desired coarser final product size.
WhatsAppGet PriceGet A Quoteoperating at 90% of its maximum power. The combined power draw of the SAG mill and ball mill was 8658 kW, which caused partial over-grinding. From experience in processing plants outside of China, the power rating of the ball mill should be higher than that of the SAG mill [5]. The pebble crusher had an over-powered configuration.
WhatsAppGet PriceGet A QuoteThe biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1 mm. The calculation shows that the crushing ratio can reach 3000 ~ 4000, while the ball mill’s
WhatsAppGet PriceGet A QuoteToor targeted the throughput, energy consumption and product size of the SAG mill, optimized the liner structure, and quantified the benefit of using shorter life liners. The results presented indicated that liners with a reduced mass and shorter life outperform their longer life counter parts in all key production parameters of throughput
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