Sep 01, 2013 It was found that the optimum composition depends on various factors, including the feed size, the product size, the mill diameter and the breakage parameters. In all cases, binary mixtures of two ball sizes (50.8 mm and 25.4 mm) performed better than a mixture of the three ball sizes
Jul 05, 2020 The balls which could be of different diameter occupy 30 – 50 % of the mill volume and its size depends on the feed and mill size. The large balls tend to break down the coarse feed materials and the smaller balls help to form fine product by reducing void spaces between the balls. Ball mills grind material by impact and attrition
Get Price
Number, size and mass of each ball size depends on mill load and whether or not the media is being added as the initial charge. For the initial chargin of a mill, Coghill and DeVaney (1937) defined the ball size as a function of the top size of the feed, i.e., d †“V = 0.40 K ˆšF dB = ball size (cm) F = feed size
Get Price
had decreased for the -2 mm +1.4 mm mono-size feed compared to the bigger -4 mm +2.8 mm mono-size feed. This therefore shows that should the material feed size continue to decrease, the smaller balls will perform better than the larger balls during milling, as was mentioned by Katubilwa et al. Effect of ball diameter size on mill power draw
Get Price
Example 2 A ball mill is fed with fresh feed (F) as 30X10 3 kg/h and the product is screened using a screen of 295 m aperture size. Oversize are recycled at a rate of 60X10 3 kg/h. Calculate the energy consumption of ball mill for open circuit as well as well as closed circuit grinding. Work index = 12.74 kWh/ton is given
Get Price
Then, determine the average particle size for the mill feed and product. (Hint: you must first determine Question : Part A: Size reduction Based on the given information: (a) Based on the feed size in Table 1 and size distribution after 10 minutes of grinding time in the ball mill in Table 2, predict the size distribution after milling based on
Get Price
A ball mill grinds ores to an end product size of thirty-five mesh or finer. The feeding material to a ball mill is treated by: • Single or multistage crushing and screening • Crushing, screening, and/or rod milling • Primary crushing and autogenous/semi-autogenous grinding. Normal feed sizes:
Get Price
Optimization of mill performance by using online ball and pulp measurements Soon after a stop, a mill is a dangerous place to enter for the personnel tasked with taking measurements or samples. Crash stops are difficult to handle. The mill and all feed streams should be stopped simultaneously but, often, they are stopped around about the same time
Get Price
mills, and use a rod mill feed size (F80) of 16,000 m and a rod mill product size of 1,000 m . Also note that in order for no correction factor for ball mill product fineness to apply, the ball mill circuit P80 should be no less than approximately 70 m (See reference by Bond, 1962)
Get Price
The product size from HPGR can be much finer than the corresponding ball or rod mill products. As an example, the results by M rsky, Klemetti and Knuutinen [12] are given in Figure 6.8 where, for the same net input energy (4 kWh/t), the product sizes obtained from HPGR, ball and rod mills are plotted
Get Price
RETSCH is the world leading manufacturer of laboratory ball mills and offers the perfect product for each application. The High Energy Ball Mill E max and MM 500 were developed for grinding with the highest energy input. The innovative design of both, the mills and the grinding jars, allows for continuous grinding down to the nano range in the shortest amount of time - with only minor warming
Get Price
Apr 24, 2015 The opening is closed and the mill is rotated for several hours. It is then stopped and the product is discharged. 5. The ball mill is used for grinding materials such as coal,pigments,and fedspar for pottery. Grinding can be carried out in either wet or dry but the former is carried out at low speeds. The advantages of wet grinding are less
Get Price
Ball Mills Mineral Processing Metallurgy. Types of Mill Feed Chute Scoop Feeders for BallRod Mills are made in various radius sizes Standard scoops are made of cast iron and for the 3′ size a 13″ or 19″ feeder is supplied for the 4′ size a 30″ or 36″ for the 5′ a 36″ or
Get Price
Note that—in order for no correction factor for ball mill product fineness to apply—the ball mill circuit P80 should be no less than approximately 70 m (Bond, 1962). This ... actual rod mill feed size of 19,300 m (although some of this work might ideally be done by crushers to achieve a rod mill F80 of 16,000 m) to a rod mill (circuit
Get Price
May 15, 2015 In general, therefore, the required mill power is calculated using the following equation. where n is the number of efficiency factors, EFi, used and fo is the feed rate of new ore to the mill. The power calculated from equation 2 can be looked up in published tables (Rowland and Kjos, 1978) and the correct mill size and type can be selected
Get Price
Jun 01, 2018 Fig. 5 shows the variation of size class 1 (M1) with the milling time for the two feed size distributions. For this coarser feed the 50 + 20+10 mm ball diameter mix breaks the material at a faster rate compared to the other ball matches. The availability of a ball size for a particular feed size ensures breakage occurs at a faster rate
Get Price
Jul 26, 2017 For the purposes of this example, we will hypothesize that the the crushing index of the hard ore with the increased energy input of 1.54 kw/t reduces the ball mill feed size to 6,500 micrometers. As a result, the mill output will increase with this reduced size to approximately 77,000 tons per day. The gain in production compared to the 13,000
Get Price
Aug 02, 2013 Based on his work, this formula can be derived for ball diameter sizing and selection: Dm = 6 (log dk) * d^0.5 where D m = the diameter of the single-sized balls in mm.d = the diameter of the largest chunks of ore in the mill feed in mm. dk = the P90 or fineness of the finished product in microns (um)with this the finished product is
Get Price
The ball mill accepts the SAG or AG mill product. Ball mills give a controlled final grind and produce flotation feed of a uniform size. Ball mills tumble iron or steel balls with the ore. The balls are initially 5–10 cm diameter but gradually wear away as grinding of the ore proceeds
Get Price