Ball Size Distribution In practice, at mill startup, instead of charging a single size of ball, usually a range of ball sizes is initially added.7.6 A ball mill is to produce a grind of 34 micron (Pso) product from a feed size of 200 microns at a rate of 1.5 t/h
where d b.max is the maximum size of feed (mm); σ is compression strength (MPa); E is modulus of elasticity (MPa); ρb is density of material of balls (kg/m 3); D is inner diameter of the mill body (m).. Generally, a maximum allowed ball size is situated in the range from D /18 to D/24.. The degree of filling the mill with balls also influences productivity of the mill and milling efficiency
Read MoreBall 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
Read MoreThe feed size of a ball mill ranges from _____ a) 50 mm b) 100 mm c) 200 mm d) 300 mm Answer: a Clarification: The feed size of a ball mill ranges from 50 mm, while the product size ranges from 100 to 200 mesh screen. 10. As the rate of feed increases, the
Read MoreFor ball mill, Bond (1958) was proposing an empirical formula giving the top size of balls (make-up balls) DM function of the feed size xG (80% passing size - m), the ore true specific gravity sg, the ore Bond Work Index Wi (kWh/st), the fraction of critical speed fc and the inside mill diameter D (m):
Read MoreThe size of feed particles to a rod mill is coarser than for a ball mill. The usual feed size ranges from 6 to 25 mm. For the efficient use of rods it is necessary that they operate parallel to the central axis and the body of the mill. This is not always possible as in practice
Read MoreJul 08, 2016 Jul 08, 2016 The Work Index values listed in Table I and II apply directly to a wet grinding overflow type rod mill 7.5 feet in diameter in open circuit; and to a wet grinding overflow type ball mill 7.5 feet in diameter in closed circuit with a rake classifier at 250% circulating load, and with 80% or more of the feed passing 4 mesh
Read MoreCalculate and Select Ball Mill Ball Size for Optimum Grinding. 2/8/2013 In Grinding, selecting (calculate) the correct or optimum ball size that allows for the best and optimum/ideal or target grind size to be achieved by your ball mill is an important thing for a
Read MoreThe feed to ball mills (dry basis) is typically 75 vol.-% ore and 25% steel. The ball mill is operated in closed circuit with a particle-size measurement device and size-control cyclones.Ball Mills - an overview ScienceDirect Topics,8.3.2.2 Ball mills. The ball mill is a tumbling mill
Read MoreFeed size is usually inch or less; product size ranges from 500 to below 5 Ball mills work well on hard, brittle materials They are not as suitable for grinding elastic, ductile or fibrous materials, or for fine grinding in general Ball mills can blend and grind at the same time, yielding a fine, intimate mixture
Read MoreJan 31, 2015 Popular Answers (1) More balls with small size results in fine powder. As a thumb rule powder to be milled should be taken as 25% of total ball weight. If
Read MoreNumber, 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 =
Read Morehad 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
Read MoreJul 26, 2017 Jul 26, 2017 We will consider an ore with a ball mill work index varying between 16 and 13, feeding into a single stage ball mill operation with one million kilowatts per day consumed power. For the particular mill configuration, a performance graph, Fig. (21), has been constructed according to Bond’s methods
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