Ball Mill is in close circuit. Recirculating load is 250% for ball mill. The contractor/technology supplier who are involved in the erection / installation of plant find after testing of ore at their end, that Bond work index of the Jig rejects is kWH/t. They insist that they will design the Ball Mill at kWH/t.
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WhatsApp: +86 18838072829If smaller particle sizes are retrieved from the ball mill, the process is known as a 'fine grind'. Note. If hard pebbles are used instead of steel balls, the mill is referred to as a 'pebble mill'. If rods are used instead of steel balls, the mill is referred to as a 'rod mill'. ClosedCircuit or OpenCircuit
WhatsApp: +86 18838072829The ball millhydrocyclone circuit and the ball millscreen circuit were sampled in order to measure and compare the performance of the circuits. The ball mills are different in design. Therefore, simulation studies were carried out to eliminate the differences in factors affecting the performance of the circuits such as milling conditions.
WhatsApp: +86 18838072829BallRod Mills, based on 4″ liners and capacity varying as power of mill diameter, on the 5′ size give 20 per cent increased capacity; on the 4′ size, 25 per cent; and on the 3′ size, 28 per cent.
WhatsApp: +86 18838072829Open Circuit, Product Topsize limited = W to ; ... A wet grinding ball mill in closed circuit is to be fed 100 TPH of a material with a work index of 15 and a size distribution of 80% ...
WhatsApp: +86 18838072829Figure shows a flow sheet where the rod mill is in open circuit and the ball mill is in closed circuit with a classifier. This is a normal setup as the primary function of a rod mill is to provide a uniform sized feed to the ball mill. Figure shows that the rod mill product is classified and a more uniform feed size is, therefore, discharged to the ball mill whose primary function is ...
WhatsApp: +86 18838072829A comparison of linear and nonlinear models for opencircuit ball mill grinding. Int. J. Miner. ProCess., 13: 143165. A detailed comparison is made of the capability of population balance models to predict steadystate product size distributions of a pilotscale ball mill.
WhatsApp: +86 18838072829Comparison of methods for sizing ball mills using opencircuit wet grinding of phosphate ore as a test example. Leonard G. Austin; and ; Chaiyot Tangsathitkulchai; ... Modeling and simulation of continuous open circuit dry grinding in a pilotscale ball mill using Austin's and Nomura's models. Powder Technology 2018, 340, 7787.
WhatsApp: +86 18838072829Four methods of analyzing ball mill design were compared for opencircuit wet grinding of a phosphate ore, and the predicted mill capacities were compared to actual plant capacities for mills of,,, and diameter. The Bond sizing method predicted capacities which were too high by 30150%.
WhatsApp: +86 18838072829Important advances have been made in the last 60 years or so in the modeling of ball mills using mathematical formulas and models. One approach that has gained popularity is the population balance model, in particular, when coupled to the specific breakage rate function. The paper demonstrates the application of this methodology to optimize solids concentration in ball milling of an iron ore ...
WhatsApp: +86 18838072829Both devices were operated in an opencircuit. The grinding efficiencies were evaluated using particle RR, SSE, and Wi o. Subsequently, the liberation characteristics of selected size fractions (−106+75 µm, −75+45 µm, and < 45 µm) of the products from both the SFC and the HPGR were investigated and compared. The liberation analyses
WhatsApp: +86 18838072829AG/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 mill sizes available, AG/SAG milling can often be accomplished with fewer lines than in a conventional rod mill/ball mill circuit.
WhatsApp: +86 18838072829Comparison of size d istribution of products form a. laboratory ball mill, open circuit pilot scale stirred mill. and the finish cement marketed at the same Blaine surface.
WhatsApp: +86 188380728291. Closed Circuit = W 2. Open Circuit, Product Topsize not limited = W 3. Open Circuit, Product Topsize limited = W to W Open circuit grinding to a given surface area requires no more power than closed circuit grinding to the same surface area provided there is no objection to the natural topsize.
WhatsApp: +86 18838072829Product Size: All passing 6 mesh with 80% passing 20 mesh. Net power from pilot plant: KWH/ST. Mill, gear and pinion friction multiplier: Mill Power required at pinionshaft = (240 x x ) ÷ = 5440 Hp. Speed reducer efficiency: 98%. 5440 Hp ÷ = 5550 HP (required minimum motor output power).
WhatsApp: +86 18838072829Each mill may operate either as open circuit or closed circuit. Advantages of open circuit grinding. 1. Simplicity of mill layout. 2. May be used where classifying is not practical. 3. May be used where control of product size is not important. 4. The use of rod mills will produce an ideal fine feed for ball mills. 5.
WhatsApp: +86 18838072829In the 1950s and 1960s ball mills dominated primary grinding, however they were supplanted in the 1970s by AG and SAG mill which also replaced two stages of crushing. Nowadays ball mills still dominate secondary grinding applications, but are increasingly in competition with closed circuit AG/SAG mill circuits and stirred mills .
WhatsApp: +86 18838072829This is not the case for the sag mill data. The implication of these differences is that the Bond method may not be valid for sizing ball mill circuits which follow an ag/sag mill circuit. This limitation is recognised by some designers who modify the ag/sag mill product size prior to applying Bond's formula for sizing the ball mill.
WhatsApp: +86 18838072829Austin,, and Brame, K., 1983, "A Comparison of the Bond Method for Sizing Wet Tumbling Ball Mills with a SizeMass Balance Simulation Model," Powder Technology, 34, pp. 261274. Article Google ..., 1980, "A Comparison of Model for the Simulation of OpenCircuit Ball Mill Grinding," MS thesis, University of Utah, Salt Lake ...
WhatsApp: +86 18838072829The 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 18838072829Then, various simulations examined the impacts of closedcircuit vs. opencircuit operation, number of compartments, and various ball size distributions. Our results suggest that integrating an air classifier into an opencircuit ball mill can increase the production rate by 15% or increase the cementspecific surface area by 13%.
WhatsApp: +86 18838072829The crushingball milling circuit specific energy was estimated on the basis of the Bond equation and the relevant Bond work indices (Table 4), with the crushing energy given from the SAG/AG F80 to a nominal product with P80 of mm being added to the ball mill energy from F80 of mm to the actual P80 of the pilot test, given either by the ...
WhatsApp: +86 18838072829The next two examples are for rod mill ball mill circuits. Figure 2 shows a conventional rod millball mill circuit. The data for this circuit and Wi0 calculations are: Rod mill size x (′ x 16′ diameter inside shell ′ ′ rods) Ball mill size x (″ x 16′ diameter inside shell ′)
WhatsApp: +86 18838072829and the IMM equations are shown for comparison. The method of use is similar to the AM section ... Optimum Feed Size for ball mills F Wb =4 000 13,* MILLCALCv2a 7 19/02/2004. ... for open circuit for closed circuit MILLCALCv2a 8 19/02/2004. Standard Mill Programmes
WhatsApp: +86 18838072829Several approaches have been used over the last 80 years or so to describe ball milling quantitatively, which can be grouped into three main types, namely energysize reduction relationships, sizemass (population) balance models and the novel mechanistic ball mill models.
WhatsApp: +86 18838072829For fine regrinding in open circuit, the ratio ranges from :1 to :1. Some ball mills are separated in to compartments by grates. The grates hold back particles above a certain size for additional grinding. The compartments could contain different ball sizes. Large to small from the feed end. Some mills have a conical section.
WhatsApp: +86 18838072829Bond ball mill versus laboratory vertical shaft stirred mill in a virtually closed circuit with classifier to grind a feed of top size mm to a product P 80 less than 100 μm (Cervellin, 2003). • Open circuit batch ball mill compared with laboratory IsaMill to grind a feed of top size around 1 mm to a product P 80 less than 100 μm (Burns ...
WhatsApp: +86 18838072829Based on data from Koski and Vanderbeek, 2011, Kock et al., 2015 a ball mill in a HPGRBall mill circuit will need about 20% more power than one in a SAGball mill circuit. On this basis it is estimated that the steel ball consumption of ball mills in HPGR circuits would be million tonnes per year a saving of million tonnes per year ...
WhatsApp: +86 18838072829The Levin test is commonly used for fine grinding with ball mills, though because it is an open circuit test and most ball mills are closed circuit, it typically overestimates energy requirements due to the test wasting energy grinding fines that would otherwise have been removed [79]. It is more appropriate for stirred media milling than the ...
WhatsApp: +86 18838072829the grinding circuit were carried out for various system configurations. The analyzed mill parameters were the size of the balls, mill filling and density of the feed to the mill. Also the diameters of the hydrocyclones, the angle and the overflow nozzles were selected at the same time. The technological circuit based on a twostage ...
WhatsApp: +86 18838072829The energy consumption of the total grinding plant can be reduced by 2030 % for cement clinker and 3040 % for other raw materials. The overall grinding circuit efficiency and stability are improved. The maintenance cost of the ball mill is reduced as the lifetime of grinding media and partition grates is extended.
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