- Test methods for characterizing ore comminution behavior

behavior although the applied fracture mechanism of the mill cannot be excluded. With crushed ore samples from Malmberget also grindability tests and mineral liberation analyses were conducted using laboratory tumbling mills of different size. Starting from the dimensions of the Bond ball mill a modified test method was developed where small size samples of approximately 220 g were pre-crushed

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Autogenous and Semi-Autogenous Mills |

The mills can be operated in open circuit, feeding downstream secondary grinding, or operated in closed circuit as single stage mills generating a finer product size. Single stage SAG Mills are very beneficial in reducing CAPEX for plants with a staged throughput approach. When future tonnage is to be increased, the SAG Mill can feed downstream ball milling to boost capacity.

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OUTOTEC AUTOMATION SOLUTIONS FOR GRINDING OPTIMIZATION

optimization. It is critical to achieve a suitable ore feed size distribution in order to reach high grinding effi ciency and throughput, especially in grinding circuits involving autogenous (AG) or semi-autogenous (SAG) mills. The investment in grinding optimization pays for itself through reduced energy costs and improved productivity.

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BATU HIJAU MILL THROUGHPUT OPTIMIZATION: MILLING

of 31% (65mm diameter ball size) to perform size reduction from 2a mm -10 mm feed size range to 180a microns - 250 microns product size range. The mills are equipped with trommel screens having an aperture of 12.7mm x 31.8 mm. The ball mill classification circulating load design basis was 230%. The ball mill

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Optimum choice of the make-up ball sizes for

Fig. 8 shows the optimum composition of the make-up ball sizes for various feed sizes as a function of the size reduction ratio, R. Because mixtures of two balls (50.8 mm and 25.4 mm ball) are always found to be optimum, the results are plotted with the ordinate being the fraction of 50.8 mm balls. It can be seen that the data appear as a straight line on a log–log scale. This is therefore

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Orway Mineral Consultants Canada Ltd. Mississauga, ON

Orway Mineral Consultants Canada Ltd. Mississauga, ON., L4W 5N5, Canada ABSTRACT Orway Mineral Consultants Ltd (OMC)as a consultancy has speciali zed in comminution circuit design for over 30 years. OMC Power Model is OMC'sThe in-house software for specific grinding energy power-based circuit calculations. The model uses ore hardness parameters from testwork,

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Calculate and Select Ball Mill Ball Size for

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 Mineral Processing Engineer AKA Metallurgist to do. Often, the ball used in ball mills is oversize "just in case". Well, this safety factor can cost you much in recovery and/or mill liner wear and

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Ball Mill Critical Speed & Working Principle -

19.06.2015· However, within the range of normal (North American) operating practice (i.e. 35 - 40% mill loading, and 70 - 80% of critical speed) and for ball-size approximating the lifter height, the

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(PDF) Performance optimization of an

Performance optimization of an industrial ball mill for chromite processing Article (PDF Available) in Journal of the Southern African Institute of Mining and Metallurgy 117(1):75-81 · January

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The process design of gold leaching and carbon-in-pulp

The ore is first reduced in size (typically 80% passing 75µm) to ensure that all non- refractory gold is readily accessible for cyanide leaching. There are several variations of comminution circuits used in the gold industry, such as: Multi-stage crushing and pebble and/or ball milling circuits, typical of older installations. The process design of gold leaching and carbon-in-pulp circuits by

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Optimization of Solids Concentration in Iron Ore Ball

Optimization of Solids Concentration in Iron Ore Ball Milling through Modeling and Simulation Patricia M. C. Faria 1,2, Raj K. Rajamani 3 and Luís M. Tavares 2,* 1 Department of Development Engineering, Vale S.A., Porto de Tubarão, Vitória-ES CEP 29090-900, Brazil; [email protected] 2 Department of Metallurgical and Materials Engineering,

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Optimization and Performance of Grinding Circuits: The

2009 and treats a sulphide copper-gold ore to produce gold in form of doré bars and a concentrate containing gold, copper and silver. The BGM comminution circuit includes a primary crushing stage with a gyratory crusher and a two grinding circuits using a Semi-Autogenous Grinding (SAG) mill and a ball mill. The SAG mill circuit also includes

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Optimization of Comminution Circuit

@article{osti_887498, title = {Optimization of Comminution Circuit Throughput and Product Size Distribution by Simulation and Control}, author = {Kawatra, S K and Eisele, T C and Weldum, T and Larsen, D and Mariani, R and Pletka, J}, abstractNote = {The goal of this project was to improve energy efficiency of industrial crushing and grinding operations (comminution).

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Mine-To-Mill Optimisation: Effect Of Feed Size

Mine-To-Mill Optimisation: Effect Of Feed Size On Mill Throughput; Over the past 15 years, mine-to-mill studies have focused attention on the impact blast fragmentation has on concentrator throughput. Blasting provides the first opportunity for comminution – or size reduction. It is also a cheaper and more efficient process, compared to both crushing and grinding. One of the most valuable

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The Selection and Design of Mill Liners - MillTraj

Figure 5. High–low wave ball mill liner Materials The selection of the material of construction is a function of the application, abrasivity of ore, size of mill, corrosion environment, size of balls, mill speed, etc. liner design and material of construction are integral and cannot be chosen in isolation. A list of the primary material of

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Grinding in Ball Mills: Modeling and Process Control

Besides particle size reduction, ball mills are also widely used for mixing, is charged with the starting material (ore, rock, etc.) and the grinding media (balls), 52 the milling process takes place during rotation as a result of the transfer of kinetic energy of the moving grinding media into the grinding product. The design of a ball mill can vary significantly depending on the size

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Optimisation of a Fully Autogenous Comminution Circuit

Optimisation of a Fully Autogenous Comminution Circuit by CW Steyn A dissertation submitted in partial ful llment of the requirements for the degree Master of Engineering (Control Engineering) in the Department of Chemical Engineering Faculty of Engineering, the Built Environment and Information Technology University of Pretoria Pretoria December 2011. Synopsis Autogenous (AG) milling is

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TECHNICAL NOTES 8 GRINDING R. P. King - Mineral Tech

The geometry of a mill with conical ends is shown in Figure 8.6. The total volume inside the mill is given by Vm 4 D2 mL 1 2(Lc L) L 1 (Dt/Dm) 3 1 Dt/Dm (8.16) The density of the charge must account for all of the material in the mill including the media which may be steel balls in a ball mill, or large lumps of ore

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THE OPTIMAL BALL DIAMETER IN A MILL

The ball size in a mill has a significant influence on the mill throughput, power consumption and ground material size (Austin et al., 1976; Fuerstenau et al., 1999; Kotake et. al., 2004). The basic condition, which must be met while grinding the material in a mill is that the ball, while breaking the material grain, causes in it stress which is higher than the grain hardness (Bond, 1962

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Ball Mills - Mineral Processing & Metallurgy

The ore from the crushing section is delivered to the fine ore bin placed at the head of the grinding section, from which it is fed, together with water, to one or more grinding units consisting of a ball mill or rod mill in circuit with a classifier. One such unit with a conical ball mill is shown in Fig. 9. A ball mill consists essentially of a conical or cylindrical shell supported on

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