A ball mill is a slightly inclined, horizontal rotating cylinder, partially filled with ceramic balls, flint pebbles or stain-less steel balls, that grinds material to the necessary fineness by friction and impact with tumbling balls 2. Throughout the 1 Different processes used in comminution 2 Ball mill at Boliden Aitik copper mine comminution ...

Design engineers generally use Bond equation to estimate specific energy requirements using a parameter called, Bond Work Index, which is determined experimentally in a laboratory ball mill [1–3]. Morrell [4–6] has proposed different equations for the specific energy and Work Index. Both the set of equations have been widely tested.

BM = Ball mill specific energy from T 80 1.7 mm to final product P 80, using Bond's Law, (kWh/t) W T = Total grinding mill circuit specific energy (kWh/t) Note that K BM is the composite of EF3, EF4 and EF5 factors for ball milling (Rowland, 1982). Morrell and SMCC Morrell (2004) developed a methodology for predicting specific energy with

C.2.4 Fine Particle Tumbling Mill Specific Energy 11 C.2.5 Total Net Comminution Specific Energy 12 C.3 Conventional Crushing/Ball Mill Circuit 12

A more in-depth look at ball mill operation clearly sug - gests the richness of the information hidden behind the value of specific energy in an operation, which should be regarded as merely an average number. The emphasis on this number suggests, in principle, that it would not mat-ter how the material receives energy, just the amount.

Energy consumption in ball and rod mills reaches up to 10–20 kWh per ton of rock. ... A specific energy model and power consumption mathematical models derived with the use of the ... Another important contribution to the development of DEM as a tool for optimization and description of the comminution process in ball mills was the ...

In contrast, when the SSE75 was calculated, it showed the SAG mill consumed 20% less energy to produce final product material than the ball mill. Since the aim of a comminution circuit is to generate final product material, the SSE methodology gives a fairer indication of energy efficiency.

the ball mill is less energy efficient than a crusher and has to input more energy to do the same amount of size reduction). Hence from equation 7, to crush to the ball mill circuit feed size (x. 2) in open circuit requires specific energy equivalent to: f x f x 2. 1 W c ic. 1.19* 4 2 M x x. 1 (10) For closed circuit crushing the specific ...

A more in-depth look at ball mill operation clearly suggests the richness of the information hidden behind the value of specific energy in an operation, which should be regarded as merely an average number. The emphasis on this number suggests, in principle, that it would not matter how the material receives energy, just the amount.

in crushers, rod mills, and ball mills. • The JK Drop-Weight Test determines specific energy vs. breakage product size distribution. We use JK Drop-Weight test breakage parameters and the JK SimMet software package to simulate comminution circuits for optimization purposes (e.g. ball size, grate open area, etc.) or to integrate

For overflow ball mills, the charge should not exceed 45% of the mill volume . For grate discharge mills, the charge should occupy about 50% of the mill volume . Bond developed a relationship that can be used to determine the percent charge by volume as a function of the vertical height above the charge, He, and the radius of the mill, R, i.e.,

Standard drop weight, SMC, and Bond ball work index tests have been conducted to investigate the comminution circuit of a magnetite ore located in Eastern Hebei, China. In addition, simulations based on JKSimMet and Morrell models have been performed to compare the specific energy consumption of various comminution circuits. According to the desired capacity and the ore communition ...

The concept of size-specific energy (SSE) is applied to determine the equipment energy efficiency in generating materials below a pre-defined marker size, for instance, 75 µm. The SSE can be employed to define the minimum achievable comminution energy that can be used for the determination of the comminution efficiency of various equipment and ...

The model predicts the total comminution energy of most types of plant that contain conventional crushers, High Pressure Grinding Rolls (HPGR) and wet tumbling mills such as Autogenous (AG) Semi-autogenous (SAG), rod and ball mills. As well as the total specific energy it will also predict

COMMINUTION CIRCUITS A SUMMARY OF ENERGY . and ball mill circuit. The "Morrell method for determining comminution circuit specific energy and assessing energy utilization efficiency of existing circuits," published by the Global Mining Guidelines Group (2016), was applied.

The comminution process reduces particle sizes by breaking, crushing, or grinding of ore, rock, coal, or other materials. The process is most often used in the field of mining and / or mineral processing, where mineral ore is broken down into small particles, by hammer, roller / vibrating disc mills and jaw, gyratory and cone crushers.

The SMC Test®, developed by Dr Steve Morrell of SMC Testing, is a cost-effective means to predict comminution circuit throughput, rock mass characteristics and blasting properties. Energy requirements for crushing and HPGR options can now be determined in addition to AG/SAG mills, and with Mic, ball mills.

Predicting the overall specific energy SMC Testing. the nominated ball mill feed size This assumes that a crusher would provide this energy However in this situation the ball mill has to supply this energy and it has a different higher work index than the crusher ie the ball mill is less energy efficient than a crusher and has to input more energy to do the same amount of size reduction .

While complete data for SAG and ball mills were available, only partial data were obtained for crushers and post-grinding, so that some results were estimated. Fig. 17 presents the results for the specific comminution energy for the grinding of copper ore. The average consumption is 1.223 MWh/t Cu.

The specific energies of the SAG and ball mills were determined using AusGrind (Ausenco's in-house software) (Lane, Foggiatto, Bueno and McLean, 2013 and Morrell's ) method. SAG mill specific energy was a function of the inverse of the Axb value, the mill geometry and the mill operating conditions.

The parameter M i takes on different values depending on the comminution machine: M ia for primary tumbling mills (AG/SAG mills) that applies above 750 μm; M ib for secondary tumbling mills (e.g., ball mills) that applies below 750 μm; M ic for conventional crushers; and M ih for HPGRs. The values for M ia, M ic, and M ih were developed using the SMC Test® combined with a database of ...

Gold Milling Comminution. Gold Ore Grinding Mill Small Ball Mill Size Gold Ore Ball Mill. mining mining ore big ball mill SAG Mill Ball Size Evaluator Evaluation Buy mills and grinding circuit, with a gravity recovery system for the free milling values of the ore overall milling energy costs Comminution models commonly predict size 2700 3600 grinding quartz lizenithne ...

ball mill circuits (Bond, 1952). With the introduction of AG/SAG milling, HGPR and fine grinding in the flowsheet, specific comminution tests followed to suit these devices. Table 1 shows a summary-list of commercial comminution tests used in various comminution models. The applicability of …

Specific Energy Requirement and Design These equations form the Basis of DJB's "Millpower2000" Simulation Program for estimating power requirements and mill sizes vs mill throughput objectives. It is an iterative process, but the software can accommodate a large number of geo-comminution samples in a time-efficient manner.

The UFLC represents the first actual measurements of the amount of energy required for comminution under conditions approximating those in industrial ball mills, and provides an absolute value of the specific fracture energy in samples of industrially important …

THE EFFECT OF BALL MILL PARAMETERS ON MINERAL LIBERATION Hector E. Rojas Committee Chairman: Dr. G.T. Adel ... the breakage rates and energy specific breakage rates indicate that a change in breakage kinetics may be ... United States power consumption is related to comminution (Comminution and Energy Consumption, 1981). With this in

CITIC SMCC's approach to determine the specific energy for comminution circuits are well published by ... This modification reduces specific energy consumption of the ball mill by approximately 10 ...

Energy saving with separate fine grinding. Separate grinding and subsequent blending is a commonly used practice in the cement industry, enabling the lowering of the specific electric energy demand by using highly efficient comminution techniques. While ball mills are not the most energy-efficient mills, VDZ's research has shown that in some ...

Up until now, tumbling mills such as AG/SAG mills and ball mills have had a dominant bearing on the design and economics of comminution circuits. However, it is commonly agreed that the majority of employed comminution processes are energy intensive and energy inefficient, accounting for up to 80% of overall process plant energy consumption and ...

Home - Solutions - specific comminution energy of ball mills 2012 pdf. specific comminution energy of ball mills 2012 pdf. Proportion of Energy Attributable to Comminution - CEEC 11TH MILL OPERATORS' CONFERENCE 2012 / HOBART, TAS, 29 - 31 OCTOBER 2012. INTRODUCTION ...

One of the standard energy curves presents the size specific energy (energy required to produce new minus 75 µm material: kWh/t-75µm). The marker size of 75 µm is effective for assessing the performance of most SAG and ball mills, but on some occasions another size might be preferred.

A particle size reduction model has been developed as the first component of an upgraded ball mill model. The model is based on a specific energy-size reduction function, which calculates the particle breakage index, t 10, according to the size-specific energy, and then calculates the full product size distribution using the t 10-t n relationships and the mass-size balance approach.

Ball mills are still the workhorse of the industry when it comes to producing the final fine product ahead of separation processes like flotation, magnetic separation, leaching and the like. And over half the total amount of energy for comminution is still used by these ball mills. We believe we can replace those ball mills with about half the ...