tonnage capacity knowing ball mill work index

The Science of Comminution | PDF | Mill (Grinding)

For secondary milling duties, a ball mill work index determination will suffice. The minimum sample requirement for the rod and ball index tests is 25 kg of either 12.7 mm (1/2) crushed rock or split NQ (50mm dia.) drillcore. For the ball mill work index test alone, only 10 kg of material is required.

Closed circuit ball mill – Basics revisited

This means that mill capacity to produce the final product increased 17%. By increasing the amount of "by-pass" of mill product to mill feed (which simulates lower classification efficiency) from 0% to 37.5%, the relative work index increased up to 9% and the capacity of the circuit decreased 15%.

BOND'S WORK INDEX: WHAT IT IS AND WHAT IT ISN'T

The reason for this variation in ball mill work index is because the ore at Mt. Milligan has an intrinsic exponent of –0.45 in the 100 µm to 200 µm size range, not the –0.50 exponent empirically measured by F. Bond. The work index increase between 100 µm and 76 µm is due to a porphyritic grain size that causes a spike in energy

Geometallurgical Modeling of the ndida Deposit

The Los Colorados mill consists of 3 SAG mills, two SAG with two ball mills each and the SAG3 with three ball mills. The Line 1 and Line 2 mill circuits in the Laguna Seca plant consist of one SAG mill and four ball mills. The SAG mill reduces the size of the ore from an average feed size of 10 cm to a product of about 5 cm in size.

Rock Crushing Rule of Thumb

If the hourly tonnage to be crushed divided by the square of the required gape in inches is less than 0.115, use a jaw crusher; otherwise use a gyratory. (If the required capacity in metric TPH is less than 162 times the square of the gape in metres, use a jaw crusher.) Source: Arthur Taggart Crushing in Mineral Processing

Understanding the Science & Art of Grinding Media

3. Size Matters: The size of the grinding media directly influences the efficiency of the milling process. Smaller media tend to provide finer grinding, but it may come at the cost of reduced ...

Ball Mill Design/Power Calculation

The bottom parameters used in ball milling design ... material to be ground, property, Bond Employment Card, bulk density, specific density, wish mill tonnage capacity DTPH, operates % stables or ... A wet grinding ball mill in closed circuit is to be detective 100 TPH of a substance with a work index of 15 and a size distributor of 80% …

(PDF) Predicting the overall specific energy requirement of crushing

While Mia defines the coarse grinding in tumbling mills, Mib defines the fine part of it, and it is determined by the conventional Bond ball mill work index test (Morrell, 2008). ...

20150821 Morrell Method-GMG-ICE-v01-r01 Morrell method …

Wi Bond Work Index Ws Specific energy correction for size distribution (kWh/t) WiBM Bond Ball Mill Test Work Index (kWh/t) 3. KEYWORDS Autogenous Grinding (AG), Ball mill, Bond Work Index (Wi), Comminution circuit, High Pressure Grinding Rolls (HPGRs), Rod mill, Semi-Autogenous Grinding (SAG), Spe-cific energy (W) 4. INTRODUCTION AND …

Ball Mill | PDF

Equations of the design By knowing the capacity quot;Cquot; {ton} of the feed; we can get approximately the length quot;Lquot; {mm} and diameter quot;Dquot; {mm} of the batch ball mill, form **D = 124.2*(C) + 485.7 **L= 85.71*(C) + 1854 Volume of mill = ^2 The bulk volume of balls charge ratio to the volume of mill is known as {Filling ratio ...

A New Approach to the Calculation of Work Index and the …

The work index Wi was defined by F. Bond as the specific energy (kWh/ton) required to reduce a particulate material from infinite grain size to 100 microns. ... The energy consumed by the ball ...

SAG Mill Ball Size Evaluator | Evaluation Factors | Calculate …

The SAG Mill has a "small" circulation load of oversize given be the 3/8″ trommel screen and the 1/2″ x 1 1/4″ discharge grates. The load of 4″ balls in this SAG is "good" but un-measured. SAG Ball consumption is "average" at 400 g/t while Ball Mill grinding media (3″ balls) usage in 550 g/t.

Ball Mill Design/Power Calculation

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% passing ¼ inch (6350 microns).

Quantifying the energy efficiency of fine grinding circuits

In the first survey the ball mill was underperforming due to the low density in the mill, which was rectified in the second survey. The ball mill was grinding to a P 80 of 50 to 70 µm, therefore the traditional marker size (75 µm) was not applicable, and this can be seen by the increase in SSE for coarser sizes as the marker size approached P ...

Is Powder Factor the smart KPI for your quarry?

Work index (Wi) I found in the Metso Handbook, and in case of limestone is equal to 12.3 for crushing and 12.74 for grinding. Let's assume that we have a mill with feed size of 5cm and product of ...

Physical Bauxite Processing: Crushing and Grinding of Bauxite

Open Circuit Rod Mill followed by Closed Circuit Ball Mill. In this case the grinding circuit comprises an open circuit rod mill followed by a closed-circuit ball mill. The ball mill is most often closed over a classifier like a hydro cyclone (Fig. 3.11) or DSM style screen with a fine cut of 1–1.5 mm. The course material is returned to the ...

Processing of Magnetite Iron Ores–Comparing Grinding Options

Bond ball mill work index (BBWi) kWh/t 17.2. Bond abrasion index (BAi) 0.3. ... A theoretical design study for a for high capacity processing of a hard, fine grained silica rich magnetite ore ...

Ball Milling

The use of ball mills for reducing crusher product to 85 per cent,: below 200-mesh in two stages, as practised at the United Eastern, Tom Reed, and Montana mines, in Arizona, is a distinct advance in fine crushing. The simplicity, small floor space and large capacity of these installations are especially notable.

How Ball Mill Ore Feed Size Affects Tonnage & Capacity

The grinding mill output will vary considerably with the Work Index. If the feed size was 13,000 micrometers for the same grind production size, theoretical output from Fig. (21) would change from about 90,000 tons per day on the 13 Work Index down to …

Bond Work Index

The ball mill work index laboratory test is conducted by grinding an ore sample prepared to 100% passing 3.36 mm (6 mesh) to product size in the range of 45-150 µm (325-100 …

How Ball Mill Ore Feed Size Affects Tonnage & Capacity

Hard ore Work Index 16 = 100,000/65,000 = 1.54 kwh/t. 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 ...

Ball Mills

The apparent difference in capacities between grinding mills (listed as being the same size) is due to the fact that there is no uniform method of designating the size of a mill, for example: a 5′ x 5′ Ball Mill has a working diameter of 5′ inside the liners and has 20 per cent more capacity than all other ball mills designated as 5′ x ...

Jaw Crusher

the maximum annual capacity of crusher with 99% availability, 3. power consumption at the optimum speed. 4.2. A single toggle Blake jaw crusher with 22.8 cm × 47.7 cm receiving hopper crushed gold ore at the rate of 85 t/h with closed setting at 2.54 cm and maximum opening of 3.8 cm. The work index of the ore was 13.5 kWh/t.

Grinding Operations Design Overview | PDF | Mill (Grinding

by the well known Bond Work Index and can be expressed as: 10 Wi. w= Where. 10 Wi. w = work. input. P = 80% passing size of product = work. index. Wi = 80%. passing size of feed. Bond's Law has been found to apply reasonably well in the range of conventional rod mill and ball mill grinding.

Keys to best practice comminution

In those days, 3 stages of crushing, and rod and ball mill grinding, were common in comminution flowsheets. Bond's Rod Mill Work Index (RM Wi) and Ball Mill Work Index (BM Wi) tests provided good designs for grinding mills. If the design was 1200 t/d, each stage had to be able to produce 1200 t/d or (54 t/h at 92.6% availability).

Small Ball Mill Capacity & Sizing Table

Calculate Ball Mill Grinding Capacity. Do you need a quick estimation of a ball mill's capacity or a simple method to estimate how …

Integrating geometallurgical ball mill throughput predictions into

A conventional mill capacity constraint is used instead, which limits the processed material per period based on a constant tonnage capacity. Fig. 10 b shows the resulting production schedule and a risk analysis of the mill tonnage that can be processed using the tonnage capacity constraint rather the throughput prediction model.

Grinding Fundamentals | PDF | Mill (Grinding) | Bearing …

The test enables basic grinding power requirement in ball mills to be determined, from the feed 80% passing size (F80) to circuit 80% passing size (P80), using the classic Bond formula. The rod mill work index test requires 20 kg of material, which is crushed to -12.7 mm (1/2) and tested in a standard Bond Rod mill.

Bond Work Index Formula-Equation

Small Ball Mill Capacity & Sizing Table

Do you need a quick estimation of a ball mill's capacity or a simple method to estimate how much can a ball mill of a given size (diameter/lenght) grind for tonnage a product P80 size? Use these 2 …