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.
ادامه مطلبThis 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%.
ادامه مطلبThe 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
ادامه مطلبThe 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.
ادامه مطلبIf 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
ادامه مطلب3. 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 ...
ادامه مطلبThe 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% …
ادامه مطلبWhile 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). ...
ادامه مطلبWi 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 …
ادامه مطلبEquations 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 ...
ادامه مطلبThe 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 ...
ادامه مطلبThe 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.
ادامه مطلبA 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).
ادامه مطلبIn 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 ...
ادامه مطلبWork 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 ...
ادامه مطلبOpen 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 ...
ادامه مطلبBond 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 ...
ادامه مطلبThe 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.
ادامه مطلبThe 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 …
ادامه مطلبThe 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 …
ادامه مطلبHard 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 ...
ادامه مطلبThe 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 ...
ادامه مطلبthe 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.
ادامه مطلبby 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.
ادامه مطلبIn 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).
ادامه مطلبCalculate Ball Mill Grinding Capacity. Do you need a quick estimation of a ball mill's capacity or a simple method to estimate how …
ادامه مطلبA 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.
ادامه مطلبThe 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.
ادامه مطلبDo 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 …
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