Commentary on the apparatus of the Bond rod mill Work Index by Alex Doll December, 2015 The Bond "Third Theory" of comminution was originally divided into three size classes reflecting the varieties of comminution equipment common during the time period when Bond (and his collaborators) were gathering the information to calibrate comminution models.
WhatsApp: +86 18838072829Introduction. A Bond Ball Mill Work Index test is a standard test for determining the ball mill work index of a sample of ore. It was developed by Fred Bond in 1952 and modified in 1961 (JKMRC CO., 2006). This index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the ...
WhatsApp: +86 18838072829work index approximate value is exactly the same as in the first two grinding cycles of. Prepare a sample, the same as for the standard Bond test (grind to 100%. mm). Determine the starting ...
WhatsApp: +86 18838072829Rod Mill Design Calculations. EF1 Dry Grinding for the same range of work, dry grinding requires times as much power as wet grinding. EF2 Open Circuit Grinding when grinding in open circuit ball mills, the amount of extra power required, compared to closed circuit ball milling, is a function of the degree of control required ...
WhatsApp: +86 18838072829The design of rod and ball mills is still carried out with the Bond ball mill and rod mill grindability tests. As discussed earlier in this paper, it is important in this case to match the reduction size of the test to that desired from the industrial mill. As such, primary ball mills should be designed with the rod mill work index, and single ...
WhatsApp: +86 18838072829The Bond Index conforming rod charge consists of: 6 rods of " diameter and 21" length; 2 rods of " diameter and 21" length; The grinding jar for the Bond Index Rod Mill is 12″ x 24″ in size and has a waveshaped design. At least 15 to 20 kg sample material is required to simulate a closed grinding circuit in a ball or rod mill.
WhatsApp: +86 18838072829standard Bond crushing, and rod mill work indices, abrasion indices and by Dawson for Bond Ball Mill Work Index tests using crushed feed, and Standard Autogenous Grinding Design (SAGDesign) Tests, patented by Outokumpu. (See reference 8 below). The comparison of these results gives context to how the various measurements relate to each
WhatsApp: +86 18838072829The reason for this variation in ball mill work index is because the ore at Mt. Milligan has an intrinsic exponent of in the 100 µm to 200 µm size range, not the 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
WhatsApp: +86 18838072829The Ball mill work index is the final Bond work index, applicable to the size range of ball milling (very roughly: from mm to about 75 µm; yes, it overlaps the Rod Mill Wi range). More on ...
WhatsApp: +86 18838072829You need a twostage solution, first stage opencircuit mill and then second stage closedcircuit mill. First stage, will be broken into two parts as well, you use a Bond rod mill work index for the coarse component of the ore (+ mm) and the Bond ball mill work index for the fine component ( mm).
WhatsApp: +86 18838072829WiBM Bond Ball Mill Test Work Index (kWh/t) Wic Bond Impact Crushing Test Work Index (kWh/t) WioACT Actual Operating Bond Work Index determined from measurements on the circuit (kWh/t) WiRM Bond Rod Mill Test Work Index (kWh/t) WiSTD Standard Circuit Bond Work Index (expected or designed) used for circuit design. Specific energy requirement at ...
WhatsApp: +86 18838072829You can also review the stepbystep Bond Work Index Test Procedure I posted here. See thisuseful summaryTable of Bond Work Index by Minerals. For any circuit, whether a crushing circuit, a rod mill, or a closed ball mill circuit, the Work Index always means the equivalent amount of energy to reduce one ton of the ore from a very large size to ...
WhatsApp: +86 18838072829The low energy crushing work index laboratory test is conducted on ore specimens larger than 50 mm, determining the crushing work index (Wi C, CWi or IWi (impact work index)). The rod mill work index laboratory test is conducted by grinding an ore sample prepared to 80% passing mm (½ inch, the original test being developed in imperial ...
WhatsApp: +86 18838072829Unrelated 'entertaining' image. The specification for the apparatus to determining a "Bond" rod mill work index is first described in Bond Maxton (1943). It states that the apparatus is a tumbling rod mill to be operated in a locked cycle test at a fixed circulating load. The geometry of the grinding chamber is described as: mill ...
WhatsApp: +86 18838072829GSL can carry out Bond Rod Mill Work Index tests to determine the energy requirements for milling ore in a rod mill. The test requires a minimum of 20kg of material. Closing screen sizes typically range from to 212µm. Abrasion Index Test. The Abrasion Index is a recognised procedure to quantify abrasiveness and approximate wear ...
WhatsApp: +86 18838072829It is a wellknown fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. In this study, a variability bysis is carried out with the Bond standard grindability tests on different critical metal ores (W, Ta), ranging from coarse grinding (rod mills) to fine grinding (ball mills). The relationship between wi and grinding size did not show a clear ...
WhatsApp: +86 18838072829The Bond Rod Mill Work Index (BRMWI) test was only possible for Blend 5 (Table 2) due to excessive fines in the other blends. The calculated power required for the remaining blends only considered grinding the coarse fraction in the rod compartment. The Bond formula and power model were used to verify the effects of operational variables, hardness
WhatsApp: +86 18838072829Cleaning and Storing of Ball Mill Charge after the Bond Work Index Procedure is done: Add about 500 g of silica sand into the mill containing the ball charge. Seal the mill. Rotate for 20 revolutions to clean. Empty the mill charge and sand into the ball try once grinding is complete. Clean out the mill using a brush. Put the lid on the mill.
WhatsApp: +86 18838072829Based on the standard procedure defined by Bond, the ball mill work index is determined by simulating a closed cycle dry grinding in a laboratory Bond ball mill until a stable circulating load of 250% is established (Bond, 1949, Bond, 1952, Bond, 1961). The ball mill work index is determined by Eq. (10). The recommendation is the ball mill ...
WhatsApp: +86 18838072829In the Bond ball mill test, the work index is finally obtained. by. w. P Gbp PF. i = ... [Show full abstract] different characteristics of rod mill and ball mill, solving the grinding problem of ...
WhatsApp: +86 18838072829Bond Rod Work Index Mill. Attention: Operators. It is imperative to use the utmost care to avoid contact with the moving parts of the machine in operation. There is no need to touch anything while it performs the intended function. ... Rod/Ball Mill 13 x 22 Operating Manual. WARNING! Do not start the motor with a safety enclosure retracted and ...
WhatsApp: +86 18838072829• WiBM The Bond ball mill work index, in metric units. • WiRM The Bond rod mill work index, in metric units. • WiC The Bond impact crushing work index, in metric units. • Density The coarse particle density measured in either the Bond impact crushing work index test or the drop weight test, t/m³.
WhatsApp: +86 18838072829The Bond rod mill work index (Wi RM, or RWi) conducted from a feed size of approximately 10 mm to a product size on the order of 1 mm. The Bond crushing (impact) work index (Wi C, CWi, LEIT or IWi) conducted on specimens of a nominal dimension between 50 mm and 75 mm. The product size is not relevant to this test; it is a determination of the ...
WhatsApp: +86 18838072829samples and perform the rod mill test on the samples blend. Bond Ball Mill (BBM) Standard Test The procedures to carry out the Bond grindability tests in ball mills and rod mills are outlined in They are usually referred to as the standard tests, but it must be highlighted that the procedures haven't been defined by ...
WhatsApp: +86 18838072829The Bond rod mill grindability test is a widely used tool to estimate the response of ores to rod milling. However, the mass of ore required to conduct the test, which can typically vary from about 8 to as much as 20 kg, may represent a challenge when sample availability is present work proposes an alternative procedure, which is based on the sizemass balance model with a ...
WhatsApp: +86 18838072829world. It shows that the ball mill work index is normally distributed with an average of and a median of kWh/t. bOnd rOd mill GrindAbility The Bond Rod Mill Grindability Test is performed similarly to the ball mill test. The feed sample is stagecrushed to ½" and the test is run under a 100% circulating load. As in
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