Jun 16, 2015 Sizing a crusher can be done reliably calculated thanks to the Impact/Crushing Work Index and the testwork research done by Fred Chester Bond and his 1952 paper. According to Bond’s Third Theory of Comminution, the work/energy input is proportional to the new crack tip length created during particle breakage and equivalent to the work
Read MoreThe Bond low-energy impact crushing work index (more informally, the Bond crushing work index) is not as common as the Bond ball mill work index, and it is a notoriously noisy test.. The test is a 'per-specimen' test where individual specimens of prepared rock are hand-picked by the test operator and placed into the apparatus.
Read MoreThe Bond Low-Energy Impact test can be used to determine the Crusher Work index (CWi), also known as the Impact Work Index. The test determines the impact energy at which a specimen fails and allows approximation of net power requirements for sizing crushers. The open and closed sized settings for given product sizes can also be determined.
Read MoreThe Bond low energy impact (crushing) work index test is specified to be performed on rock specimens between 50 mm and 75 mm in effective diameter. NQ-diameter drill core, frequently used in mineral exploration programs does not meet that specification, it being 45 mm diameter or less.
Read MoreThe Pendulum Tester / Bond Impact Crushing Work Index Tester. Working principle Crushing by impact. 76 mm maximum feed size. Test repetition: At least 10, preferably 20 test runs. The Bond Crushing Work Index (CWI) describes the competency of the ore at larger particle sizes. It is used for the calculation of the actual crusher power requirements.
Read MoreThe 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 12.7 ...
Read MoreThe Bond Low-Energy Impact test can be used to determine the Crusher Work index (CWi), also known as the Impact Work Index. The test determines the impact energy at which a specimen fails and allows approximation of net power requirements for sizing crushers. The open and closed sized settings for given product sizes can also be determined.
Read MoreThe Bond low energy impact (crushing) work index test is specified to be performed on rock specimens between 50 mm and 75 mm in effective diameter. NQ-diameter drill core, frequently used in mineral exploration programs does not meet that specification, it being 45 mm diameter or less.
Read MoreThe Bond low-energy impact crushing work index (more informally, the Bond crushing work index) is not as common as the Bond ball mill work index, and it is a notoriously noisy test.. The test is a 'per-specimen' test where individual specimens of prepared rock are hand-picked by the test operator and placed into the apparatus.
Read MoreNov 22, 2015 Relation of Bond rod mill work index and crushing work index. Similar to the ball mill work index, the rod mill work index is a tumbling test that includes both attrition and abrasion breakage mechanisms. Unlike the ball mill work index, the size of the feed to a rod mill test (10 mm–12 mm) is closer to the size of the crushing test.
Read MoreDec 01, 2007 Bond (1947) defined the impact energy per unit of thickness C B by dividing the impact energy by the thickness of each particle w, so that (1) C B = 117 (1-cos ϕ) / w where ϕ is the angle, w is given in mm and C B in J/mm. From this and the material specific gravity ρ s (in g/cm 3) Bond proposed to estimate the crushing work index using the empirical relationship (2) Wi = 53.49 C B ρ s ...
Read MoreJul 15, 2013 The work index Wi can be determined from plant operations and from laboratory ball mill grindability, rod mill grindability, and impact crushing tests. The laboratory test results are used to check the efficiency of commercial operations and to compute the proper machine sizes for new installations.
Read MoreThe Bond crushing work index test is an inherently poor test and has been shown time and time again in Round Robin studies to have poor precision (repeatability). Angove and Dunne’s paper on the subject gives results that show factors of over 2 in terms of reported work index values from the same sample from different labs.
Read Morecrusher were compared with those of the Bond crushing energies (estimated from the Bond crushability index) of the rocks. Also, the effect of the Bond crushability index on the estimated crushing energy of the rocks was studied. Materials and methods In this work, nine different rock specimens were obtained from some mines in Iran.
Read MoreJun 17, 2020 The greater the surface energy consumption, the greater the crushing work required at the same crushing ratio, and the stronger the rock. After fragmentation, small fragments contribute to a significant proportion of the added surface area. Therefore, under the same energy input conditions, coal with high hardness produces less powder.
Read MoreThis minimum value of FN is, by definition, the impact rock strength coefficient (FN), as representing the optimum specific crushing energy (minimum impact energy per unit volume of -0.5 mm material). FN has dimensions cm-3. It has been previously proved that it correlates with relative accuracy with the mechanical properties of the rock, such as:
Read MoreJan 01, 2016 According to Chakrabarti, the work index of an unknown rock material can be obtained by first crushing the rock to less than 3327 μm, avoiding over crushing by using low energy impact or compression and by closing the circuit with a 3327 μm screen.
Read Morecorrelation between the abrasion value(X2) and work index (Wi) is found to be Wi = -1.8 Ln (X2) + 11.5 with correlation coefficient of 0.80. KEYWORDS: Bond work index ± Mechanical properties of rocks ± Grinding energy- Crushing resistance 1- INTRODUCTION Comminution in a mineral processing plant, or mill, involves a sequence of crushi ng
Read MoreThe Bond low-energy impact crushing work index (more informally, the Bond crushing work index) is not as common as the Bond ball mill work index, and it is a notoriously noisy test.. The test is a 'per-specimen' test where individual specimens of prepared rock are hand-picked by the test operator and placed into the apparatus.
Read Moreoccurs. The work input, assuming no change in work index, is .194 kwh/ton. For a mine crushing 50 million tons per year, a reduction of 1.8 million kilowatt-hours, or about $125,000 per year is realized. The second possibility is a decrease in Wi. There is evidence that work index bears a
Read MoreBond Work Index (BWI) — Kilowatt hour (kWh) per short ton required to reduce the material to 80% passing 100 microns. Breaker Block (Breaker Plate) — The steel anvil surface of a crusher against which material is crushed by impact or pressure. Bridging — Blocking of crusher opening by large pieces of
Read Morebond work index uses in gold processing - crusher in India. bond crushing work index of copper slag ... Values of Bond crushing work index will vary from a 8 kWh/t for laterite hardcap through to 22 kWh/t for banded iron ...
Read MoreThe 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 calculation is based on the size-energy relationship e1,2=C.(1/x2n–1/x1n ) , which for n = 0.5, x1 = ∞ and x2 =100, by definition gives e∞, 100 = Wi and consequently C=10Wi. In theory, for a given material the value found for Wi ...
Read MoreThis minimum value of FN is, by definition, the impact rock strength coefficient (FN), as representing the optimum specific crushing energy (minimum impact energy per unit volume of -0.5 mm material). FN has dimensions cm-3. It has been previously proved that it correlates with relative accuracy with the mechanical properties of the rock, such as:
Read MoreThe amount of energy required to do this work is referred to as the ‘Work Index’ and it is an expression of the resistance that a material has to crushing (or grinding). It is a measurement of how hard the ore is. Therefore 'Work Index' can be defined as: The amount of energy (work) required to break a rock from one size to another.
Read MoreJun 17, 2020 The greater the surface energy consumption, the greater the crushing work required at the same crushing ratio, and the stronger the rock. After fragmentation, small fragments contribute to a significant proportion of the added surface area. Therefore, under the same energy input conditions, coal with high hardness produces less powder.
Read MoreThe three types of crushers most commonly used for crushing CDW materials are the jaw crusher, the impact crusher and the gyratory crusher (Figure 4.4).A jaw crusher consists of two plates, with one oscillating back and forth against the other at a fixed angle (Figure 4.4(a)) and it is the most widely used in primary crushing stages (Behera et al., 2014).
Read MoreThe reason secondary crushing works is relatively simple. The frequency of impact events greater than 100 Joules impacts, even in a large SAG mill, is very low, less than 1 per second (Morrison Cleary, 04). Rocks requiring more than 100 Joules of energy to first fracture severely limit the throughput rate of a mill. Such rocks grind slowly by
Read MoreFeb 26, 2014 FEEDER BREAKER Advantages • Avoids costly site preparation and civil work • Can transfer and crush material in a single machine • Handles wet material with ease • Very low headroom • Can handle upto 2000 MTPH Disadvantage • Very low reduction ratio • Crushing takes place in breaker bars and chains which causes wear. http ...
Read MoreYou may change any data value. Clicking outside the box will then initiate a calculation of the impact force and conversion of the data value to the other types of units. Discussion of car crash scenario: Index Work-energy principle
Read MoreThe impact crushing dust generation test device, developed by China Coal Technology Engineering Group Chongqing Research Institute, is mainly composed of a drop hammer, a guide rod, a crushing rod and a sample tank, as shown in Fig. 1.A certain mass of coal was placed in the sample tank and then crushed by the drop hammer freely released from a certain height.
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