Pre-treatment of the material to be crushed in order to obtain lower Bond index values (W i). This approach implies the measurement of variations in the Bond Work index values during the pre-treatment of the material to be crushed. The most accepted treatment is related to increasing the number of initial cracks in the particles [4].
قرأ أكثر
Once the Bond Work Index is known for a specific material the equation can be used to calculate the energy requirements for various ranges of input and output sizes. Bond's work index is given below: The indices derived by Kick, Bond and Von Rittinger all assume a constant energy requirement per unit of
قرأ أكثر
The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond Work Index, bulk density, specific density, desired mill tonnage capacity DTPH, operating % solids or pulp density, feed size as F80 and maximum 'chunk size', product size as P80 and …
قرأ أكثر
FIGURE 5: BOND ROD MILL WORK INDEX v. UNCONFINED COMPRESSIVE STRENGTH 0 100 200 300 400 UCS (MPa) 5 10 15 20 25 30 35 WiRM (metric) The lack of fit observed relating the crushing Work Index was expected to carry over to the other Bond Work Indices. Figure 5 displays the plot of rod mill Work Index (Wi RM) versus UCS. …
قرأ أكثر
"Comminution law" and for "CIPSD" substream use "3 kWhr/ton" under "Bond work index" column. See Aspen Plus built-in help: "Bond's Law" for further information on Bond work index. Bond considered that the work necessary for reduction is inversely proportional to the square root of the size produced.
قرأ أكثر
Introduction. 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:
قرأ أكثر
the impact work index, also called Bond crushability index, continues to be much used for crusher selection. The present work shows the. application of a model that combines measurements of ...
قرأ أكثر
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 …
قرأ أكثر
The Bond work indices (or "impact work index") can be used for estimating the crushability of material and the crusher's energy consumption. The crushability value can be used for estimating the degree of difficulty of the material tested. The dynamic fragmentation value gives an indication of the material's resistance against impact.
قرأ أكثر
The Bond crushing work index test (sometimes called the "impact work index" test) is noisy, and the difference you observed is perfectly reasonable. ... (1997) reports a standard deviation in crushing work index tests across laboratories as 4.5. The laboratory CWi value of 27.4 (metric) is almost within 4.5 units of the 22.4 value I calculated ...
قرأ أكثر
The traditional Bond work index proposed by F.C. Bond over 60 years ago is still today a useful tool for characterizing material crushability and grindability in the minerals industry.
قرأ أكثر
The Bond work index (BWI) is a well-known method used when selecting comminution equipment, to evaluate the grinding efficiency and to calculate the required grinding power. ... Modified Bond method for the evaluation of crusher efficiency. Min., Metallur. Explor., 6 (1989), pp. 14-17, 10.1007/BF03402519. ... grindability index and …
قرأ أكثر
P80 = 25400 x Oss x (0.04Wi + 0.40) P80 = 25400 x Css x 7Ecc x (0.02Wi + 0.70) / (7Ecc – 2Css) Where Oss = Open-side setting in inches. Css = Closed-side settings in inches. Ecc = Eccentric throw in inches. P80 = Aperture through which 80% of the …
قرأ أكثر
The crusher has a feed opening gap of 25 mm, a stroke of 4.9 mm, a cone angle of 44o (in relation to horizontal) and a mantle length of 150 mm. A constant closed-side setting of 7.6 mm was used in ...
قرأ أكثر
Rowland, C.A., 1973, "Comparison of work indices calculated from operating data with those from laboratory test data," Proceedings Tenth International Minerals Processing Congress, The Institution of Mining and Metallurgy, London, UK, pp. 47–61.
قرأ أكثر
The Bond's standard ball mill is used to determine the work index value of differ ent samples. The Bond work index is defined as the kilowatt-hours per short ton required to break from infinite size to a product size of 80% passing 100 µm. If the breakage characteristics of a material remain constant over all size ranges, the calcul ated work
قرأ أكثر
The work index covering grinding in tumbling mills of coarse sizes is labelled M. ia. The work index covering grinding of fine particles is labelled M. ib (Morrell, 2008). M. ia. values are provided as a standard output from a SMC Test ® (Morrell, 2004. a) whilst M. ib. values can be determined using the data generated by a conventional Bond ...
قرأ أكثر
PDF | The Bond work index is a measure of ore resistance to crushing and grinding and is determined using the Bond grindability test. Its value... | Find, read …
قرأ أكثر
The present trend is to replace secondary cone crushers by HPGR. The work at Polysius [3] ... the nip angle has a value of about 11–17°. However, when the rolls are in motion the friction characteristics between the ore particle will depend on the speed of the rolls. ... indicated that the Bond work index is not exactly a constant factor for ...
قرأ أكثر
Bond's work index is one of the mostly widely used metrics of mineral grindability. In spite of its ubiquity, users are often not aware of the nuances of the work index family: what …
قرأ أكثر
According to the Bond standard procedure, the work index is determined by simulating a dry grinding in a closed circuit in the Bond ball mill to achieve 250% circulating load …
قرأ أكثر
BOND WORK INDEX. The Bond Work Index is a factor that measures the energy consumed in size reduction operation of the ore. The Bond's Work Index equation is: W=WI* (10/√P80 -10/√F80) where. W= the energy input (Work input) per ton, kwh/metric ton. WI= Work Index= specific energy per ton, kwh/metric ton (characterizes the ore)
قرأ أكثر
The results showed that using the non-standard mills (between 20 and 35 cm in diameter), the Bond´s model constants (α=0.23; β= 0.82, and γ = 44.5), are unable to predict the Work Index ...
قرأ أكثر
A linear relationship between grindability index, G, and friability value was found as given in Eq. (2). The correlation coefficient is very high, at 0.99. (2) G = 0. 171 + 0. 021 (S 20) The relationship between friability value (S 20) and Bond work index (W i) also has a high correlation of 0.97 and this relationship is given in Eq. (3). (3) W ...
قرأ أكثر
The Bond (impact) crushing work index is given as 27.7 based on a laboratory determination. Use the circuit survey data to compare the operating work index to this laboratory determination. The reported power draws of these MP 1000 crushers were 460+554+583+581 for a total of 2178 kW at the DCS.
قرأ أكثر
Thus, the Bond work index value alone does not define the breakage action, whereas breakage parameters of kinetic grinding models are more expressed than Bond model for define of grinding process ...
قرأ أكثر
Also, values of crushing work index (CWi) increased inversely with the A*b breakage index, as commonly observed (Napier-Munn et al., 1996; Tavares and Silveira, 2008). In order to demonstrate the ...
قرأ أكثر
bond work index value for line crusher. Par Value . value is the nominal or face value of a bond, share of stock, or coupon as indicated on a bond or stock certificate. The certificate is issued by the lender and given to a borrower or by a corporate issuer and given to an investor. It is a static value determined at the time of issuance and ...
قرأ أكثر
When we apply the Bond Equation we found that CWi (Calculated) = 21,54 Kwh/t. And the CWi (lab test) = 27,4 Kwh/t. My question is: there is same correction factor that we must …
قرأ أكثر
The 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.
قرأ أكثر
Calculations involving Bond's work index are generally divided into steps with a different Wi determination for each size class. The low energy crushing work index laboratory …
قرأ أكثر