Title: Bond F.C., 1961. Crushing and Grinding Calculations.pdf Author: can Created Date: 4/2/2009 4:00:03 PM

The Bond low-energy impact test, also named impact work index or Bond impact crushing work index, can measure the crushing work index (CWI) and describes the competency of the ore at larger particle sizes. The Bond low-energy impact test calculates the actual crusher power requirements. The crushing work index (CWI) is …

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)

The Bond Work index decreases as the proportion of steel balls increases. When the total filling rate is 30% and the volume share of steel balls is 5% (n=5), the Bond's Work index of ceramic balls and steel balls is 35%, the same as that of ceramic ball filling rate, i.e., it is close to the traditional Bond's work index. Based on the results ...

When Erf/Erp is greater than 1.29, the work index increases as the product size decreases, and when Erf/Erp is less than 1.29 the work index decreases. Eq. (8) suggests that a standard work index Wi100, or the work index at 80% passing 100 microns calculated from the exposure ratios, can be found from the following Eq. (9):

The Bond Work Index is material specific and is obtained from laboratory crushing tests on the feed material. Hard and brittle materials have a work index in the range 4 × 10 4 − 8 × 10 4 J/kg. Bond's law holds reasonably well for a variety of materials undergoing coarse, medium and fine size reduction. (Eq. 14.3a) can also be reduced to

Perhaps the most traditional is the one proposed by F.C. Bond over 60 years ago (Bond, 1947, Bergstrom, 1985), which is still used today for characterizing material crushability in the minerals industry. The Bond crushing work index is a measure of material strength and is determined using a simple twin pendulum apparatus and a …

Understanding where the work index fits into the family of power-based grinding metrics will help operators correctly apply the work index and avoid making mistakes.

Work index is the relation between the SEC and the amount of breakage in an ore. The most common form of this relationship is given as Equation 1, and is often referred to as …

law for fine grinding; Bond's law for coarse grinding and secondary/tertiary crushing; and Kick's law for primary crushing). The novelty in the third law's proposal was the proce‐ dure for determining wi in the case of crushing, rod milling and ball milling [13,15]. The

The bond work index for a mesh-of-grind of 200 mesh for a rock consisting mainly of quartz is 17.5 kWh/ton. How much power in kW is needed to reduce the material in a wet-grinding ball mill from an 80% passing size of 1100 µm to an 80% passing size of 80 µm at a capacity of 10 ton/hr?

The metal Bond ball mill is 30.5 cm inside diameter and. 30.5 cm inside length, with rounded corners. It is smooth except for the door hole used for charging. The grinding charge consists of 285 iron or steel balls (43 @ 36.8 mm diameter, 67 @ 29.7 mm diameter, 10 @. 25.4 mm diameter, 71 @ 19.1 mm diameter, and 94 @.

The Bond' Crushing Work Index is common to calculate the power needed to crush rocks from a given F80 size to a resulted P80 product size. Bond's impact method comes from a double mirrored pendulum impact crusher test on <76mm but >51mm (3″ and 2″) square rock pieces.

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 ...

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 ...

(5): (5) W = 10 ∙ W i ∙ 1 P 80-1 F 80 where: W is the energy input (work) in kilowatt-hours per metric ton; W i is the work index (or Bond work index) in kilowatt-hours per metric ton; and P 80 and F 80 are the 80% product and feed passing sizes, in micrometers. All three comminution theories can be derived from the basic differential Eq.

It is a well-known fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. ... Bond's law for coarse grinding and secondary/tertiary crushing; and Kick's law for …

The work index can be used to evaluate the influence of various operating variables on crushing efficiency. For an industrial crushing process with a given feed …

Chapter 3 - Particle Technology (Size Reduction) Kick's law: the work required for crushing a given mass of material is constant for the same reduction ratio, ... 3.2.2 Bond crushing law and work index.

Abstract and Figures. It is a well-known 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 ...

Section snippets Grinding kinetics in the Bond ball mill. Tests of grinding kinetics in the Bond ball mill (Fig. 1, Fig. 2) has shown that over a shorter grinding period, the process follows the law of first order kinetics R = R 0 e-kt where R = test-sieve oversize at the time (t); R 0 = test sieve at the beginning of grinding (t = 0); k: grinding rate …

Rittinger's theory and law of the energy expended in crushing of rock is that the work of crushing is proportional to the reduction in diameter; or, as I have more fully expressed it: "The work done in crushing is proportional to the surface exposed by the operation; or, better expressed for this purpose, the work done on a given mass of rock …

The Bond work index is defined as the specific energy required to reduce a particulate material from infinite grain size to a size of 100 microns (Stamboliadis, et al., 2011). Simply put, work ...

Generalized Law : (n 2, 1 and 1.5 for Rittinger's, pp d (Dvs) vs Kik's and Bond's laws respectively) Work Index: the gross energy requirement in kilowatt hour per short-ton of feed (kWh/ton of feed) to reduce a very large particle to such a size that 80% of the product will pass through a 100 gm or 0.1 mm screen. — = 0.3162 w P Upp ] Lipp ...

The Bond Crushing Law calculator calculates the energy required for crushing of a solid material based on Bond's Law. It helps in predicting the energy needed to reduce the …

law for ﬁne grinding; Bond's law for coarse grinding and secondary/tertiary crushing; and Kick's law for primary crushing). The novelty in the third law's proposal was the procedure for determining w i in the case of crushing, rod milling and ball milling [13,15]. The practical interest of w i is unquestionable. From a technical ...

The Bond's work index of the above rock samples calculated from the Hardgrove index value has shown a variation from 7.7 to 10.3 kWh/sh.t. A correlation is found between the friability value and ...

The commonly used grindability tests included in the database are the Bond work indices for ball milling, rod milling and crushing; the drop weight test results A, b, A×b, DWi, Mia, Mic, Mih and ...

In spite of being called Bonds Law, the work index equations are not a law of nature; but rather an empirically ... Stage crush the ball mill test feed sample and screen through a 3.36 mm (6 Tyler mesh) screen. Avoid over-crushing by screening, then crushing the oversize successively until it all passes the 3.36 mm screen.

where Wi is the Bond Work Index, again in energy per unit mass terms. The index is defined as the energy required to crush from infinite size down to 100 µm, hence the 10 inside the brackets. Bond's Work Index values, in kWh per short ton: i.e. 2000 lbs or 907 kg, roughly follow the Moh's scale of hardness, see Table 11.1.