2020-6-17 · In fact, the PSD of the rock after fragmentation can be explained by the new surface theory; that is, the energy required to produce each unit of new surface area is constant (Bond 1955; Carpinteri et al. 2004). The greater the surface energy consumption, the greater the crushing work required at the same crushing ratio, and the stronger the rock.
2016-2-10 · The power or energy required is the sum of the work required to crush or grind the rock as well as rotate the mill. The power required depends on the hardness of the rock, the initial size and the final product size required to achieve reasonable liberation of the mineral of interest, from the host rock.
2008-8-1 · The reduction ratio in the preceding crushing circuit is about 40–100, from typically blast rock of maybe 200–500 mm down to the 5 mm particles fed to the grinding mill. But in a mine, the cost and energy consumption associated with fine grinding are considerably larger than those associated with the compressive crushing.
The 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.
2015-12-27 · Crushing and Liberation of Materials by Electrical Disintegration Toyohisa Fujita1*, ... from the host rock. The relationship between electrical breakdown voltage and time required for ... strength was approximately 240kg/cm2 and the energy required to break the sample was about 7kJ based on the stress-strain curve. Table 1
2007-1-1 · The energy required to crush rock material is proportional to the amount of new surface area that is created. Therefore, energy consumption increases with fines generation, and it can be estimated that 10 times more energy is spent in producing pond screenings than in producing 10SM sand, for the same weight.
2020-12-1 · concern that stone crushing a highly environment polluting process. Determination of critical temperature at which impact energy requirement will be minimum and also to estimate the quantity of minimum energy required for crushing are very important in this research. Investigations can be carried out
2016-1-1 · The estimation of energy for crushing by this method could be lengthy and tedious. 3.4.3. JKMRC-drop weight crushing test. Attempts at a much simpler and direct method of estimating the energy required for crushing rocks have been attempted by several workers such as Gross, Piret, Hoffler and Herbst .
2016-3-11 · 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 …
2017-6-2 · Rittinger''s Law states that the energy required in size reduction is proportional to the new surface created by the particle fragmentation. The equation for Rittinger''s Law can be written as: E = K R f c (1/L 2 – 1/L 1) Where: E=Energy, K R =Rittinger''s Constant, f c =crushing …
2016-9-29 · Energy savings could be achieved by e.g. decreasing the feed size of the primary crusher, a decrease in Bond''s work index for grinding or an increase in amount of undersize that bypasses the crushing stages. A greater energy input, i.e. a higher specific charge, at the blasting stage will often be less costly than expending the energy downstream.
2020-4-1 · The required inertia to compress the material is ... Efforts to decrease energy consumed in crushing have result ... force as the predominant force to break rock. In its state of nature, rock features a jagged and uneven surface. Applying surface force (pressure) results in unpredictable and
2014-6-27 · The crushing energy in mineral processing industry is usually determined by empirical Bond index, regardless of the mechanical properties of a rock. Although several attempts have been made to obtain the comminution energy based on theoretical approaches, it would be beneficial to examine this relation based on physical concept.
2013-4-21 · Energy Consumption in Crushing and Grinding The energy input to size ore fragments is large. Overall reduction, performed in a series of stages may be from an eighty percent feed size passing of 40 cm (15.8 inches) to a final product size of 270 to 325 mesh (.053 to .045 mm). A lot of energy is expended to accomplish this, and
If the energy required to produce unit volume of new hole is obtained from the crater experiments it includes both elastic and fracture causing parts of the energy transferred to rock. It has been shown, however,  that only a limited amount of energy can be transmitted through rock with a …
2016-6-29 · Gypsum rock 2.69 6.73 Iron ore (hematite) 3.53 12.84 Limestone 2.66 12.74 Phosphate rock 2.74 9.92 Quartz 2.65 13.57 Shale 2.63 15.87 Slate 2.57 14.30 Trap rock 2.87 19.32 Gross energy (kW/h) required per ton of feed needed to reduce a very large feed ( = ) to such a size that 80% of the product passes a 100 μm screen.
2021-8-20 · minimum cost for breaking rock may not be in the best interest of the overall mining system. A little more money spent in the rock-breaking operation can be recovered later from the system and the aim of the coordinator of the mining work should be to achieve a minimum combined cost of drilling, blasting, loading, hauling, crushing and grinding.
2021-5-14 · based on the ratio of the volume before to the volume after crushing. Thus, the energy required is directly proportional to the size reduction, e.g. the same amount of energy is required to go from 2 to 1 cm as from 1 to 0.5 cm. = i f K ln x x E k (11.4) Bond (1952) suggested that the total work required to break a cube of size x is ...
2021-2-24 · The rock strength coefficient FN is graphically determined from the curve (FΝ, Ν) and corresponds to the minimum value of the curve. This 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).
2016-1-12 · even describe the type of rock. z One way of determining crushability is to measu re the energy required to crush a material. Fred C Bond AllisFred C Bond, Allis-Chalmers developed about 1950 a method to calculate the energy using aChalmers, developed about 1950 a method to calculate the energy using a parameter called Work Index (WI).
2015-5-6 · The energy required for crushing ... In the first part of the study, the individual rock samples were crushed one by one. In the second part of the test, multiple samples were crushed simultaneously. By measuring the energy consumption for crushing rocks with different physical and mechanical properties, we explored the dependence of energy ...