Abstract. The kinetics of batch dry grinding of ceramic raw materials, which are quartz, kaolin and K-feldspar, from the feeds of sieve sizes −3·350+2·360, −2·360+1·400, −1·400+0·850, −0·850+0·600, −0·500+0·425 and −0·300+0·212 mm have been determined using a Bond mill with a mixture of five ball sizes.
Rowland, C.A., 1978, "Determination and use of operating work indices in controlled grinding circuits–A proposed concept," Mill Operator's Conference and Exhibit, Northwestern Branch, Australasian Institution of Mining and Metallurgy, Mt. Isa, Queensland Australia, June.
This paper presents how the Bond Indices have been used to calculate ball mill specific energies, and therefore throughput rates, for SAG mill based circuits. Once the ball milling specific energy is known, tower mill and vertimill energy requirements can also be calculated.
The test work involved Bond ball mill testing, rod milling, low intensity magnetic separation (LIMS), and batch ball milling down to product sizes of around P80~25 microns.
characterized using XRD, XRF, and electron and optical microscopy. A simulated test method for Bond ball mill work index (BWI) was used to perform the comminution test. The results showed BWI values vary from 5.67 kWh/t to 20.21 kWh/t. Examination of the possible correlations between BWI and the geological features
The above confirms that the design BWI for the primary ball mill is between 15 kWh/t and 18.2 kWh/t. As will be shown later, for sizing the primary mill motor the Bond method is used. The design Bond Work Indices for the primary and secondary ball mills are 16.5 kWh/t and 20.5 kWh/t respectively.
The Bond Ball Mill Grindability Test is a locked-cycle laboratory grinding test. It provides the Bond Ball Mill Work Index which expresses the resistance of a material to ball milling. This Index is widely used in the mineral industry for comparing the resistance of different materials to ball milling, for estimating the energy required for grinding, and for ball mill scale-up.
Bond ball mill work index for the ore samples collected from surveys 3 and 4 was 17.2 and 18.7 . kWh/t, respectively. Table 6 shows that the overall circuit operation index was close to work ...
Abstract. In the present paper, some calculation methodologies applied to the simulation of Bond test in grinding processes were presented. A comparative analysis was made with simulation results, using various methodologies, of the ball mill Bond test based on real values of the work index.
than predicted by Bond, based on the average performance of the plant circuits that Bond correlated with his laboratory testing. This circuit is consuming 89% of the Bond specified (design) circuit energy. 7.2.2 Common Plant Grinding Circuit Calculations 1. Rod-Ball Mill Circuit (Single-Stage Ball Mill, Multi-Stage
• Grindability as indicated by the bond ball mill work index (BWi) ranged from 10–35 kWh/t, with the majority between 15 and 27 kWh/t. No clear relationships in terms A*b and/or BWi was identified with geological aspects logged from the drill core such as weathering, lithology, alteration, alteration intensity, veining or combinations of these.
The Journal of The Southern African Institute of Mining and Metallurgy VOLUME 110 NON-REFEREED PAPER MARCH 2010 143 Table I Bond ball mill test results and composition of the LIMS product Ore Concentrate Tail Sample # Wi (kWh/t) Fe% SiO2% Fe% SiO2% 1 16.0 49.1 27.5 23.6 57.0 2 15.2 47.3 28.2 10.7 72.7
Rock Mechanics (ISRM). The Bond crushability index, uniaxial compressive strength, elasticity modulus and dry density of the rocks studied are shown in Table I. Generally, there are three Bond indices: ball, rod and crushability. The Bond ball and rod indices are determined using standard ball and rod mill, respectively, and are suitable for ...
The ball mill is usually the largest energy consumer at a mine site and significantly affects operational expenditures. Given a target particle size, Bond Mill Work Index estimates are used to predict a ball mill's throughput. In order to maximize ball mill throughput and optimize energy utilization, it is important to get these estimates right.
Meanwhile, ball mills are known for their lowest energy efficiency. The efficiency of ball mills is about 1.0% and, in some cases, less than 1.0% based on energy consumption.
The first parametric investigation is to understand the effect the critical bond strength σ ¯ max has on the flow and breakage in the batch ball mill simulation. Shown in Fig. 5 are snapshots of the flow at 10 revolutions for three different bond strengths, σ ¯ max = 1.0 × 10 8 Nm − 2, 5.0 × 10 8 Nm − 2 and 1.0 × 10 9 Nm − 2 ...
the Bond ball work index test work and the SMC and abrasion test work. The Bond ball work index tests were conducted internally at Usoke R&D Laboratory on core samples selected based on their representativeness of the orebody, and the SMC and abrasion test work were conducted at external accredited laboratories (GEMET, 2017; ROCKLAB,
Heavy metal containing solid wastes (HMSWs), the byproduct from industrial activities, bring severe environmental issues and health risks to human. Separating heavy metals from HMSWs for resourcing is the most effective way to mitigate their environmental risk. However, the composition of HMSWs is of great complexity, including various heavy metals …
and the Bond Ball Mill Test Work Index (WiBM; GMG, 2016a), and the Morrell equations and their application (see Annex B). A worked example is provided in Annex C. 5. SCOPE The Morrell method can be used to predict the specific energy of comminution circuits, where such circuits include combinations of any of the following equipment:
Oxide mineralisation grindability was relatively low with Bond ball mill work index (BWi) of 10.6kWh/t and primary mineralisation grindability medium to hard with BWi of 16.9kWh/t using a closing screen size of 106µm. For the head assay, the average gold grades for the oxide material and primary
MAN Y.T., 2002, Why is the Bond Ball Mill Grindability Test done the way it is done?, European journal of mineral processing and environmental protection 2, 34-39. NEMATOLLAHI H., 1994, New size laboratory ball mill for Bond work index determination, Minerals Engineering, 352–353.
Southern African Institute of Mining and Metallurgy 65 A Comparison of Test Procedures for Estimating the Bond Ball Work Index on Zambian/DRC Copper–Cobalt Ores and Evaluation of Suitability for Use in Geometallurgical Studies Elizma Ford and Vincent Sithole Mintek, Johannesburg, South Africa Corresponding author: [email protected]
From Bond's ball sizing formula, the recommended top ball size for this feed was 10 mm. This is the top ball size of Charge 2 (C2), the curve ( ) in Fig. 1, which should have produced the best grind. However, a finer grind was achieved using Charge 1 (C1), indicating that Bond's equation may not be entirely accurate for small mills and fine ...
Once the ball milling specific energy is known, tower mill and vertimill energy requirements can also be calculated. It is noteworthy that the method presented in this paper does not require the use of any unpublished correction factors: the proposed method uses the Bond parameters and equations published by Rowland in 1982.CITATION:Sherman, M ...
Journal of Mining and Metallurgy, 52 A (1) (2016) 11 - 25 ... savings compared to conventional ball milling. ... Bond tests was prepared by stage crushing 30 kg of the -10 mm sample to pass 3.35 mm. Half of the -3.35 mm material was split out …
Table 2 gives details of the Bond laboratory ball mill. 1320 S. Mormll and Y. T. Man Ball Mill I1_ Fresh feed ~-~ ~_. r~ ~ ~-~ ~ size Screen u/size Ball mill discharge Fig.4 The flowsheet of the Bond ball mill test TABLE 2 Bond ball mill details Diameter (m) Length (m) Speed (rpm) Speed (fr. crit) Ball load (%) Ball top size (mm) 0.305 0.305 70 ...
Bond Ball Mill Work Index: is a measure of the resistance of the material to grinding in a ball mill. It can be used to determine the grinding power required for a given throughput of material under ball mill grinding conditions. It …