and the Bond Ball Mill Work Index Test (GMG, 2016a). The sampling and surveying guideline (GMG, 2016b) provides additional detail on how to collect the required data, and is critical to this analysis. The following required parameters are standard outputs of the SMC Test®: •Miadescribes grinding of coarser material (> 750 µm)...Where, WioACTis the Actual Operating Bond Work Index (kWh/t), W is the specific energy input (kWh/t), P80 is the 80% passing size of product (µm), and F80 is the 80% passing size of circuit feed (µm). 2. Calculate the Standard Circuit Bond Work Index (WiSTD) for the material being processed (equation 3). Wtotal

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...See this useful summary Table of Bond Work Index by Minerals. For any circuit, whether a crushing circuit, a rod mill, or a closed ball mill circuit, the Work Index always means the equivalent amount of energy to reduce one ton of the ore from a very large size to 100 um. The sample was received crushed appropriately for the ball mill test.

This is accomplished by the standardization of mill dimensions, tumbling speed, grinding ball charge weight and distribution, sample ore charge weight in the mill and operating practice. The results of this investigation reveal that the Bond work index grindability values may differ substantially with different standard Bond ball mills...2.2. Ball Mill Batch Process The mill dimensions, (D × L), are 0.204 × 0.158 m and it is loaded with 6.5 kg steel balls between 25 and 32 mm in diameter. The mill rotates on rolls and its frequency is set to 70 RPM (1.667 Hertz) corresponding to 85% of the critical frequency. The mill power is P = 16.2 Watts,

1 Predicting Mill Feed Specific Energy from Bond Ball Mill Work Index Tests at Olympic Dam Y Li1, V Liebezeit2, K Ehrig3, M Smith4, B Pewkliang5 and E Macmillan6 1. MAusIMM, Senior Geometallurgist, BHP Olympic Dam, Adelaide, South Australia 5000...In our example, the grinding balls diameter needed to load into the mill must be equal to 40-50 mm. Let's sum up. The grinding balls diameter determined by the Bond formula has a recommendatory character and serves …

The Bond grindability testing procedure has been standardized to obtain the same grindability values, i.e., Bond work index (BWi), on the same ore when tests are performed in different laboratories or by different operators. This is accomplished by the standardization of mill dimensions, tumbling speed, grinding-ball charge weight and distribution, sample charge …...The Bond Ball Mill Work Index (BBWi) test is carried out in a standardised ball mill with a pre-defined media and ore charge. The Work Index calculated from the testing can be used in the design and analysis of ball mill circuits. The test requires a minimum of 10kg of sample that has been stage-crushed to passing size of <3.35 mm.

Bond Ball Mill. This 12" x 12" ball mill is universally used for grindability testing and determination of the Bond Work Index. Mill comes complete with ball charge, and control panel with automatic revolution counter. …...The Work Index (BWi) is calculated according to Fred Bond's Equation. Bond Work Index for Testing Procedure. Cleaning and Storing of …

Alsto Bond Index Ball Mill. Internationally accepted mineral metallurgical standard test procedures to determine the physical properties of ores include the Bond …...The ability to simulate the Bond work index test also allows examination of truncated ball mill feed size distributions on the work index. For grinding circuits where the feed to a ball mill is sent directly to the classifier and the cyclone underflow feeds the ball mill (see Figure 3.10), a question arises as to whether this practice will alter the ball mill work index (BW i) of the material ...

Relationship between the Bond work index (w i ) and the ore hardness designated by Denver Source publication Modelling the specific grinding energy and ball mill scale-up india final...Numerically, the work index is the energy required in kwh/t to reduce a given material from theoretically infinite feed size to 80% passing 100 microns. The work index of a particular material is determined in the laboratory by conducting the standard Bond grindability test. Bond developed separate tests for the rod mill and the ball mill.

Mill Ball Mill Closed circuit crushing to 16 mm Open circuit 8' dia. rod mill to 1 mm Closed circuit 8' dia. ball mill to P80 um The ore Test Work Index = Circuit Operating Work Index 9 The Standard Bond Circuit Coarse Ore Bins Fine Ore Bins Screen Crushing Screen Classification Rod Mill Ball Mill THIS IS THE REFERENCE BASIS FOR ALL WORK ...rod mill work index has not been de ned as yet. The ball ﬁ mill work index is con rmed at 16 kWh/t. The operating ﬁ work index, though, is in the range of 21 kWh/t to 25 kWh/t showing high inefﬁ ciency. This raises the point that, in some cases, the Bond EF4 oversize factor calculation is not suf cient to compensate ﬁ

The Titan Bond Work Index Rod Mill is one-piece cast construction with integral wave liners of a form described by Bond. This mill is used to perform the necessary metallurgical testing to determine the grinding characteristics of …...Table I shows the Bond ball mill work index obtained for the ore samples as well as the iron and silica content in concentrate and tail after LIMS. The concentrate weight recovery was in the order of 50–60%. Furthermore it may be observed that the Bond ball mill work indices for the ore (Wi) varies from 14.6 to 20.9 kWh/t.

The laboratory procedure for running a Bond ball mill work index test requires that the operator choose a closing screen sieve size. The instruction is to …...Correction of Bond Ball Mill Work Index Test for Closing Mesh Sizes It is commonly known that one must run the Bond ball mill work index test such you pick a closing mesh to give a P80 close to desired grind size.

The Bond rod mill work index is not as common as the Bond ball mill work index, and there are two different variations on the mill apparatus.The SAGMILLING models expect a mill with a "wave liner", and is not compatible with mills using "smooth liners"...Six tests were carefully performed with both mills using the same aggregate rock sample and with the same method of grindability testing based on Fred Bond's Ball Mill Grindability Work Index (BWi ...

Bond Work Index Tables (Wi) - Free download as PDF File (.pdf), Text File (.txt) or view presentation slides online. Here there are given tables from various sources for the Bond work index values of mining materials (ores, …...FIGURE 8: ROD MILL/BALL MILL WORK INDEX RATIO v. UNCONFINED COMPRESSIVE STRENGTH 100 200 300 400 UCS (MPa) 0 0.5 1 1.5 2 WiRM/WiBM (metric) Siddall et al (1996) identified the ratio of Bond rod mill Work Index and ball mill Work Index as being indicative of an ore's compentency. Figure 8 plots this ratio versus UCS; no trend is apparent ...

Work Index Ball Mill, alluding to the grind ability list of Metals, is utilized to demonstrate the granulating trouble of the material. It is measured by a rule that to compute the work file ball plant in light of yield of every unrest of the factory after the material is ground to an adjusted state by the predetermined plan...Bond Work Index (BWI) & Hardgrove Grindability Index (HGI) tests for biomass & coal. • BWI can predict the potential for mill choking of biomass in a tube and ball mill. • HGI is a poor method of predicting grindability of biomass in vertical spindle mills. • Pellets should be composed of pre-densified particles close to the target size. •