2.4. Ball Mill Grinding Tests Next, 400 g of ore and 200 mL of water were put into a Φ200 mm × 240 mm ball mill in the laboratory. The speed of the ball mill was 110 r/min and the volume was 7.5 L. In 0.01 0.1 1 10 100 0 20 40 60 80 100 Particle Size (mm) Cum. Passing (%) Raw ore Pebble

However, the difference between the dry and wet grinding condition was reduced, clearly demonstrated below frequency less than 5 kHz. The effect of increasing slurry viscosity could affect the motion of the steel balls in the mill and corresponding mill noise emission. Download : Download high-res image (429KB) Download : Download full …

The final product size depends on the retention time and grinding capability of the type of mill. The finer the grind size equates to the decision of a Ball, Vertimill, SMD (e.g. ISAmill). The pairing mill combination of a SAG/Ball mill is common in copper/gold mines for that reason. This combination can aim for a fine product sizes are around ...

includes a Bond Ball Mill Work Index test on SAG ground ore from the first stage of the test. The ratio of SAG pinion energy to Bond BM Wi is a key parameter in a SAG mill grinding circuit design, because this ratio controls the power split between SAG and ball mills at the target T80 transfer size( ). INTRODUCTION

Gross power = 265 + 1.26 × (2,233 + 215) = 3,349 kW. The conversion between motor input (gross) power and mill shell power, described earlier, is 0.931. Therefore, the predicted power at the mill shell is 3,119 kW, which is 71 kW less than the measured shell power (3,190 kW), a difference of 2%.

This paper compares the performance of a 25/75 pebble/ball (volume ratio) composite charge to ball-milling, under conditions typical for a ball-mill in SABC circuits, i.e. a large ball top size ...

Decreasing the SAG mill diameter by 2 feet from 36 to 34 ft. causes a 2 MW reduction in installed SAG power or an 18% decrease from 11 to 9 MW. This energy can …

ABC closed circuit, Autogenous-Ball-Mill-Crusher. Another similar technique is the ABC open circuit where the crusher product feeds the ball mill rather than the autogenous mill. Crusher product is typical feed to a ball mill using large diameter balls but not much grinding of 20-25 mm ore can be accomplished in an autogenous mill.

Based on experience, mill-liner designs have moved toward more open-shell lifter spacing, increased pulp lifter volumetric capacity, and a grate design to facilitate maximizing both pebble-crushing circuit …

The Ball Mill. Much like all types of mills, the Ball Mill's purpose is to grind and blend material into smaller pieces. To do this, the material is fed into the cylinder at an angle and then rotated inside. During rotation, the material travels up the internal wall of the cylinder and then falls back down to the bottom of the structure.

Choosing a SAG Mill To Achieve Design Performance. John Starkey1, Principal Consulting Engineer Sami Hindstrom2, Manager, Grinding Travis Orser2, Project Manager, Grinding. Starkey & Associates Grinding Design and Process Engineering 336 – 268 Lakeshore Rd. E. Oakville, Ontario L6J 7S4 PH: (905) 465-7512 Fax (905) 844-5297.

However, in this case the required balance between coarse and intermediate size rocks is different to that for ag mills. This is because the steel balls in the sag mill do the …

Single stage SAG Mills are very beneficial in reducing CAPEX for plants with a staged throughput approach. When future tonnage is to be increased, the SAG Mill can feed downstream ball milling to boost capacity. Fuller-Traylor SAG/AG Mills range in size from 4.3m through 12.2m in diameter with powers as high as 28,000 kW.

This is because it is common to observe a difference (sometimes significant) between the rod mill and ball mill index values for a given ore type (McKen, Verret, & Williams, …

The three tests are: The Bond ball mill work index (Wi BM, or BWi) conducted from a feed size of approximately 2 mm to a product size on the order of 100 µm. The Bond crushing (impact) work index (Wi C, CWi, LEIT or IWi) conducted on specimens of a nominal dimension between 50 mm and 75 mm. The product size is not …

mill. As such, primary ball mills should be designed with the rod mill work index, and single-stage ball mills should be with both the rod mill and ball mill indices. This is because it is common to observe a difference (sometimes significant) between the rod mill and ball mill index values for a given ore type (McKen, Verret, & Williams, 2006). On

The Discrete Element Method (DEM) was introduced as an alternative way to model mills by Rajamani (1992, 1994) who simulated a ball mill and Rajamani and Mishra (1996) with simulations of a SAG ...

The SAGDesign test was developed by the SAGDesign Consulting Group (Starkey, Hindstrom & Nadasdy, 2006) and consists of a batch grinding test conducted in a 0.488m diameter SAG mill. About 10kg of drill core is required for testing. The feed is prepared to 80% passing 19mm and ground to 80% passing 1.7mm.

Grate Discharge Ball Mills have shown 25% to 45% more tonnage ground and a substantial reduction in power consumed per ton of material compared size for size with overflow mills. To illustrate the …

In a SAG mill followed by ball mill circuit configuration, the SAG mill object ive is to maximize the production of ore at a suitable size (typically 12 mm) so the ball mill can treat the ore ...

Based on his work, this formula can be derived for ball diameter sizing and selection: Dm <= 6 (log dk) * d^0.5 where D m = the diameter of the single-sized balls in mm.d = the diameter of the largest chunks of ore in the mill feed in mm. dk = the P90 or fineness of the finished product in microns (um)with this the finished product is ...

The reason why rod mill is called rod mill is that its grinding medium is steel rod, while the grinding medium of ball grinding mill is steel ball. Because the shape of the grinding media is different, the working mode has its own characteristics. When the steel rod is in motion, the gap between the rods is a regular long strip, which plays a ...

AG Mill and SAG Mill. Feeding size: ≤25mm. Capacity: 0.65-615t/h. Output size: 0.074-0.89mm. Applications: It is commonly used in the mineral processing industry and ferrous and non-ferrous metal ore and nonmetal ore processing plants. It can also be used in cement plant, refractory plant, fertilizer plant and smelting plant.

Size: SAG mills are larger in diameter and shorter in length than AG mills. They are also usually fed with a larger size of ore than AG mills. Efficiency: SAG mills are more efficient than AG mills because they have a higher critical speed and can handle larger ore sizes. Cost: SAG mills are more expensive to operate due to the cost of grinding ...

With high aspect ratio SAG mills total charge to ball charge ratio should be greater than 2 (up to 2.5) for a coarse mill feed (say F80 > 110 mm). If the mill feed size is fine, say 50 mm or 30 mm, then you are looking at a total charge to ball charge ratio of about 1.5-1.6.

A typical SAG-HPGR-Ball mill circuit suggested by Patzelt et al. [6] is shown in Figure 9.6, where the pebbles from the SAG mill are crushed in the high-pressure grinding rolls. ... SAG mills of comparable size but containing say 10% ball charge (in addition to the rocks), normally, operate between 70 and 75% of the critical speed. ...

The results of ball mill grinding tests are shown in Figure 6. Figure 6a,d show the effect of grinding time on the particle size composition of the raw ore and pebbles, respectively. As expected, the grindability of …

These two types of mills are filled with varying compositions of grinding media. SAG mills contain balls of up to 150mm in diameter that occupy 5%-18% of mill chamber volume. Ball mills, conversely, contain grinding media up to 50mm in diameter, occupying between 25% - 40% of mill chamber volume.

What's the Difference Between SAG Mill and Ball Mill . 26/11/2019 SAG mills grinding media includes some large and hard rocks, filled rate of 9% – 20% SAG mill grind ores through impact, attrition, abrasion forces In practice, for a given ore and equal processing conditions, the AG milling has a finer grind than SAG mills12/10/2017 The ball charge of …

AG mills (or SAG mills with low ball charges) are often used in single-stage grinding applications. Based on their higher throughput and coarser grind relative to AG mills, it is more common for SAG mills to he used as the primary stage of grinding, followed by a second stage of milling. AG/SAG circuits producing a fine grind (particularly ...