In addition, very high throughput rates up to 40 000 t/d can be achieved with large-sized mills (Fig. 6). Moreover, these mills can be designed for both wet and dry grinding. Up to now, SAG mills with diameters up to 12.8 m have been designed for copper ore, at which the mills have reached the limits of their capacity.

size depending on the required mill feed rate and ore hardness. Figure 3 – Meadowbank milling flowsheet . Crushed ore is conveyed to a covered stockpile with an 8,500 t live capacity. Two variable frequency drive pron feeders reclaima the stockpiled material to a conveyer belt feeding the SAG mill in the primary grinding circuit.

SAG mills grind ore by lifting it and a small amount of grinding media and dropping it inside a horizontal mill. Ball mills are smaller and use a higher concentration of iron balls to pummel the ore. The mills can operate in an open grinding circuit, feeding secondary grinding systems, or in a closed circuit generating a fine product.

energy required which in this case was to grind the ore represented by the samples, from a feed size F80 of 152 mm to 80% passing 1.7 mm, and a simple adjustment procedure in case the SAG product size needed to be adjusted. Bond rod and ball mill work indices are readily converted to pinion energy for rod and ball mills but not for SAG mills.

SAG mills are especially suitable for grinding the ores in which the useful minerals are coarse-grained and uniformly distributed. ZJH Minerals is professional manufacturer for …

1. SAG mill is the primary tool for grinding. SAG mill is used before the other mills. Ball mill is a secondary, and it is used after the SAG mill. 2. SAG mill breaks the raw material into pieces for the further grinding. …

In this example, the OWi of the SAG mill was found to be 30% higher than the ball mill, thus suggesting that the SAG mill was less efficient than the ball mill. ... high pressure grinding roll and tumbling mill circuits. Minerals Engineering 22, 544-549. Davis, E.W., 1919. Fine crushing in ball-mills. Transactions of the American Institute of ...

The largest SAG mill is 42' in diameter, powered by a 28 MW (38,000 HP) motor. A SAG mill with a 44' diameter and a power of 35 MW (47,000 HP) has been designed. Attrition between grinding balls and ore particles causes grinding of finer particles. SAG mills are characterized by their large diameter and short length as compared to ball mills.

operation of SAG mills. SAG mills are currently the technology of choice in hard rock milling operations for reducing primary-crushed ore to ball mill feed. In recent years, the trend has been towards larger-sized SAG mills with diameters of 10.4 m (34 ft) and above, with the largest being 12.2 m (40 ft) in

These mills are one of the most used and necessary equipment in grinding. Working: SAG mill make use of steel balls included with some large and hard rocks for grinding. These mills utilize the balls in making the large fragments of materials broken into pieces. The ball charge of a SAG mill is about 9% to 20%.This process takes place inside ...

SAG mill: Types of material : Almost all materials: 1.Rough grinding 2.Brittle materials, such as tungsten, tin ore before gravity concentration: Dry SAG mill: asbestos mine, silicon carbide, etc. Wet SAG mill: minerals with mud (can omit ore washing) Feeding size: ≤25mm: ≤50mm: 300-400mm: Capacity : 0.62—180t/h: 0.65—615t/h: 1.5-338t/h ...

Grinding Mills: Ball Mill & Rod Mill Design & Parts. ... Higher percentage of critical speed is used for impact grinding of large feed. Lower percentage of critical speed is used for attrition grinding when a fine product is desired. ... An 8 x 7 diaphragm type ball mill grinding 0.5″ copper ore to 96% passing 65 mesh.

This adds grinding capability to the SAG mill and allows the selection of a smaller SAG mill. This option should be carefully reviewed before implementation because future expansions might make this a poor and restricting choice. 5. Consider extra capital for the SAG mill instead of oversizing the downstream process equipment.

SAG Mills constitute a recent innovation in terms of ore processing. SAG Mills can currently be up to 11.0 m in diameter by 4.6 m wide and are considered more ef-fi cient than Ball Mills. They can substantially reduce the crushing and milling process due to their large capacity and effi ciency. With SAG mills, the mineral is received directly ...

The earliest, and simplest method of crushing ore was the use of arrastras. When enough capital was available, stamp mills replaced arrastras at most mines. The following sections take a look at various types of stamp mills, the most common milling facilities at mines of the frontier West. The Trench mill at Silver City, Nevada 1877.

Assuming your ore is AG-amenable: 7 TPH to 15 TPH is a comfortably production average for a 13′ x 4.5′ AG Mill. A 13′ x 6′ SAG Mill has a reasonable range of: 20 to 30 TPH for …

However, the AG/SAG mill market is still healthy and the trend is larger diameter mills with high diameter-to-length ratios. Gearless mill drives (GMD) are the preferred drives for large mills ...

The SAG mill product flows to two 3.6 m (12′) by 7.3 m (24′) horizontal screens, whose combined oversize (pebbles) is diverted to two MP 800 cone …

A total of 120 t of Cristalino ore was prepared and sent to CIMM, where it was crushed and screened prior to grinding tests. The processing equipment included a 1.83 m (8′) diameter by 0.61 m (2′) length AG/SAG mill equipped with a 20 kW motor, a cone crusher, a 0.91 m (3′) diameter by 1.22 m (4′) length ball mill equipped with a 15 kW ...

Common convention generally refers to high-aspect ratio mills as SAG mills (with diameter to effective grinding length ratios of 3:1 to 1:1), low-aspect ratio mills …

AG and SAG mills are now the primary unit operation for the majority of large grinding circuits, and form the basis for a variety of circuit configurations. SAG circuits are common in the industry based on: High single-line capacities (leading to capital efficiency) The ability to mill a broad range of ore types in various … Read more

A total of 120 t of Cristalino ore was prepared and sent to CIMM, where it was crushed and screened prior to grinding tests. The processing equipment included a 1.83 m (8′) diameter by 0.61 m (2′) …

Four vibrating feeders deliver the ore to the SAG Mill feed belt. SAG Mill discharge is pumped to a primary cyclone(s). Underflow from this cyclone is recycled by …

Rod Mills — these rotating mills use rods for grinding media causing friction and attrition between steel rods and ore particles. Rod mills can accept feed up to approximately 50 mm. (2 in.) and ...

the required SAG comminution of test ore material. Specific energy consumption (SEC) measured in kWh/t is a ratio of the mill drive power to the milling circuit output, without regard to circulating load. At the constant size of the cycle feed and discharge, SEC is a prime characteristic of material grindability in a certain ore pretreatment ...

> Engineering approaches have highlighted mill performance with mill modelling and the use of improved materials > Liner design,with the advent of large diameter SAG mills, the issues of design, selection, monitoring and evaluation of mill performance is critical > Mill trajectory modelling can be used to great effect in improving liner design

Development of the mine-to-mill concept was carried out by foreign studies in the framework of the following issues: n Simulation studies on the relationship between fragmentation and throughput of a SAG mill [15,16]; Ore hardness indicators [17] and geotechnical parameters in mine block models and subsequent optimization of mill …

Furthermore, the SAG mill circuit indicated varying feed sizes (i.e. xF,80 =102 to 185 mm) which could be rectified by closer monitoring and control of ratios for the SAG mill feeders drawing the ...

AG and SAG mills are now the primary unit operation for the majority of large grinding circuits, and form the basis for a variety of circuit configurations. SAG circuits are common in the industry based on: High …

A high aspect SAG mill had an ID of 6.0. m and the length measured 4.0 m along the central line.. The mill was charged with ore having a S.G. of 2.65 and the load was 40% of the mill volume. The grinding media steel balls occupied 12.2 % of the mill volume.The mill was rotated at 75% of its critical speed, which was 12.9 rpm.Estimate: