ARE SAG MILLS LOSING MARKET CONFIDENCE?

Different combinations of SAG mill ball charge and grate open area were tested until 2006. A higher load level was achieved after several changes in the gratedesign that prevented both liner and grate

The Effect of Aspect Ratio on the Grinding Efficiency of Open and

Abstract. The aspect ratio (mill diameter/mill length) of autogenous and semi autogenous mills varies widely and can be as high as three or as low as 0.5. The literature on the subject of what ...

(PDF) Toward a Simple Approach Determining Single Stage SAG mill …

the case of a grate discharge mi ll, ... (SAG) mills it was found necessary to have mill power equations for the large D/L (pancake) type of SAG mill popular in North America and for the large L/D ...

SAG Mill Grinding Circuit Design

SAG Mill Grinding Circuit Design 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 …

Understanding the effects of liner wear on SAG mill …

This relates to varying mill throughput caused by mill liner and grate wear (Powell et al, 2012;Toor et al, 2011; Toor et al, 2015). The simulation model used for the analysis included several ...

Grinding Mills | Mineral Processing Equipment | CITIC HIC

To date, CITIC HIC has cumulatively produced and delivered over 1,550 mineral grinding mills, with a total installed power of 3,900MW. Our large-size grinding mills hold a market share of 85% in the domestic mining market, and have been exported to more than 50 countries and regions. This means that we are a world's leading manufacturer and ...

An efficient pulp lifter for ag/sag mills

The geometry of conventional pulp lifters is such that the slurry, once passed through the grate into pulp lifter will always be in contact with the grate until it is completely discharged, which makes the 'flow-back' process inevitable (Latchireddi, 2002).Though the impact of flow-back may be of lower magnitude in open circuit grinding, it can make a …

Key considerations when selecting a mill lining system | Weir

SAG mills usually have a larger diameter than length and are used to reduce large feed size ore (typically ~300mm) down to ~3mm, often for further grinding in a secondary process. ... Rubber grate plates are more resistant to pegging than steel grate plates, when fragments of rock or grinding media become wedged into grate screen apertures ...

ITP Mining: Improving Energy Efficiency in SAG Mills

Improving Energy Efficiency in SAG Mills Pilot-Scale SAG Mill Facility Will Help to Optimize Charge Motion and Slurry Flow in Plant-Scale SAG Mills - Reducing Energy Consumption The U.S. mining industry operates approximately 80 semi-autogenous grinding mills (SAG) throughout the United States. Both mine and mill site variables determine SAG ...

HPGR vs SAG

Now I finished the calculation of flowsheet with pre-crushing, SAG mill and Ball mills. The result is follows: 1. Pre-crushing- three crusher MP-2500() for crushing from 300mm to 50mm. Two working and once in reserve. 2. Primary grinding- once SAG mill with size 42ft x 24ft, power motor 28MW. F80-50mm, p80- 2mm. 3.

Sag Mill Liner Design

> 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

A General Model for Semi-autogenous and Autogenous …

an 8 m diameter SAG mill with LID = 0.5 grinding a copper ore, and predicted maximum capacity and minimum kWh/ton at about 6070 ball load at 25070 total filling. Two FAG mills of LID = 2 were necessary to give the same capacity, and the simulations indicated a lower kWh/ton for these mills. For this ore, both systems were technically feasible.

Slurry flow in mills: grate-pulp lifter discharge systems (Part …

The slurry transportation in AG/SAG mills is a two-stage process consisting of flow through the grate and the discharge of slurry by pulp lifters into the discharge trunnion. The grate-only discharge condition provides the ideal relation between slurry hold-up and flowrate. By attaching pulp lifters to the grate, the ideal hold-up–flowrate ...

SAG Mill | Autogenous and Semi-Autogenous Mills

Easily find the perfect fit from our wide range of sizes. Depend on years of proven reliability and productivity. Products. Maximise the productivity of your operation with durable high …

ARE SAG MILLS LOSING MARKET CONFIDENCE?

Different combinations of SAG mill ball charge and grate open area were tested until 2006. A higher load level was achieved after several changes in the grate design that prevented both liner and grate breakage. Upon resolution of issues related to the mill grate design, the project achieved the target throughput of 41 kt/d. Phoenix

SAG milling & grinding pilot plants

The larger units can also be matched with the SAG mill in SAB/SABC configuration. Stirred mills (Regrinding). Finer regrinding or ultra-fine grinding is a frequent requirement in pilot plants and ALS has a range of units that can run continuously in pilot applications. The following mills are located at Balcatta: ISAMill tm, Deswik, and ...

SAG Mills Archives

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 …

SAG Mill Ball Size Evaluator | Evaluation Factors | Calculate …

The SAG Mill has a "small" circulation load of oversize given be the 3/8″ trommel screen and the 1/2″ x 1 1/4″ discharge grates. The load of 4″ balls in this SAG is "good" but un-measured. SAG Ball consumption is "average" at 400 g/t while Ball Mill grinding media (3″ balls) usage in 550 g/t.

AG

Product Size: All passing 6 mesh with 80% passing 20 mesh. Net power from pilot plant: 16.5 KWH/ST. Mill, gear and pinion friction multiplier: 1.025. Mill Power required at pinionshaft = (240 x 16.5 x 1.025) ÷ 0.746 = 5440 Hp. Speed reducer efficiency: 98%. 5440 Hp ÷ 0.98 = 5550 HP (required minimum motor output power).

SAG Mill Liner Design

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The Different Types of Mill Liners You Should Know

WebAll autogenous (AG) and semi-autogenous (SAG) mills use steel or rubber grates to hold back the grinding media, whilst allowing the product slurry to flow through and out of the …

SAG Mill for Small Operation

The SAG Mill use is not the problem itself but the ore complexity and the suitable processing scheme. In DR-Congo, Kipushi Concentrator has one 18'diam X 6'L Hardinge …

Optimisation of the Cadia Hill SAG mill circuit

The Cadia Hill concentrator was commissioned in July 1998, aiming at processing 2065 t/h of monzonite ore, giving an annual processing rate of 17 Mtpa. Hart et al (2001) reported a range of ...

SAG Mill Liner Design | PDF | Mill (Grinding) | Steel

Three-piece "compression-type" liner bolt sealer is designed to prevent leakage of slurry. or dust from mill liner bolt holes. Used in conjunction with Grade 5 (high-strength) bolts, this assembly is generally applied to rod mills over 10.0′ in diameter and ball and. autogenous mills greater than 13.5″ in diameter.

Ball Charge and Grinding Efficiency

SAG % ore content SAG grate size and end mill design including grate geometry, location, shape, pan cavity, recycle % in pan cavity, et. al. SAG lifter and end cone geometry - can change SAG mill performance more than 20%-50% depending on P80 transfer size and Axb, some of which is published and some will be published at SAG 2015.

Extended grinding curves are essential to the

For grate discharge ball mills the absolute slurry level should be flush with the surface of the charge, as a check on the discharge capacity of the mill. ... For a SAG mill there are many variables against which a grindcurve can be developed. The ones that can be most readily varied, and are common control parameters, are mill speed, mill ...

Slurry flow in mills: grate-only discharge mechanism (Part-1)

1. Feed trunnion: assembly through which solids and water enters into the mill. 2. Mill Shell: main chamber where ore particles are broken due to tumbling action of the mill. 3. Grate: screen, which allows the ground ore particles and water to pass through in the form of slurry. 4. Pulp lifter: lifts the slurry, which passes through grate into ...

Modelling the influence on power draw of the slurry phase …

Citic SMCC's slurry flow model for AG/SAG mills (grate discharge mills) was constructed using the approach originally adopted by Morrell and Stephenson (1996) who related the volume of slurry held-up in the mill to its rate of flow out of the grates. Morrell and Stephenson incorporated the effects of grate design, mill speed and charge volume.

Semi Autogenous Grinding Mill

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:1.

Grate ả Sag Mill

The design of mill liners and SAG mill discharge grates will have a large effect on how efficiently the mill operates and the circuit throughput. All models generally assume that a mill is fitted with "efficient" liners and that the grate design neither limits passage of pebbles (and pulp) nor permits re-circulation of pulp back into the mill. ...

GMD system for Toromocho mine | ABB

As a result, ABB developed three of the largest diameter and most powerful drive systems for a SAG and two ball mills installed at the highest altitude to date. The fully integrated and optimized solution for the grinding circuit consists of: 1 x 28 MW GMD to power the 40 ft SAG mill. 2 x 22 MW GMDs to power two 28 ft ball mills.

SAG Mill Discharge Grates

SAG Mill Discharge Grates main function is to discharge minerals with qualified particle size and refractory stones. Therefore, if there are many stubborn minerals in the mineral, two …

Developments in the understanding of South African style SAG mills

The South African style SAG (RoM) mills operate in a window that is almost exclusive from the operation of the Australian and North American mills that have been used for the development of SAG ...

Sag Milling | PDF | Mill (Grinding) | Mining

Grate-Pulp Lifter Interaction in SAG/AG Mills in 7th Mill Operators Conf. Kalgoorlie, 2000, p63. (Australasian Institute of Mining and Metallurgy:Melbourne). Siddall, G B 1997. Recent Developments in SAG Milling, in Proceedings Conf. on Crushing and Grinding in the Mining Industry, Perth, May 1997, (IIR Conferences: Sydney) Siddall, G B, 1999. ...

(PDF) Slurry flow in mills: Grate-only discharge

Abstract. Discharge grates play an important role in determining the performance of autogenous, semi-autogenous and grate discharge ball mills. The flow capacity (grinding capacity) of these mills ...

Optimizing your SAG mill operation

The mill discharge from these mills consists of slurry, which goes to the ball mills for further grinding, and coarse pebbles/rocks, which are crushed and sent back to the mill. To maximize the capacity of these circuits, the general practice is to use grates with pebble ports (reaching 100 mm) instead of normal grate openings to increase the ...

SAG Milling

The main drawback of SAG - high power consumption. To reduce power consumption, I think: The right determine of SAG feed size. This depends on the mill diameter and the ball size. Feed size necessary to take 80% of the maximum piece of ore that will crushed by the balls. For the big SAG more than 8 meters optimal feed size will be - 50mm.

Slurry flow in mills: grate-only discharge mechanism (Part-1)

2. Mill Shell: main chamber where ore particles are broken due to tumbling action of the mill. 3. Grate: screen, which allows the ground ore particles and water to pass through in the form of slurry. 4. Pulp lifter: lifts the slurry, which passes through grate into the discharge trunnion. 5.

Pre-Processing to Increase the Capacity of SAG …

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′) …

Slurry flow in mills: grate-pulp lifter discharge systems (Part 2)

Summary and conclusions. The slurry transportation in AG/SAG mills is a two-stage process consisting of flow through the grate and the discharge of slurry by pulp lifters into the discharge trunnion. The grate-only discharge condition provides the ideal relation between slurry hold-up and flowrate.

Autogenous and Semi-Autogenous Mills

The SAG mill had a 6–8% ball charge and the power consumption was 8 kWh/t, which agreed well with the expected value. 9.6. Problems. 9.1. In an SAG mill the dimensions of the mill were 9.75 m × 3.5 m and the specific gravities of the mineral and that of the balls charged were 4.1 and 7.9, respectively.