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Jun 06, 2016 By combining with SAG discharge and screening on the SAG discharge screens, top size control to the ball-mill circuit feed is maintained while still unloading the SAG circuit (Mosher et al, 2006). A variant of this method is to direct pebble-crushing circuit product to the ball-mill sump for secondary milling: while convenient, this has the
AG/SAG mills can accomplish the same size reduction work as two or three stages of crushing and screening, a rod mill, and some or all of the work of a ball mill. Because of the range of mill sizes available, AG/SAG milling can often be accomplished with fewer lines than in a conventional rod mill/ball mill circuit. A diagram of types of AG/SAG
Optimum ball charge in a SAG mill is a function of many factors. Some are discussed below. For a SAB or SABC circuit. In general, the higher the ball charge the higher the throughput (and fine feed helps as well). Of course, you need a bigger ball mill. But, high ball loads mean higher ball consumption in the circuit.
The SAG mill trommel undersize is combined with the ball mills’ discharge and pumped to two parallel packs (clusters) of twelve 660 mm diameter cyclones. The cyclone underflow from each line reports to a ball mill, while the cyclone overflow is directed to the flotation circuit. The designed ball milling circuit product is 80% passing 150 µm.
SAG and the ball mill circuits (JKMRC, 1996). The phantom cyclone is used to classify the AG/SAG mill product into two products; the phantom cyclone overflow that is similar to the final ball mill product, and the phantom cyclone underflow is then used as an adjusted ball mill feed for the ball mill
Nov 26, 2019 The biggest characteristic of the sag mill is that the crushing ratio is large. The particle size of the materials to be ground is 300 ~ 400mm, sometimes even larger, and the minimum particle size of the materials to be discharged can reach 0.1 mm. The calculation shows that the crushing ratio can reach 3000 ~ 4000, while the ball mill’s
A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. [6] [7] The largest SAG mill is 42′ (12.8m) in diameter, powered by a 28 MW (38,000 HP) motor. [8] A SAG mill with a 44′ (13.4m) diameter and a power of 35 MW (47,000 HP) has been designed. [9]
The results showed that the HPGR-ball mill circuit achieved a 21% reduction in energy consumption over the existing SAG-ball mill circuit at the same P80 grind size of 160 mircons (μm). At a grind of 80% passing 75 μm, the HPGR-stirred mill circuit showed a 34%
A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints.Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles, and stainless steel balls.
comparison of hpgr ball mill and hpgr stirred mill circuits to the existing ag/sag mill ball mill circuits by chengtie wang b.eng., university of science and technology beijing, 2009 a thesis submitted in partial fulfillment of the requirements for the degree of master of
Maintaining the work balancebetween the primary SAG mill and secondary ball mill(s) is an overlooked bottleneck, and thus opportunity, in an increasing number of circuits worldwide. As circuit capacities are expanded by ‘releasing’ the SAG mill bottleneck, the work is progressively passed on to the downstream ball mills.
The results showed that the HPGR-ball mill circuit achieved a 21% reduction in energy consumption over the existing SAG-ball mill circuit at the same P80 grind size of 160 mircons (μm). At a grind of 80% passing 75 μm, the HPGR-stirred mill circuit showed a 34%
Comminution Circuits Featured Projects ANTAPACCAY. Southern Peru, 2009-2013 (108,000 tpd 80,000 tpd) Predictions of mill throughput from a porphyry copper open pit based on comminution test results of 22 composites and the available motor power of a “Standard” SAG Mill/Ball Mill circuit consisting of one 40 ft dia. x 22 ft EGL SAG Mill rated at 24 MW GMD and two Ball Mills, each 26
Each milling circuit is unique, and as such the goals and most optimal control strategy might differ for individual cases. Process IQ is an expert in implementing control systems for SAG and Ball milling circuits, making use of advanced stabilisation and optimisation strategies developed by Mintek.
where such circuits include combinations of any of the following equipment: AG and SAG mills Ball mills Rod mills Crushers High Pressure Grinding Rolls (HPGR) POWER-BASED EQUATIONS . General . The approach divides comminution equipment into three categories: Tumbling mills, eg AG, SAG, rod and ball mills
Grinding (AG), Semi-Autogenous Grinding (SAG), rod, and ball mill circuits operating within the normal range of appli-cation. This guideline does not directly address analysis of crushing plants and fine grinding circuits, but it is a useful reference for such endeavors. Applying power-based analysis techniques requires suf-
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.
Jan 08, 2016 In this training module, we'll cover the workings of a semi-autogenous grinding mill, or SAG mill, that's designed to be the first stage of a grinding circui...
A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints.Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles, and stainless steel balls.
SAG mill. SAG is an acronym for semi-autogenous grinding. SAG mills are autogenous mills that also use grinding balls like a ball mill. A SAG mill is usually a primary or first stage grinder. SAG mills use a ball charge of 8 to 21%. The largest SAG mill is 42' (12.8m) in diameter, powered by a
Grinding circuit design tools, including for SAG mill-ball mill circuits, and geometallurgy energy models are available to subscribers. The online library of technical articles contain several papers on metallurgical topics including comminution modelling, mass balance calculations and laboratory comminution testwork program information.
SAG/HPGR duo into new circuit design. When compared with traditional crushing circuits, clever circuit design, supplemented by some key equipment enhancements, should allow minimal materials handling issues,, while providing an ideal balanced feed to the AG or SAG mill to maximise the fine grinding capability of this equipment.
The grinding circuit consists of a SAG mill and two ball mills, all dual pinion gear driven. Copper . 3 Mountain has selected the state-of-the-art dual pinion mill drive systems, providing numerous advantageous features which were previously exclusively available on gearless mill drives.
Picture shows two ball mills and one SAG mill taken from flsmidth Printed by Chalmers Reproservice Gothenburg, Sweden 2020. i into AG/SAG mill circuits to break the critical size particles that accumulate in the mill and to increase the performance of the primary grinding circuits.
The SAG/Ball Mill Circuit has an overall processing capacity of 2300 TPD. A 20.0 ft x 7.5 ft, 1500 HP fixed speed SAG Mill is fed with ore coming from four feeders.
Maintaining the work balancebetween the primary SAG mill and secondary ball mill(s) is an overlooked bottleneck, and thus opportunity, in an increasing number of circuits worldwide. As circuit capacities are expanded by ‘releasing’ the SAG mill bottleneck, the work is progressively passed on to the downstream ball mills.
where such circuits include combinations of any of the following equipment: AG and SAG mills Ball mills Rod mills Crushers High Pressure Grinding Rolls (HPGR) POWER-BASED EQUATIONS . General . The approach divides comminution equipment into three categories: Tumbling mills, eg AG, SAG, rod and ball mills
Grinding (AG), Semi-Autogenous Grinding (SAG), rod, and ball mill circuits operating within the normal range of appli-cation. This guideline does not directly address analysis of crushing plants and fine grinding circuits, but it is a useful reference for such endeavors. Applying power-based analysis techniques requires suf-
• Single stage crush/single stage SAG mills and two stage crush/ball mill circuits are typically selected for low throughput plants (<50 t/h) where personnel costs are a large component of costs. • SAB circuits are typically selected for plants of 0.5 to 2 Mt/a.
used to balance the rate of impact breakage within the circuit) 3 SAG mill (8 15% ball charge) Variable competency ore 4 High ball charge SAG mill (15 to 25% ball charge) Incompetent ore 5 Low ball charge SAG mill, high mill speed. (4% ball charge, 90% Nc) A cross between AG and SAG for competent, abrasive ores. As typically operated in RSA.
bling mills (AG/SAG, rod, and ball mills) involved in reducing the size of the primary crusher product to that of the final product (usually the cyclone overflow of the last stage of grinding prior to flotation/leach-ing). 2. Feed rate to the circuit (dry tonnes/h) 3. Power draw of the comminution equipment (kW)
The ROM SAG mill circuit—a brief description The typical ROM SAG mill circuit is depicted in Figure 1. The circuit is usually closed with either a screen or, more commonly, a cyclone for product size classification. The focus of control can be divided into two parts, viz. the mill and the cyclone. The importance of cyclone performance should
A ball mill, a type of grinder, is a cylindrical device used in grinding (or mixing) materials like ores, chemicals, ceramic raw materials and paints.Ball mills rotate around a horizontal axis, partially filled with the material to be ground plus the grinding medium. Different materials are used as media, including ceramic balls, flint pebbles, and stainless steel balls.
supported grinding mills up to the largest sizes. SAG/ball mill circuit incorporating pebble crushers and a POLYCOM® high-pressure grinding roll. SAG and ball mill for gold ore grinding. One of three SAG mills with 9.75 m diameter and 2 x 4000 kW drive power. These mills operate in conjunction with ball mills for iron ore grinding in Iran.
The circuit consists of a 34’ x 20’ EGL SAG mill, a Raptor 900 pebble crusher and two 24’ x 39’6” ball mills. Each mill is equipped with a 2 x 8500HP dual pinion drive system. The plant was designed to process 1585 h mtpof SAG feed. From startup, the mill struggled to meet the required production rates.
Here are four applications/circuit locations accompanied by a recommended equipment solution. Each has its own set of challenges, and each is approached in a different manner. Application/Circuit Location • Pebble Crusher • SAG Mill Vibrating Screen Oversize • Ball Mill Discharge Technique/Equipment Solution − Suspended Electromagnet
Jul 08, 2016 Where the SAG mill/ball mill circuit is the bottleneck in the processing plant the pebble circuit can be a significant factor in limiting overall plant capacity. The pebble circuit recirculating load can be very significant (depending on the ore characteristics and SAG mill operating dynamics). Typically it represents around 25 % of the feed to