The ball charge is a function of the bulk fraction of the SAG mill volume (Jb) occupied by balls; the ore retained in the mill is the result of the volumetric filling which depends on the ore size distribution (specially the % +6″ and the % −6″ +1″), on the rotational speed (N/Nc) and on the solid concentration by weight fraction inside ...
SAG/Ball Mill Sizing Gross Power Draw and Specific Energy Calculator for Semi-Autogenous Grinding (SAG) and Ball Mills. Return to Mill Calculators. ... Ball Top Size / Re-fill Size: [mm] Mill Power Draw Available. Description. Value Units. Power Draw - At Pinion [kW] Metallurgical Power Requirements
This method enables one to model "sag to tension" mode for various span lengths. When a cable in modeled in O-Calc® Pro in "Tension to Sag" mode, the user determines the initial (or nominal) …
In the current study are examined ball mills used in some of the mineral processing facilities in Bulgaria. More specifically MCB 4.5x6 ball mill (МШЦ 4.5х6) working with copper-sulphide ore. SAG 8.5x5.3 mill that is processing gold ore with significant ball load are also examined. Both types of examined tumbling mills
Trommel grate aperture, pebble porting and crushing and rock load in the mill were the significant factors in determining the quantity of -150 micron fines in the trommel undersize (primary mill product). The ball load varied from zero per cent (for rock loads >650 kg) up to 12 per cent (for a rock load of 340 kg).
Detailing includes information about the overall bracing system and how sag rods contribute to it. 6. Load Considerations: The detailing process takes into account the various loads that the sag rods will be subjected to, including dead loads, live loads, and any additional loads due to environmental factors or equipment. 7. End Conditions:
Semi-autogenous plus ball mill has been the "work horse" of mills. SAG vs Ball Mill Advantages . AG & SAG Mill Grinding Compared – Which is Best. Grinding rods and balls can be obtained in uniform sizes, weights and of a specified quality. Their action in a mill can be reasonably predicted.
The basic parameters used in ball mill design (power calculations), rod mill or any tumbling mill sizing are; material to be ground, characteristics, Bond Work Index, bulk density, specific density, desired …
Due to its strong lifting capacity and excellent grinding performance, the trapezoidal liner is widely used in the SAG mill. The structure of the trapezoidal liner is shown in Fig. 1, the main dimensions are: dip angle (tau), length of the top edge (L) and height (h).Dip angle (tau) determines the trajectory of the mediums in the SAG mill, …
3.2 Design of Sag Rod. Design Calculation. Axial Force in Sag Rods (P) = 0.15Vx = 2350.5 N. Sag Rod Length (KL) and Rod Diameter = 1.5 m and 20 mm. Check on Sag Rod Section The stress and slenderness ratio check was performed as per IS 800:2007 which was found satisfactory. 3.3 Design of Built-Up Frame. Load Calculations
These SAG milling plants (Fig. 1) are designed with few pieces of equipment having a large processing capacity, replacing advantageously a large battery of traditional crushers and rod and ball mills.These characteristics make SAG mills an excellent example of critical equipments whose continuous and stable operation is essential to guarantee …
Speed reducer efficiency: 98% 5440 Hp ÷ 0.98 = 5550 HP (required minimum motor output power). Therefore select a mill to draw at least 5440 Hp at the pinionshaft. Based upon the pilot plant test results, the …
If it is coarse and hard materials, choose a larger steel ball; If it is fine and crunchy, choose a steel ball with a smaller diameter. In addition, the size and diameter of the steel ball and its ratio should be determined according to the process requirements, material properties, ball mill specifications and so on. 3.
As one of the machines widely used in mining, a semi-autogenous grinding (SAG) mill can significantly improve the roughing efficiency of rock. But the SAG mill still faces the obstacles of significant …
Sizing the mills for a new grinding circuit requires a determination of how much energy is required for grinding (using test results such as Bond work indices) and then finding the mill sizes to draw that required amount of energy.
The analysis of the influence of ball sizes in SAG grinding hasn't been developed in detail by considering the effect on process parameters inside the mill, grinding efficiency or internal classification. Historically a conventional grinding reference has been made on the empirical procedure developed by Azzaroni (1980). Further to Azzaroni's ...
Calculation of Sag and Tension at an unequal level supports. In hilly areas or sloping grounds, the supports are not usual at the same level. For the calculation of sag and tension at unequal supports level consider a conductor AOB. The portion of OA and OB may be treated as catenaries of half span x and l-x respectively shown in the figure below.
This long tail dramatically reduces the downstream ball milling requirements The evaluation of the SAG mill performance with P80 values in a Bond work index calculation has led to the common ...
The high-quality steel balls used in SAG milling can withstand heavy loads without breaking or losing shape quickly. With advancements in technology and engineering design over recent years, modern-day SAG mills come equipped with sophisticated monitoring systems that can detect potential problems before they occur.
The SAG ball series is used primarily for SAG ore grinding operations in which high impact breakage resistance and high wear resistance are the main ball attributes required.
It is because low sag means a tight wire and high tension, whereas a low tension means a loose wire and increased sag. Therefore, in actual practice, a compromise is made between the two. Calculation of Sag in Overhead transmission lines: In an overhead line, the sag should be so adjusted that tension in the conductors is within …
The discrete element method (DEM) has been used extensively in simulating multiple interacting bodies undergoing relative motion and breakage. The key to the success of this method lies in correctly establishing the interaction rules and the associated contact parameters. In this paper, this is done by analyzing the impact behavior of a …
The batch test is carried out in a laboratory mill of 304.8mm diameter x 101.6mm length, loaded with 15% steel balls of 31.8mm diameter. The SPI® test itself requires 2kg of ore with a top size of 19mm (3⁄4"), but a total of 10kg of 38.1mm (1-1⁄2") is generally preferred, which allows for the determination of.
In semi-autogenous grinding (SAG), the grinding mill inventory, (i.e. volume of total charge, volume of ball charge, etc.) is important in determining the optimum operating condition for maximum production (tph), minimum specific energy (kwh/t) or lowest cost ($/t).
W = distributed load on conductor (N/m) m = unit mass of conductor (kg/m) g = gravitational constant of 9.81 m/s 2; Overhead Line Sag Tension with Calculation and Example. When estimating sag in a transmission line, there are two conditions: When all of the supports are at the same level; When support levels are not at the same level
Towards the development of an improved and more efficient online monitoring system in an industrial AG/SAG grinding mill, the present study employs a laboratory-based AG/SAG mill and acoustic sensor to investigate the acoustic characteristics of different mill operating conditions. ... in the presence of steel balls. …
1. Introduction. Grinding is an industrial process that accounts for a large proportion of the mineral processing industry [1], SAG mill is the main mining equipment in this link.The main working device of the SAG mill is a drum that is placed horizontally and can be rotated, the lifters are provided on the inner wall of the drum that includes the …
In semi-autogenous grinding (SAG), the grinding mill inventory, (i.e. volume of total charge, volume of ball charge, etc.) is important in determining the optimum operating condition for maximum production (tph), minimum specific energy (kwh/t) or lowest cost ($/t). A two-dimensional graphical method is presented for determining the actual ball charge within …
the SAG mill and the key testwork data is given in ... Ball load, % 21.6 Steel ball size, mm 90 Average Ore SG 3.96 Voidage as after grind out 0.38 Emptied out dry charge masses
The JKMRC has been studying and modelling industrial AG and SAG mills for over 40 years, but the ability to simulate the effects of blending hard and soft components on mill performance remains quite limited.In an effort to quantify these effects for modelling purposes, a series of laboratory, pilot scale and full scale tests, using multi-component …
SAG10 software, a play on words for SAG-TEN (TENSION), is widely recognized as the industry standard for overhead conductor sag- tension calculations, utilizing the Alcoa Graphic Method. Southwire's SAG10 software is a Windows-based, user- friendly application powered by more than 80 years of expertise in sag-tension calculations.
SAG Milling Molycop manufactures balls for grinding operations (using high carbon alloy steel bars as the raw material) through special bar heating, forging and heat treatment processes, the objective of which is to obtain optimum wear and impact resistance. The SAG ball series is used primarily for SAG ore grinding
This paper presents three methods using the Morrell C-model to estimate total and ball charge volumes for SAG mills, depending on the data and measurements available.
A comparison of SAG mill power models Alex Doll * Alex G. Doll Consulting Ltd., Canada ... Sizing the mills for a new grinding circuit requires a determination of how much energy is required for grinding (using test results such as Bond work indices) and then finding the mill sizes to draw ... • εB is the porosity of the rock and ball bed, ...
face angles) generally track the fate of the "lifter ball," the ball that sits against the lifter and plate (Royston, 2001). At constant mill speed, ball trajectories should degrade (i.e., balls fall more towards the bulk of the charge than the toe) with time as the lifters wear down. Shell lifters with initially
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 ...
Cytec Handbook. Why have a large circulation load:. If a product all finer than a certain critical size is required, the capacity of the ball mill is increased considerably by using it in closed circuit with a classifier and this increase is made still greater by increasing the circulating load in between the ball mill and the classifier (Fig. 70).
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.
In Grinding, selecting (calculate) the correct or optimum ball size that allows for the best and optimum/ideal or target grind size to be achieved by your ball mill is an important thing for a Mineral Processing …
Sag Mill is a kind of heavy duty equipment used in the ore crushing and grinding industry. Its working principle is to utilize the impact and grinding effect of a small amount of steel balls and the material itself to crush the ore Through the rotation of the cylinder, large pieces of ore are gradually broken into smaller particles in the collision …