A ball mill operates more with the grinding surface action of the balls than the impact form of grinding that the rod mill uses. Taking this into account you can see that if the rod mill doesn't reduce the ore to a size that the ball mill can reduce quickly, the circuit load will climb until its volume is greater than can be handled.
optimization of the SABC comminution circuit, focusing on the primary (SAG mill) and secondary (ball mill) grinding mills, and estimating the outcomes of changes to circuit operating parameters (e.g., feed rate, mill load, ball charge, etc.).
This paper describes the design, the first three years of operation and optimization of a large, single stage SAG mill at Minera Yanacocha's Gold Mill facility located in northern Peru. The Gold Mill was commissioned in March 2008 with a 32' x 32' EGL, 16.5MW single stage SAG mill, to process 5 million tonnes per annum high grade oxide Au ...
Optimization of the energy distribution of SABC circuits Daozhen Gong 1,2, Stefan Nadolski 2 ... (SAG mill-Ball mill-Crusher) circuit is the most widely used grinding configuration in large metal mines. It has been proven that reducing the feed size of the SAG mill can improve the energy efficiency or throughput of SABC circuits (Morrell and ...
Practical examples are presented, showing applications for single stage SAG (SS-SAG), SAB and SABC circuit configurations.IntroductionConventional low throughput grinding options, consisting of multi-stage crushing followed by rod and ball mills, have almost become obsolete in the move to higher milling rates required to process lower metal grades.
Powell, Yahyaei, Mainza, Tavares Presented at the AusIMM Mill Operators Conference June 2021 ABSTRACT Maintaining the work balance between 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 c...
The IntelliSense.io Grinding Circuit Optimization application has been piloted at the Aktogay Plant of JSC "AK Altynalmas". A Digital Process Model of the SAG mill was created using first principle modeling and enhanced with machine learning algorithms – the combination which enables improved monitoring, performance prediction, and optimization to increase profitability.
SAG mill discharge slurry flow rates and densities. The implementation of soft sensors to estimate these variables can provide additional information to aid circuit optimization as well as increasing advanced control system availability. The SAG mill charge estimator combines the SAG mill mass
Grinding is carried out in a fully autogenous (AG) mill. The mill operates in closed circuit with a pebble crusher. Throughput is approximately 380 tph. Cyclone overflow from the grinding circuit is fed into a flotation circuit for the recovery of ... and evaluate circuit optimization strategies. Optimizing Grinding Circuits 2
Example of a common multi-stage grind circuit. Optimization of hydrocyclone classification by on -line detection of coarse material in the overflow stream . Jerin Russell*, ... • SAG (Simi-autogenous Grinding) mill grate or trommel panel failure • Hydrocyclone liner/wall failure • Degradation or failure of SAG mill pebble removal
The Grinding Circuit Optimization Challenge. The Ball Charge in SAG and Ball Mills, in other words, the fraction of the mill volume constituted by balls, has a significant impact on the performance of a mill and the greater Grinding circuit. Running at the wrong Ball Charge adversely impacts not only throughput but the consistency of the ...
• Ball Mill Limited: the overall grinding circuit is constrained by the Ball Mill capacity and the SAG mill and Pebble Crusher circuits have spare capacity. This limitation is commonly experienced during the processing of the low grade ores (less than 0.4%Cu). This also confirms theBWi ore hardness – grade correlation.
The flowsheet was simulated under different operating conditions to understand the behavior of the circuit. The explanation for such changes has also been discussed. The dynamic simulator was then used in designing a neural network based controller for the semi-autogenous mill (SAG).
Following a successful commissioning and start-up, we believe that two grinding lines at Las Bambas, Perú, each consisting of one SAG Mill and one Ball Mill (this mill combination is uniquely specific to Las Bambas ore types), are operating at design throughput of close to 140,000 tpd and within the range predicted by DJB from a managed multi-sample …
In the first three years of continuous operation, Vale investigated different alternatives for improving the circuit’s performance by investigating operating conditions, mainly focusing on the SAG mill. It was decided to further assess the performance of the comminution circuit as a function of ore characteristics.
Case Study #1 – Improving Circuit Stability OMC have been assisting an African gold mine in optimising the comminution circuit, with a focus on operations practices and plant utilisation. The original circuit configuration consisted of a primary crusher followed by a SAG mill with a pebble crusher and a ball mill (SABC).
According to the simulation results the maximum throughput of Wushan SABC circuit is 850 t/h. The throughput of SABC circuit showed an increase of 26.7% after optimizing the operational parameters. Meanwhile, the comminution power consumption was decreased more than 2kW·h per ton, and the economic benefit was increased over 300 million ...
Autogenous Grinding (SAG) mill in closed circuit with a hydrocyclone package. The gold ... In this research, an optimization study of Aghdarreh plant grinding circuit performance was done to lower the product particle size (P 80) from 70 Pm to approximately 40 Pm by maintaining current throughput using modeling and simulation approach. After ...
This included the bench-marking and optimization of the SABC comminution circuit, focusing on the primary (SAG mill) and secondary (ball mill) grinding mills, and estimating the outcomes of changes to circuit operating parameters (e.g., feed rate, mill load, ball charge, etc.). 2. Problem Validation and Analysis
The value T80 is the "synthetic" transfer size between the SAG mill and ball mill – a fines-corrected 80% passing size 2 of the SAG mill product (or the combined SAG mill product and crushed pebbles if the circuit is sending crushed pebbles …
A ball mill and a semi autogenous grinding SAG mill are similar in that both are industrial machines for grinding up a substance unto uniform pieces Both use . ... AG SAG mills circuit design plant performance optimization motor rated at 13 4 MW and two ball mills each powered by a 7 MW motor The plant ramp up .
Simulation models were developed at the Julius kruttschnitt Mineral Research Centre to provide accurate estimates of power consumption for a wide range of equipment. With the models, a range of circuits and operating conditions can be compared by simulation for a particular ore type. Accurate models of classification allow for the interaction between classifier …
Replacements are seldom done to SAG mills due to cost and also the constraints of other circuit equipment. Instead, often additional production lines are added. Also, if the bottleneck is the SAG mill, adding a pebble crusher can provide a small production boost (typically 5 to 10%).
SAG Mill power draw models are used in mill design and grinding circuit modelling to predict how muc h pow er wi... [↓ read more ↓] Alex Doll: modelling: A simple estimation method of materials handling specific energy consumption in HPGR circuits
The interaction of grinding circuit variations and how these affect the froth flotation process performance need to be understood for proper optimization. Typical disturbances in the grinding circuits are: Mill feed particle size distribution due to crusher circuit operation and bin or stockpile segregation
Following implementation of these strategies, SAG mill throughput when treating the harder copper/zinc ores increased from a target of 2,750 mt/h in 2007 to 4,000 mt/h in 2009 and 4,400 mt/h in 2010-11. Optimization of the overall process also resulted in less energy consumption per ton of product. Continuous Improvement Delivers Further Benefits
was achieved. Production data also indicated that the SAG mill was operated at 92% of installed power while only 62% of ball mill installed power was utilised. This indicated that the circuit was constrained by the SAG mill (SAG mill limited), even while treating oxide blends.
SAG Mill Grinding Circuit Design Aerospace Structures: 3: MAE 412: Vibrating systems of single degree and multiple degrees of freedom, flutter theory and modes of vibration, torsional divergence and control reversal. decision-making techniques, optimization, computer aided design and economic consideration. MAE 472. Engineering Systems Design ...
Sossego was the first Vale SAG mill operation to process copper-gold ore. It is located in the State of Para, southeastern Amazon region of Brazil. In the first three years of continuous operation, Vale investigated different alternatives for improving the circuit`s performance by investigating operating conditions, mainly focusing on the SAG mill.
design processing rates of the Cadia Hill SAG mill circuit and that could be easily manipulated were; SAG Mill Load Ball Charge - SAG mill power draw was guaranteed by the vendor at 13% ball charge and 30% total volume to be 20.96MW for the 40 foot diameter SAG mill. In practice this power draw was never achieved I-14 (Dunne et al 2001).