(PDF) Simulating the Impact of Ore Competence

The optimization aimed to estimate SAG mill throughput for soft and hard components based on the breakage model parameters (A and b) from the fitted curves while VMF varies at 25.501±0.3%.

Autogenous and Semi-autogenous Grinding Circuits

primary crushed ore enters the SAG or AG mill, gets ground to a "transfer size" where it exits the mill and is then passed to the closed circuit ball mill circuit. The SAG/AG mill product will usually contain a lot of finished product size, so it is useful to put the the SAG/AG product in the pumpbox that feeds the

Feed hardness and acoustic emissions of autogenous/semi …

In this study, the relationship between acoustic emissions and hardness of different rock types (model quartz, model calcite, and real iron ore) coupled with binary mix ratios of model quartz and iron ore (1:3, 1:1 and 3:1) was investigated in a laboratory-based AG/SAG mill. The acoustic emission response and sensitivity of the mill were ...

The performance improvement of a full-scale autogenous mill by setting

He observed that hard ore grinding in the SAG mill resulted in more fine products compared to the soft ore milling. Razani et al. (2018) also observed the same results by the study of feed ore hardness on the product size of a SAG mill. It is due to this fact that the dominant breakage mechanism changes by changing the ore hardness, so …

Unlock SAG mill capacity with process control optimisation

The instrumentation installed on a SAG mill is integral to control. For example, the mill load and noise sensors are instruments that provide essential information for an optimized SAG mill operation. Insufficient understanding of the ore characteristics and feed composition can result in an ineffective SAG mill operation.

Optimization of a SAG Mill Energy System: Integrating Rock …

Sag Mill Ore Hard Soft

SAG Mill Control It Shouldnt be that Hard. SAG Mill Control It Shouldn't be that Hard An economically appealing method for improving operations is available without the capital expense get more out of a mill by applying the SAG mill control fundamentally means managing the load in the mill by adjusting the feed rate of ore to the mill andor …

Ore Hardness Testing -SAG Mill Tonnage Estimation …

For design purposes, you need an estimation or prediction of your SAG Mill's tonnage; well, there are 3 ways to generate good rock "ore" hardness testing data for SAG and ball mill circuit grindability from half drill core. We can abbreviate the discussion by saying there are three "faiths" of grinding, and there are small-scale tests …

SAG Mill Control: It Shouldn't be that Hard | E & MJ

May has shown that the SAG/Bond Wi Ratio, that is, the SAG mill hardness (kWh/t to grind the ore from F80 152 mm to T80 1.7 mm) divided by the Bond Ball Mill …

Minerals | Free Full-Text | An LSTM Approach for SAG Mill

As the time support increases to two and eight hours, the accuracy drops to around 52% using a lambda value of 0.5 and 78% with a lambda value of 1.5, on both SAG mills. The inaccuracy of LSTM, when predicting extreme cases such as soft hardness when it is hard and vice-versa, is pretty low.

Improving SAG and Ball Mill Control in 4 hours

There are good and bad control techniques for SAG and Ball mill operation used in the industry. It is difficult to get an online measurement of ore hardness that can be used for process control.

BrainWave: Control solutions for SAG mills

The solution: Measure. Control. And profit. BrainWave SAG mill is a unique control package using patented model-based predictive adaptive control technology. It is well known within the mining industry that efective grinding in a SAG mill depends largely on the loading of the mill. A mill con-taining too much material does not allow for ...

IMPACT ON MILL DESIGN AND FLOTATION CONTROL …

for any ore, is a key property that should be used in the design of a SAG/ball mill grinding circuit. The value of this factor can vary from 0.1 to 2.5, the former value representing very soft ore and the latter very hard ore in the SAG mill. This was called a new discovery because the

What's the Difference Between SAG Mill and Ball Mill

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 ...

Schematic diagram of AG/SAG mill process …

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 ...

Model predictive control of semiautogenous mills (sag)

2.4. Multivariable predictive control. In the present work, a three-input-three-output scheme of control was performed. The total water feed to the mill (the feed water flow rate was added to the dilution water flow rate, so they could be specified separately, but for the SAG mill model, the total water content was the variable of interest), the …

The Use of a Semi-Rigorous SAG Mill Model for a Hands-On …

This industrially derived model of a mill is used to explain complex concepts of advanced process control () such as model predictive control and soft sensing. The resulting concepts were developed in a hands-on workshop in the wake of the IFAC MMM 2019 conference entitled "Modern Data Analytics for Control in Minerals …

Impact on Grinding Mill Design of Recent New Discoveries

Here both the hard ore and the soft ore (in the SAG mill) overlapped other hardness ranges for the Bond BM Wi database. Because the shape of these curves are so different proves that the data generated ... SOFT ORE HARD ORE SAG LIMITED ORE VERY HARD ORE . The division of this graph into 4 quadrants shows the main areas to …

STEP CHANGE IN LINER DESIGN FOR THE KANSANSHI …

Sulphide 51.0 medium 0.36 hard 8.32 soft Mixed 47.9 medium 0.54 moderately soft 12.35 medium . From the ore characterisation data in Table 1, it is evident that the Sulphide ore is more competent ... The SAG mill has treated Mixed ore on two long spells; first from September 2011 to April 2012, and the second recently from June 2014 until July ...

Minerals | Free Full-Text | An LSTM Approach for SAG Mill

The energy consumed by a SAG mill is related to several factors such as expert operator decisions, charge volume, charge specific gravity and the hardness of …

Design SAG mill production when you need it most: In …

how to control mill throughput using good mine planning, based on real data. Feed Size, F80: Primary crushed ore is mandatory to feed any SAG mill. Typical feed size range is 80% passing 130 to 160 mm. Softer ores will be a little finer but the finer size is not sustainable when the ore becomes hard. Pre-crushing to finer sizes enhances

Multi-component AG/SAG mill model

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 …

Improvements in the Operation and Control of SAG mills

Over the past decade, several hard and soft sensors have been introduced to the industry to estimate the mill charge in real-time, to address the need for better SAG mill control.

Studying the integration of solar energy into the operation …

Second, for demand-side management, a feed hardness array is generated by mixing two normal distributions with different standard deviation and mean values, representing a hard and soft ore. And third, realistic SAG mill feeds are generated with geostatistical simulations.

Improvements in the operation and control of SAG mills in …

Therefore, accurate estimation of mill charge over the liner life could assist operators in identifying the appropriate set-points for mill feed rate and mill speed. Over the past decade, several hard and soft sensors have been introduced to the industry to estimate the mill charge in real-time, to address the need for better SAG mill control.

Choosing a SAG Mill To Achieve Design Performance

Choosing a SAG Mill To Achieve Design Performance. John Starkey1, Principal Consulting Engineer Sami Hindstrom2, Manager, Grinding Travis Orser2, Project Manager, Grinding. Starkey & Associates Grinding Design and Process Engineering 336 – 268 Lakeshore Rd. E. Oakville, Ontario L6J 7S4 PH: (905) 465-7512 Fax (905) 844-5297.

Relationship among operational parameters, ore …

An increase in ore hardness corresponded to a change in the SAG mill product shape. The comminution of soft ores in the SAG mill resulted in the products having higher elongation, distinguished edges, and …

CURRENT TRENDS IN SAG AND AG MILL …

SAG mill control on two sites in Australia that have adopted the new . ... consists of three coarse ore feed ers and one soft ore feeder supply ing a . 10.97m (36') high aspect ratio single ...

Grinding of Agrium Phosphate Ores in a 3' Diameter …

The primary grinding mill is an 18 ft. diameter x 9 ft. EGL, 1500 HP variable speed SAG mill and the secondary mill is a 13 ft. diameter x 21 ft. long, 2000 HP fixed speed, ball mill. When hard ore was treated, the SAG mill restricted the tonnage that could be ground. When soft ore

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.

How to Improve SAG Mill Tonnage

The control of AG mills, fed by hard ores and soft components of oxide ore, can also be challenging, due to the sensitivity of the mill to the ratio of hard to soft components. As mentioned above by others, blending will be very important here as the mill could get overloaded with hard ore.

Integrated advanced process control with a sag mill …

of one FL 40 ft. diameter × 22 ft. long (EGL) SAG mill driven by a 24,000 kW gearless drive. The SAG mill feeds two. FL ball mills each 26 ft. in diameter × 40 ft. long (EGL), each driven by a 16,400 kW drive. The SAG mill is one of the largest volumetric capacity SAG m. lls in the world and represented the first 40 ft. S.

Unlock SAG mill capacity with process control optimisation

Continuously improve, identify and test the controller – the overall objective is to stabilize SAG mill control for high ore variability. A stable SAG mill performance enables …

A CRITICAL REVIEW OF GRINDING DESIGN …

It must include the allowance for treating hard and soft ores as defined by the profile measurements and include provision for future expansion if warranted, and for …

The performance improvement of a full-scale autogenous mill by setting

Improving the performance of the AG mill by direct addition large lumps of ore. • 40% reduction in the mill power consumption and 20% increase in the mill throughput. • The effect of blending two hard and soft iron ores on the AG mill performance. • Decreasing the AG mill power consumption by decreasing the feed ore …

Effects of ore characteristics on product shape

Hard ore grinding in the SAG mill resulted in finer products compared to the soft ore milling. In addition, it was found that the products of the soft ore milling were more elongated, angular and less rounded than those of the hard ore milling. ... industrial AG/SAG mills are difficult to control and stabilise owing to the variability of the ...