Luis Bergh - Academia.edu (original) (raw)

Papers by Luis Bergh

Research paper thumbnail of Flotation plant-wide control strategy evaluated on hybrid pilot plant

IFAC-PapersOnLine, 2017

In this work, the implementation and use of a metallurgical simulator for a flotation plant, incl... more In this work, the implementation and use of a metallurgical simulator for a flotation plant, including rougher-cleaner-scavenger, RCS, is presented. The simulator can be fed by the user with input operating and metallurgical variables generated off line or in a hybrid manner. In the last case, the operating variables of all circuits are read from instrumentation installed in the pilot plants and combined with virtual variables, generated by the user, to run the metallurgical simulator in order to predict the characteristics of each virtual stream. The pilot plant is located at the Process Control Laboratory and includes a three pneumatic cells rougher circuit, a flotation column and a two pneumatic cell scavenger circuit. The regrinding and classification stages are simulated by using models based on literature. An expert control system is built in order to find out best operating points, in the sense of metallurgical results, mainly Cu global recovery and specified characteristics ...

Research paper thumbnail of XXV International Mineral Processing Congress 2010, IMPC 2010

Research paper thumbnail of Economic impact of spargers degradation in flotation columns

Research paper thumbnail of On-line monitoring of a pilot flotation rougher circuit by using PCA models

Research paper thumbnail of Supervisory control strategies evaluated on a pilot Jameson flotation cell

Control Engineering Practice, 2019

Research paper thumbnail of Control Strategy for Salvador Concentrator Flotation Columns

IFAC Proceedings Volumes, 1998

Research paper thumbnail of Control Analysis of the Operation of a Copper Smelter and Two Sulphuric Acid Plants

IFAC Proceedings Volumes, 2004

Research paper thumbnail of Predictive Expert Control System of a Hybrid Pilot Rougher Flotation Circuit

Research paper thumbnail of Correlation between the top of froth grade and the operational variables in rougher flotation circuits

Minerals Engineering, 2016

Research paper thumbnail of Availability Principle Applied to a Fuzzy Supervisory Control of a Pilot Flotation Column

Research paper thumbnail of Modelling of residence time distribution of liquid and solid in mechanical flotation cells

Minerals Engineering, 2015

Research paper thumbnail of Advances in developing supervisory control strategies for flotation plants

IFAC Proceedings Volumes, 2013

Abstract The wide plant control integration of mineral processes poses many challenges. Flotation... more Abstract The wide plant control integration of mineral processes poses many challenges. Flotation plants consist of complex interacting circuits where minerals are processed in different stages with recycling. Today, a common arrange are the RCS circuits, where a rougher circuit is combined with a cleaning circuit and a scavenger circuit. The global objectives of a flotation plant are to maximize the value metal recovery while the grade of the final concentrate is kept inside a narrow band. To achieve this, for any time variant feed attributes (flow rate, solid percent, grade, particle size distribution, pH, and chemicals), a capability of modifying the operation of each circuit, in order to achieve some local objectives, is demanded. To advance in this study, a family of simulators can be of great help. Recently, an algorithm to set the froth level profile in a rougher circuit, have been proposed. The simulator used was based on phenomenological models with parameters estimated from industrial data, collected under designed experiments. In this work, a simulator for the cleaning and scavenger circuits, including a regrinding stage is presented. This simulator is based on phenomenological models, with parameters estimated from industrial data. The simulators are used to provide insight on how the available resources in each circuit can be administrated, to obtain some local objectives which are harmonized in a global control strategy. Copyright © 2013 IFAC

Research paper thumbnail of Diagnosis and Control Strategy for a Teniente Converter

IFAC Proceedings Volumes, 2005

Research paper thumbnail of Control strategy for a Teniente Converter

Minerals Engineering, 2005

Research paper thumbnail of The Long Way Towards Multivariate Predictive Control of Flotation Processes

IFAC Proceedings Volumes, 2009

Research paper thumbnail of Flotation rate distribution in the collection zone of industrial cells

Minerals Engineering, 2010

Research paper thumbnail of Industrial evaluation of a new flotation mechanism for large flotation cells

Minerals Engineering, 2012

Research paper thumbnail of On the collection of valuable minerals along rougher flotation banks

Minerals Engineering, 2014

ABSTRACT

Research paper thumbnail of Control alternatives for flotation columns

Minerals Engineering, 1993

Research paper thumbnail of Measurement of axial pressure profiles in large-size industrial flotation columns

Minerals Engineering, 1995

A portable and submergible pressure sensor was developed in order to measure the axial pressure p... more A portable and submergible pressure sensor was developed in order to measure the axial pressure profiles in large-size industrial flotation columns. The system was used to evaluate the effect that operating variables, such as pulp density (1.1–1.3 g/cm3), gas flowrate (1–2 cm/s) and interface level (0.2–2.5 m), have upon the pressure profile. It was found that local pressure varies with changes in pulp level, in the same order of magnitude that varies with common changes in gas flowrate and pulp density. These measurements show the large uncertainty in pulp level estimation using a single pressure sensor.Axial pressure profiles were estimated from different baffled sections in large-size flotation columns. Typically, the data observed from different column sections showed an homogeneous gas distribution over the cross-section of the columns.Local pressure measurement was used to estimate the axial gas holdup profile along the collection zone of large-size columns. A typical increase in gas holdup of 50–60(%), from the bubble generator up to the interface level was determined in industrial columns of 14–15(m) height and 1–16(m2) in cross-section. These data allowed the validation of models to estimate local mean bubble size. Average bubble sizes in the order of 0.9–1.3(mm), were estimated at superficial gas rates of 1.1–2.1(cm/s).

Research paper thumbnail of Flotation plant-wide control strategy evaluated on hybrid pilot plant

IFAC-PapersOnLine, 2017

In this work, the implementation and use of a metallurgical simulator for a flotation plant, incl... more In this work, the implementation and use of a metallurgical simulator for a flotation plant, including rougher-cleaner-scavenger, RCS, is presented. The simulator can be fed by the user with input operating and metallurgical variables generated off line or in a hybrid manner. In the last case, the operating variables of all circuits are read from instrumentation installed in the pilot plants and combined with virtual variables, generated by the user, to run the metallurgical simulator in order to predict the characteristics of each virtual stream. The pilot plant is located at the Process Control Laboratory and includes a three pneumatic cells rougher circuit, a flotation column and a two pneumatic cell scavenger circuit. The regrinding and classification stages are simulated by using models based on literature. An expert control system is built in order to find out best operating points, in the sense of metallurgical results, mainly Cu global recovery and specified characteristics ...

Research paper thumbnail of XXV International Mineral Processing Congress 2010, IMPC 2010

Research paper thumbnail of Economic impact of spargers degradation in flotation columns

Research paper thumbnail of On-line monitoring of a pilot flotation rougher circuit by using PCA models

Research paper thumbnail of Supervisory control strategies evaluated on a pilot Jameson flotation cell

Control Engineering Practice, 2019

Research paper thumbnail of Control Strategy for Salvador Concentrator Flotation Columns

IFAC Proceedings Volumes, 1998

Research paper thumbnail of Control Analysis of the Operation of a Copper Smelter and Two Sulphuric Acid Plants

IFAC Proceedings Volumes, 2004

Research paper thumbnail of Predictive Expert Control System of a Hybrid Pilot Rougher Flotation Circuit

Research paper thumbnail of Correlation between the top of froth grade and the operational variables in rougher flotation circuits

Minerals Engineering, 2016

Research paper thumbnail of Availability Principle Applied to a Fuzzy Supervisory Control of a Pilot Flotation Column

Research paper thumbnail of Modelling of residence time distribution of liquid and solid in mechanical flotation cells

Minerals Engineering, 2015

Research paper thumbnail of Advances in developing supervisory control strategies for flotation plants

IFAC Proceedings Volumes, 2013

Abstract The wide plant control integration of mineral processes poses many challenges. Flotation... more Abstract The wide plant control integration of mineral processes poses many challenges. Flotation plants consist of complex interacting circuits where minerals are processed in different stages with recycling. Today, a common arrange are the RCS circuits, where a rougher circuit is combined with a cleaning circuit and a scavenger circuit. The global objectives of a flotation plant are to maximize the value metal recovery while the grade of the final concentrate is kept inside a narrow band. To achieve this, for any time variant feed attributes (flow rate, solid percent, grade, particle size distribution, pH, and chemicals), a capability of modifying the operation of each circuit, in order to achieve some local objectives, is demanded. To advance in this study, a family of simulators can be of great help. Recently, an algorithm to set the froth level profile in a rougher circuit, have been proposed. The simulator used was based on phenomenological models with parameters estimated from industrial data, collected under designed experiments. In this work, a simulator for the cleaning and scavenger circuits, including a regrinding stage is presented. This simulator is based on phenomenological models, with parameters estimated from industrial data. The simulators are used to provide insight on how the available resources in each circuit can be administrated, to obtain some local objectives which are harmonized in a global control strategy. Copyright © 2013 IFAC

Research paper thumbnail of Diagnosis and Control Strategy for a Teniente Converter

IFAC Proceedings Volumes, 2005

Research paper thumbnail of Control strategy for a Teniente Converter

Minerals Engineering, 2005

Research paper thumbnail of The Long Way Towards Multivariate Predictive Control of Flotation Processes

IFAC Proceedings Volumes, 2009

Research paper thumbnail of Flotation rate distribution in the collection zone of industrial cells

Minerals Engineering, 2010

Research paper thumbnail of Industrial evaluation of a new flotation mechanism for large flotation cells

Minerals Engineering, 2012

Research paper thumbnail of On the collection of valuable minerals along rougher flotation banks

Minerals Engineering, 2014

ABSTRACT

Research paper thumbnail of Control alternatives for flotation columns

Minerals Engineering, 1993

Research paper thumbnail of Measurement of axial pressure profiles in large-size industrial flotation columns

Minerals Engineering, 1995

A portable and submergible pressure sensor was developed in order to measure the axial pressure p... more A portable and submergible pressure sensor was developed in order to measure the axial pressure profiles in large-size industrial flotation columns. The system was used to evaluate the effect that operating variables, such as pulp density (1.1–1.3 g/cm3), gas flowrate (1–2 cm/s) and interface level (0.2–2.5 m), have upon the pressure profile. It was found that local pressure varies with changes in pulp level, in the same order of magnitude that varies with common changes in gas flowrate and pulp density. These measurements show the large uncertainty in pulp level estimation using a single pressure sensor.Axial pressure profiles were estimated from different baffled sections in large-size flotation columns. Typically, the data observed from different column sections showed an homogeneous gas distribution over the cross-section of the columns.Local pressure measurement was used to estimate the axial gas holdup profile along the collection zone of large-size columns. A typical increase in gas holdup of 50–60(%), from the bubble generator up to the interface level was determined in industrial columns of 14–15(m) height and 1–16(m2) in cross-section. These data allowed the validation of models to estimate local mean bubble size. Average bubble sizes in the order of 0.9–1.3(mm), were estimated at superficial gas rates of 1.1–2.1(cm/s).