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R. Schiemann et al.
Introduction
Roasting of sulfide ores (such as zinc ores) in fluidized bed plants is a commercially
available process route and has been since the 1950s. While the number of greenfield
roasting projects had reached its peak in the 1970s and has been declining since the
concentrate processing capacity for fluidized bed plants is still increasing today. This
trend was mainly achieved by larger sized plants, whereas in recent years the focus is
shifting towards more efficient usage of digitalization tools. Plant size seems to have
reached their optimum in terms of feasible design and cost efficiency. Metallurgical
and process principles of the roasting process remain unchanged and are based on the
fluidization behavior of the feed material, produced calcine and the chemical main
and side reaction as the oxidation of Zinc sulfide. Over time, technological advances
took place impacting availability, maintenance, effectivity, and profitability in many
positive ways.
While environment and safety standards are still as important as ever, plant efficiency and optimization remain an active area of further research and improvement.
Additionally, with today’s challenges such as declining ore grades, further refinements of processing, and operating principles become necessary to maintain high
plant profitability and to comply with environmental regulations. This transition also
impacts the operability of the roasting process so that more and more process control is required. The control room operator of today faces a different skill set as the
operator two decades ago. In order to reach the high level of new production targets,
these new operators must adapt to the new technology where process know-how is
an integral part of the control philosophy.
In that regard, a shift in operating philosophies can be observed: Operating decisions and plant control have long been the responsibility of human operators alone.
Today, however, more and more advanced plant automation is introduced, especially
digital solutions with embedded process know-how by technology providing companies. This can be seen from the earliest design stages through commissioning and
into production as evidenced by roasting plants in Mexico, Brazil, and Turkey.
This paper will describe the need and benefits of optimizing roasting plant operations as discussed. It explains how digital process know-how can be used to great
advantage to achieve such optimizations. This is further exemplified in an approach
for an advanced control system, combining an expert system based on process knowhow and modern digitalization tools as described in the following chapters. The
conclusion will also describe the outlook in the fast-developing technology.
Optimization of Roasting Plant Operation
Control philosophy of traditional roasting plants has long been straight forward
with clear instructions and rules for the operators. Such rules would, for example,
involve increasing air by a certain amount for a certain throughput increase or an
R. Schiemann et al.
Introduction
Roasting of sulfide ores (such as zinc ores) in fluidized bed plants is a commercially
available process route and has been since the 1950s. While the number of greenfield
roasting projects had reached its peak in the 1970s and has been declining since the
concentrate processing capacity for fluidized bed plants is still increasing today. This
trend was mainly achieved by larger sized plants, whereas in recent years the focus is
shifting towards more efficient usage of digitalization tools. Plant size seems to have
reached their optimum in terms of feasible design and cost efficiency. Metallurgical
and process principles of the roasting process remain unchanged and are based on the
fluidization behavior of the feed material, produced calcine and the chemical main
and side reaction as the oxidation of Zinc sulfide. Over time, technological advances
took place impacting availability, maintenance, effectivity, and profitability in many
positive ways.
While environment and safety standards are still as important as ever, plant efficiency and optimization remain an active area of further research and improvement.
Additionally, with today’s challenges such as declining ore grades, further refinements of processing, and operating principles become necessary to maintain high
plant profitability and to comply with environmental regulations. This transition also
impacts the operability of the roasting process so that more and more process control is required. The control room operator of today faces a different skill set as the
operator two decades ago. In order to reach the high level of new production targets,
these new operators must adapt to the new technology where process know-how is
an integral part of the control philosophy.
In that regard, a shift in operating philosophies can be observed: Operating decisions and plant control have long been the responsibility of human operators alone.
Today, however, more and more advanced plant automation is introduced, especially
digital solutions with embedded process know-how by technology providing companies. This can be seen from the earliest design stages through commissioning and
into production as evidenced by roasting plants in Mexico, Brazil, and Turkey.
This paper will describe the need and benefits of optimizing roasting plant operations as discussed. It explains how digital process know-how can be used to great
advantage to achieve such optimizations. This is further exemplified in an approach
for an advanced control system, combining an expert system based on process knowhow and modern digitalization tools as described in the following chapters. The
conclusion will also describe the outlook in the fast-developing technology.
Optimization of Roasting Plant Operation
Control philosophy of traditional roasting plants has long been straight forward
with clear instructions and rules for the operators. Such rules would, for example,
involve increasing air by a certain amount for a certain throughput increase or an