510 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
of these motions imparts specific screening characteristics,
influencing the efficiency and effectiveness of the screening
process (Figure 1).
Screening surfaces, the focal point of the sizing pro-
cess, exert a critical influence on screening performance.
The design of these surfaces involves considerations that
significantly impact their efficacy. Two fundamental cat-
egories of screen surfaces are pre-tensioned panels and loose
panels. Pre-tensioned panels, typically modular in design,
are replaced as complete units, whereas loose panels are
typically secured under tension rather than compression.
Materials utilized in these surfaces include stainless
steel, polyurethane, nylon, rubber, and composite materi-
als. The choice of material introduces substantial variations
in surface life, process compatibility, operational adapt-
ability, and overall screening performance. The consider-
ation of de-blinding mechanisms is imperative, especially
for non-self-cleaning panels. Common industry practices
involve the use of de-blinding media, such as rubber balls,
mechanical brushing, or ultrasonic vibration to mitigate
panel blinding.
Advancements in screening technology include self-
cleaning or anti-blinding panels, notably in stainless steel
wire panels and polyurethane panels. Derrick, for instance,
offers innovative anti-blinding Sandwich ™ stainless steel
surfaces, featuring two fine mesh screens supported by a
coarser backing wire screen. The cross wires of the second
screen create interference in the free openings, prevent-
ing particle lodging and extending the screen panel
life. Additionally, Derrick provides polyurethane panels
designed for non-blinding with a tapper relief design, offer-
ing openings as fine as 400 mesh (438μm) and a high open
area of 35 to 45 percent. These developments underscore
the evolving landscape of screening surfaces, emphasizing
enhanced durability, reduced blinding, and improved over-
all screening efficiency (Figure 2).
FACTORS AFFECTING DRY SCREENING
VSMA vibrating screen handbook has identified many
parameters that affect the selection of screen size and type.
Much of the VSMA vibrating screen handbook discussion
focused on coarse dry screens, although those factors are
also applicable to dry fine screens to a great extent. Derrick
Corporation has incorporated these principles into our
operating philosophy, expanding on the industry’s under-
standing of these factors on the fine end of operation. In
summary, feed characteristics, as well as machine design
and operating parameters, affect the performance of a dry
screen. Several key parameters are discussed below.
Moisture
The moisture content of the feed to a dry screen can be the
most troublesome single factor affecting performance. For
fine separations, even 0.5% moisture can cause a screen to
Plantary
Dynamic Screens
Vibrag415ng Screens
Linear Mog415on
Circular Mog415on
Ellipg415cal Mog415on
Ultrasonic
Sig332ers
Tumbling Mog415on
Linear Mog415on
Gyratory Mog415on
Ultrasonic
Stag415c Screens
Sieve Bends
Flat Sieves
Pneumag415c Screens
Basket
Trommel Screens
Centrifugal Sig332ers
Figure 1. Types of dry fine screens
Dr y
Fine
Screening
of these motions imparts specific screening characteristics,
influencing the efficiency and effectiveness of the screening
process (Figure 1).
Screening surfaces, the focal point of the sizing pro-
cess, exert a critical influence on screening performance.
The design of these surfaces involves considerations that
significantly impact their efficacy. Two fundamental cat-
egories of screen surfaces are pre-tensioned panels and loose
panels. Pre-tensioned panels, typically modular in design,
are replaced as complete units, whereas loose panels are
typically secured under tension rather than compression.
Materials utilized in these surfaces include stainless
steel, polyurethane, nylon, rubber, and composite materi-
als. The choice of material introduces substantial variations
in surface life, process compatibility, operational adapt-
ability, and overall screening performance. The consider-
ation of de-blinding mechanisms is imperative, especially
for non-self-cleaning panels. Common industry practices
involve the use of de-blinding media, such as rubber balls,
mechanical brushing, or ultrasonic vibration to mitigate
panel blinding.
Advancements in screening technology include self-
cleaning or anti-blinding panels, notably in stainless steel
wire panels and polyurethane panels. Derrick, for instance,
offers innovative anti-blinding Sandwich ™ stainless steel
surfaces, featuring two fine mesh screens supported by a
coarser backing wire screen. The cross wires of the second
screen create interference in the free openings, prevent-
ing particle lodging and extending the screen panel
life. Additionally, Derrick provides polyurethane panels
designed for non-blinding with a tapper relief design, offer-
ing openings as fine as 400 mesh (438μm) and a high open
area of 35 to 45 percent. These developments underscore
the evolving landscape of screening surfaces, emphasizing
enhanced durability, reduced blinding, and improved over-
all screening efficiency (Figure 2).
FACTORS AFFECTING DRY SCREENING
VSMA vibrating screen handbook has identified many
parameters that affect the selection of screen size and type.
Much of the VSMA vibrating screen handbook discussion
focused on coarse dry screens, although those factors are
also applicable to dry fine screens to a great extent. Derrick
Corporation has incorporated these principles into our
operating philosophy, expanding on the industry’s under-
standing of these factors on the fine end of operation. In
summary, feed characteristics, as well as machine design
and operating parameters, affect the performance of a dry
screen. Several key parameters are discussed below.
Moisture
The moisture content of the feed to a dry screen can be the
most troublesome single factor affecting performance. For
fine separations, even 0.5% moisture can cause a screen to
Plantary
Dynamic Screens
Vibrag415ng Screens
Linear Mog415on
Circular Mog415on
Ellipg415cal Mog415on
Ultrasonic
Sig332ers
Tumbling Mog415on
Linear Mog415on
Gyratory Mog415on
Ultrasonic
Stag415c Screens
Sieve Bends
Flat Sieves
Pneumag415c Screens
Basket
Trommel Screens
Centrifugal Sig332ers
Figure 1. Types of dry fine screens
Dr y
Fine
Screening