Loïc Pottier and Philippe Niel, Fives, detail the development of
a new generation of classifiers designed to work with ultrafinemineral loads.

Cement producers can enhance theperformance of their products byadding ultra fine filler to the groundclinker. Ultrafine particles have a d50of < 3 μm. Other minerals industries can also
benefit from using ultrafine filler. For instance,ultrafine grinding and classifying of limestone
can allow producers to replace more expensive
and polluting fillers.
The FCB TSV™ classifier is known for its
high performance separation capabilities andminimal electricity consumption. The morethan 250 operational installations and thesatisfaction of its users demonstrates theperformance and reliability of this systemin the field, which is mainly focused on(but not limited to) the processing minerals
and cements. The primary benefit of thissystem is the high level of production
efficiency that it offers to grinding plants.
It enables the reliable and accurate control

of the distribution of the products’ particle
size, and optimises the inherent qualities offinished products themselves (sharpness ofPSD curves, burnability of cement raw mix,
controlled combustion of solid fuels, cementstrength, etc.).
The FCB TSV technology has been extended
and is now also available in the UHF (UltraHigh Fineness) field with a Tromp curve
cut-size lower than 3 µm. It allows UHFpowder production with d50 down to 2 µm.
The FCB TSV UHF is designed to address
the production of such fine powders at anindustrial scale, up to 15 tph throughput in asingle wheel classifier.
Natural mineral materials such as limestone
as well as industrial products like granulated
blast furnace slag, have already been
experimented on and evaluated for suitability.
Figure 1. CFD numerical simulations.

Figure 2. Test bench configuration.

Figure 3. Cut size ranges.

Development

The usual fineness areas are commonly
covered by the proven technology with cut
sizes between 10 µm (very high fineness) and500 µm (very low fineness).
The FCB TSV UHF development allows forthe application of extensive in-house knowledgeof separation technology within many industrial
processes, associated with a new mechanicaldesign imposed by the higher centrifugal force
applied.
The basic arrangement of the previous design
has been maintained. The classifier is fed withthe vertical axial air inlet. The fed material firstmeets the guide vane, the purpose of whichis to ensure proper tangential speed for anadequate and consistent speed profile all overthe height of the turbine. By balancing thetangential speed of the gases with the turbine’s
tangential speed, the adjustable guide vane
induces the best conditions for the selection
efficiency of the turbine.
The material then goes through the turbine,which has blades shaped with a patented
profile. This allows for the mostprecise selection, even for highmaterial concentration loads at theseparator inlet. This in turn leads tohigh capacities in a given gas flow
circuit and equipment.
In addition, the anti-vortex bladesin the inner part of the turbine arealso a patented Fives design andcontribute to minimising system
power consumption.
Particular attention was paid
to the distribution of gases overthe entire height of the turbine.
Based on CFD numericalsimulations (Figure 1), different
World Cement Reprinted from October 2022

geometric adapted models were evaluatedand then validated on a pilot test bench. The
configuration of the test bench is shown in
Figure 2.
The main characteristics of the FCB TSV UHFpilot test bench are:ff FCB TSV UHF 400; Motor 3 kW – Variable
speed
ff Bag filter 50 m2
ff Feed max 1.5 tph
ff Max ventilation 1500 m3/h
The material load at the separator
inlet can be selected from a range of0.1 – 1.5 kg/m3. The incidence of thematerial load is illustrated (Figure 4) withthe average experiment gathering results
on materials as different as blast furnaceslag, gypsum, or carbonates.
Fives FCB testing facilities are able
to verify the separation efficiencies
achievable in a FCB TSV UHF and toestablish optimal sizing that meets thegiven objectives of a project.
Figure 5 shows examples of particle
size distribution curves of the feeds andobtained products with the pilot plant.

Applications

Ultrafine mineral loads are widely used
in industry, especially for plastics,
thermoplastics, and polymers. Suchultrafine mineral loads are also frequently
requested in many other industries(paints, paper, etc.) or applications(ultrafine binders for water proofing ofrock, oil-gas well cementing, repair of civilworks, etc.).
The following are typical applications ofFCB TSV UHF:

Figure 4. Incidence of the material load.

Ground Limestone
Directly taken from the pilot installation,
Table 1 shows typical process data andPSD of products obtained from groundlimestone. Table 2 shows the calculated
operating data and product quality
produced by an industrial implementationof the FCB TSV UHF.

Figure 5. PSD Feeds.
Table 1. Process data and PSD products: ground limestone.
FEEDPRODUCTTSV UHFFINEStph

P8 µm1.225%

Limestone

d97d50

tph

7 µm

2 µm

0.13

10 µm

3 µm

Ø mm

air m /h

400

1500

346%

0.1961%speed rpm

ΔP daPa

3600

5402700

384

Table 2. Operating data and product quality produced using industrial FCB TSV UHF.
FEEDPRODUCT

tph

P8 µm

3625%

Limestone

TSV UHF

d97

d50

tph

7 µm

2 µm

4.010 µm

*Exhaust fan after bag filter.
Reprinted from October 2022 World Cement

3 µm

5.8

Ø mmmotor KW

air m3/h

2000

160

45 500Fan (*)

speed rpm

ΔP daPa

kWh/t

kWh/t

880

5403236704

390

1420

The corresponding Tromp curve is given inFigure 6.

ff Low operational cost with low power
consumption.
ff Low maintenance cost.
f f Reliable technology.

Ground granulated blast furnace slag (GGBS)GGBS with the appropriate PSD can partiallyreplace cement in high-performance
concrete. It can also improve theperformance characteristics of oil wellcements and squeeze cementing in order
to seal leakages in oil and gas wells.
Ultrafine binders are defined by theirsteep particle size distribution. The d95
or d97 values are typically key parameters
for the performance of the grouting ofmicrofine binders, and the cementing ofsealing powders.
GGBS (4500 – 5000 Blaine) from ballor vertical mills has been treated in thepilot test bench and results have been
extrapolated to an industrial scale. Table 3
gives the main operational data from a 4
tph production unit at d50 = 2 µm.
The corresponding Tromp curve is given
in Figure 7.

Conclusions

The application of Fives technology tothe separation of ultrafine particles allows
high selection performance with a reliable
process and mechanical design at anindustrial scale.
Products such as limestone, slag, andgypsum have been successfully tested
in the Fives research centre located innorthern France.
D50 around 2 µm are achievable withvery good fines yield at industrial scale. As
an example, starting from ground productswith d80 around 50 µm, a production of
4 tph d50 = 2 µm can be achieved in one
single turbine.
The limited pressure drop allows a low
power consumption of the plant. For thesetypes of product, the FCB TSV UHFclassifier gives the following advantages:
ff Very steep selection at high inlet
material load.
ff Minimal over size contamination.
ff Lowest cost investment.

Figure 6. Tromp curve for ground limestone.

Figure 7. Tromp curve for GGBFS.

Table 3. Operational data and product.
FEEDPRODUCTtph

P8 µm

3344%

TSV UHF

d97d50

tph

7 µm

2 µm

4.0

9 µm

3 µm

8.8

Ø mmmotor KW

air m3/h

2200

20055 100

Fan (*)

speed rpm

ΔP daPa

kWh/t

kWh/t

810

520

3142660

410

917*Exhaust fan after bag filter.

World Cement Reprinted from October 2022