Hardplate

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4 grinding questions
Question 1: How can we can reduce the
environmental impact of grinding?
Question 2: And increase productivity?
Question 3: And increase availability?
Question 4: And decrease cost?

4 grinding questions
Question 1: How can we can reduce the
environmental impact of grinding?
Question 2: And increase productivity?
Question 3: And increase availability?
Question 4:And reduce cost?

Environmental impact

- Cement production requires 90-130 kWh per ton of
cement.
“Best available Techniques” for the Cement Industry, A contribution from the European Cement Industry to the exchange of information
and preparation of the IPPC BAT REFERENCE Document for the cement industry, December 1999, Cembureau

“Competitiveness of the European cement industry”,Cembureau. In http://www.cembureau.be/Cem_warehouse/2COMPETITIVENESS%20OF%20THE%20EUROPEAN%20CEMENT%20INDUSTRY.PDF

Environmental impact

Major consumers of electrical energy in cement
manufacture:
• mills (cement mills, raw mills, coal mills)
• large fans (kiln system and cement mills).

“Best available Techniques” for the Cement Industry, A contribution from the European Cement Industry tothe exchange of information and
preparation of the IPPC BAT REFERENCE Document for the cement industry, December 1999, Cembureau

Environmental impact

Grinding: specific electricity consumption

– Cement raw grinder, dry-process cement
plants: ~7 kWh/t [1]
– Slag grinding: 20% higher than in Portland
cement grinding (4000 Blaine) [2]

[1] “Best available Techniques” for the CementIndustry, A contribution from the European Cement Industry to the exchange of
information and preparation of the IPPC BAT REFERENCE Document for the cement industry, December 1999, Cembureau
[2] “OK Vertical Roller Mill”, F.L.Smidth brochure

Environmental impact

The waste hierarchy triangle

“Guidelines for the selection and use of fuels and raw materials in the cement manufacturingprocess”, World Business Council for
Sustainable Development, Version 1.0, December 2005

Environmental impact - prevention

For a given configuration (grindability, fineness, mill
design, etc)

ll
Mi

r

ea

W

n

o

u
ns

P

c
er
ow

m

io
pt

Environmental impact - prevention

Environmental impact - prevention

E1

Actual

E0
EN

0

T1

Stage 2Stage 3

Optimum

Stage 1

Specific Electrical Consumption, kWh/t

Stage 3: (EN-E1)×(T3-T2)÷2

T2

Time, h

Avoid wasting energy:
Do not operate in Stage 3

T3

Environmental impact - reuse

“£ 5 15
m illio n /y e a r a s a
r e s u lt o f
ig n o r a n c e a b o u t
th e s u r fa c e
in t e r a c t io n
mecanisms”
Maximise time to EOL:
Adopt abrasion-resistantproducts
UK Department of Education and Science, Lubrication (Tribology) Education and Research, HMSO

Environmental impact - recycle

Reprocessing waste material:
Recycled grinding components

Question 1
How we can help reducing the
environmental impact?

4 grinding questions

4 g r in d in g q u e s tio n s
Question 1: How can we can reduce the
environmental impact of grinding?Question 2: And increase productivity?
Question 3: And increase availability?
Question 4: And decrease cost?

Productivity

For a given configuration (grindability, fineness, mill
design, etc)
ar

e
Mill W

Pro

duc
t

ivit

y

Productivity

Optimum

PN
P0
Actual

0

T1

Stage 2

Stage 3

P1
Stage 1

Mill Throughput, t/h

Stage 3: (PN-P1)×(T3-T2)÷2

T2Time, h

T3

Example:
P1 = 280 t/h
PN = 340 t/h
T2 = 3,000h (est)
T3 = 6,000h
Combined loss:
90,000 t
× 0.66 recovery
× Euro 50/t
= Euro 3,000,000
Action:
Do not operate
in Stage 3

Productivity

Optimum

PN
P0
Actual

0

T1

Stage 2

Stage 3

P1
Stage 1

Mill Throughput, t/h

Stage 1

T2

Time, h

T3

Action:
Optimise Stage 2
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