pulp & paper industry
A novel pulp bleaching
technology
www.nedmag.com
Nedmag Industries is the leading producer of magnesium hydroxide in Europe.
We offer the pulp & paper industry a novel and sustainable pulp bleaching technology, based on a uniquely
formulated stabilised magnesium hydroxide suspension. In addition to being environmentally-friendly, the
technology also delivers cost savings by ensuring optimised use of magnesium, caustic soda, silicate and/or
hydrogen peroxide in the recipes.
Multiple performance benefits can be achieved by using
in pulp bleaching. Depending on the pulp processes
used to separate the wood fibres, magnesium hydroxide provides
additional benefits. Basically one can distinguish between
mechanical, chemical and deinked pulping processes.
- perfectly produc ed in the Netherlands
2
3
Benefits of magnesium
hydroxide in mechanical
pulping
Filtrate cationic demand (meq/l)
40
35
• Less COD/BOD load. Typically a reduction of 40%
each other by mechanical energy. Within the pulp
can be achieved at equal brightness [see figure 2 ].
bleaching process magnesium hydroxide provides the
This also results in cleaner water systems and less
following specific benefits:
anionic trash in your filtrate [see figure 3],
COD load (kg/T)
In mechanical pulping wood fibres are liberated from
30
25
20
15
10
5
0
3
2
and consequently higher yield [see figure 4].
• Furthermore, magnesium hydroxide has the
1,4
1,2
1,0
0,8
0,6
0,4
0,2
0,0
0
5
100
Bleached PGW filtrate cationice demand (meq/l)
Figure 2
pulp dewatering.
60
Bleadched TMP filtrate cationic demand (meq/l)
Mg(OH)2
paper machines and pulp production lines by better
• Higher brightness. There are various ways to
30
Mg(OH)2 of total alkali (%)
NaOH
potential to ­significantly improve productivity of
caustic soda and sodium silicate.
4
1,6
H2O2 (%)
• Significant cost savings per ton pulp at equivalent
or higher pulp brightness, by eliminating or reducing
Cationic demand of filtrate (anionic trash)
COD load
Figure 3
influence brightness in your recipe. Different ratios
of alkali and peroxide will impact brightness, as well
as the amount of residual peroxide [see figure 1].
Effect on yield
Properties of bleach
98,0
97,5
120
97,0
80
60
40
NaOH
95,5
Mg(OH)2
95,0
20
94,5
0
Reflection Res. Peroxide
NaOH
Figure 1
96,5
96,0
COD
Conductivity
Mg(OH)2
4
Yield
94,0
2
3
4
H202 (%)
Figure 4
5
mechanical pulping
Yield (%)
100
In chemical pulping, notably kraft pulping, wood fibres are
proposed, protection of C-C bonding in cellulose, and deactivation
separated by dissolving in a chemical solution. Magnesium
of transition metal ions by precipitation and colloidal hydroxides.
hydroxide can be utilised in the oxygen delignification step,
But magnesium hydroxide also acts as an alkali source.
the alkaline extraction step, and the peroxide bleach stage.
As a result, significant cost savings can be realized by replacing
Within these processes magnesium hydroxide provides the
magnesium sulfate and partly caustic soda.
following specific benefits:
• Increased pulp brightness due to optimised pH profile.
• Magnesium hydroxide pulp acts as a dual ingredient.
• Additional cost savings by decreasing chemicals like hydrogen
Like magnesium sulfate, it is used during oxygen delignification
peroxide and caustic soda [see figure 5].
and the bleaching processes, to protect cellulose from
degradation and viscosity loss. Two main mechanisms are
10
9
8
Dosage levels (kg/T)
Benefits of magnesium
hydroxide in chemical
­pulping
Chemical dosage during P stage
7
6
5
4
3
2
1
7
Mg(OH)2
DA
Y
0
6
00
:0
0
:0
0
DA
Y
5
12
:0
0
00
:0
5
DA
Y
DA
Y
4
12
:0
H202
Figure 5
6
0
0
00
DA
Y
4
3
DA
Y
DA
Y
3
00
12
:0
:0
0
0
:0
0
DA
Y
2
12
:0
00
00
2:
DA
Y
2
11
DA
Y
NaOH
chemical pulping
DA
Y
10
0:
00
0
Co-operative research between the University of Grenoble INP-Pagora and Nedmag R&D has shown that
• Selective addition of magnesium hydroxide to
• Dosing magnesium hydroxide to only one stage,
various stages of a modern kraft pulping bleach
as in sequence A, leads to a somewhat lower vis-
sequence can give additional cellulose protection
cosity, 1160 versus 1350. Introducing magnesium
and/or chemical cost savings, without jeopardizing
sulfate to the D1 stage, as in sequence C, results in
final brightness and kappa numbers.
the lowest final viscosity (1130) and also a slightly
• Three different Magnesium dosing sequences
lower brightness figure (86,7 vs 87,1 and 87,3).
(A, B, and C) were investigated in combined Ep
• These results show that magnesium hydroxide
and D2 stages. Intermediate and final sequence
is a very interesting and multi-functional ingre-
viscosities were the highest in sequence B, i.e.,
dient, and can be used to optimize modern bleach
when magnesium hydroxide was dosed to both
sequences.
stages.
Sequence A
Sequence B
Sequence C
Stage
Additive in D1
Mg(OH)2 1%
Mg(OH)2 1%
MgSO4 0,5%
Additive in Ep
None
Mg(OH)2 1%
None
% H2O2 cons.
0.5
0.3
0.5
10.9
Ep
EpD2
11.8
11.0
Kappa number
pH
2.0
2.0
Brightness (% ISO)
77.4
79.3
77.2
1210
1390
1190
DPv
% H2O2 cons.
pH
1.2
0.9
0.8
0.9
3.7
4.2
3.8
Kappa number
1.2
1.2
1.1
Brightness (% ISO)
87.3
87.1
86.7
1160
1350
1130
DPv
Source: Mortha, G., Arenas-Suescun, C., Van Vliet, R. and Gärtner, R.(2014) Towards new applications of magnesium
hydroxide in the bleaching sequences of chemical pulps, IPBC 2014 Grenoble, proceedings book p. 284-291
8
99
chemical pulping
Bleaching results after Ep and EpD2 stages, case of sequences with or without additives added in Ep.
Our product
Nedmag Industries provides an extremely stable concentrated magnesium hydroxide suspension,
a suspension of fine particles in water, at a concentration of about 53% by weight.
With no product stirring is needed
during transport, and for storage gentle agitation or
recirculation is recommended. One should avoid freezing
of the product and it should not be mixed with other
alkalis. is non-hazardous,
non-corrosive and very safe and easy to handle.
Product safety & Food contact
Our magnesium hydroxide is generally safe to use and is:
• registered with ECHA in compliance with REACH.
• not classified as so-called ‘Substances of very high
Chemical composition
concern’.
On dry basis
Typical
Specification
Mg(OH)2
%
98.5
97.5 min
Furthermore, it is safe to use in the paper and board
Ca(OH)2
%
0.65
1.20 max
food applications and is:
Physical properties
• compliant with BfR XXXVI. Magnesium hydroxide is
TypicalSpecification
a synthetically produced, insoluble mineral that is
pH 10
harmless to health.
Density kg/m31440
• listed as authorized for use as additive in the
Commission regulation (EU) 10/2011 of 14 January 2011
on plastic materials and articles intended to come into
52 - 54
Typical
• generally recognized as safe (GRAS).
11
d50
µm
2 - 2.5
our product
10
%
Particle size distribution
contact with food.
10
Solids
Our services
& partners
Nedmag has entered into a strategic alliance with
Imerys to cater to the European pulp & paper
industry. Through their combined resources, the
Imerys is the world leader in mineral-based
partners are in an excellent position to bring a
specialty solutions for the industry.
unique combination of technology and application
Imerys transforms a unique range of minerals to
expertise to the pulp industry.
deliver essential functions (heat resistance,
mechanical strength, conductivity, coverage,
An experienced team specialised in pulp bleaching
barrier effect, etc.) that are essential to its
with magnesium hydroxide will provide full
customers’ products and manufacturing
support with your conversion to magnesium
processes. Imerys serves the global pulp and
hydroxide. Nedmag’s research facilities are
paper industry through a network of industrial
equipped to simulate various fibre delignification
sites, sales offices and R&D centers spread across
and bleaching stages including oxygen
the globe.
delignification. These facilities and those of Imerys
are at its customer’s disposal.
Banmark Oy is a leading Finnish service company
development in most European countries while the
for the pulp and paper industry. During their years
Nordic countries will be served exclusively by
in business, Banmark has expanded their
Nedmag’s well established distribution partner
operations beyond the Finnish borders and holds
Banmark.
strong positions in Russia, Sweden and Poland.
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Our services & partners
Imerys will ensure exclusive market and sales
Nedmag Industries - Getting you closer to perfection
Nedmag Industries Mining & Manufacturing B.V. is a Netherlands
Another crucial material in the production process is selective
based producer of magnesium oxide, magnesium chloride,
mined dolomite from the Belgian Meuse-valley. Our dolime
magnesium hydroxide and calcium chloride. Nedmag’s products
supplier Lhoist is one of our shareholders, granting continuous
find their way to customers in several market segments and
availability of this raw material.
applications worldwide. The main markets served by Nedmag
are the refractory market, pulp & paper industry, oil & gas
Nedmag Industries Mining & Manufacturing BV is owned by the
exploration, de-icing and de-dusting applications, food industry
Lhoist group and the NOM. Lhoist is a leading Belgium producer
and wastewater treatment.
of lime and dolime. NOM is a Dutch direct investment agency for
the Northern Netherlands.
Nedmag Industries was founded in 1981, by Shell/Billiton, after
very pure and unique magnesium salt deposits were discovered in
Nedmag is accredited for ISO 9001 and ISO 14001.
the North-East part of The Netherlands. The salt deposits,
situated at a depth of over 1500 meters, were formed in the later
Permian 250 million years ago. Nedmag succeeded in extracting
these salts to the surface by using a unique mining method, called
solution mining. The thus obtained magnesium chloride brine is the
key raw material for the production of Dead Burned Magnesia.
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pulp & paper industry
Nedmag Industries
Mining & Manufacturing B.V.
P.O. Box 241
9640 AE Veendam
The Netherlands
T +31 598 651 911
F +31 598 651 205
E [email protected]
Rpublic \ Groningen \ 31.543
I www.nedmag.com
www.nedmag.com