Growth in sales of consumer products and
materials used in building is increasing demand for flame
retardants, with mineral-based compounds being among the most
popular chemicals for reasons of performance and safety,
relative to alternatives such as halogenated chemicals.
Flame retardant additives are widely used in
flame resistant plastics, which are needed for applications
such as electronics, building insulation, polyurethane foam,
and jackets and insulation for wire and cable.
Magnesium hydroxide (MDH) is one of the principal
compounds used in this industry. The majority of MDH is made by
adding water to caustic calcined magnesia (CCM), but can also
be manufactured as a by-product of synthetic magnesia
production; from brucite or huntite/hydromagnesite.
In its raw form, MDH is a fine white powder or
slurry, which is non-toxic and insoluble, with a low level of
transition element impurities. Although it is more expensive on
a price per unit basis than its main mineral-based rival,
alumina trihydrate (ATH), it is able to withstand higher
temperatures (up to around 332°C, whereas ATH decomposes at
As requirements for performance continue to
tighten, MDH demand continues to grow. According to Kerry
Satterthwaite, senior analyst at Roskill Information Services,
this expansion is being driven by the polymers
"We are expecting 6.6% per annum growth for MDH
flame retardants worldwide to 2019, driven largely by increased
demand for polypropylene and polyamide – the main
polymers that have to use MDH rather than ATH, because MDH has
better thermal stability," Satterthwaite told
Asia is the largest market for polymers,
representing around half of overall consumption, followed by
Europe, North America and South America. The growth in Asian
consumption, particularly in China, is beginning to slow,
however, in step with lower GDP.
Mature markets like Europe and North America are
also exhibiting flat to slow growth, with slight changes in
this trend usually triggered by regulatory revisions rather
than economic factors.
Industry observers believe that new market
opportunities exist in South America, but at present this
region has shown few signs of implementing the measures
required to boost consumption of MDH, or of flame retardants
Global MDH capacity
Roskill has quantified MDH production capacity
worldwide as approximately 2.5m tpa. This includes brucite and
huntite and is based on output from plants for which production
data is available.
"Most of this – around 1.3m tpa
– is brucite, followed by MDH, at 1.1m tpa,"
Roskill’s Satterthwaite told
IM. "Very small amounts of huntite and
hydromagnesite are produced in Greece and Turkey."
As well as flame retardants, the wastewater
treatment and flue gas desulphurisation industries also take up
a large share of overall MDH output.
According to Roskill, markets for synthetic MDH
can be divided into three main categories. Material derived
from seawater or brine is used mainly for wastewater treatment
and other environmental applications; material derived from
serpentine or magnesite is principally consumed in the
manufacture of flame retardants and high purity grades of
magnesium hydroxide; and thirdly, MDH derived from a variety of
sources including magnesite, brines and seawater is used in
relatively small amounts in pharmaceuticals and foodstuffs.
MDH often competes with much lower cost
alternatives, such as ATH in its flame retardant applications,
and lime and caustic soda in some of its other
In the flame retardants industry, most products
are required to have a 60 wt.% loading of either MDH or ATH.
This therefore represents a significant cost constituent of the
final product and these loadings can also compromise other
This situation has created an opportunity for the
development of substitute materials. US-based Applied Materials
Inc. has launched a range of Dragonite-branded halloysite clay
products as cheaper alternatives to MDH, ATH and antimony
trioxide, which it claims rivals these materials on
Sweden-headquartered LKAB Minerals, meanwhile,
has developed its own competitor material, UltraCarb, which it
says is both less expensive and more efficient as a flame
retardant than MDH formulations.
However, MDH producers have one eye on the
competition and have sought to improve their product offerings
to stave off the encroachment of market challengers.
US-based Huber Engineered Materials has
introduced a number of high performance products into the
market in recent years, including some surface modification
products, which it claims address the problem of physical
property impairment caused by MDH loadings.
Manufacturers of new types of MDH flame
retardants are having to be price sensitive, as fire safety has
proven to be an industry where even better-performing products
struggle to penetrate markets if they represent a slight
increase in costs.
According to Roskill’s analysis, the
MDH industry is set to benefit from steady growth for at least
the next three years and given that the supply side is also
fairly stable, with the ability to adjust capacity where
needed, the outlook for MDH is that it will continue to be a
niche but significant market for magnesia in the medium