Abrasives, both natural and
synthetic, are substances that are used to grind, scour, clean
or otherwise remove material by rubbing or blasting.
They are commonly used to prepare
the surface of a material for treatment, for example, for
painting as part of a corrosion prevention strategy.
The important physical properties
of materials that qualify as an abrasive is the hardness,
rigidity, grain shape and size, friability and purity.
The hardness of minerals is
frequently defined using the Mohs scale Ñ although this
has been considered as inadequate by Gretchen K Hoffman,
writing for Industrial Minerals and Rocks,
“because the methods of testing are very crude and the
intervals between the steps are not uniform”.
Offered as an alternative to this
is a diamond indentation method of measuring hardness, devised
by Knoop, Peters and Emerson in 1939, which is still used
today.
Traditionally, abrasives have been
naturally occurring minerals such as garnet, industrial diamond
and silica. But there are now many manufactured abrasives also
on the market, such as fused alumina and silicon carbide. These
are sometimes preferred as they have a homogenous consistency
and can be more cost effective.
The broader industry splits between
naturally occurring and manufactured abrasives, bonded (for
example, sand paper), loose (sand blasting) and between
disposable and recyclable abrasives.
The loose abrasives market chiefly
serves the oil and gas, marine and fabrication sectors.
The bonded abrasives market is
largely separate from the loose abrasives sector and usually
employs high-end manufactured abrasives, although some
naturally occurring ones are also used.
France’s Saint-Gobain is the
world-leader in the bonded-abrasives businesses, although it
also manufactures thin grinding wheels, coated abrasives,
superabrasives and construction products.
3M and Tryolit follow, but there
are also many other smaller producers.
The industry is also split further
between the standard abrasives (such as silicon carbide and
fused alumina [see pp47-54]) and superabrasives, such
as diamond and cubic boron nitride.
What influences
demand?
Abrasives markets are mainly
influenced by activity in a range of manufacturing sectors, as
well as in construction, shipping, and oil and gas drilling.
Manufacturing sectors include the aerospace, automotive,
furniture, housing and steel industries.
The US manufacturing industry has
shown some recovery, seeing its fastest rate of growth for nine
months in January 2013, according to PMI compiler Markit
Research.
The index posted 55.8 for January
2013, up from 54 in December 2012, meaning that manufacturers
received a larger volume of new orders in January and that the
overall rate of growth was the fastest since May 2010.
In Asia, manufacturing continued to
improve in January 2013. The Chinese index posted 52.3 in
January 2013 up from 51.5 in December 2012, the highest level
seen since January 2011.
The Eurozone recession continued to
create a negative picture for European manufacturing but,
despite this, the index posted 47.9 - its highest result for 11
months.
In the loose abrasives sector,
demand was stable during the economic downturn because of a
buoyant petrochemical sector, a market source told
IM.
“Petrochemical demand remained
somewhat stable, owing to long-term project planning and
maintenance schedules, though some rigs associated with
exploration were furloughed,” he said. Sand blasting of
oil and gas rigs is a major application.
Trends
“In general, there has been
lower demand of abrasive grain in Europe, especially in
southern countries like Spain, Italy and partly France,”
Hans-Georg Leitner, Treibacher Schleifmittel sales manager,
told IM.
The recession in Europe led to
declining industrial activity in the larger driving markets
such as steel, construction and auto production,” Leonardo
Curimbaba Ferreira, general manager, US Electrofused Minerals,
Curimbaba Group said.
“This slowdown in world
demand, coupled with Chinese overcapacity, affected the
abrasives industry and also reshaped the marketplace (...)
European manufacturers started entering in North America due to
slowdowns in their traditional markets.”
He added that he had seen an
increase in demand in emerging markets such as China, Thailand,
Brazil and South East Asia.
The Gulf Cooperation Council (GCC)
states continue to enjoy strong petrochemical demand, which has
fed into the market, a second source told IM,
although the source noted that fabrication remains flat.
Australia and Russia, meanwhile,
are displaying robust growth.
“We can see a general increase
in higher-quality raw materials like fused zirconia alumina and
Sol Gel grain. For coated abrasives, we see also a general
trend to finer sizes,” Leitner said.
“Demand for abrasives is
driven by durable goods manufacturing automotive, machinery,
metals and construction,” Curimbaba Ferreira said.
“Therefore, all the countries
that have a strong durable goods industry will demand more
abrasives. Coated abrasives demand is also driven by repairs
and maintenance besides durable goods,” he added.
In terms of products, parts are
being produced “near-net-shape”, Curimbaba Ferreira
added.
This means that demand has risen in
fine grit sizes and also in high performance products such as
semi-friable, Sol-Gel and diamonds.
But in general, the market declined
between 5-7%, market sources said. The decline was not as
widely noted because although the key industries had fallen off
the automotive and aerospace industries, which use abrasives,
were still strong.
Also, Curimbaba Ferreira added,
although construction fell overall, this promoted growth in
home repairs, which meant higher use of coated abrasives.
Prices
Rising energy costs has driven up
prices, along with increases in raw material costs. Bauxite
prices, for example, have risen on the back of scarce supply
(see pp41-49).
This is the largest input cost the
industry faces, because creating an abrasive takes so much
energy.
However, one possible solution
comes at International Innovative Technologies Ltd (IIT), where
George Milburn, Applications Manager, told IM
that its process using dry milling can use up to between 25-30%
less energy than jet milling for finer abrasive grades. The IIT
mill can also save considerable energy as a pre-milling stage
for ultra-fine grades, Milburn said.
“Our m-series mill uses
markedly less energy for size reduction than typical ball mills
or jet mills,” he said.
“And, with very hard materials
such as SiC and zirconia, the Specific Grinding Energy,
measured in kilowatt hours per ton, is amongst the highest
applied for size reduction in the world,” he added.
Each abrasive is priced
differently. SiC prices have come off from highs (see below),
while natural abrasives, such as garnet, are now trading at
levels 25% higher than their peak price levels enjoyed in 2009,
according to market sources.
“SiC is priced higher than BFA
and typically higher than WFA and other white aluminas,”
Curimbaba explained, although other market sources said that
SiC sits between BFA and WFA, with BFA being the lowest-price
grade (see pp47-54).
“SiC pricing over the past
four years has gone up and then back down. Pricing for SiC
seems to have leveled off, or dropped a bit more as suppliers
are continuing to fight over market share,” he added.
In regards to alumina-zirconia, as
zircon sand pricing has increased over the past few years, this
has made alumina-zirconia higher in price than SiC.
Zircon prices have dropped
recently, to a range of $1,250-$1,550/tonne (FOB Australia)
after rising to a range of $2,600-2,400/tonne in late 2011 and
over 2012, according to the IM prices
database.
The full range of garnet prices,
incorporating all grades (blasting and waterjet cutting), high
and low quality is Û150-450 ($200-600) FOB.
Premium grades are priced between
Û240-300 ($320-400) range.
“This is the sweet spot for
premium, low-chloride blasting grades, with specialist coarse
grades above and waterjet cutting (finer particles) and
poor-quality blasting grades below,” a market source told
IM.
Selected manufactured
abrasives
Silicon carbide and fused
aluminium oxide
Traditionally, SiC’s main end
markets have been refractories and abrasives, and in
particular, steel refractories and silicon wafer cutting in the
solar cell market have been areas of growth since the
recession.
China is the world’s leading
producer of both fused alumina and silicon carbide, with an
output of 700,000 tpa of fused alumina and 455,000 tpa silicon
carbide in 2012, according to USGS.
Germany is the second largest-fused
alumina producer, with an output of 80,000 tonnes in 2012.
North America and Brazil accounted
for 60,400 tonnes and 50,000 tonnes of the world’s share
of fused alumina, and 42,600 tonnes and 43,000 tonnes of
silicon carbide in 2012, respectively (see pie
chart).
The price of silicon carbide on a
FOB basis in the US rose slightly in 2012 to $1,280/tonne from
$1,260/tonne, USGS said.
According to the
IM prices database, the European markets
remained relatively stable, in the ranges pegged in 2011,
between Û1,500-1,800/tonne ($2,000-2,400/tonne) for
refractory grade min 98%.
But other market participants say
that the price is a lot lower, citing levels between
€1,200-1,300/tonne ($1,600-1,740/tonne).
Meanwhile, fused alumina prices,
FOB US, slipped to a $555/tonne average for regular grade and
$1,180/tonne for high-purity grade. This compares with
$627/tonne and $1,360/tonne respectively the previous year.
“Imports and higher operating
costs continued to challenge abrasives producers in the US and
Canada [in 2012],” USGS said.
Sol-Gel
Abrasives
These are prepared by gelling a
form of alumina derived from boehmite, adding various
precursors to enhance the properties with a nucleation agent
and then extracting the water to produce a hard material. This
is then crushed.
Sol-Gels are patented and produced
solely by Saint-Gobain and 3M.
“In 1991, Sol-Gel abrasives
were predicted to dominate the high-quality abrasives market;
the market share has not materialised, however, because of high
manufacturing costs,” Hoffman writes.
Saint-Gobain reported in its 2011
results that it was “invest[ing] in new capacity and
targeted acquisitions to keep up with the very rapid pace of
abrasives market growth in Asia and South America”.
Sintered bauxite (see
pp41-47) is used as an alternative.
“Sintered bauxite is a cheaper
alternative to aluminium oxide, around 75% of price,” a
source told IM.
“Al203
in sintered bauxite is 76%, whereas brown aluminium oxide is at
92%. This means, in practice, it is softer, although cost-
effective in applications which allow it,” the source
added.
Natural
minerals
Garnet
Global production of garnet today
is approximately 1.7m tonnes, according to USGS. Substitutes
include fused alumina and staurolite as a sandblasting
material.
“Diamond, corundum and fused
aluminium oxide compete for lens grinding and for many lapping
operations. Emery is a substitute in non-skid surfaces,”
USGS said.
Garnet is an interesting market
area because it is presented as an attractive alternative to
silica sand as a natural abrasive.
“The trend is toward cleaner
abrasives for both occupational health and safety as well as
for the environment,” a market source told
IM.
“This means countries rightly
continue to ban the use of silica sand and are also making it
difficult to cost-effectively dump the mineral’s slag
abrasives, which form the bulk of loose disposal abrasives,
after use,” the source added.
“Garnet falls somewhere
between cheap disposable and a specialist abrasive. This is
owing to the various grades [fine to expensive coarse] and
applications presented, but also since its performance and
occupational health and safety and environmental profile is
appealing.
“As such, it has been
difficult for producers to meet increasing demand for the
commodity and, save for a short period after the crisis, prices
rises are a constant in this space,” the source said.
Diamond
The US was the world-leader in
industrial diamond production in 2012, with an estimated 104m
carats production. There are two firms which produce industrial
diamonds. Total US secondary production of industrial diamonds
was estimated to be 37m carats.
“About 97% of the US
industrial diamond market now uses synthetic industrial diamond
because its quality can be controlled and its properties can be
customised to fit specific requirements,” USGS said.
Demand is expected to continue to
be high for US industrial diamonds as the country continues to
build, mill and repair its highway system.
China leads the world in synthetic
diamond production, with an annual output or more than 4bn
carats, according to USGS.
Materials that can compete with
industrial diamonds in some applications include manufactured
abrasives, such as cubic boron nitride, fused aluminium oxide,
and silicon carbide. Globally, synthetic diamond rather than
natural diamond is used for about 99% of industrial
applications, USGS said.
Outlook
Foreign competition, particularly
from China, is expected to persist and further curtail
production of manufactured abrasives in North America, USGS
said.
It expects demand for synthetic
diamond grit and powder to remain greater than that for natural
diamond material.
Elsewhere, producers told
IM that they expected prices to rise into the
new year on the back of increased demand from the manufacturing
and petroleum sector.
“As a business, we are
expecting volumes and margin recovery in 2013, which clearly
separate it from the years of the crisis,” a raw materials
producer for the abrasives industry told
IM
“The market outlook for the
first half of 2013 shows a slight decline over 2012,”
Curimbaba Ferreiro said.