Kieselgur diatomite from Thiele-Granits operation
in the Chad Basin, North Africa.
Diatomite, garnet, perlite, zeolites and sand are the key
industrial minerals that serve a range of diverse filtration
systems. From beer filtration to swimming pools, to separating
oils and metals, each mineral filter aid performs a crucial
role in its own dynamic market.
As a broad definition, diatomite
and perlite tend to be used in fine filtration for physical
entrapment (blocking) of solids, while zeolites act as a
chemical filter through absorption. Garnet, meanwhile, has a
high specific gravity and thus its primary use is to weigh down
other filtration media - although finer grades are also
useful filter aids.
Diatomite is by far the most widely
used filtration mineral, accounting for around 65% of the
market (see p.65). It is a sedimentary mineral that
consists of the remains of microscopic floating algae -
diatoms Ð that, when alive, remove dissolved silica from
water and precipitate it as cell walls.
The minerals particle shape
and high pore volume give good strength and natural filtering
and absorption attributes. Diatomite can be further subdivided
into marine and freshwater for greater scope of filtering
The might of diatomite
Diatomite is used in many food and beverage filtration
applications around world. Its also used in numerous
chemical filtration processes, Gregg Jones, vice
president of global sales and marketing at EP Minerals LLC,
As GDP grows around the
world, diatomaceous earth (DE) demand will closely mirror this
growth rate. Growth in the global need for clean water and
alternative fuels is also helping to drive demand growth for
DE, Jones explained.
A leading producer of diatomite and
perlite, USA-based EP Minerals began operations in Nevada in
1945. It is a subsidiary of EP Management Corp. and was spun
off from EaglePicher Management Co. in 2005.
We experienced a drop in
demand in late 2008 and into 2009 as did most industries.
Demand recovered slowly through 2010 and we expect to be above
2008 levels again in 2011, Jones revealed.
The diatomite capacity picture over
the last few years has been relatively constant with no major
additions or eliminations. World diatomite production totalled
1.83m. tpa in 2010, led by the USA, China and Denmark,
according to statistics from the US Geological Survey.
The filtration market is
quite busy at present and has been for the last 15
months, a French diatomite producer told
IM. Although demand reduced during the
recession, since then it has been very positive. We have
returned to the levels seen before the recession.
The rapid recovery of the diatomite market is an indicator of
its importance in the filtration sector. Although a number of
minerals and synthetic materials can be substituted for
diatomite, its unique properties mean it is preferred in many
In filtration certain grades of
garnet, expanded perlite, silica sand and zeolites compete for
a share of the fine filtration market. Synthetic filters,
notably ceramic, polymeric, or carbon membrane filters and
filters made with cellulose fibres, are also trying to break
into the industry.
Many companies have
experimented with synthetic filter technology over the last
decade, EP Minerals Jones commented.
Its really a matter of economics and, at the end of
the analysis, DE is still the most flexible and economic
solution available for solid liquid separation.
If people invest in synthetic
filter technology, the decision is typically driven by
incentives and performance guarantees from the filter
manufacturers, Jones told IM.
Other diatomite producers agree. A
leading UK company commented: Consumers are finding that
the economics of synthetic filters are not as good as
The diatomite market has lost
a small amount of market share to synthetic products, but not a
huge amount. A lot of the synthetic filter aids have not been
successful from a cost point of view, the company
To stay ahead of the curve, diatomite producers have focused on
research and development into new applications for filter aids
- including fuels.
Product development resources
are focused on developing new filtration applications in energy
(biofuels filtration, and fossil fuels exploration and
production) and in developing clean water solutions -
including industrial wastewater, recreational water, and
potable water, Jones commented.
Aside from this, consumers of
diatomite have partnered with producers to find new ways of
recycling spent filter cake in a move to reduce landfill.
Today many of our food and
beverage filtration customers use spent cake for animal feed
and agricultural applications, EP revealed.
We are working with our
customers to develop cost effective solutions for spent cake
re-use and we are dedicating significant resources to this
initiative, said Jones.
The outlook is positive for
diatomite but remaining competitive is a concern for producers.
As one source explained, prices for diatomite are largely
determined by utilities and transport costs - and the
general trend within the market is that prices are only heading
in one direction.
We implemented a 5% price increase in the market this
year, Jones told IM. In general
pricing in the market is up 3-5% in 2011.
Diatomite at a glance
Diatomite is a chemically inert sedimentary mineral that
consists of the remains of microscopic floating algae, ranging
in size from 50 to 100µm. When alive, diatoms remove
dissolved silica from water and precipitate it as their cell
walls. The majority of diatomite is amorphous silica, with a
small percentage of crystalline silica which increases when the
mineral is calcined.
The intricate structure of diatoms
and their complex primary and secondary porosity gives
diatomite a very low bulk density combined with excellent
capabilities as a filter aid, absorbent, filler, carrier and
abrasive - with filtration being its primary market.
Three principal grades of diatomite
exist. These include: natural, calcined and flux calcined.
Other names for diatomite - such as diatomaceous earth and
kieselguhr - often refer to grades of less pure material
which may contain significant amounts of clay or other
Diatomite can contain up to 60% moisture, hence it is
important that the product is dried on-site at the mine -
otherwise transportation costs are high.
Global diatomite production (1.83m. tpa)
Source: US Geological Survey, 2010
US diatomite markets
Source: US Geological Survey, 2010
Minerals used in filtration
Diatomite and perlite filtration markets
Beverages: beer, wine, spirits, and non-alcoholic
Food: sweeteners, edible oils, various
additives and components
Chemicals: both organic and inorganic
Source: World Minerals Inc.