Vermiculite is a hydrated magnesium-aluminium silicate - its
typical composition is 38-46% silica (SiO2), 10-16% alumina
(Al2O3), 16-35% magnesia (MgO) and other compounds such as
calcium, iron, potassium and titanium oxide.
Owing to its lamellar structure, similar to that of mica,
vermiculite expands 6-30 times the original volume of
vermiculite concentrate when heated above 870°C
(1,598°F) through a process called exfoliation.
Exfoliated vermiculite is chemically inert, with a melting
temperature of between 1,200°C (2,192°F) and
1,320°C (2,408°F). It is non-combustible and is a good
insulator of electricity, heat and sound.
Vermiculite is widely used in horticulture, owing to the
structure of the mineral, which allows it to control soil
moisture and host mineral fertiliser. Because of its specific
mineral properties, vermiculite lends itself to a variety of
other commercial applications such as in construction and
Horticulture accounts for at least 50% of
vermiculite’s end market. Other market
applications include building plaster; fire protection;
refractory; friction linings; special coatings; animal feed;
Demand varies between 450,000 tonnes per year and 500,000
tpy, according to Palabora, the world’s largest
Production of vermiculite increased in 2017 from the previous
year via a ramp-up of new facilities in South Africa and
Uganda, according to the United States Geological Survey.
This year, expansions in Brazil and Turkey have led to
expectations of bolstered supply, along with some production
increases in China.
But supply issues in China caused by increased environmental
legislation means that the perceived increase in supply may not
be as significant as first thought.
"We have not noticed an impact so far in Europe. We do
monitor trade statistics and won’t be able to
draw comparison until later in the year when new data is
available," Richard Knight, Palabora Europe’s
commercial director, told Industrial Minerals when questioned
on the reported Chinese shutdowns.
The restart of Namakera by Black Mountain Resources, which
acquired the vermiculite mine from African Phosphate Pty Ltd
in 2016, raised vermiculite production in Uganda last year.
Prior to African Phosphate owning the mine, it belonged to
"[The mine] is considered one of the largest and highest
quality vermiculite assets globally,’" brokers
Verdant Capital said of the sale.
African Phosphate was listed on the Australian Stock
Exchange through a reverse takeover by Black Mountain, which
was - somewhat confusingly - renamed African Phosphate
following the completion of the process.
According to the USGS, Ugandan vermiculite production
increased to 20,000 tonnes in 2017 from 3,000 tonnes in 2016.
Steady on the US
After South Africa, the largest producer of vermiculite is
the US. Two companies in North Carolina and Georgia mine and
process the material - they collectively produced 100,000
tonnes in 2017.
Dicalite Management Group recently announced an increase in
its vermiculite prices, attributing them to "plant improvements
as well as citing its intention of "aggressively exploring
additional lands to increase ore reserves."
It did not disclose the size of the rises, which were due to
come into effect of July 1.
Dicalite also said it has been "continually adjusting the
production conditions to ensure they can produce the grades to
match the requirements of the market. The price increases are
necessary to mitigate rising costs related to labor, utilities,
packaging, and capital investments and allow for more capacity
on high demand grades."
This indicates that demand for higher grades of vermiculite
Indeed, according to Palabora’s Knight, demand
for vermiculite has been strong so far this year, with fresh
interest coming from the fire protection product market.
"As this is linked to construction, demand for vermiculite
will grow in the parts of the world where there is a
concentration of building projects," Knight told Industrial
Minerals. "As we approach the mid-point of the year, demand and
resulting sales have been very strong."
The company has raised its warehousing capacity in the port
of Antwerp and will do likewise in the UK in August to
accommodate this extra demand, it said.
"We continue to supply our traditional markets -
construction, board and horticultural - and are always keen
to work on R&D projects with existing customers or other
interested parties, normally educational establishments. Past
experience has shown that a new market does not always
translate to a spike in volume; it will depend on the actual
amount of vermiculite present in the end process or product,"