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 TITANIA A/S is one of the largest producers of
ilmenite in the world with approx. 6 % of the World production. The company
supplies ilmenite to the European titanium pigment industry, which converts
the black ilmenite into a white titanium dioxide pigment. This pigment has a
multitude of uses, such as paints, plastics, paper and cosmetics.
The company was established in 1902 with its main
office in Hauge. 14 years later it started mining at the Storgangen deposit
at Sandbekk 3 km NE of Hauge, and a new company, Titan Co A/S of Fredrikstad,
now Kronos Titan A/S, acquired the share majority.
In 1927 the company was taken over by the US based
National Lead Company, now NL Inc. Through Kronos Norge A/S it now owns
Titania.
The Tellnes deposit was discovered in 1954 by an
aeromagnetic survey. Production started at Tellnes in October 1960, while the
Storgangen operation continued until 1965. Since then all of Titania's mining
activities have been confined to Tellnes.
Production from the Tellnes open pit is 2 million
tons of ore and 1.6 million tons of waste rock, resulting in a production of
approx. 580,000 tons ilmenite concentrate (1999).
The deposit is mined in 15 m high benches. For each
blast a series of holes, 310 mm in diameter and 17 meters deep, are drilled.
These blast holes, which are placed according to a carefully designed
pattern, are three-quarters filled with a slurry explosive. Each blast result
in about 200,000 tonnes of material, sufficient for roughly one month of
production. From the open pit the ore is hauled to the primary crusher by 170
ton payload trucks.
In the primary crusher the ore is broken into
200-250 mm pieces. Conveyer belts take the ore through a tunnel to the fine
crushing and grinding plant. Suspended in large amounts of water the crusher
ore is further pulverised in ball mills to fine sand less than 0.5 mm in
diameter.
Next come mineral separation. Ilmenite, magnetite
and sulphides are separated from the other minerals in the ore by exploiting
their different characteristics. In the gravity separation plant where the
coarse particles are treated, the higher density of ilmenite comes into play.
The smaller ilmenite particles are extracted by high-intensity magnetic
separation followed by floatation. Here surface treatment in the form of tall
oils is used to buoy up the ilmenite in the foam. Between 1983 and 1986 the
process was redesigned, and nowadays only 20 % is flotated.
From the Tellnes ore dressing plant the concentrate
is transported 4 km by pipeline to the drying unit at Jøssingfjord. There the
ilmenite concentrate is leached in acid solution to remove phosphorus,
sulphur and residual oil. The magnetic concentrate undergoes floatation to
separate out sulphides. Water is removed by vacuum filtration and byproduct
magnetite and sulfide concentrates are stockpiled in separate silos.
The ilmenite concentrate is further dried in
oil-fired rotary kilns to reduce moisture content to about 3.5 %, and then
stored in underground silos. From the silos the ilmenite is transported by
conveyor belts over the loading pier onto the ships.
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