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Ausmelt Non Ferrous TSL Technology |
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The Ausmelt Technology bath smelting system is suitable for the
recovery of non ferrous and ferrous metals from a range of feed
stocks including concentrates, secondary materials, residues and
dross, precious metal-containing materials, and for processing
a range of industrial by-products. Central to the high-intensity Ausmelt furnace system is the vertically
suspended lance submerged in a molten slag bath. Process gases
(air and oxygen) are injected through the lance. Fuel also passes
down the lance and is combusted at the lance tip to heat the furnace.
The slag is well mixed by the injection of the process gases.
Controlled swirling of the process gases inside the lance cools
the outer section sufficiently to solidify a layer of slag around
the outer surface of the lance. This provides a protective coating
in the highly aggressive bath environment. |
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Feed materials,
fluxes and reductant coal are delivered through a port in the roof
of the furnace and drop directly into the molten bath. If materials
are fine they can be agglomerated or injected directly into the
bath to minimise dust loss through entrainment in rising exhaust
gases. |
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| PROCESS |
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Critical
processes such as feed material dissolution, energy transfer,
reaction and primary combustion all take place in the slag layer.
The intense agitation in the vessel caused by gas injection ensures
that reactions occur rapidly and residence times are low. The
degree of oxidation and reduction is controlled by adjusting the
fuel to oxygen ratio supply to the lance, and the proportion of
reductant coal to feed. This enables the furnace to be operated
at strongly oxidising through to strongly reducing conditions.
Operating temperatures range from 900°C to 1400°C. |
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| GENERATION 3 LANCES |
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The Generation 3 lances offered
by Ausmelt are a “pipe within pipe” assembly. They
are constructed from a composite of stainless and mild steel and
incorporate specially designed helical gas swirlers that enable
the use of low pressure air and oxygen. Ausmelt lances are not
consumed, but the lance tips do wear and are repaired in a simple
and inexpensive procedure with minimal disruption to operation. Lances can also be fitted with a dedicated shroud section that
delivers controlled volumes of air for post combustion of volatile
matter and metals. The subsequent energy generated is partially
recovered to the process by the splashing bath. |
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| ANCILLIARY EQUIPMENT |
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The cost of
Ausmelt facilities is kept low by incorporating low cost furnace
innovations that results in smaller and less complex gas handling
systems, particularly acid and sulphur fixation plants, fuel and
air/oxygen delivery plants. Feed and other material preparation
and handling requirements are kept simple. The feed handling systems
use standard equipment and involve no drying or grinding of materials. |
