FUELS & LUBRICANTS
Fuel to the fire
Fuel additives, new technology lubricants, better fuel management
& analysis – the latest high tech and autonomous mining
equipment and the latest engines need the right strategy to
achieve their TCO targets, reports Paul Moore
n the fuels and lubricants space, global
supplier Total argues that the most effective
ways mines can reduce energy costs include
using lighter viscosity grades of lubricants;
using synthetic lubricants in industrial gear
equipment; high VI viscosity hydraulic fluids;
fuel cleanliness; and fuel additives.
Total teams have identified, for example, how
fuel additives help to reduce energy use and
costs. Additives are often added at the refinery
to amend the properties of the base fuel to
meet the required specifications at optimal
costs. These may include additives to adapt
cetane property, lubricity, and cold flow
properties to meet legislative fuel requirements
for a region.
Oil companies may use an additive package
at different treat rates customised to improve
the quality of the diesel usually used on the
market. Such additives are added to the fuel
during distribution or at the mining end user’s
facility.
The role of an injector in a mining diesel
engine is to atomise fuel, that is, to convert the
required volume of “liquid fuel” into many tiny
droplets with a size and spray pattern
appropriate for auto-ignition combustion.
Converting this fuel into a “spray” form allows
for mixing of the fuel with oxygen to form a
combustible mix. A fully functioning injector is
required for even engine operation and efficient
combustion. Any damage or defect to an
I
International Mining | JULY 2019
injector may affect atomisation of the fuel,
which reduces the effectiveness of the
atomisation process, resulting in lower
efficiency of the combustion process.
Elevated temperatures at the injector nozzle tip
generally propagate external injector deposits.
Once initiated, continued build-up of
carbonaceous deposits around the injector nozzles
is heightened. Although these deposits will not
usually lead to injector failure, the formation of
these external deposits on the injector may impact
the quality of the combustion process.
The effect of injector fuel spray properties is
an unseen issue and may go undetected,
resulting in power loss, reduced fuel economy
and increase in emissions.
As technology in mining engines improves,
the move to higher fuel temperatures and
pressures can also lead to fouling of the internal
parts of the injectors, a process known as
Internal Diesel Injector Deposits (IDID). IDID
form on the internal parts of the injector, such
as the injector needles and valves. While these
deposits can form on any type of injector, recent
mining engines are particularly sensitive to this
kind of deposits.
Fuel additives can be categorised as organo-
metallic or metal-free additives. Organo-metallic
additives are commonly used as octane
boosters and anti-knock agents. These additives
were then introduced into fuels for diesel
engines for their ability to further oxidise soot
Shell Lubricants argues that for miners to
realise the potential TCO savings from new
high-tech equipment, proper maintenance and
lubrication will be essential
(particulates) from combustion. There are a
number of metal additives known to improve or
catalyse combustion in diesel engines, including
barium, cerium, copper, iron and magnesium.
Unfortunately, metallic additives have the
tendency to form external deposits. These
deposits can build-up within the combustion
chamber and lead to combustion in-efficiencies,
higher fuel consumption and maintenance,
resulting in an increase in costs.
Further, the use of metal-based additives in
fuels is not recommended by many OEMs of
newer technology mining engines, especially
those equipped with exhaust after treatment
equipment (diesel particulate filters or DPFs).
The EXCELLIUM ashless option
Total recommends the use of its TOTAL
EXCELLIUM CONCENTRATE DIESEL fuel
additives, a premium range of products that
“cleans” the engine and provides longstanding
protection to make the mining engine more
efficient, more economical and less polluting.
The additive contains no metallic
constituents. Therefore, the fuel additive is
regarded as ashless in accordance with OEM
recommendations and the compliance with local
fuel specification is preserved. TOTAL
EXCELLIUM CONCENTRATE DIESEL enables
optimum performance of the combustion
process within the engine to be sustained, thus
maintaining maximum power output. The
additive is also fully proven for preventing any
IDID formation.