john visser - johen consulting - practical dust management strategies in materials handling &...

P r a c t i c a l D u s t M a n a g e m e n t S t r a t e g i e s I n M a t e r i a l s H a n d l i n g S y s t e m s

J o h n V i s s e r

P r i n c i p a l E n g i n e e r

J u n e 2 0 1 5

Practical Dust Management Strategies


Presentation Outline


2

Learnings for today

How big is this dust thing?

Ore characterisation

Value chain approach?

Where should we do it?

Many parts to the total answer (i.e.

no silver bullet)

Other considerations

Questions & Answers

Dust in Space


3


How Big Is This Dust Thing?


5

Tonnages from

Space rains down 36,500 t annually

Deserts 1 vs. 3 Bt annually

Salt flecks 3.5 Bt annually

Trees/plants 1 Bt annually

Sulphur

Plankton/volcanoes/swamps 20-30 Mt annually

Fossil fuels 90-100 Mt annually (2001)

Human skin cells: 50 Million cells produced daily

700,000 cells inhaled daily

Secret Life of Dust, Hannah Holmes


How big are the particle sizes?


6

0.001 0.01 0.1 1 10 100 1000

Microns


Ore Characterisation


7

Dust Extinction Moisture (DEM): defined (Australian standard) moisture level at dust number = 10

(DEM of 10=10 t dust per 100,000 t ore)

i.e. 1 rail car lost for 10,000 cars

Transportable Moisture Limit (TML)

Other moistures (water holding, in-situ, etc.)

Flowability (TUNRA/Jenicke & Johansson/etc.)

Mineralogy

Geology

Particle size distribution (PSD)


Dust extinction moisture (DEM)

Jan 2011 Dust concerns and problems

Australian Standard: AS 4156.6-2000

International standard: ISO 20905-2004

What is a Value Chain Approach?


9


Why a Manage Dust?


10

Safety Mobile Equipment

Fixed Plant Personnel

Transportable Moisture Limit (TML)

Health of employees

Licence to operate

Ore losses

Legislation becoming more strict: New operations not allowed to add to current

dust loadings

Maintenance

Water management

Availability (coast v. mines)

Quality (salinity, process water, etc)

Dust extinction moisture (shipping water)


Health 11

Inhalable 10 to 150 µ

Thoracic 5 to 30

Respirable 0 to 10 µ


Examples Of Solutions


12

Administration: Staff authorised to halt the operation

Communication up and down the value chain

In-pit irrigator

Greening cleared areas

Sprays: Stockyard, transfer points and belts

Belt scrapers & washers

Chemicals

Where?


13

Mining: Prior to mining/loading

Open areas: cleared land, around plant and

offices

Materials Handling: stockpiles, materials

handling equipment, mobile equipment, rail cars,

processing, truck dumpers, ship loaders

In the pit


14

15

In-pit Irrigation

Irrigator

Cost = $30,000

Has an irrigation diameter of 50m

Used on ROM Stockpiles which are

typically 100m x 50m 10m

Connected by fire hose to a manifold at

the tail end of the stockpiles

Can winch itself along towards an

anchor or work from a stationary point


In the Pit


16


Layout of reticulation

Truck Dump Station


17

Stockyard 18


Transfer Points: One example 19


Acknowledgement: The Raring Corporation

20

Stockyard and Opens Areas

Return it at transfer points

Wind barriers

Dust generation is linked to incident velocity

Dust generation will not occur below a certain threshold velocity

Dust Barrier up-wind of stockyard can divert wind flow and reduce velocity on the stockpiles

Dust barrier down-wind can collect the dust

Barrier effectiveness

– If we can reduce the wind velocity, we can reduce the dust!

Wind


Before and After: an example


21

In-pit, Dump Pocket and Conveyor sprays


Rail


22

Water

Compaction

Chemical veneers

Covers


Roads


23

Port 24

What

Ore conditioning

Moisture

Blending

Chemical veneers

Where

Stockpiles

In-loading

Stockyard

Ore handling


A Chemical Example: Stockpiles


25

Ore stockpiles

Waste stockpiles

Ore and waste characteristics

Mineralogy

Flowability

Natural moistures (water HC, moisture HC, in-situ)

Incoming moisture

DEM (dust extinction moisture)


Links to a Public Rio Tinto Dust Site


26

http://www.pilbarairon.com/dustmonitoring/


http://www.pilbarairon.com/dustmonitoring/

Laser Measurement for Dust


27


Recapping 28

Why manage dust? Safety

Health

Licence to operate

Ore losses

Tighter legislation

Costs

Where: Think Value Chain

No silver bullet

Start at the beginning: In-pit irrigator

How big is this dust thing?

Ore characterisation


References


29

T. A. Rector & B. A. Wolpa. 2009. Astronomy Picture of the Day. [ONLINE] Available at:http://apod.nasa.gov/apod/ap090208.html. [Accessed 12 August 13].

Johen Consulting Image Library 2015

Holmes, H, 2001. The Secret Life of Dust. 1st ed. USA: Wiley.

http://apod.nasa.gov/apod/ap090208.html






Thanks & Questions?


30

• My wife

• Informa Australia


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