"Carbon rich graphite deposits found in Sri Lanka are of...

"Carbon rich graphite deposits found in Sri Lanka are of inorganic origin and they occur as narrow steeply dipping veins. The vein width of these deposits varies from a few centimetres to metres, with an average vein thickness of 1 m. It is believed that the carbon rich fluid intruded into fracture zones under high pressure and the temperature has crystallised into graphite.

This process has also generated many minuscule graphite veins centred on main mineralisation, which has reduced the host rock overall rock mass rating. These discontinuities could also be considered as joints with graphite infill. Graphite mining at Bogala Mines, Sri Lanka is a unique example of narrow vein mining faced with numerous wall stability issues resulting from weak graphite infilled joints.

The Bogala vein type graphite orebody has an average vein width of 1 m. Overhand cut-and-fill mining method is used for stoping. The stope consists of two boundary winzes for material handling, access and ventilation. Mining is done on the strike of the vein and the average mining slice height is 2 m. A void to the height of one mined slice is left below the mining level during mining.

Waste rock resulting from vein blasting and mine development is dropped into this void as fill rock. Any void height left greater than a single slice height will increase stresses in the stoping zone. This will increase formation of rock blocks and their effective separation from wall rocks. Split miniscule veins occurring around main mineralisation intensifies rock block formation in an environment of mining induced stress release.

Consequently, any rock blocks sliding into stopes on graphite infilled joints will behave under constant normal stiffness (CNS) conditions and their shear strength will converge rapidly towards remoulded shear strength of graphite alone. Unlike with general infill deposited in joints, graphite has a very low friction angle and with its slippery nature, a small thickness may affect in great deal to reduce joint shear strength.

In addition to immediate filling of excavated voids, controlled vein blasting and spot bolting have improved mine safety. Furthermore, rock bolts connected to each other through iron plates and anchored to anchor bolts installed in non-fractured solid rock are practiced to stabilise rock falls and wedge failures in narrow vein graphite mining. These practices have significantly contributed to safe mining without any rock bursts and catastrophic failures.

CITATION:
Welideniya, H S and Ekanayake, K, 2012. Challenges faced by narrow vein graphite mining and influence of graphite infill on wall stability, in Proceedings Narrow Vein Mining 2012 , pp 71-76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

SOURCE: https://www.ausimm.com.au/publications/epublication.aspx?ID=15176

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Allot is involved for MRL Corporation to start Producing...

Even 1 TON will be huge in my opinion...

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UK professor leads effort towards developing 3D printed graphene batteries
Aug 4, 2015 | By Simon

http://www.3ders.org/articles/20150...developing-3d-printed-graphene-batteries.html

As we continue to load our pockets and bags with mobile devices that help us stay connected to our digital lives, the need to power them has to come from somewhere. Because of this, more research than ever has been focusing on optimizing batteries to make them, smaller, lighter, more energy-efficient and ultimately, more powerful than ever before.

Among others who have been developing longer-lasting batteries for tomorrow’s smartphones and other devices include Professor Craig Banks, the Associate Dean for Research and Professor in Electrochemical and Nanotechnology at Manchester Metropolitan University in the UK.

Recent developments for a three and a half-year project being led by Banks have been focused on building a desktop printer that is capable of creating batteries, supercapacitors and energy storage devices for phones or tablets, and solar, wind and wave power storage using conductive graphene ink.

Graphene was discovered at the University of Manchester in 2004 and it is 200 times stronger than steel and is a highly efficient conductor of heat and energy.

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By utilizing the conductive properties of graphene ink as a form of filament, Banks and his team are able to create optimized 3D structures that are designed to increase the amount of power storage that a battery is capable of.

“Energy storage systems (ESS) are critical to address climate change and, as clean energy is generated through a variety of ways, an efficient way to store this energy is required,” explains Banks.

“Lithium and sodium ion batteries and super/ultracapacitors are promising approaches to achieve this. This project will be utilising the reported benefits of graphene - it is more conductive than metal - and applying these into ESS.”

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In addition to the choice of material used, the design of the ESS’s 3D structures itself is critical in order to maximize its capabilities. Among other considerations include high surface areas, good electrical properties and hierarchical pore structures/porous channels.

“We’re trying to achieve a conductive ink that blends the fantastic properties of graphene with the ease of use of 3D printing to be manipulated into a structure that’s beneficial for batteries and supercapacitors,” added Banks.

Although there have been similar studies and techniques done with graphene, the majority of them use ‘semi-graphene’ inks that feature additives including graphite and carbon black, which ultimately compromise the efficiency of the graphene’s performance and potential.

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While the technology looks promising, there are still some details that need to be ironed out before the printer becomes a true ‘Plug n’ Go’ experience that Banks hopes to see it become one day. Among others, this includes the need to cure each layer of the 3D printed object for at least one hour before another layer is applied to it.

When considering how many layers make up a 3D printed object, it’s clear how time consuming this can be. Currently, Banks and his team are looking at ways of curing the material directly after it has been extruded.

"At the moment it takes ages to make anything above the micron level, so we want to shine a UV light onto the ink as it is printed, to cure it in situ and ensure it holds its structural integrity," added Banks.

"Ultimately, we could all print our own batteries from a 3D printer in our office or home. You could imagine just clicking in a cartridge containing graphene-conductive ink, and manipulating it into a unique structure."

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When we follow the Bread Crumbs I think MRL Corporation has a very strong presence and will enjoy these Tech Drivers as long as it continues to make smart decisions and Partnerships...

http://www.colombopage.com/archive_15B/Aug04_1438684610CH.php

http://investorintel.com/graphite-g...alysts-for-disruption-in-the-graphene-sector/


What do you think?



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To Make Mistakes is Easy !!!
Could be 100% Wrong !!!
To Err is Human !!!
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