'New diamond prospective area in Greenland

A test run with part of the modular plant: a high capacity, vibrating grease table, developed for Avannaa by Gondwanaland Diamonds, South Africa. Courtesy: Avannaa Resources

Avannaa Resources Ltd, operating in Greenland via its fully owned subsidiary Avannaa Exploration Ltd, reports 18 February 2008 (Nicholas Rose, CEO) that it has diamond- tested a dyke in the vicinity of Ataa Sund, central West Greenland, within its licence area no. 2007/52. The 39 kg sample was analysed for its diamond content by SGS Lakefield, Canada, and yielded 102 diamonds with a total weight of 0.013 carat. One stone can be characterized as a macrodiamond with dimensions of 0.83 x 0.66 x 0.53mm, translucent and white with graphite inclusions, while the remaining 101 stones all are microdiamonds. In terms of colour, 95 stones are white and 7 are off white, and in terms of clarity, 62 stones are transparent and 60 translucent. The majority of the stones (76) are crystal fragments suggesting a high probability that larger stones are present. The discovery significantly extends the regional extent of diamond-prospective bedrock in West Greenland, which has primarily focused on the Maniitsoq - Sarfartoq belt 300 kilometers to the south of the Ataa region.

Avannaa will follow up on this discovery in 2008 by bulk sampling the diamondiferous dyke itself and by detailed evaluation of an alluvial diamond target also within its 2007/52 licence area including sampling of up to 500 tonnes of channel facies sands and gravels of the Atane Formation on eastern Disko. The company will also be prospecting for other dykes and plugs of kimberlitic affinity in the Ataa Sund region, where Avannaa has applied for an exploration licence via a newly formed subsidiary Avannaa Diamonds Ltd. The company's other activities in 2008 are targeted at gold and nickel in several existing and new licences in West Greenland. To process sands and gravels on its alluvial diamond project, Avannaa has acquired a light modular plant specially designed for the Atane Formation sediments by Gekko Systems, Australia. This includes a 2 ton/hr in-line pressure jig (IPJ600) equipped with a 5 ton/hr feed trommel and concentrate sorting screens. A high capacity vibrating grease table, with a pre-cleaning scrubber, designed for Avannaa by Gondwanaland Diamonds (South Africa), will make a final processing of the concentrate before delivery to SGS Lakefield for diamond identification and characterisation. The combined processing plant will allow recovery of 0.6 to 12 mm diameter diamonds.'
Copied from MINEX No. 32 - February 2008

Gondwanaland Diamonds

GAVIN ARMSTRONG

The Armstrong vibratory screen system cuts conventional system's power usage.



Gavin Armstrong MD of
Gondwanaland Diamonds

MATERIALS HANDLING

'Vibratory screen system cuts conventional system's electricity usage

By: Leandi Rostoll

Published: 10 Apr 08 - 8:57 in Mining Weekly

Plant, equipment and accessory manufacturer Gondwanaland Diamonds South Africa MD Gavin Armstrong said this week that the company had developed a vibratory screen that could cut conventional screen systems' electricity usage by up to a quarter of the electricity.

The system was developed to be a cost and space effective option, he said in an interview with Mining Weekly.

The Armstrong screens were lighter than conventional screens, had a low profile and could be placed in confined spaces.

The Armstrong conveyor belt, which transports the raw materials to the vibratory screen, was a new concept that completely runs in a pipe protecting the belt and the material transported on the belt from natures elements, he said.

"The belt is easy to replace. By just removing the pulley, the belt can be removed and replaced within ten minutes."

The Armstrong vibratory screen and conveyor belt has been in production for three years and have been used in the diamond mining industry, but can be adapted for other mining industries as well.'
Reproduced here with the permission of Creamer Media's Mining Weekly online

Armstrong Vibratory Screen

The Armstrong vibratory screen, patents 2003/4539 and 2004/9572, consists of a heavy duty 25x75mm rectangular frame to accommodate a standard 2300x920mm woven wire screen. The screen is attached to a square tubing blocked out frame by means of posi-drive screws and rubber-lined metal washers. The vibratory motors are attached to the sides of the screens for maximum screening efficiency and to allow easy fitting of security covers or a cover carrying a number of air fans which converts the screening arrangement into an effective drying screen, with minimum power requirements. The screen can be easily converted into a double or multi deck screen by adding additional decks and larger vibratory motors. This screening system has the following advantages over conventional screens:

1. The screening efficiency is ±60% greater than for poly-deck screens of equivalent size and aperture.

2. The open spaces on the woven wire screens are up to 40% more than that for equivalent poly-deck screens.

3. The screen weight is less than one third that of poly-deck screens of equivalent surface screening area.

4. The power to drive the screen is less than a quarter required for driving the conventional poly-deck screen of the equivalent surface screening area.

5. The screen is compact, of low profile and can be accommodated into smaller spaces than conventional screens which make for ideal use in shipping containers where space is at a premium.

6. The screen is easy to replace, simply undo eight retaining bolts and remove the frame holding the screen in an upward or downward direction. Clean or replace the screen cloth and refit the frame or fit a frame with a new screen mesh. The screen frames and frame bodies are factory produced on accurate jigs so as to be interchangeable.

7. The screens with their side mounted motors are easy to cover for security reasons.

Vibratory Screens

Pipe Conveyors continued

7	The uniform nature of the spliced belt allows for a segmented spring loaded scraper to be used for a belt running on a straight or crowned pulley, copyright. This scraper is highly effective.
8	The conveyor system can be supplied in multiple flanged lengths of 6 or 12 meters and of various pipe diameters and motor sizes.
9	The conveyor system is easily transported and installed. 3 x 12 meter conveyors can be transported on a trailer setup using the conveyors as the trailer chassis and using a 4 wheel SUV or small truck. http://www.gondwanalanddiamonds.com/conveyors.htm

Pipe Conveyors

Armstrong Pipe Conveyor and Belt Scraper

From practical experience over the past three years while developing and operating a diamond recovery plant, the following pipe conveyor system, Patents 2002/00644 and 2006/3646 have been developed.

The entire conveyor belt both in the forward and reverse or return direction is arranged to run within the conveyor pipe. With this system the following advantages over conventional conveyors are achieved.

1	No guide rollers are required to support the belt as the belt is supported within the pipe. This results in the conveyor being more stable in windy conditions as there is no external return belt to create wind resistance, conveyor instability and vibration.
2	There is no appreciable increase in power required to drive this conveyor even when under load.
3	The complete rubber belt is installed by pulling an accurately hot-spliced complete belt into the pipe by using the motorized drive pulley. Removal of the belt is done in the same way. There is therefore no necessity to join the belt into the conveyor system as previously required. A PVC belt can be used which can be installed and removed by hand.
4	No conveyor belt guide pulleys are required except for the entry and exit guide pulleys which keep the belt clear of the pipe ends. The pipe takes over the function of any guide pulley assemblies.
5	The cradles on both the drive and idler pulleys are both easily adjustable with additional fine adjustment on the idler pulley. Once the belt is adjusted to run in the center very little if any adjustment is required.
6	Where conveyor belts are joined on site an attachment is available to grind the splice to the exact thickness of the belt patent 2006/3646. Conveyors

Gondwanaland Diamonds

Gondwanaland Diamonds is a developer and manufacturer of diamond prospecting and recovery equipment and diamond polishing equipment such as precision ground scaives and polishing benches. We build mobile diamond recovery plant and related equipment, such as vibratory screens, driers, pipe conveyors and belt scrapers. The manufacture of portable jigs and milling and screening units for use in the diamond prospecting industry will be continued. Details of the above mentioned plant and equipment presently being manufactured appear here.