Calling a spade a spade

An Australian research centre has funded the development of a dozer spade blade that is already showing promising results with a reduction in fuel consumption. Jessica Darnbrough writes.

Ripping it up on a minesite may soon be a thing of the past.

The Australian Coal Association Research Program (ACARP) has funded an an innovative new loading blade for doz­ers that has the ability to reduce the amount of ripping required onsite, while also improving wear resistance and fuel efficiency.

The product is the new spade blade, and while it is still in its preliminary test­ing stages, the various attributes the blade is producing may mean it could become a new option for the industry.

Research showed the blade had increased fill capacity, reduced load time, fuel consumption and wear and tear on the drive components.

These finding have been detailed in a recent report titled Develop­ment of a Centre Loading Blade for Doz­ers.

The Author, David Hall, told Aus­tralian Mining that the spade blade has a unique design that combines the best characteristics of a blade with the best characteristics of a scraper.

“All blades are designed to have the material flow from the cutting edge to the skin where it flows up and spills for­ward. This is sometimes referred to as the ‘rolling action’,” he said.

“The spade blade is different. The material flows from the centre cutting edge and back up, but not against the skin, similar in the way a motor scraper bucket would load.

“The material is carried rather than pushed along the ground which helps increase the speed of production and, in turn, reduce fuel consumption.”

According to the ACARP report, the objective of the project was to evaluate the concept of using a spade nosed dozer blade in dozer push applications.

The research was undertaken in tri­als working alongside Caterpillar D11R carry blades.

The research showed that the blade had increased fill capacities in compar­ison to a conven­tional blade and

it also had the ability to penetrate very hard material without rip­ping, producing oppor­tunities for reduced blasting.

“The blade is designed to minimise ripping onsite,” Hall said.

“The idea was to design a blade that had a large capacity but that could also dig into the ground very easily.

“The blade is designed to allow the centre section to penetrate the ground the most.

“Each blade carries a certain amount of dirt. With a wide blade operators can carry a lot of material, but that does not necessarily mean that they can get a lot into the blade in the first place because it does not have the horsepower or weight behind it needed to push the blade into the ground.

“Therefore, if the blade is big, it has to have a high penetration force in order to get the full blade penetrating the dif­ficult conditions.”

The centre of the spade blade is pointed so that it hits and digs into the ground first. When you push a blade into the ground, it takes a certain amount of horse­power. If you minimise what you are pushing into the ground, you effectively double the horse power used to pene­trate.

“The blade is designed in such a way that, when the blade is penetrating the ground, the dirt flows away from the cen­tre section leaving the cutting edge at the front free to dig instead of having to push the dirt away first.”

Fuel savings

The spade blade was trialled with a con­tractor at Millmerran Mine and preliminary results indicated that the blade showed superior load time and cycle time when loading blasted material where fragmentation was not ideal.

Fuel consumption per hour of oper­ation and per cubic metre moved was reduced. When benchmarked against the carry blade for a particular push length and lift in blasted martial, a reduction in fuel consumption of 12% per cubic metre was achieved.

“The first prototype, just looked at penetration issues,” Hall said.

“We wanted to test the theory and shape of the cutting edge, which proved very successful.

“In fact, the harder the conditions, the better the blade performed. The best advantage of the blade is that it loads very quickly, so what that should mean is that the blade is not tearing through harsh conditions for as long.”

Hall said the current focus is to find the right manufacturer to help promote and sell the blade. However, the testing stage is still not complete with Hall cur­rently looking for the right minesite on which to conduct a longer and more inten­sive trial.

“The preliminary results have been extremely promising and we think we have designed a unique and marketable product, however, the road is very long and we still have a way to go before we are 100% satisfied that this product is the best it can possibly be and a product that will set record production mile­stones,” Hall said.

David Hall

ACARP

djhall60@bigpond.com.au

www.acarp.com.au