Thyssenkrupp crusher revolutionises primary comminution

The eccentric roll crusher (ERC) from Thyssenkrupp has taken the business of hard rock crushing to another level.

A totally new type of primary crusher promises to significantly reduce installation height while maintaining many of the production and service advantages of traditional gyratory crushers.

Contrary to conventional crushers, the ERC uses a unique integrated pre-screening device that allows for bypassing of fines. This significantly reduces power consumption, compaction risk and the wear rate of crushing tools.

The ERC features a patented combination of pre-screening and crushing to represent the best of two worlds. This agile attribute lends the ERC the ability to crush hard rock in high throughputs and energy efficiency unparalleled to commonly used crushers.

For a long time, double roll crushers and sizers have become established as primary crushers across mining operations. But their design constraints are more suited to soft feed applications and are limited on how efficient and economical hard rock processing can be.

Due to the high-headroom, gyratory and jaw crushers require construction of large-scale caverns when used in underground operations. When used in open pit operations, they require large installation structures and residual imbalance induced forces limit their suitability for mobile applications.

But Thyssenkrupp has redefined the concept of primary crushing of hard rock with the ERC this year. The German-engineered crusher is suited for both underground and open pit mining operations, thanks to a reduced installation height of 20 to 50 per cent compared to gyratory or jaw crushers.

Thyssenkrupp head of technology, innovation and sustainability Benedikt Meier says operations across the mining industry are increasingly moving from open pit to underground mining.

“We need to grasp that reality with our product because the crushers that we have in place at the time were not sufficient for these underground mining opportunities,” Meier says.

“Our idea initiation process started from talking to a lot of our customers, technicians, engineers and service people. New ideas and new trends were brought to the development team, and we got to make sure we react to that.”

Thyssenkrupp’s development team then decided to draw up specifications for the ERC and invented a compact crusher with a throughput of at least 1000 tonnes per hour, capable of dealing with hard rock of up to 200 megapascal compressive strength and generating resulting product between 0 and 200 millimetres.

This idea was finally brought into reality. In a six-month test campaign at a hard rock quarry in Germany, a prototype of the crusher model ERC 25-25 was selected as the pilot plant.

This machine boasts a crushing roll of 2500 millimetres in diameter and width, and a feed opening into the crushing chamber that’s 2500 millimetres wide and 1230 millimetres high.

It was fed with both coarse and fine run of mine feed, as well as selected lumps of up to five tonnes in weight.

The desired product size of 0 to 200 (x) millimetres was achieved at various settings, with feed particle size P80 at closed side settings (CSS) of 140 millimetres recorded with approximately 130 millimetres.

The ERC’s integrated grizzly contributed to around 30 to 40 per cent to the total equipment capacity.

And with equipment parameters varied according to eccentric shaft speed and gap CSS, average capacities of 2000 to 3000 tonnes per hour were recorded.

While power consumption at nominal capacity ranged between 200 and 500 kilowatts the high energy efficiency of the ERC was evident in its power consumption of 0.1 to 0.2 kilowatts per hour over time.

Now the ERC is ready for Industry 4.0, integrated with an extensive monitoring system that enables local or remote control, and the automation of equipment from the crusher’s display.

“Prior to developing a product, somebody came up with an idea, a statement, a thought. We needed to do something different,” Meier says.

Little did the industry know, however, that one idea would end up revolutionising the processing of mineral raw materials across global underground and open pit operations.

This article also appears in the February edition of Australian Mining. 

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