ERC® – a new generation of mining equipment

thyssenkrupp’s eccentric roll crusher revolutionizes primary crushing

thyssenkrupp Eccentric Roll Crusher

The new eccentric roll crusher (ERC®) boosts efficiency in mining operations

For the mining industry, competitiveness is about having efficient and productive operations. New technologies can help mine operators increase productivity, cut wasteful costs and get the most out both their deposits.

thyssenkrupp’s expertise in mining equipment and industrial machinery has led us to develop an innovative and unique hard rock crusher, the ERC® eccentric roll crusher. Its low-wear design and durable components enhance efficiency in mining operations.

Extensive tests carried out under industrial conditions with the first ERC® defined the most important process and machine parameters: throughput, power consumption and product benefits.

Thanks to its particularly flat and robust design with an integrated screen and high throughputs of up to 8,000 metric tons per hour, the ERC® is suitable for operation in both underground mines and in mobile or semi-mobile crushing plants in open-pit mining.

Eccentric Roll Crusher

Applications

  • Primary crushing
  • Stationary, mobile and semi-mobile applications
  • Hard rock and ores
  • Below and above ground

thyssenkrupp ERC® in a semi-mobile crushing plant

Innovation

For mine operators, carrying out the primary crushing below ground and directly at the working face is generally an attractive solution that offers a number of advantages compared to open cast mining. Underground operations place particular demands on the processing technology especially in terms of compactness, mobility and maintenance friendliness.

Above all, machines for the first in-mine crushing stage need to fulfill special requirements resulting from the specificity of these mining methods. The working faces and processing sites are relocated relatively often. In order to minimize costs, the underground plant sites (aka caverns) are kept as small as possible. Each additional meter in the height of such a cavern entails high investment costs so the comparatively large height of conventional hard rock crushers is disadvantageous.
This resulted in four important requirements for the new crusher: a flat, compact design, transportability, easy underground maintenance, and the ability to process hard rock with a feed size of up to 2,000 x 1,500 x 1,000 mm.

In ore processing the strength and quartz content of the rock are mostly high, which places high demands on the machine in terms of wear resistance and easy interchangeability of the crushing elements. Moreover, as the crusher may well be overloaded due to foreign bodies or other causes during the mining process, a suitable overload protection has to be installed.

The patented design of the ERC® featuring a roll mounted eccentrically between the crushing chamber and the integrated screening chamber results in greater efficiency and productivity, which allows mining operations to be optimized, better integrated and automated. The ERC® was tested in the crushing of andesite, a material with strengths of up to 200 MPa that are similar to many copper and iron ores. Its characteristics make it ideal for effective primary crushing of hard rock and ores in any mining industry.

Interview about the functionality of the ERC® with Frank Drescher

Key advantages of the ERC®

With its numerous advantages over conventional crushers the eccentric roll crusher (ERC®) opens up many new fields of application and solves several problems that often occur in the first crushing stage. The most important advantages are:

  • Compact construction: The specially designed crushing geometry with an integrated screen results in a particularly low construction height of the crusher – 20-50% lower than other primary crushers. The height can be additionally reduced for transport or maintenance purposes by dismounting the hood.
  • High throughput: The kinematics of the crusher with its large, constant stroke enables particularly high comminution intensity and high throughput rates, which are also increased by the integrated screen. Throughputs of up to 8,000 tons per hour can be achieved.
  • High machine efficiency: The integrated screen increases the efficiency of the machine as fine material is discharged directly and not passed through the crushing chamber. This reduces the power consumption as well as the risk of material compaction and overloading the machine. It also minimizes wear on the crushing elements.
  • Integrated automatic gap adjustment with overload protection: As part of the crushing chamber, the adjustable swing jaw enables the gap to be specifically adapted to suit a required product. The adjustment range of up to 200 mm is sufficient for adjustment of the gap to offset wear on the crushing elements. An overload protection function is also integrated into the gap adjustment. A special hydraulic cylinder controls the pressure and thus the load in the crushing chamber. When the acceptable load is exceeded, e.g. by non-crushable foreign bodies, the valve opens and the gap is increased. This protects the crusher against overload damage.
  • Balanced crusher with very low unbalance during no-load operation: The symmetrical arrangement of the roll makes it easy to balance the eccentrically moving crushing element. This reduces the residual unbalance forces, machine vibrations in no-load operation, and the load on the surrounding structure. The ERC® is thus very suitable for use in mobile crushing plants.
  • Reduction of energy peaks: The machine is equipped with large gyrating masses, the flywheel and the V-belt pulley. Their great inertia reduces the energy peaks occurring in the comminution process.
  • Higher service life of wear elements on the roll: The back turning of the roll occurring during the crushing process distributes the loads over the entire circumference. This prevents local wear zones and results in uniform wear. Moreover, the wear volume of the crushing segments on the roll is more than twice that of large jaw crushers due to the large circumference of the roll.
  • Impact resistance: : When fed into the crushing chamber, large chunks of feed material do not fall directly onto the mounted working element, but hit the hood, which is significantly more resistant to such loads than other components. That is a key advantage over many conventional crushers.
  • Fewer elongated material particles: The curved shape of the crusher ensures elongated rock fragments do fall directly into the crusher outlet. Their length is reduced through additional stressing or crushing.

Five ERC® types for various applications

Model
Specifications
ERC®
18-14
ERC®
20-20
ERC®
25-25
ERC®
25-30
Weight [kg] 1) 83.000 120.000 178.000 204.000
Drive motor rating [kW] 2) 160-300 300-450 450-600 500-700
Roll diameter A [mm] 1.800 2.000 2.500 2.500
Roll diameter B [mm] 1.400 2.000 2.500 3.000
Feed opening [mm] 3) 1.000 1.180 1.280 1.280
Grizzly length [mm] 4) 1.100 1.200 1.300 2.000
Gap setting CSS [mm] 5) 70-200 70-220 70-220 100-300
Capacity [mt/h] 6) 600-1.400 1.000-2.500 2.500-3.100 3.400-6.000

ERC® Types

1) Weights indicated do not include base frame, drive motor and tools. Weights may vary depending on actual machine configuration.

2) Motor rating range applicable, actual motor rating depending on the feed material characteristics,
desired product size and actual machine configuration.

3) Maximum vertical dimension between jaw liners and roll liners.

4) Standard length. Screen length may vary depending on actual machine configuration.

5) Close side setting (CSS). Maximum range of gap adjustment 150 mm (ERC 18-14) and 200 mm (ERC 25-25, ERC 25-30, ERC 25-34).

6) Equipment capacity calculated based on a bulk density of 1.7 t/m³. Actual values are depending on feed material characteristics (e.g. hardness UCS, R.O.M. particle size distribution, moisture content), desired product size and actual machine configuration (e.g. gap setting OSS).

References

Eccentric Roll Crusher in a construction hall

A major Australian gold producer is operating an underground block caving mine in the New South Wales region. So far, the customer has been operating jaw gyratory crushers. Currently  four of these crushers are in operation.

Now, it has been tested if our newly developed ERC® 25-25, would be up for the job as well as its characteristics promise great potential in terms of performance, a smaller footprint and construction height for the customer’s further expansion projects.

The results were great!

Click here to learn more about this reference!

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