Wirtgen surface mining technologies
In 1980, Wirtgen GmbH built the first surface miner for the mining of minerals in opencast deposits. Today, Wirtgen is the market leader in this segment, offering a technically mature product portfolio for opencast mining which has been tried and tested in operations around the globe. Surface miners from Wirtgen offer cutting widths ranging from 2.20 m to 4.20 m and cutting depths of between 20 cm and 83 cm. Wirtgen is the only manufacturer covering a scope of performance ranging from 100 tons to 3,000 tons per hour with direct loading by conveyor belt. This measure of productivity is attributable to the miners’ efficient cutting technology and a wealth of experience gained in nearly three decades of applications technology.
Wirtgen GmbH has meanwhile been acknowledged as the technology leader in surface mining worldwide: machines for the mining of rock by cutting have been developed for opencast mining since the end of the 1970s. Wirtgen is the sole manufacturer to have continuously pressed ahead with the development of surface mining equipment for mining rock by cutting, setting innovative standards in this technology. The biggest challenge consisted in introducing the surface mining technology as an alternative to conventional mining methods, such as drilling, blasting and crushing, and to demonstrate to customers the performance, economic efficiency and environmental friendliness of the method in most diverse applications. Wirtgen opened up a long-term market in this field, and has continued to expand it over the years.
The machine population currently comprises more than 350 machines in all parts of the world; in particular customers in Western and Eastern Europe, North Africa, the Middle East, Australia, India and North America enjoy the advantages offered by the surface miners.
Product portfolio: range of basic machines and cutting drums
With the 2200 SM, 2500 SM and new 4200 SM, Wirtgen offers its customers three tried and tested performance classes which can be equipped with a large variety of options and customized to specific project requirements. All models can be designed for loading the material into dump trucks or depositing it as a windrow behind the machine. Over two dozen drum designs with, for instance, different tool spacings are available for the machines as standard cutting drums while additional special designs are developed and built to meet specific application requirements.
The 2200 SM surface miner offers cutting widths ranging from 2.20 m to 3.80 m for most diverse rock hardnesses up to an unconfined compressive strength of 50 MPa. The front loader is used for the mining of, for example, gypsum, soft limestone or coal. A special, 3.80 m wide cutting drum assembly is available for this surface miner model which impresses with high production rates in particular when applied in soft rock, such as coal.
The 2500 SM rear loader is used for the selective mining of medium-hard to hard rock with unconfined compressive strengths of up to 80 MPa. It has a cutting width of 2.50 m and cutting depth of up to 60 cm. The machine can be supplied in reinforced design to enable rock of up to 120 MPa or higher to be mined in special earthwork and rock operations.
The new, enhanced design of the high-performance 4200 SM, the largest surface miner model, incorporates the findings and field experience gained with the 2500 SM and its predecessor model, the 3700 SM, on construction sites around the world. The 4200 SM has a working width of 4.20 m and is available in two different versions. The 4200 SM for soft rock is capable of cutting materials with unconfined compressive strengths of up to 50 MPa, such as coal, at cutting depths of up to 83 cm. The 4200 SM for hard rock is used as a high-end miner for the mining of medium-hard to hard rock with unconfined compressive strengths of up to 120 MPa, and is capable of cutting at depths of up to 60 cm. It is suitable not only for opencast mining but also for use in rock operations or trench construction.
Cutting technology: made to measure for any application
Wirtgen’s mining expertise is based mainly on the extensive know-how in applications technology. The effectiveness and strength of the solutions offered lie in particular in the field of cutting technology.
Each basic machine in the three performance classes offered by Wirtgen can be adapted to most diverse materials depending on the customers’ requirements or project-specific conditions. This applies in particular to the cutting drum, which is the core component of the surface miner technology. In addition to the mature range of standard cutting drum assemblies on offer, both the number of cutting tools and the tool spacing on the drum can be individually adapted to comply with the customer’s goals. The right cutting technology will then enable the material to be mined at the specified grain size, and the required cutting performance to be achieved.
In addition to the standard drums available for the 2200 SM, 2500 SM and 4200 SM models, Wirtgen GmbH is capable of developing and building special cutting drums in an extremely short period of time, the entire technical specification of which is tailored to accurately fit the operation and project at hand.
The effective performance of the Wirtgen cutting technology covers rock hardnesses ranging from less than 10 MPa to up to 120 MPa or even higher in special applications. The surface miners are primarily used for mining limestone, coal, gypsum and iron ore, but special operations in salt mining, granite, bauxite, phosphate or oil shale are also part of the miners’ current scope of applications.
Wirtgen offers heavy-duty components for reduced wear and tear, easy maintenance and fast tool replacement also in the field of toolholder systems. A significant advantage of all the toolholder systems on offer is that the upper parts can be replaced on site quickly. In addition to the tried and tested HT6 and HT11 toolholder systems, the new heavy-duty HT14 toolholder system has been developed for use in the 2500 SM and 4200 SM models. The HT14 system is useful in applications where high hourly production rates are achieved, high annual mining capacities are realized, and hard, highly abrasive material needs to be mined. A special, battery-driven cutting tool extractor is available for this system, which considerably facilitates the replacement of tools and minimizes the time required to do so.
In addition to the choice of toolholder systems, Wirtgen GmbH offers a comprehensive range of mining tools comprising in excess of 50 cutting tool types optimized for wear and tear and suitable for most diverse applications and types of rock.
Applications technology: the Wirtgen Surface Mining Manual
International experts at Wirtgen GmbH have pooled the knowledge on everything to do with applications technology on more than 170 pages, visualized by means of instructive illustrations, photographs taken on job sites, and performance diagrams. The Mining Manual can be downloaded from Wirtgen GmbH’s website at www.wirtgen.com or ordered with the Mining Division at email@example.com. The manual describes the performance and process capabilities of the Wirtgen surface miners. It helps customers to choose the right machines for their intended applications or requirements.