Bolder than ever

Sandvik MB670 bolter miner is the company’s flagship product for developing roadways in longwall mining. This method of mechanical continuous mining, also involving hydraulic roof supports and longwall shearers, is mainly used for coal in countries including Russia, India, Australia and China; in fact, more than 90 percent of global longwall installations are found in China.
With several hundred units delivered globally over 20 years, Sandvik is a leading supplier of longwall development machines. However, even great machines need continuous improvement to meet customers’ evolving needs. Sandvik aims to proactively keep and strengthen its position against other premium bolter miners, as well as help new customers and markets improve their safety and productivity. One aspect is the modularization of electric-hydraulic systems between different flame-proof standards and different machine offerings.

The basis of Sandvik MB670-1 and all the legacy models is the patented design concept of a sump mechanism that incorporates two different operations and functions – cutting and bolting – into a single machine. Practically this means the capability to sump into the face to be cut independently of the mainframe and tracks, and to simultaneously bolt the roof and the rib of the roadway.
Feedback that Sandvik received from the field indicated that the customers’ needs could be summarized in five main points: The machine should allow data logging and an automated cutting cycle; there is constant need to reduce operating costs and the total cost of ownership; the mean time between failures must be increased; safety requirements are ever more stringent; and there is constant pressure to improve productivity.
Sandvik set out to methodically address these needs in order to offer improvements that translate into tangible benefits for mining companies and contractors as well as individual operators and maintenance mechanics.
Sandvik MB670-1 for the first time offers a fully automatic cutting cycle, in which the cutter head moves to predetermined coordinates within a predetermined time window. The same cycle is consistently repeated time and again, which enables more efficient planning. More even roadway floors result in less equipment damage and better safety. Coal sizing is more accurate thanks to adjustable sumps. The bolter miner itself suffers less wear and tear. All these things increase productivity and lower the total cost of ownership.
The electric and hydraulic systems of the new Sandvik MB670-1 have also undergone significant upgrading, including features such as a new simplified hose and connection point layout and a new, more compact power pack, as well as new electric panels and displays and remote control systems.

Perhaps the two most important improvements over the old versions in this respect are the new spool monitoring systems and strategically placed emergency stops. Essentially a safety feature, the spool monitoring system will automatically prevent the machine from starting up if it detects a spool in an open position that would lead to an instant movement of a component when starting the machine.
The mechanical parts and systems have also received a lot of attention during the upgrade process, including a new capability of removing cutter pick sleeves by means of oil injection in the cutter drum, new wear materials to ensure longer lifetime in the boom, slide mechanism and loading device, and a number of individual structural and maintenance improvements. The common thread tying all of these together is better safety thanks to less need for manual work as well as increased productivity and lower total cost of ownership through simplified maintenance needs.
One of the most important innovations in the subsystems of Sandvik MB670-1 is the new wet scrubber exhaust system. The redesigned scrubber emits much less noise than the predecessor model. Mean noise levels have decreased by more than 10 percent, from around 90 to 100 decibels, depending on the scrubber version, to around 77 to 90 decibels.
As in all industries, mining operators are keen to utilize the possibilities afforded by the modern data acquisition and transmission systems. The live view data logging features of Sandvik MB670-1 enable simple web-based, device-independent reviewing of the machine status, runtimes, counters and other customizable content, potentially from any computer connected with the mine network and without any need for installed software. The machine provides that data via OPC data interfaces into the mine-based network environment.