Fault Zones in Borth Rock Salt Mine successfully stabilized
esco european salt company is Europe's largest salt producer and is part of the global production network of the K+S Group with locations in Europe as well as North and South America.
esco european salt company operates three salt mines in Germany. This includes the Borth rock salt mine in Rheinberg at the Lower Rhine in North Rhine-Westphalia. Approx. two million tons of salt are extracted in this mine per year. Rock salt from Borth is known for its high purity and is used in domestic salt shakers and in the chemical industry as well as in pharmaceutical products. It is used as road salt for winter services in Germany as well as throughout Europe.
In the Borth rock salt mine, the rock salt of the Lower Rhine region’s salt pan is extracted from depths between 500m and nearly 1,000m over an area of 88km². The salt deposit has a thickness of approx. 200m and extends for a length of about 10km from the German town of Rheinberg to the Netherlands.
All the salt removed from the mine is transported via a conveyor system. A large fault zone was identified near the main conveyor that had to be comprehensively stabilized. Together with project management, DSI developed a stabilization concept that included DYWI® Drill Hollow Bar Anchors with expansion shells to immediately secure the anchors in their bore holes and posterior injection using DYWI® Inject SILO 8044 Resin.
After assessing the submitted proposals, the Borth rock salt mine decided to use DSI’s solution. A total of 900 Ø R32-280 DYWI® Drill Hollow Bar Anchors with expansion shells, Ø 32mm and maximum loads of 280kN in lengths of 5.7m was installed for stabilization. In the next step, the hollow bar anchors were fully injected with DYWI® Inject SILO 8044 Resin.
DYWI® Inject SILO 8044 is a 2-component silicate resin with excellent adhesive properties that cures quickly and solidly. It has been specifically developed for use with DYWI® Drill Systems. Both R32-280 DYWI® Drill Hollow Bar Anchors and DYWI® Inject Silo 8044 Resin have been approved for use in underground mining by the District Council of Arnsberg, department 6 mining and energy in North Rhine-Westphalia.
The DYWI® Drill Hollow Bar Anchors with expansion shells were installed into pre-drilled boreholes and ensured immediate stabilization and fixation of the anchors in the borehole by expansion shell activation. In a second step independent of anchor installation, the annular space between the anchor and the borehole was completely injected using DYWI® Inject SILO 8044 Resin. Injection was realized through the hollow core of the DYWI® Drill Anchors from the bottom of the borehole. The short curing time of the silicate resin permitted the transfer of the full anchor force a mere 30 minutes after installation. This way, the fault zone at the Borth rock salt mine was comprehensively stabilized to the full satisfaction of esco european salt company.