MBT Australia, part of the global Degussa construction and chemicals group, market Masterseal 845A – a specially formulated cementitious polymer powder for spray application onto coal, rock and soil.

The one component powder is simply wetted at the nozzle of a dry shotcrete machine, such as the widely used Meyco Piccolo, and sprayed onto the surface in a wet form.

The product dries within 10 to 15 minutes to a tack free surface, which then continues to cure and increase in tensile strength over time.

Masterseal 845A has been targeted into underground hard rock and coal operations in Australia, having been successfully trialed in North and South America, Europe, South Africa and Australia.

MBT’s Pacific regional manager for underground construction, John Gelson said Masterseal 845A has excellent bond and tensile strength characteristics when applied to both coal and hard rock surfaces. It also maintains a degree of flexibility to cope with movement.

“The simple and cheap application equipment required with this one component product is another bonus for contractors,” said Gelson.

Using the dry powder feed system with final wet application at the nozzle means there is no danger of blocked pump lines or the need to continually flush out pump lines or mixing tanks. This increases the rate of application efficiency and enables stop/start operations to be carried out with ease.

Masterseal 845A’s potential applications include rib side support, replacing mesh, reducing and minimising coal rib spalling and assisting in maintaining the roadway profile.

The flexibility of the product means it also has applications in ventilation seals and repairing areas where a degree of flexibility is required. Due to the polymer component it is also practically a waterproofing membrane.

Another potential application is the surface support of the longwall face during take-offs.

TSL’s have traditionally been coined “super skins” due to its high support characteristics for a thin (3mm) thick membrane.

MBT Australia offer a range of products to the mining industry including anchor grouts for cable and rock bolts, grout pumps, manual and robotic shotcrete equipment, various abrasion resistant floor toppings, precision construction grouts and epoxy flooring products, foaming grouts, dry shotcrete products, injection materials and chemical admixtures for concrete.