Solutions - Backfill and Vent Control

Using mine tailings for backfilling is standard practice on South African mines. Where water loss must be reduced or high-strength fill is required the tailings must be cemented. Conventional Portland Cement does not offer the ultimate solution due to its sensitivity to contaminants in the fill. Minova has two patented innovative binder formulations which overcome these problems. Formulations can be taylor made and adjusted to suit almost every requirement.

Backfilling - View Video

Conbex Backfill Binder is a cementitious blened powder used in place of OPC in conventional cemented backfill applications. Its advantages include lower costs and a final product which is stronger and has an improved and predictable performance. A small percentage of this blended product is mixed with the mine tailings or sand mix to form the required strength and properties.

Fillset is a patented two-part backfilling binder system designed to overcome the problems of volume loss and low early strength when classified or run-of-plant tailings are used as backfill. A small percentage of this blended product is mixed with the mine tailings or sand mix to form the required strength and properties.

Void filling

Filling of voids left from fall-outs is necessary to prevent accumulation of hazardous gases and to stop the excavation from progressive enlargement by self-mining. Void filling material must have a controlled but generally low strength. The Minova void filling materials range from 0.3 Mpa to 10 Mpa strengths and from slow setting to fast setting foams to almost suit every requirement. Large volumes must often be filled, usually within tight time constraints. Minova’s cement foams – the Tekseal and Air-O-cem range - are ideal void filling materials. These are supplied as powders, to be mixed with water and pumped directly into the void. The amount of powder used is typically only 7 – 20 percent of the quantity of solid material that would have been required. The foam is placed as a formulated cementitious foam, enabling rapid placement. Strength and setting speed is controlled by selection of the appropriate grade of Tekseal and of the water/powder ratio during pumping. A special foam mix and placement pump is used for these products and also varies in size to suit placement of quantities.

High-strength seals for backfilled stopes and explosion sealing

Tekseal HS is used for construction of high-strength bulkhead seals at the base of high backfill stopes, and for explosion-proof seals in coal mines. The high strength combined with low volume to be transported make them suitable for both purposes.

Ventilation Air Control - View Animation

Air-O-Cem cement foam can be used for general void filling and the construction of lightweight barriers for normal ventilation air control and for sealing off fires to starve them of air.

Grout Packs Minova RSA can supply cementitious powder that replaces OPC for use in standard grout packs. The powder blend formulations are customised to user’s requirements and offers high strength and fast setting times.