Rapid International has supplied Kasco Mining and Construction with a new Rapidmix mobile continuous concrete mixing plant in the North Mara region of Tanzania. The company bought the Rapidmix 400CW to supply mine backfill for one of Africa’s largest mining organisations. Mine backfill is the process by which material is used to fill the voids/cavities created by mining excavations. If the voids are left unfilled this can create instability for extraction of adjacent pillars underground and above ground, leading to subsidence.
The process makes effective use of waste rock extracted during the mining process by reusing it as aggregate within the backfill mix.
Kasco utilised a cemented rockfill as the backfill type, whereby waste rock is mixed with a cement slurry to improve the bond strength between the fragments of rock.
The cemented rockfill contains cement slurry concentrations at typically 55% by weight and a mixture of coarse (<150mm) and fine (<10mm) aggregates. In this application, the Rapidmix 400 CW plant mixed a pre-graded aggregate, cement and water to produce the backfill.
Using its own fleet of Volvo dump trucks alongside the Rapidmix 400CW, which has outputs of 400tonnes/hour, Kasco completed the backfill process faster, resulting in saved time, manpower and money.
Fully mobile and self-contained, the Rapidmix 400CW is powered by its own power source, with on-board compressor and generator, and is fitted with a self-erecting system that means the plant can change from travel mode to fully operational within a few hours.