Sigma PlantFinder have recently supplied a complete crushing line to a contract in Tanzania. The crushing line, which contained a jaw crusher, a cone crusher and a 2-deck screener, was all the same brand – Terex Powerscreen/Terex Pegson to ensure ease of maintenance, as the units were destined for a remote location.
The contract is for facilitating the Central Transport Corridor, a group of roads connecting DRC, Uganda, Rwanda and Burundi to the port of Dar Es Salaam in Tanzania.
In order to promote use of these routes, and help ensure the maintenance of the road surfaces, the transport authorities are bringing in more advanced policing methods including vehicle stops, weigh bridges for overloaded trucks, and road condition monitoring.
In order for these facilities and supporting buildings to be constructed in remote locations, the most cost-effective way to provide the crushed stone needed for the access roads and buildings was to establish a self-contained mobile crushing line, which could be moved easily once the project was complete.
The crushing line consisted of a Pegson XR400 jaw crusher, which is a primary crusher, used to crush the raw rock from the quarry blast face. This will reduce the rock from 600-800mm diameter to 120mm down.
Jaw crushers give a rough product, as the stone is only retained in the crushing chamber long enough to be reduced in size, and no shaping or finishing is carried out. The product is therefore a mixture of sizes, in this case from 120mm down to dust.
In order for the stone to be shaped, we supplied a Pegson Maxtrak 1000 cone crusher, which is a track-mounted, self propelled cone crusher with a capacity of up to 250tons/hour. The cone must be choked with stone, as the cone crusher uses abrasion between the stones themselves as much as between the crusher metal and the stone. The cone crusher gives a grinding action, which shapes the stone and produces stone that is suitable for good quality asphalt.
The crushing line was completed with a Powerscreen Chieftain 1400 screener, which provides 3 different fractions from the 2-deck screenbox. In order to provide versatility, we supplied with the machine different sets of screen mesh, to produce different sizes of stone to the client’s requirements.
All the machines were fitted with Caterpillar engines, to ensure easy availability of spare parts, and we ensure that all machines were Tier 3A emissions standards, to avoid problems with the high-sulphur fuel usually supplied in Africa. Tier 3B, Tier 4 (interim) and Tier 4 (final) engines can have issues with this.
Once the deal was agreed, Sigma also arranged the shipping from Europe to Africa, with our in-house shipping department.
In order to keep the machines running as well as possible, Sigma will also supply a full package of spare parts which will be required to keep the equipment producing.