Selection of the Crusher for Manufactured Sand Production

The use of manufactured sand is increasing year on year. Its continued and expanded use will only come from improved knowledge about its utilisation and the implementation of process technology that allows successful use. Optimisation of process to suit source rock characteristics is the key part of the design process.

The use of aggregate in concrete is to fill voids. This must be done in such a way that the concrete will have the right performance attributes in the field, whether this is workability, strength, pumpability or finishability. Figure 1 shows the main constituents of concrete, coarse aggregate, sand and filler usually in the form of cement. When produced through the correct process manufactured sand will improve the quality of concrete.

Correct process for the production of manufactured sand is key to producing an aggregate of sufficient quality for concrete production. The process used must match the properties of the source rock. If the fragmentation of the source rock is such that the sand produced meets gradation requirements then the process can be simplified. In the case of source rocks with higher intrinsic strength, the process needs to be refined to produce the required shape and gradation requirements.

Selection of the crusher for manufactured sand production depends on source rock properties such as fragmentation pattern and hardness and the application to which the sand will be applied. Two crushers have proven capability to produce high quality sand for concrete and asphalt - autogenous VSIs and new generation high speed cone crushers. Formats owns global leading technology in both crusher types through VSI5X and HP cones.

Figure 1 Manufactured Sand Processing Plant.

The selection of a crushing circuit should be such that the quality of the source rock is taken into account. We have found the energy input is directly proportional to the strength of the rock. Higher strength rock requires more energy input to create surface area. The consequence is the production of amounts of filler too high for normal concrete production or which may be out of specification. For successful use the filler must to classified. A typical process flow can be seen in Figure 1, where a VSI, high frequency screen and air classifier have been installed to produce high quality fine aggregate products.