Gravicon increases its production of half-inch gravel by 40%

For 40 years, Gravicon has been dedicated to manufacturing and marketing stone aggregates. It supplies raw material for the production of concrete for roadway engineering works and infrastructure in Colombia. Its biggest challenge was increasing its market share while simultaneously providing its clients with a higher quality gravel.

In the face of this challenge, the plant’s conditions were studied in a joint effort with Metso and Gecolsa, a distributor of Metso for aggregates in Colombia. It was determined that implementing Metso’s Nordberg® HP4™ cone crusher would lead to a 40% increase in the production of ½’’ gravel and a 35% increase in the plant’s total production (due to its high crushing capacity), as well as improvements in the percentage of long and flat particles in conformance with ASTM standards. This radical change in the final product’s size would accommodate the new and demanding requirements of the Bogotá market, the capital of Colombia.

Added challenges to overcome

The aggregate market in the Bogotá metropolitan area – where Gravicon is the main source of materials for the most important concrete and construction companies operating there – is primarily distinguished by the lack of sources of good quality materials within a short distance. In the case of concrete materials, production zones are between 80 and 220 km away, so freight charges are a significant factor in the final cost of materials during construction.

There has also been a rise in industrial-type construction requiring concrete mixes of fine granulometry, where ½’’ gravel and sand dominate and with strict shape requirements in order to improve how concrete is pumped. In terms of quality and price, the demands are high for aggregate producers and there aren’t many companies that have managed to succeed in the market.

How was the solution implemented?

The process began in 2011 when Gravicon decided to initiate tertiary crushing in its main plant. Metso recommended the installation of a Nordberg® HP300™ cone crusher, which included a lung stack feeder in order to ensure a full cavity and thus better shaped material and higher production.

Several years later, the increase in the demand for material and the need to go from 1” gravel as the main product to ½’’ gravel made it necessary to pursue an optimal solution that would adapt well to Gravicon’s requirements.

“Metso and Gecolsa recommended the switch to a new, state-of-the-art HP4 cone crusher with a high crushing force that perfectly fit the client’s needs,” said Diego Pulido, Metso’s Andean Area Dealer Distributor Manager.  The suggested change was based on a complete analysis of the plant’s production performance and the mass balances examined by Metso specialists with the help of Bruno process simulation software.

Results

The 400hp HP4 Gravicon uses is state-of-the-art and the first of its type in Colombia. With the HP4 setup, Gravicon increased its production of ½’’ gravel by 40% and improved the quality of the product shape. Meanwhile, it increased the total production of the plant by 35% compared to the previous HP300, thanks to the HP4’s ability to process up to 340 t/h.

Gravicon uses the Guayuriba River as its source of crude material, with a maximum size of 50cm and approximately 40% natural sand content. It’s a hard and abrasive material, with 16% wear and tear. It’s a top quality raw material for the production of sand and concrete gravel.

The crude material is extracted from the Guayuriba River banks with beach refill excavators and transported by trucks to the crushing plant. The plant has a primary crusher with a 24’’x36’’ jaw, a 4¼’’ secondary Simmons cone, a closed circuit, a tertiary fine HP4 cone worked with a lung stack feeder in a closed circuit, two 7’x20’ sieves and a hydrocyclone for sand washing. The quality and quantity of the final product is highly dependent on the performance of the HP4.