Granite is a natural raw material ready for use
Granite is a natural stone that has formed over millions of years. As a material, it does not require manufacturing, but the raw material is quarried from the soil. High-quality natural stone products have precise quality requirements for appearance and characteristics. Therefore, not any rock is suitable for stone quarrying. In Finland, natural stone quarrying always requires permission, and it is regulated by legislation. Granite quarrying requires a quarrying permit under the Land Extraction Act and an environmental permit under the Environmental Protection Act. Nature and the environment are taken into account in every stage of the stone quarrying process. Kovakivi quaries Kuru grey, Kuru reddish-brown, and Kuru black granite. Our quarries are located in Kuru and Tampere.
Granite Quarrying
In granite quarrying, first a large rock block called a kame is detached from the solid rock. After detachment, it is divided into smaller blocks and eventually into dimensionally and uniformly shaped stone blocks. Granite is quarried by drilling, blasting, and wedging. The goal is to obtain large and intact blocks. The side stone generated during quarrying is utilized by crushing it into various aggregate materials. Natural stone quarrying methods are mechanical and do not involve chemical processes. Similarly, no chemical substances are added to the produced stone. The quarrying of necessary stone is precision quarrying, where the total amount of extraction is relatively small and the effects of quarrying are limited to the extraction area.
Stone prosessing
The processing of granite begins at the quarry, where a rock block is extracted from the rock and turned into a stone block. There are precise quality requirements for the blocks in terms of shape, appearance, integrity, and size. The block brought from the quarry to the processing plant is first cut into desired slab thicknesses. Afterwards, the slab is surface treated, for example by burning or dressing. When making blocked products, the slab is divided into blocks by hydraulic presses or by hand wedging. Ultimately, the slab is cut and shaped into the desired end products according to the order. The blocks are further processed into various stone products at our own processing plant in Kuru, Ylöjärvi, or by other stone operators domestically or around the world.
Stone as End Product
Granite is used as a building material in various environmental stonework, such as wall, bridge, and pool structures, street furniture and pavement, stairs, slab floors, edging stones, and as a building stone in for example facades, plinths, and floors. The different qualities of the stone are utilized as needed with surface treatment tailored to each project.
Granite is an almost eternal building material
As a material, granite is entirely recyclable. Its lifecycle speaks in favor of using it. When the purpose for which the granite was used comes to an end, it can be reused for different purposes. Granite can often be reused as is, or as crushed stone for road construction. Finnish granite also withstands weathering excellently, both on building facades and on streets. This is often associated with winter maintenance and salting. Granite does not crumble due to salt or frost stress. This is a significant advantage compared to concrete, for example.
Utilizing side stone
Side stone is rock that is quarried or produced during processing, which cannot be immediately used in production. It is visually varied, fragmented, or sized unsuitable for block or use in processing. Our goal is to utilize all generated side stone. Work is constantly being done to utilize side stone and we are involved in developing the use of side stone in various projects.
We have commissioned the necessary rock tests for the side stones made from Kuru grey granite. These aggregates can be used in various applications, such as road and foundation construction. The gravel made from Kuru granite side stone is of high quality. In 2022, we received PIRELY’s approval for the use of Kuru gray gravel in the creation and maintenance of gravel-surfaced roads. A small portion of the side stone can be used in environmental construction as individual products, such as retaining walls, as long as the product is allowed a sufficiently large range in terms of measurements and color, for example. The most significant factor in utilizing side stone is their processing into aggregates. This way, a sufficiently large volume and efficient process can be achieved.