Chemical Research

Granite is an intrusive igneous rock which is widely distributed throughout Earth's crust at a range of depths up to 31 mi (50 km). Granite's characteristic grainy structure and strength is the result of many individual crystalline structures which form tightly together as magma slowly cools within large, deeply buried rock bodies known as plutons. True granite contains 20-60% quartz as well as both plagioclase and alkali feldspars of which the former may not exceed general balance.

Other minerals such as hornblende and biotite may also occur in granite, accounting for its variety of appearances (Alden 2004). Commercially, the term 'granite' includes a range of other types of non-granite dimension stone including any feldspathic crystalline rocks or other igneous or metamorphic rocks which possess qualities similar to granite's grainy, interlocking texture.

Many variations of granite appear on the commercial market with white, gray, pink, and red being the most common primary colors. Granite color also ranges to darker shades of colors like greens, browns, grays, and black.

Extraction and Block Selection

Extraction (more commonly referred to as quarrying) consists of removing blocks or pieces of stone from an identified and unearthed geologic deposit. Differences in the particular quarrying techniques used often stems from variations in the physical properties of the deposit itself—such as density, fracturing/bedding planes, and depth.

The first step in quarrying is to gain access to the granite deposit. This is achieved by removing the layer of earth, vegetation, and rock unsuitable for product with heavy equipment and transferring to onsite storage for potential use in later reclamation of the site. After the face of the granite is exposed, the stone is removed from the quarry in benches, usually 8 to 12 feet square extending 20 feet or more using a variety of techniques suitable to the geology and characteristics of the granite deposit.

Quarrying operations typically include the drilling of holes along the perimeter of the bench, followed by either cutting the stone out of the deposit using saws equipped with diamond wire, or by splitting the stone using hydraulic splitters or small explosive charges. Once the bench is cut or split loose from the deposit, heavy equipment is used to lift the granite bench and transfer it to an inspection area for quality and size specifications.

Every block that meets the size requirement is then thoroughly checked for quality specifications. We have the most experience personnel including the directors, visiting the quarry and inspecting blocks that will be further processed. The blocks are checked for cracks, fissures, color pattern and other variations that help in ensuring the best blocks are selected and further moved to processing. Only one out of every ten blocks are selected ensuring we only select the most premium blocks.

Block cutting

The first step of the process is a primary cutting or shaping of the material. This is typically accomplished for granite using a diamond wire-saw. When operating a circular or diamond wire saw, a continuous tream of water over the saw is required in order to dissipate heat generated by the process; sufficiently-elevated temperature can cause major machine and material damage.

Multiwire

Hedel

In Hedel Delta Wire 2MH76-V6, the diamond wire runs on PU liner with 3+3 type. So we can cut slabs with thicknesses from 2 cm to any size. The wire tension was done by pneumatic and not by hydraulic like other brands, so it is easy to maintain Hedel machines. Its Delta (triangular) system, is an efficient method in market, provides longer useful life, better quality of sawing and cutting speed.

It is produced with motorized vertical and horizontal adjustments, the cutting system is easy to handle with speed adjustment to meet different cutting needs. The machine control system can capture wide range of production data like cut history, parameters history, maintenance history etc in addition to production details.

The area occupied by the multiwire machine can reach a quarter of that used by the conventional loom, reflecting higher production per occupied area. By not using any other product (shot, sludge, lime etc) other than diamond wire and water, the operation is extremely simple, practical and environmentally friendly.

Breton

The other machine to help us yield the desired results is Breton PARAGON EVO 2100/6/V/76. The diameter of all transmissions is 1.000mm, guarantees minimum wire fatigue and a very low cooling water consumption. Its adjustable wire driving drums makes it possible to get closer to the block. The drums and pulleys are installed inside a rigid, boxed steel structure, which runs along the load-bearing columns, stiffly anchored to the ground. It provides robustness, lower wire vibrations while cutting, leading to a higher cutting quality.

Every 2-3 hours the machine and the block is observed and re-adjusted, if needed to ensure a steady and straight cut for the blocks. Once the slabs are cut, they are inspected for any defects and then are marked individually for inventory tracking and moved for further processing.

Grinding, epoxy application and polishing

Grinding

Once the slabs are cut and marked, they are then sent for grinding. Grinding is a process to smoothen the surface of the granite, so they lose their grainy finish, as a result of the cutting process and achieve a smooth to touch finish.

Grinding is done in a grinding machine with multiples heads attached to diamond abrasives of different densities to achieve an even surface finish. Again water is used in this process to minimise heat created from friction.

Epoxy application

Each resinlike plant is customised according to processed material, required production quantity, resin type, required automation level and available area confirmation. It is required to treat all the materials with natural defects, porosity, cracks, fissures so to get their structural reinforcement and a homogeneous surface. A reinforcement cat or net is also applied and fixed with epoxy resin on the back side of the slab, in case of brittle materials.

A deep material dying before the resin application is fundamental and requires around 20-40 mins depending on the material and temperature. The warm air flows opposite to the material direction, heats the slab so that the moisture is first moved away and then totally dried during its passage into a heating exchanger, properly placed outside the tunnel. Working parameters can be programmed one the control panel through color touch screen monitor.

Resin plants are equipped with a program for the different operation cycles managing. A special software controls all the components composing the line by synchronising the support movements

Polishing

This is the final step before the granite slabs are ready. This step is done to remove any excess resin on top of the granite surface as well as smoothen the surface finish.

The slabs are processed with special silicon carbide abrasives in a polishing machine and goes through a process of differing hardness and pressure with 21 abrasives to ensure a smooth surface finish and a mirror like shine

The polishing machine GALAXY B220GX works with a series of polishing heads equipped with abrasives with increasingly finer grain as the processed material proceeds from the machine entrance to the exit. The polishing heads are mounted on exclusive Rotor spindles patented by Pedrini, characterised by a system of counterpressure movements supplied as standard.

GALAXY B220GX is sturdy, reliable and flexible machine capable of polishing with the maximum accuracy all types of granite and quartzite while preserving the integrity of the slab even with thickness as thin as 10 mm.

Finishing Types

NATURAL

The natural finish is basically the absence of treatment. The stone is sold as extracted from the quarry, once cut into the desired format. The final look depends entirely on the characteristics of the stone and its exploitation. This finish is appropriated for cladding and cobblestones.

POLISHED

Stones are polished by repeated application of abrasive treatments. This technique produces a shiny surface, with almost zero porosity, while improving resistance. Polished finish highlights the color and properties of the natural stone. It is commonly used as interior wall and floor dressing, as well as bench tops and in kitchen countertops. It is not recommended for outdoor paving, since it reduces slip resistance.

LEATHER

A leather finish is obtained by a process of brushing the slab with a range of brushes. The result is a slightly undulating surface, very soft, warm and smooth to the touch. Only a few materials are sourced with this finish such as granite.

FLAMED

This finish is achieved by exposing the surface of the stone directly to a high temperature flame. Flamed finish generates a thin roughness and protects the material for outdoor installation.

LAPPATURA

The granite tiles / slabs are brushed, polished and again brushed for a combination of polished and again brushed for a combination of polished and honed finish.