Natural Stones Processing

After the raw stone is queried and crushed in the queries in order to produce final products, the stone is transferred to the processing plant to be cut into the ordered dimensions or to prepare different thicknesses tiles. After cutting the stone in the desired dimensions, the stone is processed using different methods to prepare the final product. Fan cutting and polishing and accuracy in this matter are effective to a large extent in the plate quality.
The stone thickness uniformity, the sides smoothness, the plaque size limit and the stone polishing amount are among the factors that depend on the stone cutting factory precision and the relevant technology level. Using the right technology, controlling and monitoring their work and formulating the necessary rules and standards play an effective role in improving the work of this industry and thus improving the quality of the license plate. Good technology and the appropriate machines use and tools in a country like Italy has made it possible to import a granite considerable amount from different countries in addition to extracting stone from Italian queries , and at the same time to export a plaque stone considerable amount to the country. have different and even to the country producing the same stone.
In stone processing units, since the product has a definite and fixed type and is produced in large volume, the production line is designed based on the product. In this way, the machines are arranged in one place and in the operations order. This method advantages are preventing the waste of employees’ time, reducing the total production time and easier production control. The production process different stages in stone processing units are shown in the figure below.

First Step: Unloading and Loading by Crane

At this stage, the mop is removed from the unloading machine and placed on the wagon. Then the unloaded large block is pulled by the winch under the top or saw. A gantry crane is needed in factories to move stone blocks or unload and load them. These cranes have two vertical columns and the arm moves with two vertical legs. An overhead crane, like workshop overhead cranes, is mounted on an arm that can move along the arm.
The length of the wings and the travel of the moving rails are determined according to the type and location of the machines and the halls number, etc. Usually, the gantry crane power is between 20 and 35 tons. To move stone sheets or to repair machines etc. in the halls, overhead cranes are used, their capacity is about 3 to 7 tons.

Second Step: Initial Cutting

Various plaques are prepared from large block and mill blocks stones in stone-cutting factories. In a stone-cutting factory, equipment such as cutters, saws, or wire cutters are used to cut tiles with desired thicknesses and cut plates into desired geometric shapes and ordered dimensions (plates). For this purpose, the stone placed on the wagon moves on rails and is guided under the cutting machine.
For the peaker, the measuring stone height and the cut depth are determined on it so that the next cuts have the desired width and the waste is minimized in the last cut, but for the saw, there is no limit to the cut depth, so determining the first cut depth is meaningless, that is, only Once it is taken under the saw, and after the cut is finished, it is taken out and the sheets are discharged. The top and saw are the heart of the processing unit and the factory owners are very sensitive about them. In fact, they can be considered as the production bottleneck.
In the cutting operation, it is noteworthy that most of the stones queried from the queries have different seams and cracks, in some cases these seams and cracks can cause many problems, such as the breaking of the stone block during cutting, and the cutting blades getting stuck in the stone. and create more waste. To solve this defect, the desired stones are usually cut in such a way that the length of the cutting blades is parallel to the length of the seams and gaps in the stone.
In this case, while the cutting operation is easier and the aforementioned problems are avoided, the amount of waste is also reduced.
Cutting is done using the following:
• Cropping using peaker
• Cutting using a saw
• Cutting using a wire cutter

Sources:
Atai, M., (1352), Construction stones, Technology Shahrood University, 1397