Cope or block stone is the first product extracted from stone mines. The importance of extracting high-quality marble slabs is one of the most important challenges in stone processing, so that without a good slab, it will not be possible to produce suitable and durable building slabs.
The first step in the production of marble for construction projects is to extract the stone from the quarry. This work is usually done with a chain saw or more advanced devices.
After extracting marble from the heart of the rocky mountains, what is obtained are raw stones that are cut on the spot and loaded into pieces of different dimensions. Then these pieces enter the next stage of processing in the factory, these pieces or stone blocks are called “coop”.
Copes or blocks obtained are divided into three main categories, this category depends on the health and dimensions of the extracted stone:
• The first category: It is single cup, that is, the best type of raw stone that is loaded in the form of rectangular cubes weighing about 25 tons and individually in each trailer, and that is why it is called single cup.
• The second category: it is two cups, two cups are raw stones in smaller dimensions and two pieces of it are loaded in a trailer. The price of two coupes is lower than one coupe.
• The third category: it is called three cups and carcasses, these are stones that are loaded in threes. Carcasses are stones whose one dimension is far less than the other dimension.
The tools and methods of extracting marble from the mine and turning it into a marble cup:
Today, stone coupes are cut by well-equipped and ultra-advanced machines. In the following, we explain the two methods that usually extract marble from the mountain and cut it.
Cutting method with steel wire:
In this method, first, holes with a length of more than 30 meters are dug, which intersect each other at different levels; Then, by passing the steel wires through the holes, they cut the part of the stone that is limited by the steel wire. The work is based on the rotational movement of a steel wire under tension, which cuts the stone with the help of silica powder and water.
This cutting system consists of a driving force device, a number of guide pulleys, a tensioning device and related auxiliary tools. In order to create the necessary tension, the method of hanging a weight on a cart containing a pulley is used. With this method, it is easy to cut horizontal or vertical surfaces by changing the angle given to the reel. This method works well in carbonate stones, including marble.
Extraction method with diamond cutting wire:
The diamond wire cutting machine includes a diamond wire 25 to 45 meters long (maximum 150 meters) that is permanently cut on the stone in a certain direction by a winch with a guide pulley.
For this purpose, first, they dig two perpendicular holes in the rock that form the boundary of the block, then they pass the diamond wire through it. The cutting device is located on the rail while working and automatically moves on the rail using electronic and hydraulic facilities and pulls itself back by performing the cutting operation.
The tension force of the wire, which is about 100 to 150 kg, is kept constant. The winch device is usually placed at a distance of 5 to 8 meters from the work chest. In this way, about 15 meters of diamond wire works freely. The mechanism of the device is such that the stone can be cut horizontally or vertically by moving and changing the direction of the winch axis from horizontal to vertical.
Horizontal cutting should be done when the vertical cutting of the mountain is not done yet, because otherwise, at the end of the horizontal cutting, it is possible for the stone block to be separated from the mountain and crush the cutting wire that is working horizontally.
Transportation of mineral blocks after the cutting stage to separate the cut block from the work chest is done by hydraulic jacks and compression pads.
There are different wires for cutting stones that have different hardness. The speed of the wire depends on the hardness of the stone. The wire speed is usually around 20 to 30 meters per second in hard stones and around 30 to 36 meters per second in porcelain and marble stones.
Another important point in doing this is the speed of stone cutting. The speed of stone cutting depends on the type and quality of the stone. This speed in marble mines is from 4 to 7 square meters per hour, which ideally reaches 9 square meters.
As a result of the friction that occurs between the wire and the stone, the metal parts of the diamond wire wear out quickly.
In this article, we got to know about stone coupe, its types and explained the methods of extraction and cutting of marble coupe. You should know that among the types of coupes that are sent from the mine to the factories, the best and most valuable coupes are the first category, which are usually used for the production of marble slabs.
The difference between the cups used to produce slabs and other cups, in addition to the larger dimensions, is the material of this piece of stone. These coupes are very high quality in terms of not having cracks and color harmony, they are cut in a hexagonal shape, and their weight is usually between 25 and 27 tons.
What happens to the rest of the coupes ?
Stones that have smaller dimensions or do not have a regular geometric shape are turned into tile stones with a cutting machine. The next stage of marble production takes place in the factory, which we have reviewed in detail in other articles.