A brief discussion on stone quarrying methods

The extraction, processing, trade, and use of natural stone is an ancient human activity that has spanned the entire history of human civilization. Since the 1990s, with the rise of emerging economies such as China, the building and decorative stone industry has developed rapidly.

According to the World Building and Decorative Stone Association, by 2025, the world's annual consumption of natural stone will reach 4 billion square meters, with marble accounting for 40%, granite for 50%, and the remainder consisting of sandstone, slate, basalt, limestone, agate, etc. Over the past thirty years of China's reform and opening up, the national economy has developed rapidly, leading to an increasing demand for natural stone, making China one of the world's most important producers and consumers of stone.

 

This strong demand has stimulated the development of the global stone industry. Traditional stone-producing countries such as Italy and Spain have seen their production decline year by year due to resource depletion and environmental pressures; while countries such as Turkey, Brazil, Iran, India, and Egypt have experienced rapid growth in natural stone extraction.

 

The world's stone production and processing center is shifting from Europe to China in Asia. Modern stone mining and processing in China is exemplified by the use of Italian wire saws in the Hubei Dahualü stone mine, demonstrating a process of introduction, learning, imitation, innovation, and refinement to achieve a leading position.

 

Stone equipment designed and manufactured in China is sold worldwide, renowned for its economy, practicality, and efficiency. China's stone mining technology, safety, environmental protection, and production scale have surpassed those of traditional Western stone-producing countries.

 

 

The extraction of stone from quarries differs fundamentally from the extraction of other types of minerals. The former aims to extract large blocks of raw material (in a sense, the larger the block, the better), while the latter aims to extract effective minerals (ideally, the smaller the better). Therefore, the mining methods for dimension stone quarries are unique.

 

Quarrying requires a comprehensive analysis of the ore body's length, width, depth, occurrence, and surrounding rock conditions, adapting the methods to the specific location and type of deposit. Depending on the shape of the ore body, the orientation of the ore layers, veins, pillars, and stocks, each mine has different conditions, different types of stone, and different occurrences, requiring different mining methods and corresponding equipment.

 

The goal is to achieve the most suitable mining method by combining traditional extraction methods with modern technologies.

Quanzhou Huice Company specializes in the production of diamond tools for stone quarrying, including diamond wire saws and diamond saw blades, stone diamond segment, known for their stable performance and high cost-effectiveness.

 

There are several ways to classify stone quarries. From the perspective of mining methods, they can be divided into low-bench quarries (approximately 2 meters, using quarry saws), medium-bench quarries (approximately 4 meters, using chain saws), and high-bench quarries (6-8 meters, using wire saws).

 

They can also be classified into three main categories: hillside open-pit mining, flat-ground open-pit mining, and underground mining.

 

For hillside open-pit mining, it's important to distinguish between mining from the top of the hill downwards and mining on the hillside. The latter requires the design and reservation of safety platforms and cleaning platforms.

 

The mining working face should be no less than 20m wide and more than 30m long, following the principle of "top-down step-by-step mining," gradually forming a multi-bench, multi-working face mining situation.

 

The stone mining process includes six steps:

1. stripping →
2. separation →
3. disintegration →
4. shaping →
5. loading and transportation →
6. slag removal and waste disposal.

 

Due to the extensive use of new technologies and equipment, the traditional distinctions between mining methods for marble, granite, sandstone, and slate have become less pronounced. The best method is the one that can extract raw blocks efficiently, at low cost, and with high profitability.

 

1. Traditional mining methods

Traditional methods primarily involve manual mining and are very suitable for mines with good cleavage properties, intact ore bodies, or distinct layering. These methods combine fire-assisted drilling and manual drilling for hole placement and splitting, along with techniques such as controlled blasting with detonating cord, expansive agent static blasting, and carbon dioxide blasting for stone extraction.

 

Fire-assisted drilling is mainly used in granite mining. To make the separation of the extracted block from the ore body easier and more reliable, a fire cutting process is employed using a flame cutting machine to cut and separate one connecting surface between the block and the ore body. This method is currently used less frequently and has largely been replaced by wire saw cutting.

 

 

2. Diamond wire saw full-cut mining

Ore body separation, block disintegration, and rough block shaping are all completed by wire saw cutting. As long as the mining costs are acceptable, full wire saw cutting is currently the best method for mechanized mining. It is suitable for various types of stone, especially marble mines with well-developed fractures.

The separation and cutting using a diamond wire saw involves three connecting surfaces; a special air bag or water bag is used to push the separated block away from the ore body, and then, with the assistance of excavators and loaders, the separated block is overturned; the wire saw is then used to cut the separated block into smaller pieces and to shape the rough blocks.

To reduce mining costs, under suitable conditions, rock drills for drilling holes or large-diameter circular saws can also be used to shape the rough blocks.

 

 

3. Mining method using a combination of circular saw and manual rock drilling.

The earliest method of granite mining used in Fujian Province involved directly cutting the rock body with a circular saw-type block cutting machine for vertical cuts, and using manual wedging and splitting for horizontal cuts. This semi-mechanized method was efficient and low-cost, but its drawbacks included poor flatness of the quarry face and significant resource waste.

 

 

 

4. Mining method using a combination of circular saw and bead saw.

To conserve resources, diamond wire saw cutting is used to cut the horizontal bottom surface of the stone block, replacing manual rock drilling and wedge splitting to separate the stone horizontally, thus forming another method of fully saw-cutting granite.

Using a wire saw to cut the horizontal bottom surface of the stone block, replacing manual wedge splitting, this method has been successfully applied to marble mining, and is very suitable for mining marble deposits with intact ore bodies, few cracks or simple joints, and uniform and consistent color patterns. It has been highly successful in mines in Xianfeng, Hubei, Shanshan, Xinjiang, and Huaihua, Hunan.

 

5. Bench-mounted rock drill and wire saw mining method

The frame-mounted rock drill and wire saw mining method is an advanced mining technique that replaces manual operation of handheld rock drills and flame cutting machines for granite extraction. It has become the basic method for mechanized granite mining in major granite producing countries such as Spain, South Africa, Brazil, and India.

 

 

6. Marble Quarrying with Wire Saw and Arm Saw on High Benches

Typically, the arm saw is used to cut and separate the long blocks from the rock mass, especially for the more difficult cuts at the connection surface. The wire saw then completes the cutting and separation of the long blocks from the rock mass on the other two sides. After the blocks are overturned, the wire saw or chain saw is used for further cutting and shaping.

 

For rock masses with numerous fissures or those lacking sufficient free faces, this mining method offers high efficiency and a high yield of raw blocks. It is suitable for various patterns of marble, especially for large-scale marble quarries requiring high production and a high degree of platform flatness.

 

The arm saw uses grease lubrication and cooling, making it suitable for use in high-altitude, cold, and arid regions. Recently, some stone equipment manufacturers have developed band saws that use water cooling, resulting in higher efficiency and potentially leading to a new revolution in mining methods.

 

A circular saw is used to cut the separated block into slabs or standard-sized blocks according to the specifications of the rough block, and a diamond wire saw is used to cut and separate the horizontal bottom surface, forming the rough block.

 

 

7. Underground Mining Using a Combination of Arm Saw and Wire Saw

The exploration and research of underground mining began quite early. Since the 1990s, attempts have been made in Gansu Jiuquan, Shaanxi Hanzhong (for white marble), and Jiangsu Yixing (for beige marble). With the use of blind cutting and arm saws, significant breakthroughs have been achieved.

 

In Hunan Chenzhou, Sichuan Ya'an, Shaanxi Ankang, and Guangdong Yangshan marble mines, the underground mining process is becoming mature. The basic methods of underground marble mining have been mastered, but some marble mines are being mined blindly without clear geological exploration, understanding of ore body color variations, fracture development, or ore body occurrence, posing considerable safety risks.

 

The principle for selecting a mining method for a stone mine, whether a single method or a combination of methods, is to improve the recovery rate of raw blocks, reduce mining costs, and maximize resource utilization. With the advancement of technology and the continuous deepening of mining processes and techniques, mining technology and safety production levels will continue to improve. The future trend for stone mines will be high efficiency, environmental friendliness, and intelligence. As an excellent supplier of diamond tools for stone mining, Quanzhou HuiceTools Company will always adhere to continuous innovation and improvement, providing users with high-quality diamond tools.