To begin with, we can define an abrasive tool as a grinding implement formed by processing abrasives in combination with various bonding agents-often simply referred to as an "abrasive."
The abrasive tools utilized in stone grinding are highly specialized. Since the grinding machinery employed varies in terms of weight, rotational speed, mechanical power, and travel speed, the manufacture of these abrasive tools must be tailored to meet these specific requirements. Consequently, the processing, application, and selection of abrasive tools constitute the foundational knowledge of comprehensive stone grinding.
Based on the type of abrasive material used, stone abrasives can be classified into two major categories:
1. Ordinary Abrasives (also referred to as Traditional Abrasives)
This term refers to abrasive tools manufactured using conventional abrasive materials (such as corundum-based abrasives-including white corundum and brown corundum-silicon carbide, etc.).
Performance Characteristics: Suitable for lightweight grinding machinery operating at low rotational speeds. They are low in cost but possess relatively limited grinding capacity, though they yield good results in terms of surface finishing and polishing.
2. Super-hard Abrasives
This term refers to abrasive tools manufactured using super-hard materials, such as synthetic diamond.
Performance Characteristics: Suitable for heavy-duty grinding machinery, and particularly well-suited for the surface grinding and polishing of hard stone materials-such as hard marble, granite, and microcrystalline stone. They offer superior grinding capacity and high grinding efficiency.
In practical application and manufacturing, it is common practice to utilize a combination of both conventional and superhard abrasives. This approach allows us to achieve abrasives characterized by both high sharpness and extended service life, while simultaneously reducing production costs and delivering superior cost-effectiveness.
Based on the type of bonding agent, abrasives can be classified into three categories:
1. Metal-bonded
2. Resin-bonded
3. Conventional powder-bonded
Common Stone Abrasive Tools Include:
1. Magnesite-Bonded Abrasives
These are manufactured using silicon carbide abrasives bonded with magnesium oxide and magnesium chloride. When using silicon carbide, green silicon carbide is generally preferred, although black silicon carbide is a relatively more affordable option. Grit sizes typically range from 16 to 1200 mesh, and the resulting abrasive tools can be produced in a wide range of hardness levels, from very hard to very soft.
Advantages: Low cost, excellent self-sharpening properties, and strong adaptability to various processing tasks. They are suitable for processing materials such as granite, marble, artificial stone, and ceramic tiles.
Disadvantages: Lower processing efficiency and a relatively longer production cycle. The grinding heads require significant pressure during operation, making them a standard, rather than high-performance, grinding tool. While they enjoy high market acceptance, the performance characteristics of these abrasive blocks-such as self-sharpening ability and hardness-may deteriorate if stored for more than one year.
2. Diamond Abrasives
These tools are produced by sintering diamond abrasives together.
- Advantages: Compatible with most stone grinding machines and offer rapid grinding speeds.
- Disadvantages: Prone to causing severe "gouging" or surface damage to the stone, making the subsequent transition to finer grits (the next processing stage) quite cumbersome. They require experienced workers to formulate the appropriate grinding and polishing plan.
If you are looking to boost production efficiency and reduce operating costs by switching to diamond abrasives, we invite you to contact our company. Cheefung have served numerous stone processing plants for many years, accumulating extensive experience and developing comprehensive solutions for grinding and polishing various types of stone. We possess particularly deep expertise regarding the application and utilization of novel abrasive materials and tools.
3. Ceramic-Bonded Abrasives
These are manufactured by mixing silicon carbide abrasives with a vitreous (glass-like) phase, followed by high-temperature sintering. They are characterized by excellent durability; however, they are prone to clogging and "slipping" during grinding operations. Additionally, their high cost has led to a decline in their usage in modern practice.
4. Metal-Bonded Abrasives
These tools are produced by sintering diamond abrasives together with metal powders. They are characterized by high processing efficiency and superior finishing results. Typically, the grit sequence begins at 50 mesh; however, extreme caution must be exercised when selecting coarse-grit tools (e.g., 20 mesh), as any deep scratches inflicted during this stage can be extremely difficult to remove in subsequent processing steps. Furthermore, the finest grit size used in this category should generally not exceed 400 mesh. These tools are most effective for leveling and conditioning rough surfaces, enabling the user to achieve a satisfactory, flat finish. While the cost is slightly higher compared to the abrasives previously discussed, their processing efficiency is unmatched by ordinary abrasives.
5 Silicon Carbide Resin-Bonded Abrasives
These are formed by mixing and bonding silicon carbide abrasive grains with resin. They fall into two main categories: pressed types, which utilize phenolic resins, and cast types, which are produced by mixing with liquid resins and casting. They are primarily used for fine grinding. The pressed types are characterized by their excellent durability and superior wetting properties during grinding; specifically when processing marble, they yield a high-gloss finish with relatively high efficiency. However, their cost is somewhat higher, and they are predominantly used with fine grit sizes. A drawback of phenolic-bonded abrasives is their tendency to stain light-colored stone during grinding and polishing-a primary reason why their widespread adoption has been limited. The cast types consist of grinding stones produced by mixing very fine silicon carbide micro-powders and other materials with resin before casting; these are primarily used for polishing granite, terrazzo, and concrete.
6 Diamond Soft Abrasives (Flexible Diamond Abrasives)
Diamond soft pads are a new type of tool introduced in recent years for floor renovation. Their lightweight nature and unique flexibility allow them to conform closely to the surface being processed. They are available in a wide range of grit sizes, from 20 mesh to 3000 mesh. These pads utilize diamond as the abrasive material; being lightweight, they effectively protect the softer components of the stone surface during grinding, resulting in a finished product with a high-gloss luster. During operation, they attach via a nylon hook-and-loop fastening system, making them convenient and easy to use. Furthermore, this technology holds significant potential for future development and improvement.
7 Resin-Bonded Abrasives
Resin-bonded grinding discs are formed by bonding single-crystal diamonds and diamond micro-powders with resin. They are characterized by a lower cost compared to metal-bonded discs and offer high processing efficiency. Primarily used for the fine grinding and polishing stages of stone processing, they serve as the subsequent polishing tool following the initial leveling and grinding performed by metal-bonded discs. Their cost is relatively moderate.
8 Thickened Renovation Abrasives
These are grinding tools formed by combining abrasive grains with a bonding agent, followed by compression molding and high-temperature treatment. They are widely utilized during the grinding and surface optimization phases of comprehensive floor renovation projects. Their key characteristics include excellent grinding performance and superior leveling capabilities. 9. Dry Polishing Pads
These are abrasive tools manufactured using synthetic diamond as the abrasive material and a high-temperature resin binder, formed through a process of molding and curing. They are widely utilized for the dry grinding and polishing of stone surfaces. They are particularly well-suited for working on edges and corners during the overall grinding of stone walls and floors.