Natural barium sulfate exists in the form of mineral barite in nature. Barite is an important strategic non-metallic mineral resource with a hardness of 3-3.5 and a specific gravity of 4.3-4.5. It is a non-metallic mineral with the largest specific gravity and is widely used. In the fields of petroleum, chemical, building materials, medicine and military. Guikuang Machinery is a barite grinding mill manufacturer, our barite grinding mill has been widely used in the production of barite powder industrial fillers. The following introduces the application requirements and production equipment of industrial filler barite powder.
China’s annual production of barite is about 3 million tons, of which more than 60% are exported for oil drilling grade products. In the self-consumption part, nearly 80% are used in the fields of oil drilling drilling fluid, barium compound processing raw materials and radiation protection medical treatment, and only a small part is used for polymer filling such as coatings, plastics and adhesives.
1. Drilling grade barite
In oil drilling operations, barite is mainly added to the drilling fluid as a weighting agent. Therefore, for the drilling-grade barite powder, its specific gravity is used as the main index to investigate. There are also certain requirements for the content of magnetic substances.
For oil wells with different depths, the specific gravity requirements for barite powder are also different. The specific gravity of drilling-grade barite powder is divided into three grades: the specific gravity of the third-grade product is greater than or equal to 4.05g/cm3, the specific gravity of the second-grade product is greater than or equal to 4.2 g/cm3, and the specific gravity of the first-grade product is greater than or equal to 4.3 g/cm3.
2. Barite for polymer filling
Barite has distinct and excellent physical and chemical properties, and plays an irreplaceable role in many application fields. Barite compounds and barite used in oil drilling are traditional applications of barite with low added value, while barite powder used for polymer filling is the performance of barite materialization, which greatly improves the weight of barite. The application value of spar also puts forward higher and more complex requirements for its indicators. In the field of polymer filling, barite powder is mainly used in powder coatings, industrial coatings, plastic modification, ink and other fields.
GB/T37041-2018 “Fine Barite Powder” has made requirements for barite powder used in the field of polymer filling, but its indicators are relatively broad, and it is difficult to accurately regulate and guide each subdivision field.
3. Barite for powder coating
Powder coating is a solid coating in the form of fine powder. It is an environmentally friendly coating with low VOC emission and is widely used in ships, pipelines, automobiles, home appliances and other fields. The barite powder used in powder coatings has certain requirements on its purity, whiteness and particle size, and the purity will affect the anti-corrosion performance of barite products (especially in anti-corrosion powder coatings such as ships and anti-corrosion pipelines) and specific gravity (the higher the specific gravity is, the higher the specific gravity is). The leveling of large powder coatings is better) and oil absorption, while whiteness will affect the color and gloss of powder coatings. Generally, the use of blue-phase high whiteness barite powder is beneficial to obtain brightly colored coatings.
There are usually two categories of barite powder used in powder coatings, that is, what we often call “extinction barium” and “high-gloss barium”. As the name implies, “matting barium” is beneficial to obtain “low gloss” powder coatings without affecting other performance indicators of the product. The main influencing factors are the average particle size and distance of barite products, that is, particle size distribution. In the same way, the main influencing factor of “high-gloss barium” is also the particle size distribution. Generally, a coarser average particle size and a wider distribution are conducive to obtaining low-gloss products, while a smaller average particle size and a smaller radius can obtain higher quality. luster.
At present, the fineness of “extinction barium” that is widely used is between 400-800 mesh, and the selection is slightly different according to the requirements of grinding, while the fineness of “high-gloss barium” is generally required to be above 2500 mesh.
4. Barite for industrial coatings
Industrial coatings can be divided into solvent-based and water-based industrial coatings from the perspective of dispersion media. Due to its excellent chemical inertness, natural low oil absorption value and moderate hardness, barium sulfate is widely used in industrial paints. Due to environmental protection issues, traditional solvent-based industrial paints are currently developing towards high solids and water-based properties. The low oil absorption and good water resistance of barium sulfate are very suitable for high-fill systems and water-based systems.
In some industrial paints, such as steel structure anti-corrosion paints, due to the harsh use environment, the purity of barium sulfate is required to be high, especially the carbonate content must be strictly controlled; most industrial paints are dark in color and natural Barium sulfate is mostly used in primers, so the whiteness of barium sulfate in industrial paints is not high. In addition, due to the large specific gravity of barium sulfate, it is easy to sink to the bottom in the coating, so to obtain high-performance coating-grade barium sulfate products, it is necessary to carry out surface modification treatment to improve the suspension of barium sulfate.
5. Barite for rubber filling and modification
The main inspection indicators of barite ore for rubber and plastic filling and modification are specific gravity and whiteness. The addition of barite to rubber and plastic products mainly uses its high specific gravity, high gloss, low oil absorption value and other characteristics to obtain high-performance products with high specific gravity, high brightness and scratch resistance. Therefore, the higher the purity of barite, the better. The barium sulfate content is generally required to be more than 90%; for some “black materials” that do not require whiteness, the requirements for the whiteness and hue of barite are not strict. Generally, the whiteness can reach about 80, while for “white materials” “Products, which have higher requirements for whiteness and color, have higher requirements for barite’s whiteness and hue, generally requiring a whiteness of 88 or more, and a low b value.