Known as a common filler, barium sulphate is often used in coatings, plastics, rubber, and industries the like. Compared with other fillers such as calcium carbonate and talcum powder, barium sulphate has many more advantages due to its special properties. Natural barium sulphate is a kind of barium sulphate, which is made by physically grinding barium sulphate ore (barite). This blog provides detailed information on how natural barium sulphate is formed and its physical and chemical features. Read on to learn what excatly natural barium sulphate is, and the industries where it can be used as a quality filler.
What Is Barium Sulphate
Before talking about natural barium sulphate, let’s review what barium sulphate is. In terms of its physical and chemical properties, barium sulphate (BaSO4) is a kind of white or colorless crystal. It has a relative molecular mass of 233.4, specific gravity of 4.0-4.5, refractive index of 1.637, Mohs hardness of 3-3.5, and a melting point that can be as high as 1580°C.
The chemical property of barium sulphate is very stable. It is almost insoluble in water, for the solubility is 0.00022 at 18℃ and 0.0041 at 100℃; it’s also insoluble in ethanol or other acidic and alkaline solvents. However, it’s soluble in concentrated sulfuric acid and in carbonate alkali metal solution, in which it is converted into barium carbonate.
Barium sulphate is odorless, non-toxic, non-magnetic, and can absorb X-rays and γ-rays. Therefore, it is used as a medical agent for intestinal and gastric X-ray examinations (barium meal). Although barium sulphate itself is non-toxic, barium ions or soluble barium salts are toxic.
Barium sulphate exists in nature in the form of barite (or baryte) minerals. Barite is a heavy natural ore, often in the form of thick plate or columnar crystals. The color of barite is mainly determined by the type and amount of impurities it contains. Pure barite is colorless and transparent; when there are impurities, it is dyed in various colors such as red, yellow, green, and gray. It has glassy luster and is transparent to translucent. Barite is not directly harmful to humans.
What Is Natural Barium Sulphate
As mentioned above, natural barium sulphate is made from the physical processing of barite, which is the biggest difference from precipitated (synthetic) barium sulphate made through chemical reaction. The raw barite is processed by crushing and filtering to become natural barium sulphate powder. Apparently, the quality of barite directly affects the quality of natural barium sulphate. The high quality barite is more conducive to processing into barium sulphate powder with high purity, small particle size, and high whiteness.
Globally, barite resources are mainly located in China, Kazakhstan, Turkey, India, Thailand, the US, and Mexico. China is rich in barite resources and ranks first in terms of reserves and production across the world, and is the largest barite exporter. Barite in China is of high grade (average barium sulphate content ≥ 92.8%) which can be used as a very good raw material for many industries.
Hoyonn Chemical has 2 barite mines with a total reserve of 8 million tons. The mines contain a large quantity of high-grade barium sulphate. The purity of processed barium sulphate from the mines can reach 95% or more, the D50 mean particle size as fine as 1.3μm, and the whiteness higher than 94.
Barite Processing Steps
Barite is usually processed into natural barium sulphate powder through the following steps.
Crushing: Large chunks of barite are crushed into smaller particles through two times of repeated crushing processes. The jaw crusher, impact crusher and roll crusher are used to make the particle size small enough to meet the requirements of the sorting equipment.
Sorting: After crushing, the barite is divided into different particle sizes to enter the jigger for sorting. Sorting usually uses a circular vibrating screen that has higher work efficiency. Water is added during the sorting process to prevent dust.
Buffering: Since the working jigger needs a stable amount of particle feed, a silo and vibrating feeder are set up to evenly add materials to the jigger.
Dewatering: The concentrates and tailings after jigger separation contain a lot of water, which needs to be dewatered by the sedimentation method or mechanical dewatering method.
Hoyonn uses professional production and testing equipment to ensure excellent properties of natural barium sulphate, such as the D50 / D97 particle size distribution, purity, whiteness, oil absorption, etc. Our development and testing center has a group of Doctors, coating engineers, and plastic engineers to ensure that our products meet the requirements of the polymer material industry.
Applications of Natural Barium Sulphate
Natural barium sulphate can improve the mechanical properties of the final product in the following industries.
Barium sulphate is used in coatings as an extender pigment, which plays an important role in improving the thickness, abrasion resistance, water resistance, heat resistance, surface hardness, and impact resistance of paint film.
In addition, barium sulphate has high reflectivity in the wavelength range of 300-400 microns, so it can be an effective and inexpensive white inorganic light stabilizer to protect the paint film from light aging.
Because of its low oil absorption and high filling capacity, it can reduce the costs of coating products.
It can be used in water-based paint, oil-based paint, primer, intermediate paint, etc. Barium sulphate can replace 10%-25% of titanium dioxide in water-based coatings to achieve higher whiteness with no decrease in coverage.
Barium sulphate is applied in different types of plastics to improve their performance.
General plastics: Barium sulphate’s excellent covering capability with pigments can obtain bright colors and high gloss for plastics, and have good mechanical and wear resistance.
Engineering/modified plastics: It can improve the rigidity, hardness, and wear resistance of plastic products. It can help shorten the cycle time of plastic injection molding and also increase the crystallinity of thermoplastic polymers.
Masterbatch: Barium sulphate helps to improve the dispersion of pigments, and reduce the possibility of coagulation or flocculation. The pigment tone won’t be affected even with high percentage filling.
Pigment: Barium sulphate is used as a gasket for titanium dioxide and pigment in plastic, which can reduce the amount of added pigment and save about 10% cost. Its light reflection can keep the maintenance of color.
Rubber: Barium sulphate is used as filler in silicone rubber and compounding rubber, which can increase the hardness and reduce its elasticity.
Glass: It’s used as a flux and additive of glass to increase the refractive index of glass products.
Paper: Barium sulphate is used in the production of paper coating, which can increase the gloss and fluidity for art paper and medium white transparent paper. It can replace titanium dioxide with the double amount and not lose the gloss.
Ink: Barium sulphate’s low abrasiveness, high gloss, color stability, low cohesiveness, and ease of flow, make it suitable for high-quality printing inks.
Automotive brake pads/clutch: Adding barium sulphate in the production of automotive brake pads and clutches can improve the material density, wear resistance, acid and alkali resistance, etc.
Hoyonn Natural Barium Sulphate – Your Perfect Fit
Since 2001, Hoyonn Chemical has 20 years of experience in mine development, research, manufacturing, and sales. We specialize in the production of natural barium sulphate, precipitated barium sulphate, nano barium sulphate, and other filler materials for polymers. We adopt advanced formulation systems and innovative R&D technology to provide customized functional filler and additives solutions for our customers. Our products are trusted by all our customers and are exported to well-known brands of coatings and plastics manufacturers worldwide.
Hoyonn Natural Barium Sulphate Series is available in 7 types of parameters. Click here for the technical index of each type. Contact us for a quote, or ask us to provide you with professional advice and free samples.