Yuan Lei told you | barium sulfate has brought too many surprises to mankind
Barium sulfate, for most people, is an unfamiliar material, and people who do not understand it may even think it is a toxic chemical.
In fact, in our daily life, barium sulfate is everywhere. For example, the refrigerator, air conditioner shell and plastic accessories at home, the plastic bags used in supermarkets, paints and coatings all have barium sulfate.
So, what is barium sulfate and where does it come from?
In nature, barium sulfate is a natural ore, called barite. Pure barite is colorless and transparent, has no direct harm to human body, and can be directly contacted. Melting point up to 1580 ° C, chemical properties are very stable, difficult to dissolve in water and acid and alkali resistance, non-toxic, non-magnetic, but also can absorb X, Y rays.
China's barite resources are quite rich. The geological reserves of barite at the junction of Hunan, Guizhou and Guangxi provinces are more than the total reserves of foreign countries, thus making China the world's largest barite reserves.
What impact does barium sulfate have on our lives and what convenience does it bring?
Barium sulfate masterbatch, alias: barite. Is a kind of polyolefin polymers (such as polyethylene, polypropylene, polystyrene, etc.) as the carrier, through the surface treatment of high concentration, high whiteness of ultrafine barium sulfate after processing.
Barium sulfate masterbatch is divided into two categories, ordinary and transparent, the production process is basically the same, the difference is that the transparent use of activated nano-scale materials. The basic process is activated barium sulfate-mixed with other small materials-mixed with carrier-twin-screw extrusion granulation.
Main functions:Improve the acid and alkali resistance of products, used for sneakers and other products; can enhance the weight and touch, can be used for plastic audio shell. It has unparalleled thermal stability, excellent dispersion, and significantly reduces production costs.
Key features:Barium sulfate used as titanium dioxide and pigments in the plastic gasket can reduce the amount of pigment added, and can save about 10% of the cost. The application of about 25% barium sulfate to PP can make PP surface like ABS without affecting the existing characteristics of PP, providing high gloss and high hardness surface.
Many manufacturers use ABS household appliances as raw materials. As the hardness requirement of the household appliance shell is very hard and the gloss requirement is also very high, it creates a feeling that looks relatively high-grade, so they choose to add barium sulfate filling masterbatch. It can save costs and will not affect the appearance of the product.
Some manufacturers choose to add calcium carbonate, but because the calcium carbonate product itself is a matting filler masterbatch, so the appearance of home appliances is difficult to achieve the desired effect. As a raw material is ABS customers, barium sulfate filling masterbatch is the first choice.
There are a lot of people do not understand, why will have a high transparent barium sulfate filler masterbatch effect?
There are two types of barium sulfate, one is precipitation type, the other is water wash type, the natural output is barite; industrial products have barite powder and barite as raw material by chemical reaction of the precipitated barium sulfate barite powder is white crystalline powder. Insoluble in water, soluble in carbonate alkali metal salt becomes barium carbonate, slightly soluble in concentrated sulfuric acid, X-ray can not pass through, non-toxic.
Barium sulfate powder in the barite crushed natural grinding stone powder, no additional processing of ordinary powder; barium sulfate powder, transparent powder is different from the need to go through a process, that is, precipitated powder, the price is higher than ordinary powder, transparency is better than ordinary powder.
Barium sulfate can play a role in improving wear resistance and aging resistance in plastics. It increases the hardness, strength, heat resistance and wear resistance of products. It has the advantages of strong chemical inertness, good stability, acid and alkali resistance, high whiteness, moderate hardness, and ability to absorb harmful rays. It is widely used in various plastics, rubber, coatings, and other production fields. It is one of the most promising functional inorganic fillers.
The new plastic material with barium sulfate as filler can play its excellent performance in various plastics, not only can reduce the cost of composite materials, but also can improve the comprehensive performance of composite materials, which has high economic value and broad development prospects.
Functional filling masterbatch is a new product in recent years. Barium sulfate can improve the tensile force of plastics because of its small powder size, high transparency, good gloss, good appearance and hue. The masterbatch prepared by adding it to plastic film products can replace most petrochemical products, reduce the use of plastics, maintain the transparency of the film, and reduce the use and processing costs, compared with traditional talcum powder masterbatch and calcium carbonate filling masterbatch, it has great advantages in quality and processing. It can be used for filling modification of polyolefin products such as polyethylene blown film, injection molding, plastic weaving, etc., reducing costs, improving mechanical properties, acid and alkali resistance, no precipitation, good weather resistance, no harmful substances, less impurities, no crystal points, high purity, and can effectively ensure the safety of products and surface gloss.
barium sulfate production process:
barite powder:The preparation method of barite powder is to coarsely crush barite, wet mill with ball mill, etc., collect fine particles after washing with water, add a small amount of sodium sulfide, wash with sulfuric acid to remove iron, wash with water, dry and crush to obtain the finished product.
precipitated barium sulfate:The production of precipitated barium sulfate, the current industrial use of more for the mirabilite-barium sulfide method of this method by-product for alkali sulfide.
Although precipitated barium sulfate is the same as barite powder in chemical properties, it has no crystalline properties, but is amorphous, has a very fine and soft texture, a relative density of 4. 3 g/cm 3, higher oil absorption and hiding power than barite powder, is stable to air and heat, and does not change color in case of hydrogen sulfide and toxic gases.
The specific preparation method is:Barite and anthracite or coke are crushed, mixed, and reduced and roasted in a rotary kiln to obtain a roasted product, commonly known as black ash, which is leached with hot water to obtain barium sulfide solution, and reacted with mirabilite solution purified by potassium permanganate in advance to obtain refined barium sulfate precipitate, which is filtered and separated, washed with sulfuric acid, washed with water, filtered, and crushed after drying to obtain finished product consumption quota: barite [Ba;. 100) 1. It /t; Glauber's salt (Na2 S04, 1007c) Q 63 t/t; Soda ash 0. 02 t/t: raw coal
In industry, barium sulfate is commonly classified as follows:
1. Heavy barium, also known as barite powder or natural barium powder. People choose natural barium sulfate ore (barite) after cleaning, polishing, drying and other processes, its impurities are more, the quality is mainly determined by the mine itself, but its price is low, usually used in white pigment production or low-grade paint, plastic, ink industry as a filler.
2. Precipitated barium sulfate, also known as industrial barium sulfate or precipitated barium. It is made by man-made processing, unlike heavy barium is almost free of impurities. It is slightly soluble in water and insoluble in acid. It does not contain poison, but if it contains soluble barium, it can cause poisoning. Precipitated barium sulfate in the industry is mainly generated by the reaction of barium sulfate with sulfuric acid, barium chloride with sulfuric acid or sodium sulfate, and barium sulfide with sodium sulfate. Precipitated barium sulfate is used in medicine, medium and high-grade coating ink, plastic, rubber, glass, ceramics and other fields as a filler because of its stability. People are usually divided into coating grade precipitated barium sulfate, plastic grade precipitated barium sulfate and so on according to different applications, which is relatively high in price compared with heavy barium.
3. Modified barium sulfate is further divided into modified barium sulfate and modified precipitated barium sulfate. barite powder or precipitated barium sulfate is treated to enhance its performance in a certain aspect. Its application is similar to precipitation and mainly depends on its related performance. Among them, modified ultrafine barium sulfate or modified ultrafine precipitated barium sulfate after further processing and refinement is also called modified ultrafine barium sulfate, which is more expensive than precipitated barium sulfate.
4. Nano-scale precipitated barium sulfate is to control its D50 (median particle size distribution) between 0.2 μm and 0.4 μm through deep processing of modified precipitated barium sulfate. Because of its high processing requirements, there are still few manufacturers that can produce nano-scale precipitated barium sulfate in our country at present, and its price is relatively high. Nano-scale precipitated barium sulfate is mainly used in high-grade paints, coatings and other industries.
Barium sulfate has brought too many surprises to people, and its role may not be fully reflected now. Some people predict that in the future 3D printing, barium sulfate will become the main raw material.
Barium sulfate, barite, precipitation, filling, plastics, modification, processing, coatings, products
Kaolin is a non-metallic mineral, which is a kind of clay and clay rock mainly composed of kaolinite clay minerals. Because it is white and delicate, also known as white earth. It is named after Gaoling Village, Jingdezhen, Jiangxi Province.
Barium sulfate is based on barite as the main raw material, through beneficiation, ore washing, crushing and other processes. Barium sulfate has a hardness of 3~3.5 (Mohs) and a specific gravity of 4.3~4.7. It has the characteristics of high specific gravity, low hardness and brittleness. Barite is almost insoluble in water, ethanol and acid, soluble in hot concentrated sulfuric acid. With the development of some high-performance barium sulfate products, the application field of barium sulfate is constantly expanding.