Hubei Tianlang Nanotechnology Co., Ltd

The Marvelous Metal – Barium

I. Basic Properties

• Chinese Name: Bèi (钡)
• English Name: Barium
• Element Symbol: Ba
• Atomic Number: 56
• Group: Group IIA Alkaline Earth Metal
• Physical Properties: Density 3.51 g/cm³, Melting point 727°C (1000 K, 1341 °F), Boiling point 1870°C (2143 K, 3398 °F). Barium is a soft, malleable metal with a silvery-white luster. Its flame test produces a yellow-green color.
• Chemical Properties: Highly reactive, it readily reacts with most non-metals and does not exist in elemental form in nature. Furthermore, metallic barium possesses extremely strong reducing power, capable of reducing various metal oxides, halides, and sulfides to obtain the corresponding metals.
• Occurrence & Minerals: Barium constitutes approximately 0.05% (by mass) of the Earth's crust. The most common barium-containing minerals in nature are Barite (BaSO₄) and Witherite (BaCO₃).
• Toxicity: Soluble barium salts (except barium sulfate) are generally toxic.
• Application Fields: Widely used in electronics, ceramics, medicine, petroleum, and other fields.

II. Discovery History

The phosphorescence phenomenon of alkaline earth metal sulfides (persistent glow in the dark after exposure to light) first drew attention to barium compounds.

• 1602: V. Casciorolus, a shoemaker in Bologna, Italy, mixed barite (containing barium sulfate) with combustible material and roasted it, observing its glow in the dark. This phenomenon piqued the interest of European chemists.

• 1774: Swedish chemist Carl Wilhelm Scheele discovered a new element in barite but failed to isolate the pure metal, obtaining only its oxide.

• 1776: Johan Gottlieb Gahn similarly isolated the oxide in parallel research.

• Naming: This oxide was initially called "barote" by Guyton de Morveau and later renamed "baryta" (heavy earth) by Antoine Lavoisier.

• 1808: British chemist Sir Humphry Davy, using a mercury cathode and platinum anode, electrolyzed barite (BaSO₄) to produce barium amalgam for the first time. Distilling off the mercury yielded impure metallic barium, which he named Barium.

III. Industrial Applications & Resources

Barium has a history of industrial application spanning over a century.

• Early Applications: Starting from the mid-19th century, barite (a key mineral for obtaining barium and barium compounds) was used as a filler in paints.
• Modern Applications: Since the 20th century, barite has become the primary raw material for producing various barium-containing chemical products. Due to its high density and stable chemical properties (insoluble in water and acids), it has been used as a weighting agent in drilling muds for oil and natural gas wells since the 1920s to balance downhole oil and gas pressure and prevent blowouts. Barium sulfate is also used to produce white pigments (lithopone/zinc barium white), rubber fillers, and colorants.

IV. Resource Reserves & Distribution

• Global Distribution: Barium makes up approximately 0.05% of the Earth's crust. The main minerals are Barite (BaSO₄) and Witherite (BaCO₃). Global barite reserves are estimated at approximately 350 million tonnes. China possesses the most abundant barite resources globally. Other countries rich in barite resources include Kazakhstan, Turkey, India, Thailand, the United States, and Mexico. Famous deposits are found in Westmorland and Cumberland, UK; Felsobanya, Romania; Saxony, Germany; etc.
• China's Status: China is the world's largest barite producer, accounting for approximately 44.3% of global production, followed by India, Morocco, and the United States.

• China's Resources:

• China has abundant barium mineral resources, with predicted total reserves exceeding 1 billion tonnes. The ore grade is relatively high, and China ranks first globally in both reserves and production.
• China's barite reserves are approximately 100 million tonnes, accounting for about 29% of global reserves and ranking first worldwide.
• Resources are distributed across 24 provinces (autonomous regions). There are 195 explored reserve areas, with total identified resource reserves of about 390 million tonnes of ore.
• Reserve Distribution: Guizhou Province holds 34% of the national reserves, followed by Hunan, Guangxi, Gansu, and Shaanxi. These five provinces together account for 80% of the national total.
• Deposit Types: Sedimentary deposits are predominant (60%), followed by stratabound (endogenic), volcanic-sedimentary, hydrothermal, and weathering (residual-slope wash) types. The main metallogenic epoch is the Paleozoic era.

• Major Barite Mineral Belts in China:

• Eastern Guizhou-Western Hunan-Northern Guangxi (Dahebian, Xiangqian Type) Sedimentary Belt: 

Located on the southwestern margin of the Yangtze Platform. Representative deposits: Dahebian (Tianzhu, Guizhou), Gongxi (Xinhuang, Hunan), Banbi (Sanjiang, Guangxi).

• Southern Gansu-Southern Shaanxi-Northern Hubei (Qinba Type) Sedimentary Belt: 

Located on the northern margin of the Yangtze Platform. Deposit types: Sedimentary, stratabound. Representative deposits: Dongfenggou (Wen County, Gansu), Liulin (Suizhou, Hubei).

• Southwestern Hubei-Southeastern Sichuan-Central Guizhou (Nanzhuangping Type) Stratabound Belt: 

Located within the Upper Yangtze Fold Belt. (Note: Duplicate section in original merged)

• Xingtai-Jixian-Yuncheng (Dachishan Type) Stratabound Belt: 

Located in the eastern and southern parts of the Shanxi Uplift, North China Platform (Western Hebei, Southern Shanxi, Northern Henan). Representative deposit: Dachishan (Jixian/Weihui, Henan).

• Anqiu-Linshu-Hanshan (Songguantuan Type) Belt: 

Controlled by the Tan-Lu Rift Zone (Eastern Shandong, Northern Jiangsu, Central Anhui). Representative deposit: Songguantuan (Anqiu, Shandong).

• Southwestern Fujian (Lifang Type) Sedimentary Belt: 

Located on the southwestern margin of the Cathaysian Fold Belt, South China Fold System. Representative deposit: Lifang (Yong'an, Fujian).

• Guangxi-Guangdong (Pancun Type) Hydrothermal Belt: 

Distributed along the western and southern margins of the Dayaoshan Uplift (Xiangzhou-Wuxuan, Guangxi; Yongfu-Lingui, Guangxi). Often associated with residual-slope wash deposits. Representative deposits: Pancun (Xiangzhou, Guangxi - primary); Sicun (Xiangzhou, Guangxi - residual-slope wash).

• Xitieshan-Jingtieshan-Qingtongxia (Jingtieshan Type) Volcanic-Sedimentary Belt: 

Located within the North Qilian Eugeosyncline (Gansu). Deposit types: Predominantly volcanic-sedimentary, with hydrothermal types secondary. Representative deposit: Huashugou (Jingtieshan, Sunan County, Gansu) Iron-Barite deposit.

• Characteristics of China's Barite Resources:

• Reserves are mainly distributed in the central region.
• High-grade ores are highly concentrated in Guizhou and Guangxi.
• Deposits are predominantly large and medium-sized (Dahebian, Tianzhu, Guizhou and Gongxi, Xinhuang, Hunan account for over half the reserves of large/medium deposits).
• Ore types are often simple barite, with simple mineralogy and chemical composition, and high purity (e.g., Gongxi deposit, Xinhuang, Hunan).
• Significant reserves of associated and co-occurring minerals allow for comprehensive utilization.

V. Major Uses & Application Fields

Barium compounds play vital roles in numerous fields:

• Electronics Industry:

• Getter: Barium is a crucial component of flash getters (e.g., Barium Aluminum Nickel getters) used in devices like vacuum tubes and cathode ray tubes (CRTs). These getters absorb trace gases, protecting cathodes (e.g., oxide cathodes) from harmful gas reactions and maintaining device performance. Nitrided barium aluminum getters used in CRTs optimize barium film distribution, enhancing brightness and gettering performance.

• Ceramics Industry:

• Glaze: Barium carbonate is used as a component in pottery glazes, capable of producing pink or purple hues.

• Electronic Ceramics Base Material: Barium titanate (BaTiO₃) is the foundational material for electronic ceramics. It possesses high dielectric constant, low loss, and excellent ferroelectric, piezoelectric, voltage-resistant, and insulating properties. It is widely applied in Positive Temperature Coefficient (PTC) thermistors, Multilayer Ceramic Capacitors (MLCCs), thermoelectric elements, piezoelectric ceramics, sonar, infrared detectors, electro-optic display panels, memory materials, etc.

• Pyrotechnics Industry: Barium salts (e.g., barium nitrate) burn with a bright green-yellow flame and are key ingredients for producing green fireworks and signal flares. Barium oxide is sometimes used in white fireworks.

• Petroleum Extraction: Barite powder (natural barium sulfate) is the core weighting agent for oil and natural gas drilling muds. It increases mud density to balance downhole oil and gas pressure and prevent blowouts.

• Pest Control: Barium carbonate (a white powder, poorly soluble in water, soluble in acids) was historically used as a rodenticide due to its toxicity. It reacts with stomach acid to release toxic barium ions, necessitating strict precautions against accidental ingestion.

• Medical Industry:

• X-ray Contrast Agent: Barium sulfate (a white, odorless, tasteless powder, insoluble in water, acids, or alkalis) is widely used as a gastrointestinal contrast agent ("barium meal") due to its high X-ray absorption and lack of toxic ion release. It coats the lining of the digestive tract, providing clear imaging under X-rays, and is excreted in feces after the examination.

• Other Applications:

• Pigment: Lithopone (zinc barium white) is a common white pigment.
• Metallurgy:

1. Barium is used as a nodulizer in the production of ductile (nodular) iron.

2. Used in the production of barium-nickel alloys and barium-containing lead alloys (e.g., bearing alloys containing 0.5%-4% barium).

3. Serves as an excellent deoxidizer in copper refining.