To understand barite, we need to start with the discovery of barium.

First, the discovery and properties of barium

Barium (Ba, Barium): Alkaline earth metal, period 6 of the Periodic Table IIA Group, atomic number 56, atomic weight 137.327, element name derived from the Greek βαρύς (barys), meaning "heavy".

In 1602, in the city of Bologna, Italy, a shoemaker named Casio Lauro roasted a barium sulfate-containing barite with a combustible substance, and saw a light in the dark. The stone was later called Borola.

In 1774, Swedish chemist C.W.Scheele researched Bororite and found that Bororite is a combination of a new type of soil (called "Baryta", heavy soil) oxide and sulfuric acid.

In 1776, Scheler heated the nitrate of this new soil to obtain pure soil (oxide).

In 1808, the British chemist H. Davy prepared barium amalgam by using mercury as the cathode, platinum as the anode, and electrolytic barite (BaSO4). After the mercury was distilled off, a metal of low purity was obtained. It was named after the Greek barys (re), called barium, and the element symbol was determined to be Ba.

Barium is a silver-white metal. Its atomic volume is 39.24 cubic centimeters / mole, thermal expansion is 20.6µm / (m • K) (25 ° C), Mohs hardness is 1.25, paramagnetic, melting point is 725 ℃, boiling point is 1600 ℃, density is 3.51g / cm³ (25 ℃) , Thermal conductivity 18.4W / (m • K), resistivity 332 nΩ • m (20 ° C), tensile modulus 13GPa, shear modulus 4.9GPa. There are 7 stable isotopes of barium including 138Ba (71.66%), 137BaBa (11.32%), 136Ba (7.81%), 135Ba (6.59%), 134Ba (2.42%), 130Ba (0.101%) and 132Ba (0.097%).

Barium is a chemically active element in alkaline earth metals. Barium element has strong reduction and ductility. If only electrons are lost, the reducibility of barium in water is strong; but it is relatively difficult for barium to lose the second electron, and the reducibility of barium decreases a lot. Even so, it is one of the more active metals in acidic solutions, second only to lithium, cesium, rubidium and potassium. The valence electron state of barium atom is 6S2, and the chemical value is +2, which is close to the properties of strontium, calcium and potassium ions.

Barium is slowly oxidized in the air to form barium oxide. When burning, it emits a green flame to produce barium peroxide. Barium oxide is a colorless cubic crystal, soluble in acid, insoluble in acetone and ammonia water; it reacts with water to form barium hydroxide, which is toxic. 2Ba + O2 = 2BaO 2BaO + O2 = 2BaO2

Barium hydroxide is a colorless transparent crystal or white powder. It can lose 7 molecules of crystal water in a sulfuric acid dryer and lose all crystal water at about 78 ° C. It is soluble in water, methanol, slightly soluble in ethanol, and hardly (hardly) soluble in acetone. If carbon dioxide is rapidly absorbed from the air to become carbonate, it cannot be completely dissolved in water. The relative density is 2.188. Melting point 78 ° C (octahydrate,> 408 ° C in the case of pure barium hydroxide). The refractive index is 1.471. poisonous. Corrosive. Barium reacts with water to form barium hydroxide and hydrogen. Because the solubility of barium hydroxide is low and the sublimation energy of barium is high, the reaction is not as violent as the alkali metal. The generated barium hydroxide will cover the sight. Ba + 2H2O = Ba (OH) 2 + H2 ↑

Barium can dissolve in liquid ammonia to produce a paramagnetic, conductive blue solution, which essentially forms ammonia electrons. After being left for a long time, barium can decompose ammonia to form barium amino and hydrogen.

Barium sulfate is a colorless orthorhombic crystal or white amorphous powder. Easy to agglomerate when dry. The relative density is 4.50 (15 ° C) and the melting point is 1580 ° C. Almost insoluble in water, ethanol and acids. Dissolved in hot concentrated sulfuric acid. Polycrystalline transformation occurs around 1150 ° C. Significant decomposition started at about 1400 ° C. The chemical properties are stable. The water-soluble part of barium sulfate is completely ionized and is a strong electrolyte. Barium sulfate is insoluble in dilute nitric acid.

Barium has a wide range of industrial uses. It is mainly used for barium salts, fireworks, nuclear reactors, etc. It is an excellent oxygen scavenger for refined copper. It is widely used in alloys, including lead, calcium, magnesium, sodium, lithium, aluminum, and nickel. Barium metal can be used as a getter to remove trace gas in vacuum tubes and picture tubes, and a degassing agent for refined metals. Barium nitrate mixed with potassium chlorate, magnesium powder, and rosin can be used to make flares and fireworks. Soluble barium compounds are often used as pesticides. They can be used to refine the caustic soda brine and boiler water produced by the electrolytic method, as well as to prepare pigments. The textile and leather industries are used as mordants and rayon matting agents. Barium sulfate is an auxiliary drug for X-ray examination, which can provide positive contrast in the body. Medical barium sulfate is not absorbed in the gastrointestinal tract and has no allergic reactions. It does not contain soluble barium compounds such as barium chloride, barium sulfide, and barium carbonate. It is mainly used for gastrointestinal angiography and occasionally for other purposes.

Barite can be used as drilling mud weighting agent, filler and mineralizer for cement.