Introduction to barium metaborate

CAS: 13701-59-2

Barium metaborate B2BaO4, molecular weight 222.95, white rhombic crystalline crystalline powder. Relative density 3.25 ~ 3.35.

Melting point 1060℃. Slightly soluble in water, easily soluble in hydrochloric acid.

It has the properties of rust prevention, powder resistance, high temperature resistance, fire prevention and mildew prevention.

Modified barium metaborate is a new non-toxic anti-rust pigment used in primer and topcoat in coating industry, and is also used in ceramics, papermaking,

rubber, textiles and plastics industries.

Synthesis method:

1, borax barium sulfide method (usually) :

① The mixture of barite and pulverized coal is calcined, leach with hot water in the extractor, and the barium sulfide liquid is obtained, and then the borax aqueous solution and sodium silicate aqueous solution are separately added to the reactor. After adding the three kinds of materials, the reactor is closed, the temperature is raised to 110℃±5℃, and the reaction is stirred for 2 hours, and the cooling is 70 ~ 80℃. The precipitate was centrifuged, washed, dried and crushed to produce the finished barium metaborate.

BaSO4+C→BaS+2CO2↑, 2NaOH+2BaS+Na2B4O7→2Ba(BO2)2↓+2Na2S+H2O

② The mixture of barite and powder is roasted and leach with hot water through the extractor to obtain the barium sulfide liquid, concentrate to 14 ~ 16g/L, and heat to 55 ~ 70℃. Borax is prepared into 0.22 ~ 0.28g/L, the temperature is 70 ~ 85℃, the two and flow into the reactor, and then add the measured sodium silicate aqueous solution, after the three materials are added, the pH value is greater than 11. The reactor was closed, the temperature was raised to 110 ~ 140℃,the reaction was stirred for 1 ~ 6h, the cooling was to 70 ~ 80℃, and the precipitate was centrifuged, washed, dried and crushed to obtain the finished barium metaborate.

2, the top seed crystal molten salt method, China for the first time by this method to grow a new inorganic nonlinear optical crystal material barium metaborate.

The raw material barium carbonate and boric acid are added to the crucible in proportion, while the appropriate amount of flux sodium carbonate is added.

Resistance heating is used. When the raw material is melted, it is kept warm for several hours, so that the molten liquid is completely melted and evenly mixed.

The seed crystal is lowered into the solution, the temperature is lowered, the seed crystal is rotated and slowly pulled upward to grow a high-quality crystal of size Phi 46mm×18mm. This method overcomes the disadvantage of excessive spontaneous nucleation.

Application: It can enhance the properties of anti-mildew, anti-rust, fire and anti-pulverization of the coating.

1, used in the paint industry primer, top paint, is a new type of anti-rust pigment, also used in ceramics, paper, rubber and plastics and other industries.

2, used as an additive flame retardant, the flame retardant efficiency is not as good as antimony oxide, but because of its low price, it can be used as a partial

substitute for antimony oxide flame retardants, and has a synergistic effect with halogenated flame retardants. Suitable for epoxy resin, unsaturated polyester,

phenolic resin, polyvinyl acetate, acrylic resin, polyurethane, polyvinyl chloride and so on

Optical properties:

Barium metaborate is a nonlinear optical crystal with comprehensive and excellent properties. It has a wide transmittance band (190nm-3500nm) and phase

matching range (409.6nm-3500nm), a large nonlinear optical coefficient, and a high anti-light damage threshold. The wide temperature bandwidth and superior

optical uniformity provide practical possibilities for a variety of nonlinear optical applications.

Main applications of BBO:

Generation of 2nd, 3rd, 4th and 5th harmonics in Nd:YAG and Nd:YLF lasers.

Frequency doubling, frequency tripling and frequency mixing of dye lasers.

Generation of 2,3,4, and 5 harmonics in titanium gem and amethyst lasers

It can be used in the development of a variety of advanced laser technologies such as all-solid state, wide band modulation laser, ultra-short pulse laser, and DUV laser.

Optical parametric amplification (OPA) and optical parametric Oscillation (OPO)