Borax pentahydrate, white crystalline powder. Density 1.815g/cm3, melting point 75℃. Freely soluble in hot water, glycerol, slightly soluble in ethanol, carbon tetrachloride. Aqueous solution is alkaline. Completely lose water of crystallization when heated to 120℃. From sodium tetraborate decahydrate solution, control the feeding temperature is higher than 70 ° C, the crystallization temperature is higher than 60 ° C recrystallization, filtration, drying at 120 ° C below the system. Can also be made from natural borax ore dissolved in hot water, filtration and separation, cooling crystallization and control of crystallization temperature above 60 ℃, with a concentration of 25% of the mother liquor washing system. Used in the manufacture of special glass. Used as antifreeze and anticoagulant in mining and metallurgy. Also used as additives for electroplating solution, non-ferrous metals and special alloys of the co-solvent.

Boron in the physiological role of plants, broadly the following aspects

1, boron is a component of plant body parts, affecting cell membrane formation.

2, boron is involved in the process of cellular communization of the meristematic tissue. Boron deficiency, poor cell division a few days long point of necrosis.

3, boron promotes the conversion and operation of carbohydrates, accelerates plant growth and development, and promotes early maturity.

4, boron has a good effect on the formation and stability of chlorophyll, boron deficiency, new leaves albino, old leaves early yellow.

5, boron can inhibit the biosynthesis of harmless phenolic compounds and lignin, to prevent the top bud brown rot, heart rot disease.

6, boron plays an important role in the formation and development of plant reproductive organs, promotes pollen germination, stimulates the elongation of pollen tubes, has a special impact on plant fertilization, is conducive to the formation of seeds, and reduces the role of flower and fruit drop.

7, boron can increase plant resistance. Can enhance the crop drought, disease resistance; boron in the crop body has the role of water control, enhance the ability of colloid binding water; boron can promote the formation of vitamin C, vitamin C increase can improve crop resistance.