China 
Africa 
Explore chapters and articles related to this topic
Heavy Metals
Published in Abhik Gupta, Heavy Metal and Metalloid Contamination of Surface and Underground Water, 2020
Boron (B) has an atomic number of 5, an atomic weight of 10.811, and a density of 2.34 g cm–3. Colemanite [CaB3O4(OH)3·H2O] and borax [Na2B4O5(OH)4·8H2O] are the major sources of boron, which finds many uses such as making glass, ceramics, and enamels. Compounds of boron are used in water softeners, soaps and detergents, agricultural chemicals, fire retardants, and medicine (Encyclopaedia of Occupational Health and Safety 2012).
Recent Advances in Boron-Based Flame Retardants
Published in Yuan Hu, Xin Wang, Flame Retardant Polymeric Materials, 2019
A variety of calcium borates can be prepared by reacting calcium hydroxide and boric acid. Synthetic gowerite (CaO·3B2O3·5H2O) and calcium metaborate (CaO·B2O3·4H2O or CaO·B2O3·6H2O) are commercially available mostly for the glass industry. Among all of the known calcium borates, the natural mineral colemanite (2CaO·3B2O3·5H2O) is the most well known in the field of flame retardants.
Investigation of solubility parameters prior to processing of Kestelek colemanite
Published in Gülhan Özbayoğlu, Çetin Hoşten, M. Ümit Atalay, Cahit Hiçyılmaz, A. İhsan Arol, Mineral Processing on the Verge of the 21st Century, 2017
Although there are at least 150 minerals known to contain the elemental boron, few of the boron minerals are mined as an ore in nature. Boron is naturally found in oxide type minerals containing some alkali ions, i.e. colemanite (2CaO 3B2O3 5H2O), tincal (Na2O 2B2O3 10 H2O) and ulexite (Na20 2CaO 5B2O3 16H2O). Colemanite is a preferred calcium-bearing borate used mainly for production of fiberglass, borosilicate glasses, soaps, detergents, fire retardants, enamels, frits and the agricultural, metallurgical and nuclear industries, directly or after being transformed to boric acid (H3BO3) (Celik et al. 1993, Ozkan 1994).
Iron Ore Pelletization: Part II. Inorganic Binders
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Colemanite is a boron containing clay with a formula of Ca2B6O11 · 5H2O. Its role in iron ore pelletization is to increase the quantity of slag fusion and recrystallization which occurs within the sintering step and to lower the temperature at which slag fusion begins (Sivrikaya et al. 2013). The melting point of colemanite is 986°C. Molten colemanite has been observed to bind with magnetite particles during the sintering process once this temperature is exceeded (Sivrikaya et al. 2013). Colemanite is effective for increasing fired pellet strength at dosages between 0.25 wt%-1.0 wt% (Sivrikaya et al. 2013). Higher dosages are also likely effective but increasing the boron impurity and reagent expenditure contraindicates higher dosages.