Use of Boron Compounds as Binders in Iron Ore Pelletization

Abstract

Low grade iron ores with impurity gangue minerals containing silica and alumina must be upgraded to an acceptable level of iron content. Concentrates, due to their fine sizes, are not suitable to be directly charged to the iron-making processes such as the blast furnace or the DR-plant. Hence, an agglomeration technique should be applied to fine concentrate. The most commonly employed one is pelletizing in iron ore industry. In pelletizing, iron ore, water and a binder are balled in a mechanical disc or drum to produce agglomerates. Bentonite is the most widely used binder. However, it is considered as an impurity due to its high SiO 2 and Al 2 O 3 content. Many researchers have investigated different binders, mostly of organic origin, in pursuit of finding a viable alternative binder to bentonite. Organic binders were found to yield good quality green and dry pellets. However, they fail to impart enough strength to the pre-heated and fired pellets as a result of insufficient slag bonding. Boron compounds free of silica and alumina are thought to be a potential solution to overcome the lack of slag forming constituents encountered with organic binders as they are known for their low melting temperatures as well as for their ability to also lower the melting temperatures of silicates. A few researchers have investigated the use of boron compounds in iron ore agglomeration and found promising results which have been covered in this paper.

Expeditious and efficient synthesis of Strecker’s α-aminonitriles catalyzed by sulfated polyborate

“…53 Boric acid dehydrates above 100 °C and converts to its polymeric forms, which presumably is the active species catalyzing the reaction. [54][55] Dehydrative polymerization of boric acid liberates water molecules which may hamper the progress of the reactions. This inspired us to develop a polymeric boric acid catalyst with mild Bronsted acidity.…”

Ligantes Alternativos Para Aglomerados Autorredutores: Uma Análise

“…Com isso esses componentes podem melhorar a resistência dos aglomerados a temperaturas a partir de 500 °C. Resultados aceitáveis estão reportados com 0,5% de silicato de sódio [11] e com colemanita calcinada (componente básico é o óxido de boro) [12,13]. A tabela 3 mostra alguns resultados com colemanita e efeitos sinérgicos com alguns componentes orgânicos, para pelotas convencionais, não autorredutoras.…”

Zeta potential of inorganic fine particle—Na‐bentonite binder mixture systems

“…Bentonite is a hydrated alumino-silicate clay mainly composed of montmorillonite with the layered structures loosely bound by counter ions [4]. In an aqueous solution, bentonite behaves as a binder to bridge mineral particles.…”