Pelletization Technology Research Papers - Academia.edu (original) (raw)

The use of conventional bentonite binder is favorable in terms of mechanical and metallurgical pellet properties, however, because of its acid constituents bentonite is considered as impurity especially for iron ores with high acidic content. Therefore, alternative binders to bentonite have been tested. Organic binders are the most studied binders and they yield pellets with good wet strength; they fail in terms of preheated and fired pellet strengths. This study was conducted to investigate how insufficient pellet strengths can be improved when organic binders are used as binder. The addition of a low-melting temperature and slag bonding/strength increasing constituent (free in acidic contents) into pellet feed was proposed. Addition of boron compounds such as colemanite, tincal, borax pentahydrate, boric acid together with organic binders such as CMC, starch, dextrin and some organic based binders, into iron oxide pellet was tested. Wet and thermally treated pellet physical-mechanical qualities (balling - moisture content - size - shape - drop number - compressive strengths - porosity - dustiness) were determined. The results showed that good quality wet, dry, preheated and fired pellets can be produced with combined binders (an organic binder plus a boron compound) when compared with bentonite-bonded pellets. While organic binders provided sufficient wet and dry pellet strengths, the boron compounds provided the required preheated and fired pellet strengths at even lower firing temperature. Especially, the contribution of boron compound addition is most pronounced for hematite pellets which do not have strengthening mechanism through oxidation like magnetite pellets during firing. Therefore, addition of boron compound is beneficial to recover the low physical-mechanical qualities of pellets produced with organic binders through slag bonding mechanism. Furthermore, lowering the firing temperature thanks to low-melting boron compounds will be cost-effective for firing part of the pelletizing plants.

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- Pellets, Iron Ore Extraction and Environmental Problems, Iron ore, Pelletization Technology

Diseño Conceptual de una Maquina Peletizadora de Alimentos para Aves de Corral

- by Daniel Flórez-Orrego
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- Poultry Science, Poultry Nutrition, Indian Poultry Industry, Pellets

Sinter of high basicity is well known for affecting the permeability of the burden in the lower portion
of the blast furnace due to the formation of more viscous slag. The high-basicity pellets possess
less weather resistance if hardened below 1200°C due to the presence of free lime particles.
When hardened above 1200°C, the weather resistance increases with increasing sticking
tendency among the pellets due to the formation of low-melting eutectics. In the present
investigation, efforts were made to make composite-coated iron ore-fluxed pellets to minimise
the problems mentioned above. Lime addition to the core of pellets varied from 5 to 100%. The
composite pellets subsequently were fired at 1150, 1200 and 1250°C for 30 min. Increasing lime
content in the pellets resulted in increasing crushing and drop strength of the green pellets. The
percent of reduction and cold crushing strength were found comparable to the conventional
pellets with varying lime content up to 30% (core basicity 4.68). Weathering resistance was also
found increasing trends with increasing firing temperature. XRD analysis revealed the presence
of free lime particles inside the core of composite pellets with increasing lime content. From the
present work, it could be concluded that the composite-fluxed pellet made with 20% lime in the
core (core basicity 3.0) has enough physical strength (187 kg), a high percentage of reduction
(96%) and excellent weather resistance properties.

- by Dr. Arup Kumar Mandal and +1
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- Iron and Steel Making Troogh Blast Furnace and Sinter Making, Iron ores, Iron Making, Pelletization Technology

Abstract. Integrating Sphere (IS) is an instrument formed a cavity sphere with its inner surface act as a Lambertian
reflector. IS is needed in many optical measurements which involves a high diffused reflection. In addition, IS very
essential in photometry and radiometry measurement system. However, currently, IS is still an imported product which
considered very expensive. The material for the sphere and inner surface coating affect the performance of the IS
systems. Therefore, the main challenges in designing IS are the material engineering for the sphere and the procedure for
the inner surface coating. The inner surface was coated using BaSO 4 which has a low absorption and high diffuse
reflection. Spectral responses of the IS system was characterized using USB2000+ and calibrated using a standard
Spectralon from ocean optic. The obtained IS system used an inner surface coating from a mixed 80% Barium Sulfate
(BaSO4) and 20% Nippon Elastex paint which yield a reflection factor = 0.955 and amplification factor M=10.69. The
validation was conducted using an emitter with known specification from Luxeon of LXHL-DW01 which produced light
flux 40.5 lumen with injection current 350 mA and junction temperature Tj 25oC.

- by bmukti wibawa
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- Pelletization Technology