The Effect of Reduction Parameters on Iron Nugget Production From Composite Pellets

ABSTRACTDynamic mechanical properties of polypropylene (PP) and grafted polypropylene (PP-g-MA) composites reinforced with acetylated wheat straw fibers (WSF) is reported in this work. The materials were prepared with different fiber particle sizes (40, 80 and 140 U.S. mesh) and at different fiber contents (5, 10 and 15 wt.%). The PP and PP-g-MA composites, where anhydride maleic (MA) was used as coupling agent, were obtained using a twin-screw extruder; whereas an injection-molding machine molded the composite pellets into testing specimens. To observe the morphology of the composites, micrographs were taken with an optical microscope. The Dynamic mechanical properties were analyzed using a torsional rheometer. The morphological analysis showed a high porous structure somehow similar to foamed materials. The storage modulus (G′) increased by increasing the fiber content, and decreased with fiber particle sizes for the PP composites. Meanwhile, the use of the coupling agent additive promoted a modulus increase due to higher fiber-polymer interaction, from better adhesion and chemical bonds formation between the fibers-coupling agent-PP.

Download Full-text

Numerical analysis of the carbon containing pellets direct reduction process

Metallurgical Research & Technology ◽

10.1051/metal/2021008 ◽

2021 ◽

Vol 118 (2) ◽

pp. 209

Author(s):

Nan Li ◽

Feng Wang ◽

Wei Zhang

Keyword(s):

Direct Reduction ◽

Reduction Process ◽

Operating Conditions ◽

Utilization Efficiency ◽

Heat Absorption ◽

Furnace Temperature ◽

Chemical Reaction Kinetics ◽

Direct Reduction Process ◽

Pellet Surface ◽

Composite Pellets

In view of the carbon-containing composite pellets direct reduction process in rotary hearth furnace, a mathematical model coupling heterogeneous chemical reaction kinetics, heat and mass transfer of this process was established. The effects of furnace temperature (from 1273.15 K to 1673.15 K) and pellet radius (from 6 mm to 16 mm) on the direct reduction of carbon-containing composite pellets were studied by adopting computational fluid dynamics software. The pellet temperature and composition changes under different operating conditions were analyzed. CO and CO2 fluxes, heat fluxes on the pellet surface were especially studied. Total heat absorption by the pellet, CO and CO2 overflow from the pellet surface together with pellet degree of metallization (DOM) and zinc removal rate (ZRR) were calculated. Results show that with the increasing of furnace temperature or the decreasing of the pellet radius, the temperature difference between pellet surface and its center and the final DOM, ZRR increased. The larger the pellet radius, the smaller the heat absorption, also the smaller CO and CO2 overflow. But heat absorption and CO overflow per unit volume are higher. There is an optimal pellet radius with high CO utilization efficiency. Pellet porosity decreases at first and then increases with reducing time. It is also found that effective thermal conductivity is a major factor limiting the pellets temperature increasing. The reduction sequence of the pellets is Fe2O3→Fe3O4→FeO→Fe.

Download Full-text

Concept Ship Design for the Iron Nugget Trade

Marine Technology and SNAME News ◽

10.5957/mt1.2005.42.4.184 ◽

2005 ◽

Vol 42 (04) ◽

pp. 184-191

Author(s):

Miltiadis Kotinis

Keyword(s):

Great Lakes ◽

Ship Design ◽

Pig Iron ◽

Marine Transportation ◽

Iron Range ◽

Design Concepts ◽

Inventory Costs ◽

Freight Rates ◽

Pig Iron Nuggets ◽

Iron Nugget

The projected growth in production of pig iron nuggets on the Iron Range of northeastern Minnesota provides new opportunities for marine transportation on the Great Lakes. The shipping of this higher-value commodity necessitates low freight rates and minimum inventory costs. This paper examines viable ship design concepts to provide competitive transportation solutions.

Download Full-text

Effect of different forms of carbon on the reduction behaviour of iron ore-carbonaceous material composite pellets in multi-layer bed rotary hearth furnace (RHF)

Canadian Metallurgical Quarterly ◽

10.1080/00084433.2021.1997279 ◽

2021 ◽

pp. 1-13

Author(s):

Shailesh Priyadarshi ◽

Srinibash Mishra ◽

Binay Kumar ◽

Gour Gopal Roy

Keyword(s):

Iron Ore ◽

Carbonaceous Material ◽

Rotary Hearth Furnace ◽

Hearth Furnace ◽

Reduction Behaviour ◽

Composite Pellets ◽

Forms Of Carbon ◽

Material Composite

Download Full-text

Direct reduction of copper slag-carbon composite pellets by coal and biochar

Environmental Technology ◽

10.1080/09593330.2018.1561757 ◽

2019 ◽

Vol 41 (17) ◽

pp. 2240-2252 ◽

Cited By ~ 1

Author(s):

Zongliang Zuo ◽

Qingbo Yu ◽

Huaqing Xie ◽

Fan Yang ◽

Zhicheng Han ◽

...

Keyword(s):

Direct Reduction ◽

Copper Slag ◽

Carbon Composite ◽

Composite Pellets

Download Full-text

Investigation of Novel Composite Materials for Thermochemical Heat Storage Systems

Energies ◽

10.3390/en13051042 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1042

Author(s):

Salih Cem Akcaoglu ◽

Zhifa Sun ◽

Stephen Carl Moratti ◽

Georgios Martinopoulos

Keyword(s):

Thermal Conductivity ◽

Heat Storage ◽

Storage Systems ◽

Space Heating ◽

Energy Prices ◽

Compression Pressure ◽

Scanning Calorimetry ◽

Thermochemical Heat Storage ◽

Composite Pellets ◽

Heat Storage Materials

Increasing energy prices make space heating more expensive every year in The Organisation for Economic Co-operation and Development (OECD) member countries. Thermochemical heat storage systems (THSS) can be used to reduce residential energy consumption for space heating and to control humidity. Utilizing compressed thermochemical pellets as heat storage materials is a way to increase volumetric energy storage capacity and to improve the performance of the THSS. In this work, expanded natural graphite (ENG), activated carbon (AC), strontium bromide, and magnesium sulphate were mixed in different mass ratios and compressed under applied pressures in a range of 0.77 to 5.2 kN⋅mm−2 to form composite pellets with a diameter of 12 and 25 mm, respectively, and a thickness from 1.5 to 25 mm. These pellets were characterized using thermogravimetric analysis and differential scanning calorimetry. Cyclic tests of hydration at 20 °C and dehydration at 85 °C were conducted to investigate changes in the surface morphology and the heat and mass transfer characteristics of the composite pellets. The permeability and thermal conductivity of the composite pellets were also measured. It was found that the structural stability of the pellets was enhanced by increasing the compression pressure. Utilizing AC and ENG in the composite mixture enhanced the porosity, thermal conductivity, and the permeability of the pellets.

Download Full-text