Production of reduced pellets from lignite semicoke

Blast furnace process is still an important process for producing pig iron. The process needs high grade iron ore and coke. The two materials can not be found easily. In addition blast furnace process needs cooking and sintering plant that produces polluted gases. Utilization of composite pellet for pig iron production can simplify process. The pellet is made of iron ore and coal. In addition the pellet can be made from other iron source and coal. This paper discusses the evolution of phase during reduction of composite pellet containing lateritic iron ore. Fresh iron ore and coal were ground to 140 mesh separately. They were mixed and pelletized. The quantity of coal added was varied from 0 %, 20 % and 29 % of pellet weight. Pellets were heated with 10 °C/minute to 1100 °C, 1200 °C, 1300 °C and 1350 °C in a tube furnace and temperature was held during 10 minutes. Heated pellets were analyzed with XRD equipment. XRD of reduced pellets showed that iron phase change with coal and temperature. Lack of coal during heating results the re-oxidation of iron phases. This process is due to replacement of reductive atmosphere by oxidative atmosphere.

Download Full-text

Utilization of SL/RN reduced pellets in electric arc furnaces

JOM ◽

10.1007/bf03378716 ◽

1968 ◽

Vol 20 (5) ◽

pp. 108-114

Author(s):

J. G. Sibakin ◽

P. H. Hookings ◽

G. A. Roeder

Keyword(s):

Electric Arc ◽

Electric Arc Furnaces ◽

Arc Furnaces ◽

Reduced Pellets

Download Full-text

Effect of Thermal Charging of Iron Ore Pellets on the Reduction Rate and Compressive Strength in Gas-Based Reduction Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.532-533.262 ◽

2012 ◽

Vol 532-533 ◽

pp. 262-266 ◽

Cited By ~ 1

Author(s):

Zhu Cheng Huang ◽

Dao Guang Yang ◽

Ling Yun Yi

Keyword(s):

Compressive Strength ◽

Iron Ore ◽

Inner Core ◽

Direct Reduction ◽

Reduction Rate ◽

Reduction Process ◽

Optical Microscope ◽

Ore Pellets ◽

Iron Crystal ◽

Reduced Pellets

Burden in gas-based direct reduction process is iron ore oxide pellet, which has experienced oxide roasting and cooling before reduction. However, it would be heated again in the reduction process. This may cause much energy waste and adverse effects on reduction process. In this paper, roasted pellets with and without cooling were charged for gas-based reduction respectively. The reduction rate and compressive strength during reduction were studied to reveal the effects of charging methods. Results showed that there is little difference on reduction rate between the two. However, the compressive strength of reduced pellets via thermal charging improves obviously. And nucleation and growth mechanisms of iron crystal grain in gas-based reduction were investigated by optical microscope (Leica DMRXP). The iron crystal nucleuses firstly form at the interface of grains and edge of wustite, and then gradually grow from surface layer to inner core as reduction proceeds. Thermal charging can promote the migration and accumulation of iron crystal grain effectively.

Download Full-text

Production of unroasted briquets based on small lignite semicoke particles from Kansko-Achinsk coal

Coke and Chemistry ◽

10.3103/s1068364x0809007x ◽

2008 ◽

Vol 51 (9) ◽

pp. 370-375 ◽

Cited By ~ 3

Author(s):

V. M. Dinel’t ◽

V. M. Strakhov ◽

V. I. Livenets ◽

M. S. Nikishanin ◽

A. E. Anikin ◽

...

Keyword(s):

Lignite Semicoke

Download Full-text

Effects of Treated Cow Dung Addition on the Strength of Carbon-Bearing Iron Ore Pellets

Advances in Materials Science and Engineering ◽

10.1155/2017/1019438 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Qing-min Meng ◽

Jia-xin Li ◽

Tie-jun Chun ◽

Xiao-feng He ◽

Ru-fei Wei ◽

...

Keyword(s):

Iron Ore ◽

Direct Reduction ◽

Amorphous Region ◽

Cow Dung ◽

Alternative Source ◽

Iron Ore Pellets ◽

Ore Pellets ◽

Pellet Strength ◽

Increased Strength ◽

Reduced Pellets

It is of particular interest to use biomass as an alternative source of fuel in direct-reduction ironmaking to ease the current reliance on fossil fuel energy. The influence of cow dung addition on the strength of carbon-bearing iron ore pellets composed of cow dung, iron ore, anthracite, and bentonite was investigated, the quality of green and dry pellet was evaluated based on FTIR analysis, and the mechanism of strength variation of the reduced pellets was investigated by analysing the phase composition and microstructure using XRD and SEM. The results show that cow dung addition decreased the green pellet strength due to expansion of the amorphous region of the cellulose in the cow dung; however, the dry pellet strength increased substantially. In the process of reduction roasting, it was found that cow dung addition can promote aggregation of iron crystals and increase the density of the pellets, resulting in increased strength of the reduction roasted pellets, while excessive cow dung addition resulted in lower strength.

Download Full-text