IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE)
e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 7, Issue 4 (Jul. - Aug. 2013), PP 42-51
www.iosrjournals.org 42 | Page
Particulate Sintering of Iron Ore and Empirical Analysis of
Sintering Time Based on Coke Breeze Input and Ignition
C. I. Nwoye1, E. E. Nnuka1, V. O. Nwokocha1, 2 and S. O. Nwakpa1
1Department of Materials and Metallurgical Engineering, Nnamdi Azikiwe University Awka, Nigeria
2Federal Ministry of Works, Abuja
Abstract: Particulate sintering of iron ore has been carried out using the necessary ingredients. Empirical
analysis of the sintering time based on the coke breeze input concentration and ignition temperature were also
successfully obtained through first principle application of a derived model which functioned as a evaluative
tool. The derived model;
S = (√T)0.95 + 0.0012α
indicates that amongst ignition temperature and coke breeze input, sintering time is more significantly affected
by the coke breeze input concentration. This is based on the higher correlation it makes with sintering time
compared to applied ignition temperature, all other process parameters being constant. The validity of the
model was rooted in the core expression S – Kα ≈ (√T )N where both sides of the expression are correspondingly
approximately almost equal. Sintering time per unit rise in the operated ignition temperature as obtained from
experiment, derived model and regression model were evaluated as 0.0169, 0.0128 and 0.0159 mins. / 0C
respectively. Similarly, sintering time per unit coke breeze input concentration as obtained from experiment,
derived model and regression model were evaluated as 4.0, 3.0183 and 3.7537 mins./ % respectively indicating a
significant proximate agreement and validity of the model. The standard error (STEYX) incurred in predicting
sintering time for each value of the ignition temperature and coke breeze input concentration considered, as
obtained from the experiment, derived model and regression model are 1.6646, 0.7678 and 2.98 x10-5 % as well
as 2.2128, 1.0264 and 1.2379% respectively. The maximum deviation of mode-predicted results from the
corresponding experimental values was less than 11%.
Keywords: Particulate Iron Ore Sintering, Sintering Time, Ignition Temperature, Coke Breeze Input.
Sinter characteristics are basically a principal factor on which the blast furnace performance
significantly depends . It is widely accepted that sintering increases the particle size, to form a strong
reducible agglomerate, to remove volatiles and sulphur, and to incorporate flux into the blast-furnace burden.
Report  has shown that in sintering, a shallow bed of fine particles is agglomerated by heat exchange and
partial fusion of the quiescent mass. Heat is generated by combustion of a solid fuel admixed with the bed of
iron bearing fines being agglomerated. The combustion is initiated by igniting the fuel exposed at the surface of
the bed, after which a narrow, high temperature zone is caused to move through the bed by an induced draft,
usually applied at the bottom of the bed. Within this narrow zone, the surfaces of adjacent particles reach fusion
temperature, and gangue constituents form a semi-liquid slag. The bonding is affected by a combination of
fusion, grain growth and slag liquidation. The generation of volatiles from the fuel and fluxstone creates a frothy
condition and the incoming air quenches and solidifies the rear edge of the advancing fusion zone. The product
consists of a cellular mass of ore bonded in a slag matrix.
One of the most important thermal operations in integrated iron and steel plant is sintering of raw iron
ore, mostly haematite (Fe2O3). In the sintering process, a mixture of iron ores, coke, lime or limestone, and iron
bearing residue (e.g blast flue dust, mill scale, scrap and other waste material recycled from within or outside the
steel plant.) is heated at high temperatures and sintered into a porous, calibrated feedstock acceptable to the blast
furnace. Almost all types of ferro waste available in iron and steel works can be utilized in appropriate
proportions to produce quality sinters .
Studies  have shown that approximately 6.7% of the total energy consumed in iron and steel
production is required for sinter production. Development and growth in the iron and steel industries all over the
world has militated against the availability of prime coking coal with adequate properties to yield metallurgical
coke. This situation has increasingly becoming more severe, making procurement of such coke expensive .
A several researches in the sintering area include energy consumption and productivity process control.
Significant reduction in energy have already been achieved in sintering plant as a result of utilization of
improved raw materials characteristics of ores and coke breeze in terms of size and composition . This