Thesis Abstract

<p> </p><p>The beneficiation of the Agbado Okudu iron ore deposit located in<br>Kogi State, Nigeria was investigated. The investigation involved<br>determining the chemical composition and mineralogical characteristics of<br>the run-of-mine. Followed by determination of the work index of the ore<br>and then separation tests using shaking table, magnetic technique and a<br>combination of the two techniques. The results of the tests carried out<br>revealed that the Agbadu okudu iron ore contained on the average a total<br>iron content (38.82% FeT), 49.10% (Si02) and other element. Thin sections<br>of the ore sample examined under polarized light revealed that the iron<br>bearing minerals are predominantly magnetite and hematite with a<br>combined average percentage distribution of 69% and the mineral in<br>abundant after the iron bearing minerals is quartz. The grindability test<br>reveals that the Agbado Okudu iron ore has and average work index of<br>about 4.32 kwh/tonne. The results of gravity separation shows that a<br>concentrate with a maximum grade of 55.81% (FeT), and a recovery of<br>66.40% at particle size fraction -56 + 45m could be produced. While<br>magnetic separation alone produced a concentrate with an optimum grade of<br>57.43% (FeT), and a recovery of 82.12% at particle size fraction of –<br>80+63m. However, combination of gravity separation technique (shaking<br>table) followed by magnetic separation technique could only produce a<br>concentrate with an optimum grade of 57.17% (FeT), and a recovery of<br>80.85% at a particle size fraction of –63+53m. Hence, based on the results<br>obtained from the concentration tests, the Agbado Okudu iron ore deposit<br>can be best beneficiated using magnetic technique to produce a concentrate<br>that can serve as feed for pig iron production by conventional blast furnace<br>route.</p><p>&nbsp;</p><p>&nbsp;</p> <br><p></p>

Thesis Overview

<p> NTRODUCTION<br>Iron is one of the most common elements on earth. Nearly every<br>structure put on by man contains at least a little iron. It is also one of the<br>oldest metals and was first fashioned into useful and ornamental objects<br>about 3,500 years ago (Lambert and Mark, 1988).<br>One of the most important determining factors for establishing Iron<br>and steel plants is the availability of iron ore deposit with good geological,<br>mineralogical and metallurgical properties. There is an estimated 2,707<br>million tonnes of iron ore deposit in the country out of which 200 million<br>tones are in the proven reserve (Umunnakwe, 1988). Iron ore is simply the<br>largest single raw material input in iron and steel making process and the<br>country is endowed with abundant reserves of it but with varying<br>characteristics. The deposits abound in different parts of the country as<br>shown in Table 2.1. Most of the iron ores discovered in the country are<br>however, low grade (their iron content in the crude ranges between 28-45%<br>FeT). This meant that for them to be used in iron and steel production they<br>have to undergo substantial beneficiation and upgrading. (Also and Yakubu,<br>1995). The Itakpe iron ore had been the most intensively studied and<br>exploited deposit with a proven reserve of 200million tones with an average<br>iron content of 36% FeT. This is presently being up-graded to obtain a<br>2<br>concentrate of 64% FeT for use at Ajaokuta and Aladja steel plants. Apart<br>from the Itakpe iron ore deposit there are other deposit which reserves are<br>estimated at over 2.3 billon tonnes as shown in (Table 2.1) within 150km<br>radius of the Ajaokuta steel plant. To ensure security of supply of the iron<br>ore for the nation Steel industries, further research and development need to<br>be carried out on these new founded deposits to enable their full<br>exploitation. With these reserves, conservative estimates indicate that the<br>nation could be self-sufficient in iron ore for a period ranging between 100-<br>150 years (Umunnakwe1988).<br>The role of iron and steel in the national economy is enormous.<br>One cannot name an economic branch where iron and steel find no<br>application and to some extend the economic power of a country is<br>determined by its consumption and output of steel products. It is on this<br>basis, that the Federal Government of Nigeria in 1971 launched the country<br>into a new era of iron and steel technology by the establishment of the Delta<br>and Ajaokuta steel projects. Though, the establishment of these projects was<br>laudable inadequate attention was given to the development of local raw<br>materials to feed the plants thus, making the plants on commissioning to<br>import iron ore concentrate form countries like Brazil, Liberia and Guinea.<br>Recently there has been renewed interests on the souring of locally available<br>raw materials to feed these plants because the Itakpe iron ore project and the<br>total iron ore requirement of Ajaokuta at 1.3 million tonnes of steel per<br>3<br>annum is about 2.135 million tones of iron concentrate and at this rate the<br>Itakpe iron ore project is conservatively estimated to last for about 25 years,<br>(Also and Yakubu, 1995).<br>Also, the Itakpe iron ore plant commissioned on the 80s to deliver<br>iron concentrate to Ajaokuta and later closed and now concessioned to<br>Indians. Would not be able to meet the demand of Ajaokuta Steel plant<br>when it finally takes off fully. It is therefore, important that these types of<br>studies be conducted so as to increase the source of Iron Ore for Ajaokuta<br>plant. And through such studies the technology for the beneficiation of<br>various Nigerian iron ore deposits for onward supply to Ajaokuta and Delta<br>steel plants will be developed.<br>Since the goal of every beneficiation process, mineral-processing<br>operation in particular, is to effectively separate the valuable material from<br>the gangue with minimum loss to the tailings; the need to develop and<br>employ a sustainable, effective and relatively economical method of<br>separation is imperative. The concentration of the valuable minerals from<br>the gangue involves exploitation of the differences in physical, chemical and<br>electrical properties of the ore after effective comminution Akande et al<br>(2000). This work, therefore, is aimed at developing a process route for the<br>beneficiation of the Agbado- Okudu iron ore deposit located close to Jakura<br>village in Kabba, Kogi State for its possible utilization in Ajaokuta and<br>Delta Steel Plants. <br></p>