National Metallurgical Development Center

Jos, Nigeria

National Metallurgical Development Center

Jos, Nigeria
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Ihom P.A.,National Metallurgical Development Center | Agunsoye J.,University of Lagos | Anbua E.E.,Federal Polytechnic Bauchi | Ogbodo J.,Scientific Equipment Development Institute
Leonardo Electronic Journal of Practices and Technologies | Year: 2011

The effect of moisture content of Yola natural sand has been studied. The moisture content was varied from 1 to 9%. The effect of the moisture content on the green compression strength, green permeability and bulk density was investigated. Particle size distribution of the natural sand, the grain fineness number, average grain size, grain shape and the clay content of the natural sand were also studied. 5% moisture gave the optimum green compression strength of 118.6KN/m2. The dry compression strength increased with moisture content, an optimum value of 4000KN/m2 was obtained at 9% moisture. The Yola natural sand had a grain fineness number of 88.05AFS, average grain size of 335.78 microns and a clay content of 26%. A sand mixture containing 5% moisture was prepared and used to produce a test casting with aluminium scraps, the test casting was sound.


Ihom P.A.,National Metallurgical Development Center | Abella A.S.,Metallurgical Training Institute Onitsha | Anbua E.,Federal Polytechnic Bauchi | Ogbodo J.,Scientific Equipment Development Institute Enugu
Leonardo Electronic Journal of Practices and Technologies | Year: 2011

The use of Kruskal-Wallis test as an analytical tool for the key components of a newly developed core mixture was studied. The study showed that Kruskal- Wallis test can be use to analyze a core mixture using data collected on the properties of the core mixture. In this work the data used was the dry compression strength of cores produced using the core mixture. The key components of the core mixture; the binders and the sands were analyzed. The result showed that the dry compression strength values of the core mixture depend on the type of sand and on the nature of the binder used. This analysis agreed with previous works carried out by several other authors using conventional methods for analysis of core mixtures.


Abdulwahab M.,Ahmadu Bello University | Abdulwahab M.,Tshwane University of Technology | Madugu I.A.,National Metallurgical Development Center | Asuke F.,Ahmadu Bello University | And 3 more authors.
Journal of Materials and Environmental Science | Year: 2013

Studies have been made on the mechanical properties upon thermal ageing of a sand cast antimony-modified A356-type Al-Si-Mg alloy. The produced alloy was solution heat treated at 540oC/1h then subjected to thermal ageing treatment at 180oC for 1-5h. There mechanical properties; Tensile properties, Hardness and Impact strength were used as criterion. From the results, the tensile properties and hardness increased with thermal ageing treatment. While the impact energy and elongation decreased upon ageing. The tensile properties of antimony-modified Al-Si-Mg alloy improved with ageing time and that the microstructures indicate spherodization of the silicon flakes to fine structures, which account for the improved properties.


Mohammed R.A.,Ahmadu Bello University | Abdulwahab M.,Ahmadu Bello University | Abdulwahab M.,Tshwane University of Technology | Madugu I.A.,National Metallurgical Development Center | And 2 more authors.
Journal of Materials and Environmental Science | Year: 2013

The effect of Cyperus esculentus L. oil as a corrosion inhibitor on the corrosion rate of A356.0-type Al-Si-Mg alloy in simulated seawater environment was investigated using gravimetric method. The corrosion rates were studied in different concentrations of Cyperus esculentus L. oil (0.2, 0.4, 0.6, and 0.8g/v) at temperatures of 30, 50, and 70°C. The results revealed that Cyperus esculentus L. oil in 3.5% NaCl-aluminium environment decreased the corrosion rate at various concentrations considered. Results also showed that Cyperus esculentus L. oil decreased the corrosion rate of Al-Si-Mg alloy immersion time considered. The minimum inhibition efficiency was obtained at 70°C while the maximum inhibition efficiency of 69.97% was achieved with 0.8g/v inhibitor concentration at 30°C. Cyperus esculentus L. oil acted as an effective corrosion inhibitor for Al-Si-Mg alloy within the temperature and concentration range studied. The results demonstrated that Cyperus esculentus L. oil adsorbed on the surface of Al-Si-Mg alloy and obeyed Langmuir adsorption isotherm.


Adeleke A.A.,Obafemi Awolowo University | Ibitoye S.A.,Obafemi Awolowo University | Afonja A.A.,Obafemi Awolowo University | Chagga M.M.,National Metallurgical Development Center
Petroleum and Coal | Year: 2014

Fractions of Okaba coal OK±250 ground to pass the 250μm sieve in three stages were subjected to proximate/ash composition analyses, hot aqueous leaching de-ashing with sodium carbonate and water (at atmospheric pressure) in multiple stages and in a Na2CO3-H2O- H2O sequence. The results obtained indicate that the ash contents percent of Okaba fractions OK-250(1), OK-250(2) and OK+250(2) were further reduced below the upper limit of 10 by 1.9, 2.2 and 1.8, respectively. These reductions translate to an average overall ash decrease percent of 12.57, while the volatile reduced by 9.85 and fixed carbon increased by 18.65. The ash content of the concentrates blend at 8% is lower than 10% required for coal blends for standard coking practice. The light transmission microscopy of the coal fractions showed that the chemical leaching process produced finer coal particles and caused a decrease in the ash content of the coal fractions. The reduction in ash content obtained at the atmospheric pressure treatment of Okaba coal will further enhance its participation in blend formulation for cokemaking.


Olulana A.O.,National Metallurgical Development Center | Adeleke A.A.,National Metallurgical Development Center | Adeleke A.A.,Obafemi Awolowo University | Adahama A.B.,National Metallurgical Development Center | Ibitoye S.A.,Obafemi Awolowo University
Petroleum and Coal | Year: 2011

A coal blend consisting of 95% Australian Agro-Allied coal and 5% Nigerian non-caking Okaba coal was carbonized in a 250 kg capacity coke oven at a flue temperature of 1,250oC by normal wet and preheated charging for 18 and 15 hours, respectively. Screen distribution analysis and micum drum tests on the coke products gave M10 of 24.60% and 9.5% and M40 of 67% and 76.2%, for normal and preheated charge, respectively. These results showed that the coke produced from the preheated charge has a better resistance to abrasion (M10) and fragmentation (M40) and the micum indices obtained are similar to the micum characteristics of cokes produced in coke ovens in some other countries. Furthermore, the coke micum 10 and micum 40 strength are very close to the M10 and M40 specifications for coke to be used for blast furnace operations at the Ajaokuta Steel Plant, Nigeria.


Adeleke A.A.,Obafemi Awolowo University | Ibitoye S.A.,Obafemi Awolowo University | Afonja A.A.,Obafemi Awolowo University | Chagga M.M.,National Metallurgical Development Center
Petroleum and Coal | Year: 2011

Fractions of the high ash Nigerian Lafia-Obi coal L±250 ground to pass the 250 μm sieve in three stages were subjected to proximate/ash composition analyses, hot aqueous leaching de-ashing with water and sodium carbonate in multiple stages and in a H2O-Na2CO3-H2O sequence (with initial solution homogenization). The results obtained showed that ash contents percent of 24.60, 14.70 and 24.07 were obtained for fractions L-250(1), L-250(2) and L+250(2); respectively as against 32.55% in the as-received coal. The ash reductions obtained translate to overall average ash removal of about 38.66% at the 19.90% ash content of the concentrates blend at a good 1:20 ratio of reagent to coal. The study also showed that a three stage leaching in the sequence H2ONa2CO3- H2O (HSH) produced a higher leaching rate than Na2CO3-H2O-H2O (SHH). The ash content of the concentrates blend at 19.90% is lower than 23.80% required for coal blends for Indian standard coking practice, but higher than the maximum of 10% upper limit for the conventional cokemaking practice. The reduction in ash content obtained at the atmospheric pressure treatment of Lafia-Obi coal was found to compare favourably with that of a high pressure elevated temperature autoclave leaching of an Illinois coal. Binary blend formulation between the prime coking western Canada coal and Lafia-Obi coal as-leached showed that inclusion of 16.63% of the latter was probable and this translates to reduction in cost per ton of about $23.67. A successful upgrade of the leaching route derived to industrial scale will make Lafia-Obi coal available as a blend component for economical cokemaking.


Asuquo L.O.,University of Uyo | Ihom A.P.,University of Uyo | Mayaleeke K.,National Metallurgical Development Center
Leonardo Electronic Journal of Practices and Technologies | Year: 2013

The morphology and hardness improvement of lead bearing alloy through composite production: 75Pb-15Sb-10Sn/ 15%v/v SiO2 particulate composite, was studied. 75Pb-15Sb-10Sn white bearing alloy produced at the foundry shop of National Metallurgical Development Centre Jos was used for the production of the composite using stir-cast method. The reinforcing agent was 63 microns passing particles of silica. This was produced from pulverizing quartz using laboratory ball mill. The specimens of the composite produced were then subjected to metallographic to study the morphology of the structures produced both in the as cast and aged conditions of the composite. The samples were also tested for hardness and the result showed that the as cast composite had a hardness value of 33 HRB which is an improvement over the hardness value of 27.7 HRB for the 75Pb-15Sb-10Sn alloy which was used for the production of the composite. The effect of age hardening on the produced composite was also investigated; the result showed that the maximum hardness of 34 HRB was obtained after ageing for 3 hours. The micrographs revealed inter-metallic compound SbSn, eutectic of two solid solutions-one tin-rich and the other lead-rich, reinforcing particles, and solid solution of β. The results revealed that particle hardening can be used to improve the hardness of 75Pb-15Sb-10Sn white bearing alloy for use as heavy duty bearing material.


Ihom P.A.,National Metallurgical Development Center | Ayeni F.,National Metallurgical Development Center | Mohammed S.,National Metallurgical Development Center | Ola S.,National Metallurgical Development Center
Leonardo Electronic Journal of Practices and Technologies | Year: 2013

In this research study, the inhibitive potential of Arecaceae extract on the corrosivity of aluminium based matrix composite and medium carbon steel in different media have been undertaken. The composite and the carbon steel were exposed in 0.5M NaOH and 0.5M HCl solutions as the control solutions. The Arecaceae extract from the fruit juice was added in volume percentages of 5%v/v and 10%v/v. The exposure time covered 12 days, and the monitored temperature range during the exposure time was 25-39°C. The result indicated that the most corrosive media were those without the Arecaceae inhibitor; where corrosion rate ranged from 0.106mpy to 0.409mpy. The medium carbon steel did not show any sign of corrosion in the 0.5M NaOH solution. Arecaceae inhibitor addition of 5%v/v gave optimum corrosion rate reduction; the corrosion rate was in the range of 0.018mpy to 0.199mpy. Although the lowest range of 0.013mpy to 0.192mpy was obtained with 10%v/v of Arecaceae, however on the overall performance the 5%v/v of Arecaceae was better. The inhibition of corrosion by Arecaceae was as a result of adsorption and phase layers on the surface of the metals.

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