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Search Results: 1 - 10 of 537011 matches for " A.O. Olulana "
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Effects of Stamped Charging on the Strength of Coke from the Weakly Caking Australian Agro-Allied Coal Blend Mixed with Coke Breeze  [PDF]
A.B. Adahama, A.O Adeleke, A.O. Olulana, S.A. Ibitoye
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2008, DOI: 10.4236/jmmce.2008.74027
Abstract: The weakly caking Australian Agro-Allied coal sample mixed with 7% un-reactive coke breeze was subjected to stamped charging prior to carbonization for 22 hours in a 250kg pilot plant to improve the resulting coke strength. The coal was carbonized with a bulk density of 1,000kg/m3 and heating flue temperature of 1,340℃. The screen distribution analysis and the micum tests conducted on the coke gave M10 and M40 of 15.90% and 73.20%, respectively. These results show that the Agro-Allied coke produced is inferior to the coke from a normal top charged counterpart with M10 and M40 indices of 15.40% and 78.20%, respectively and do not satisfy the requirements for the blast furnace ironmaking process. These results thus suggest that the stamped charging coking improvement method designed for high caking, high volatile coals may not be able to improve the strength of coke resulting from a weakly caking, medium volatile coal mixed with coke breeze.
Study on the Reliability of Coke Research Establishment Micum 40 Formula to Predict Coke Micum 40 Strength at The Ajaokuta Steel Plant, Nigeria  [PDF]
A.O. Adeleke, A.O. Olulana, A.B. Adahama, R.S Makan, S.A. Ibitoye
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2007, DOI: 10.4236/jmmce.2007.62011
Abstract: G-values of 0.97, 0.93, 0.94 and 1.01 were determined for Polish Bellview blend 1 (BV1), Polish Bellview blend 2 (BV2), Australian Agro-Allied blend (AA) and American Carbon Energy blend (CE), respectively. The coking duration of 18 hours, 17 hours, 16 hours and 22.5 hours, respectively were used to carbonize the coals each having volatiles 31.8%, 31.3%, 30.22%, and 21.90%, respectively. The Coke Research Establishment (CRE) formula predicted M40 micum strength of 77.98%, 77.12%, 77.55% and 92.05% for BV1, BV2, AA and CE blends, respectively. These predicted values were found to deviate from the experimentally determined M40 indices of 77.80%, 70.80%, 78.20% and 64.16% determined for BV1, BV2, AA and CE respectively by 0.18 units, 6.32 units, -0.65 units, and 27.89 units respectively. Thus, the best M40 index predicted was determined for BV1 blend with 0.97 G-value and 18 hours coking time with only a small allowable deviation of 0.18 units. The CRE formula has therefore been shown to be valid to predict M40 index of coke produced from coal blends with G-value of about 0.97 and carbonized at a moderate coking time of 18 hours. It has also been shown that the coking conditions that produce the best M40 index also produced the best M10 index.
PILOT SCALE CARBONIZATION STUDIES ON POLISH BELLVIEW COALS FOR METALLURGICAL COKEMAKING
A.O. OLULANA,A.B. ADAHAMA,A.O. ADELEKE,S.A. IBITOYE
Petroleum and Coal , 2009,
Abstract: The pilot scale carbonization of the normally charged bituminous Polish Bellview coal blends wasconducted in a 250kg capacity coke oven with a bulk density of 800kg/m3, flue temperature of 1250°Cand coking time of 18 to 20 hours. The micum drum test conducted on Bellview A and B cokes gaveM10 abrasion resistance of 11.40% and 15.40% and M40 resistance to fragmentation of 77.80% and70.80% for Bellview coke A and B, respectively. The results of this study showed that Bellview A coalblend is of a higher bituminous grade than Bellview blend B, though its micum indices do not meet thespecification of 9% (maximum) M10 and 78% (minimum) M40 for blast furnace ironmaking at theNigerian Ajaokuta steel plant. It is however expected that the small deviations of +2.4% and -0.2%,in the M10 and M40 of Bellview B coke may be eliminated during industrial scale cokemaking under ahigher static load and the application of coking improvement techniques such as pre-heating andstamp charging .
A PREDICTION OF MICUM STRENGTH OF METALLURGICAL COKE USING RUHR DILATOMETRIC PARAMETERS OF PARENT COALS
A.O.Adeleke,A.O. Olulana,A. B. Adahama,R.S. Makan
Petroleum and Coal , 2009,
Abstract: The Polish Bellview, Australian Agro-Allied and American Carbon Energy coals were subjected to Ruhrdilatometric analysis to predict their suitability for cokemaking. The Ruhr dilatometric softening point,maximum contraction, maximum dilatation, maximum contraction temperature and the G-value cokingcapacities were determined from which G-values of 0.97, 0.93, 0.94 and 1.01 were calculated forBellview 1, Bellview 2, Agro-Allied, and Carbon Energy respectively. Also, micum 10 indices of 11.40%,15.40%, 15.40% and 25% and micum 40 indices of 77.80%, 70.80%, 78.20%, and 64.16%,respectively were determined for Bellview 1, Bellview 2, Agro-Allied and Carbon Energy coals. Thestudies confirmed that Simonis’ G-value provides a reliable indication of coke micum strength indices,with the two strength parameters found to be poor at G-values below and above the Simonis’ rangeof 0.95 to 1.15. The analysis results showed that Bellview 1 with the nearly mid-value cokingcapacity of 0.97 has the best combination of resistance to abrasion and fragmentation.
EFFECTS OF PRE-HEATING ON THE MICUM STRENGTH OF COKE FROM A COAL BLEND INCLUDING 5% OF NON-CAKING NIGERIAN OKABA COAL
A.O. Olulana,A.A. Adeleke,A.B. Adahama,S.A. Ibitoye
Petroleum and Coal , 2011,
Abstract: A coal blend consisting of 95% Australian Agro-Allied coal and 5% Nigerian non-caking Okaba coal wascarbonized in a 250 kg capacity coke oven at a flue temperature of 1,250oC by normal wet and preheatedcharging for 18 and 15 hours, respectively. Screen distribution analysis and micum drum tests on thecoke products gave M10 of 24.60% and 9.5% and M40 of 67% and 76.2%, for normal and preheatedcharge, respectively. These results showed that the coke produced from the preheated charge has abetter resistance to abrasion (M10) and fragmentation (M40) and the micum indices obtained are similarto 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 coketo be used for blast furnace operations at the Ajaokuta Steel Plant, Nigeria.
Numerical Computations to Produce Cokeable Coal Blends at The Ajaokuta Steel Plant, Nigeria  [PDF]
A.O. ADELEKE, P. ONUMANYI
Journal of Minerals and Materials Characterization and Engineering (JMMCE) , 2007, DOI: 10.4236/jmmce.2007.62010
Abstract: A mathematical model and its associated numerical search algorithm has been developed for routine coal blending to include local coals for cokemaking at the Nigerian blast furnace-based Ajaokuta Steel Plant. A typical binary blend proposed using the model includes 28.38% and 29.00% of the ash- laden Lafia and non-caking Okaba coals, respectively. The proposed blends satisfy basic chemical and mechanical strength requirements at the lowest cost per ton of coal. The blending calculations showed that only low ash, low sulphur, medium volatile and high vitrinite reflectance prime grade coals such as the UK Ogmore should be imported for blending with the ash-laden medium coking Lafia coal. When the proposed blends are successfully confirmed with bench and pilot scale carbonization tests, cokemaking at Ajaokuta will be conducted with substantial savings in foreign exchange.
A determina??o espectrofotométrica do cobalto pelo método da 2,2'dipiridil cetoxima (II) - escolha do solvente e estudos sobre a extra??o do composto
Jacintho, A.O.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1975, DOI: 10.1590/S0071-12761975000100023
Abstract: this paper belongs to a series of articles about the 2,2'-dipyridyl ketoxime method for the espectrophotometric determination of cobalt. it presents a study on the extration procedure of the color compound formed by using chloroform or dichloromethane. it was established that the former is more efficient than the latter one. the region of maximum absorption of the color compound in chloroform is between 375 and 390 nm. on the other hand, 3.0 ml of the solvent, is sufficient for the extration of the water-soluble chelate obtained from 5.0 micrograms of cobalt, with a shaking time of 15 seconds. the color compound is stabile both in contact with the solutions (120 minutes) and after extration with chloroform (180 minutes).
A determina??o espectrofotométrica do cobalto pelo método da 2,2'-dipiridil cetoxima (I) - estudos sobre o reativo, pH e tamp?o
Jacintho, A.O.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1975, DOI: 10.1590/S0071-12761975000100019
Abstract: the initial studies are presented, relative to the experimental part of the method of the 2,2'-dypiridyl ketoxime, for determination of cobalt. the preparation technique of the reagent from the corresponding ketone was presented. the use of 1.0 ml of the 1% reagent solution in 80% ethyl alcohol was suggested, for the determination of up to 10 micrograms of cobalt. the above solution was tested until 90 days after it's preparation, and no alteration was detected. the best ph conditions, for the formation and extration of the colored compound is between 7.0 and 8.0. among several buffer solutions used, the most efficient was the one prepared with sodium citrate 1 molar, triethanolamina (1+2), in the proportion of 2:1, after ascertaining the ph at 7,8 with 30% citric acid. studies about solvents, effects of several ions and the application of the method to plant analysis, will be presented later.
A determina??o do cobre pelo método calorimétrico do dietilditiocarbamato de sódio
Jacintho, A.O.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1967, DOI: 10.1590/S0071-12761967000100033
Abstract: a study is made on several aspects of the spectrophotometric method for the determination of copper by sodium diethyldithiocarbamate (ddc-na). from this work could be observed that: a) the ideal amount of reagent a 1% of (ddc-na) aqueous solution, was 1 ml and it was observed that the reagent keeps well until 40 days after its preparation. b) the absorbancy of the copper diethyldithiocarbamate (ddc-na) solutions, to a certain limit is independent of the amounts of edta na2. but, in the absence of edta-na2 the amounts of copper added where not recovered, when working with pure solutions. c) among the solvents used, carbon tetrachloride was considered the most appropriate. d) ddc-cu in ccl4 shows maximum absorption in the wave lenght range 430-435 milimicrons. the greatest sensibility was obtained with filters numbers 42 and 44 (klett-summerson). e) interferences of the ions studied were eliminate, by the use of edta-na2 only. f) in this procedure, the ddc-cu is stable until 45 minutes. g) the method obeys beer's law in the range of 5-50 ppm, and shows good accuracy. h) the recommended procedures for the determinations of total copper both in plants and soils by the ddc-na, are considered efficients.
A determina??o espctrofotométrica do cobalto pelo método da 2,2' dipiridilcetoxima (III): .efeito de diversos íons, remo??o das interferências
Jacintho, A.O.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1976, DOI: 10.1590/S0071-12761976000100003
Abstract: in the spectrophotometric determination of cobalt with 2,2'-dipyridyl ketoxime, the effects of several ions were studied. among tre ions studied, only cupric nichelous, ferric and manganous cations interfered. the interference caused by cupric, nichelous and ferric cations was iliminated by a second extraction of the colored compound with a 2n hydrochloric acid solution. the interference, of the manganous cation, disappear when cobalt is determined in the presence of other ions.
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