Spelling suggestions: "subject:"bickel metallurgy"" "subject:"dickel metallurgy""
1 |
THE RELATIONSHIP BETWEEN ROLLING TEXTURES AND ELASTIC MODULI OF POLYCRYSTALLINE THORIATED NICKEL FOILSStokes, James Leroy, 1934- January 1969 (has links)
No description available.
|
2 |
Leaching of low grade nickel laterite ore from Waterval mine in Mpumalanga through electrochemical processRadingoana, Precious Manti January 2014 (has links)
M. Tech. Chemical Engineering / The depreciation of high grade sulphide ores has resulted to the use of low grade laterites to meet the global nickel demand. Available low grade laterite ore reserves in South Africa are underutilised. Suitable metallurgical process for recovery of nickel from these reserves is not yet implemented because the mineralogy is not well understood. Hence, in this research the mineralogy and recovery of nickel from low grade laterites was studied through electrochemical process. The research shows that it is feasible to selectively recover nickel from the low grade laterite ore using electrochemical leaching method. It is recommended that optimization of the electrochemical cell design be looked into to evaluate the possibility of scaling up for industry application.
|
3 |
Nickel recovery from reject lateriteGoodall, Graeme. January 2007 (has links)
Falconbridge Dominicana C. Por A. operating in the Dominican Republic produces nickel as an iron-nickel alloy from laterite ore. Material that is rejected from their mining operations due to its incompatible chemistry is currently being stockpiled against mine depletion. Recent interest in recuperating nickel from this reject material led to the examination of the suitability of carbothermic reduction followed by magnetic separation for nickel recovery from this reject ore. Five parameters were considered in a Design of Experiment framework, namely: heating time; temperature; material type, coke addition and oxygen partial pressure. Magnetic separation was conducted with a Davis Tube and a low intensity hand magnet. / It was found that this reject material can successfully be treated using a carbothermic reduction process to produce 50 to 75 mum diameter metallic components within a gangue matrix. The recovery of nickel ranged from 61.7% to 21.9% to 16.4% in the high, low and non magnetic fractions, respectively, separated from the reduced material. The grade of nickel ranged from 1.97 wt% Ni to 1.58% to 0.75 wt% Ni in the high, low and non magnetic fractions, respectively. / Heating temperature had the greatest positive influence on the performance of the process followed by material type and heating time. Oxygen activity and coke addition were seen not to influence the performance. The Boudouard reaction was considered to be the rate controlling step and a maximum possible operating temperature was considered to depend on the physical properties of the material, specifically the softening temperature.
|
4 |
Nickel recovery from reject lateriteGoodall, Graeme January 2007 (has links)
No description available.
|
5 |
Reduction roasting and sulphuric acid leaching of nickel from garnieriteClarkson, Christopher John. January 1974 (has links)
No description available.
|
6 |
Ni²⁺ extraction from low grade leachate of tailing dumps materials using cloned indigenous bacterial speciesFosso-Kankeu, Elvis 02 November 2012 (has links)
D.Tech. (Extraction Metallurgy) / Please refer to full text to view abstract
|
7 |
An attempt into identification of suitable recovery process for nickel value from nickel sulfide ore and tailingsMadiba, Mapilane S. 25 November 2013 (has links)
M.Tech (Metallurgy) / Nickel in South Africa is scarce. Other than as a by-product from platinum mining, its only source is the Uitkomst Complex, a satelite of the Bushveld Igneous Complex, located between Machadodorp and Barberton and mined by Nkomati Nickel. Pentlandite occurs as the main nickel-bearing mineral, disseminated within a sulfide matrix of pyrrhotite, pyrite and chalcopyrite. Accessories are of chromite and platinum in solid solution with the sulfides. The sulfides are hosted in mainly ultramafic rocks. The presence of talc is of particular nuisance. Head grade is in the decline, from earlier 0.7 to more recently 0.3% or even lower. Standard froth flotation yields a concentrate of 7 – 9% nickel at a recovery of up to 70%. A higher nickel recovery from such low – grade feed stock would be desirable. To achieve these two methods were investigated and reported in the following: Non-oxidative leaching as an alternative to flotation, using strong hydrochloric and sulfuric acid and also aqueous ammonia solutions at various liquid-to-solid ratios. Only the degree of nickel dissolution over time at room temperature was studied and no attempt was made to recover the dissolved metal from solution. Froth flotation after pre-treatment with microwaves at various power levels and over various periods of time of irradiation. It was surmised that a certain amount of inter-granular cracking could thus be achieved that would improve the flotation behavior in respect of grade and recovery. An extensive literature study, in particular, of the nature of microwaves, their interaction with matter and possible metallurgical benefits derived as a consequence of such interaction, forms part of the investigation and is reported in detail. A lot of theoretical and experimental work has been done in this respect, although the obtained results were not conclusive.
|
8 |
Acidified ferric chloride leaching behaviour of a complex Ni – Cu matte at atmospheric pressureSekhukhune, Lehlogonolo Mokgadi 10 April 2013 (has links)
M.Tech. (Chemical Engineering) / Please refer to full text to view abstract
|
9 |
Reduction roasting and sulphuric acid leaching of nickel from garnieriteClarkson, Christopher John. January 1974 (has links)
No description available.
|
10 |
Kinetic and mechanistic studies on the biological and chemical leaching of nickel from sulphide ores.Corrans, Ian James. January 1974 (has links)
The aim of this investigation was to extend the knowledge of the
bacterial leaching of copper and zinc sulphides into the area of
nickel sulphide leaching.
By far the major portion of both theoretical and practical
expertise which is available in the field of bacterial leaching
is based on the treatment of copper and zinc sulphides. As yet
there is little information available on the bacterial leaching
of nickel sulphides to meet the growing interest in this field
both in South Africa and elsewhere.
To a large degree, it was necessary to start from basic principles
in this novel extension of bacterial leaching technology so that
the work covers a fairly wide field in general rather than one
particular aspect in detail.
A strain of 'nickel adapted' Thiobacillus ferrooxidans was
isolated from the tailings dam of a disused nickel mine. The
growth characteristics of this strain were studied in some detail
on sulphur using both batch and continuous techniques. This was
done as it was considered that growth on sulphur would provide
useful information which could be correlated with the mineral
leaching results.
The mineral pentlandite (NiFeS2) was chosen as the one with which
to work because of its economic importance. This was prepared in
a highly purified form from a concentrate of the Rhodesian
Shangani deposit.
Bacterial leaching tests in both batch and continuous operation
were then carried out in order to define the effects of various
physico-chemical parameters on the leaching of nickel from this
mineral. As a preliminary to these tests, a detailed chemical
kinetic study in the absence of bacteria of the leaching of
nickel was carried out using similar physico-chemical conditions.
The results of the bacterial and chemical leaching tests were
then compared and used to postulate a mechanism and model for
the process.
It was found that the rate of leaching of nickel from pentlandite
in acid ferric sulphate solutions was directly proportional to
the concentration of ferric ions and speed of agitation of the
stirrer and to the square root of the oxygen concentration. The
form of the rate expression was interpreted in terms of a mixed
diffusive and chemical rate controlling mechanism.
Bacterial growth rates on flowers of sulphur were found to be
controlled by the rate of dissolution of oxygen from the gas
bubbles into the bulk solution. When this latter condition was
made non-rate limiting, it was found that growth rates were still
dependent on the rate of agitation, implying mass transport
control by another mechanism.
The batch bacterial leaching results showed a linear pattern of
nickel leaching and bacterial growth, with a marked dependence on
oxygen concentration and rate of agitation. A mechanism in
accordance with the batch data was postulated, which proposed
that the rate of bacterial leaching was proportional to the
concentration of bacteria attached at the mineral surface and
to the square of the oxygen concentration. The rates of
bacterial leaching were computed by taking the difference between
the overall measured leach rate and the chemical leach rate based
on the chemical kinetic data.
The leach rates in continuous bacterial leaching were higher than
those predicted from the batch data. This effect was interpreted
in terms of higher specific growth rates being achieved in
continuous operation.
An economic assessment was made of the process based on the
optimum leach rates obtained in continuous leaching and found to
show some promise. / Thesis (Ph.D.)-University of Natal, Durban, 1974.
|
Page generated in 0.0433 seconds