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Jan 1, 1947

Summary of the morning's events with a Written Contribution to Paper No. 4 and author responses

Jan 1, 1947

By D. F. Ball, P. R. Dawson, J. T. Fitton

Report of discussion at December, 1970, IMM general meeting (Chairman: M. J. Cahalan, President) and contributed remarks on the paper published in Transactions/Section C (Mineral Processing & Extractive Metallurgy), vol. 79, September, 1970, pp. C189-96, plus the authors' replies. Contributors included Cohen E., Hope B., Wasse D.G., Shakespeare A.G., Burwood D.S., Jones H.A., Dartnell J., Carter G.C., Henderson T.A., Relf G. and Clark S.W.

Dec 1, 1971

By Asfa-Wossen L.

Davy saw science to be the ultimate truth. He loved the utility and permanence of it and the feeling of progression. He was a bold chemist and an inventor, but he thought like a writer

Feb 1, 2015

A study of the thermodynamic properties of magnesium chloride ammines was carried out with the ultimate objective that the thermal decomposition of the hexammine MgCl2.6NH3 may prove successful on a commercial scale for the manufacture of anhydrous magnesium chloride, which is required for the efficient electrolytic production of magnesium. The experimental data are presented in the form of an equilibrium diagram that aids the understanding of the conditions associated with the thermal decomposition of ammines

Jun 13, 1905

By M. J. Matos, W. Patruk

The correct version of Equation 1 is represented and Tables 3 and 6 are revised to consider all size fractions, including those coarser than 300 micrometres, in calculating the total liberation from King's fractional liberation

Jun 18, 1905

By L. J. Barnes, R. O. Koch, J. H. Versteegh, P. J. H. Scheeren, F. J. Janssen

Following two years of laboratory research with bench scale reactors, a 9 m3 experimental process demonstration reactor was installed at Budelco's zinc refinery to treat their underlying groundwater. A 600-fold scale-up was successfully achieved. It has demonstrated that this anaerobic microbial process can remove a wide range of heavy metals and sulphate to the required levels. Extended operation of the demonstration unit has shown that the process is robust, can withstand wide variations in feed composition, rapidly recovers from operational upsets and is easy to start up and shut down. The metal sludge produced can be processed in a metal refinery to recover both metals and sulphur.

Jan 12, 1992

By H. L. Shergold, O. Mellgren

The conditions of amine concentration and pH necessary for the concentration of fine haematite particles at the iso-octane-water interface have been determined. Results obtained from the related studies on the effect of pH and dodecylamine concentration on the adsorption density, electrokinetic potential, contact angle and concentration of various amine species in the system are included. A good correlation was obtained between these different variables. Maximum concentration of haematite at the oil-water interface was obtained when the haematite zeta-potential was small or equal to zero

Dec 1, 1971

By R. E. T. Hill

"A laboratory study was undertaken to determine the condensed equilibrium phase relations at 600°C in that portion of the quaternary Fe-Ni-Cu-S system which lies in the neighbourhood of the monosulphide solid solution (MSS). The study sought to determine to w hat extent copper affects the temperatures of stability and compositions of iron-nickel sulphides in bulk compositions similar to those of massive Fe-Ni-Cu ores. Experimental data, including stable phase assemblages and phase compositions, are presented.In the quaternary system at 600°C MSS forms stable phase assemblages with pentlandite, chalcopyrite solid solution, pyrite and vaesite. Over the range of bulk compositions displayed by natural ores copper as well as metal/sulphur ratio have a significant effect on the thermal stability of pyrite and pentlandite. Errors therefore accompany the widespread practice of ignoring copper or chalcopyrite when the mineralogical and compositional changes that have accompanied the initial cooling of primary magmatic sulphides or their subsequent homogenization during isochemical metamorphism are being deciphered. These errors are most significant for ores the bulk compositions of which lie tow ard the sulphur-deficient side of the cupriferous MSS. Temperatures as much as 300°C above the copper-absent value are possible for the interpreted upper stability limits of pentlandite in these ores.The experimental data show that up to 2.0 at% copper can occur in pentlandite stable at 600°C in a bulk composition equivalent to natural magmatic ores. This is equivalent to nearly 10 vol% chalcopyrite. Pentlandite contains more copper than coexisting MSS and the copper content of both phases increases with increasing iron."

Jan 1, 1984

By Emanuel Shinwell, Douglas Hay

"Opening statements relating to the health and welfare of underground workers and the nature and prevention of silicosis and pneumokoniosis. During 1945-47, 10,500 UK coal-miners were certified by the Silicosis Medical Board to be suffering from pneumokoniosis and suspended from work in the industry. Over 80% of cases occurred in the South Wales coalfields. Silicosis and pneumokoniosis also occur among metalliferous miners, such as the tin-miners of Cornwall. The slate-quarries of North Wales are also troubled by these conditions as are the haematite mines of the North-West of England."

Jan 1, 1947

Discussion at the The Midland Counties Institution of Engineers' general meeting, held in Nottingham on 6th May 1916, included contributions by Bramall E., Bragge G.S. and Watkins W.G. regarding possible measures for reducing energy consumption in coal-winding and pumping by centralising engines, using exhaust steam, improving coal quality and size uniformity, or mechanical stoking

Dec 1, 1916

By Dickinson C.

Discussion at the The Midland Counties Institution of Engineers' general meeting held in Nottingham on 6th May 1916, on the paper published in Trans. I.Min.E., vol.XLVIII, 1914, p.400, included brief oral contributions by Bragge G.S. and Hepplewhite W.H. with the author's responses regarding leakage and boring of cement into the coal

Dec 1, 1916

By M. L. Schmulian

"The Windarra nickel deposits display many of the characteristics that typify Archaean volcanic peridotite-associated nickel sulphide ores of Western Australia. The Fe-Ni-Cu sulphide mineralization, which comprises dominantly disseminated sulphides, occurs at the base of a differentiated ultramafic volcanic pile grading upwards from massive meta-peridotitic flows to thin, locally spinifex-textured meta-picritic units. The entire mafic-ultramafic belt has been subjected to mid-amphibolite- facies metamorphism. The ore-bearing ultramafic is immediately underlain by dominantly sulphide-facies banded iron formation (BIF), which commonly contains nickel sulphides adjacent to its contact with mineralized ultramafic. BIF-hosted ores are formed both by physical remobilization of ultramafic-hosted sulphides and by migration of Ni and Cu into pre-existing iron sulphides.At Mt. Windarra the mineralization comprises eight steeply dipping, steeply plunging elongate oreshoots, which display a marked parallelism with major and minor fold structures in the underlying BIF. Seven of the shoots occur at or close to the base of the ultramafic pile, and are hosted by at least three overlapping flows. The zone of overlap occurs at the northern end of each flow, where picritic ultramafic, representing a dominantly liquid portion of the flow, occupies the basal contact. A gross south- north ultramafic flow direction is inferred. The eighth shoot occurs in a stratigraphically higher position within the ultramafic sequence.At South Windarra at least two overlapping mineralized flows occupy the basal contact, the ore zone having a strike extent three to four times its downdip extent. There is no obvious structural control to the mineralization."

Jan 1, 1984

By R. G. Jones

Chris Hinde talks us through his career from BSc in Mining Engineering to roles with Golder Associates, Schroder Securities, Mining Journal and SNL. He discusses the issues facing the mining industry.

May 1, 2015

By G. J. Lyman

Mayer curves are used for process calculation in coal preparation. They can also be used to smooth washability data by fitting a hyperbola of particular properties to ash and yield, but to introduce the density variable an independent relationship with ash content must be adopted. When this ash-density relationship has a realistic form at low density, the implied form of the mass distribution function is unrealistic, suggesting that Mayer curves represented by a hyperbolic functional form are unsuited to coal washery calculations for low-density separations. Their use at higher densities is also uncertain. A similar conclusion can be anticipated when Mayer curves are used for other mineral systems.

Jan 8, 1992

By J. R. Budden, P. A. Spencer, J. Barrett

The initially produced arsenic (III) is very toxic to the unconditioned culture but the mixed culture has the capacity to oxidise it to arsenic (V) in the presence of iron (III). It was possible to build up the resistance of the culture through progressive sub-culturing on arseno-pyrite until it could tolerate steady-state concentrations of 30 mM arsenic (III) and 200 mM arsenic (V). With some samples tested in the continuous systems the final arsenic concentrations reached 330 mM. It proved possible to use the laboratory batch data to establish the optimum operating conditions for continuous test systems with capacities of up to 32 m3. Data on the residence time, oxygen uptake rates and gold extraction from the bio-oxidised residues could then be confirmed by continuous testing without the need first to use empirical means to determine optimum conditions for continuous bio-oxidation. The data on residence time, oxygen uptake rate, solids density and neutralisation could be used to estimate the capital and operating costs of treating any given tonnage of the concentrate of interest. It was established that the arsenopyrite concentrates can be suitably bio-oxidised to cause the liberation of at least 90% of the gold content. The method is simple to operate and is flexible over a wide range of external conditions

Apr 1, 1991

By J. V. Wood, P. Davies, J. L. F. Kellie

A new range of wear-resistant materials is being produced by technology that has been used to develop high performance metal-matrix composites. These include steels and aluminium alloys that can be made as sheet, plate, rod or bar. The incorporation of hard, wear-resistant particles in an alloy matrix is achieved by reactive casting, spray deposition and powder metallurgical techniques. For example, large particles of TiC can be homogeneously distributed in steel during casting and the subsequent product can easily be rolled to plate. Similarly, up to 20% alumina particles and SiC can be injected, respectively, into steel and wear-resistant aluminium alloys by spray deposition. The current state of development of the process is reviewed and indications are given of the projected applications of such materials.

Jan 12, 1992

Jan 1, 1947

Jan 1, 1947

By G. Mellgren, O. Mellgren

The conductivity of a solution is often used industrially to control the salt concentrations of reacting systems, normally using electrodes made of glass fitted with platinised platinum electrodes. When a standard platinum conductivity electrode was used to control the acid fed to the leaching circuit for an ilmenite flotation concentrate at Titania, Norway, a deposit of calcium sulphate (containing some calcium phosphate) covered both the platinum electrode and the external glass fitting, rendering the electrode inefficient in the course of a few minutes. A new electrode consisting of a casing, two measuring tubes and an electrode stem is described and illustrated. A significant advantage of its design is that the useful range of conductivity measurement can be adjusted by adjusting the concentration of the electrolyte in the electrode. It has been in use at Titania for about four years with an electrolyte consisting of 0-1 n HCI. It is robust and demands little maintenance.

Dec 1, 1971