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By Hirsch H. H.

The paper, presented at the North of England Institute of Mining Engineers' general meeting held in Newcastle-upon-Tyne on 12th February 1916, gives a short description of the Hirsch lamp, which, though largely used in the United States of America, has not yet been adopted in Great Britain. The lamps, which consist of (1) the watchman's lamp and (2) the miner's lamp, are portable, and have been designed to provide a safe and reliable light for use by watchmen, and in mines, rescue-work, powder-works, oil-refineries, and other places where special precautions become necessary on account of the presence of explosive materials or gases. The lamps are in each in­stance operated by a storage-battery contained within a casing, and this supplies the current necessary for a miniature incandescent lamp. Each safety-lamp forms a complete unit and can be carried from place to place or held in any position. Appendices give details of battery cleaning, test results and safety reports

Dec 1, 1916

By Ruddle R. W.

Magnetite occurs in the reverberatory furnaces, blast furnace and converter (a) as the result of its presence in the materials charged, and (b) as the result of oxidation of the FeS in the charge in the absence of sufficient SiO2 to slag the FeO as it is produced and thus prevent its subsequent further oxidation. Magnetite is reduced by FeS according to FeS+3Fe3O4=10FeO+SO2 and similar reactions. This reaction is markedly affected by temperature and does not proceed to any important extent below about 1200°C. To ensure comparative freedom from magnetite it is therefore necessary to raise the temperature of the furnace to the highest practicable figure and to use plenty of siliceous flux. Since the maximum operating temperature is likely to be limited by the resistance of the refractories to attack by the slag, investigation of the factors affecting this attack should be helpful. It is reasonable to suppose that the formation of magnetite might be minimized by ensuring intimate admixture of matte and slag during conversion so that silica is readily available for combination with ferrous oxide as the latter is formed. The literature gives no clue to the importance of this factor and some experimental work on this aspect might be fruitful

Jan 1, 1953

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 N. Djordjevic

It is commonly accepted that the strength of rock measured from small samples tends to give unrealistically high estimates of the strength of larger samples, in situ blocks of rock or the rock mass in situ. The Weibull theory of the statistical strength of material provides a possible means for calculation of the strength of large rock volumes, based on the routine testing of small samples. Application of the Weibull approach to estimation of the strength of Moura coal showed an encouraging agreement with experimental results and the method was also applied to hard-rock andesitic and porphyry ore from Bajo de la Alumbrera, Argentina

Jun 21, 1905

By ed. comp., S. H. White, A. J. Naldrett, P. R. Simpson

Peter Simpson's introduction, Tony Naldrett's concluding remarks and discussion by Prof. White of D.M.A. Flight's report of the proceedings are presented from the conference held in Keyworth, UK, in April 1992

Apr 1, 1995

By D G. Oldfield

Pall has developed and supplied to several airlines cabin air libers to provide clean air for passengers and crew in flight, while reducing airline operating costs. Most of today's modern commercial passenger aircrafts employ cabin air recirculation as a means of reducing operating costs. With large numbers of passengers being subject to an increasing proportion of recirculated air for hours at a time, the matter of cabin air quality, with particular respect to the health effects on passengers and crew, has to be addressed. Commercial pressure will ensure that the airlines and aircraft manufacturers will not revert back to the total fresh air systems of the 1960s and 1970s. In fact, feasibility studies are already being undertaken to look at increasing the proportion of recirculated air to 80% and above. With the application of specialist nitration technologies. Pall is able to ensure that the requirements for economy are met whilst ensuring that the air is effectively rendered as 'fresh air’ each time it is recirculated.

Jan 9, 1996

By J. A. Saunders, E. L. Rowan

It is now widely accepted that the metal-rich waters found in the oil wells are possible present-day analogues of the mineralising solutions that formed the Mississippi Valley-type (MVT) deposits throughout mid-continental USA and elsewhere. A study characterising the trace-metal content provides additional circumstantial evidence for a genetic link between sediment-hosted mineral deposits and basin brines: Ag, Co, Ni, As and Mo, detected in the scale, are locally present in accessory minerals in MVT deposits and the levels of Ag found in the wells support the conclusion that sedimentary sources for silver should be considered in evaluating the origin of Pb-Zn-Ag deposits in sedimentary terrains

Jun 12, 1905

By G. D. Nicholls

There have been very few attempts to isolate the various factors that contribute to the overall imprecision of geochemical analytical procedures, due in part to the difficulty of distinguishing between them. The technique of spark source mass spectrography permits a ready distinction between the contributions to overall precision from sampling error and instrumental and other errors. With conventional methods of sample preparation for this technique sampling difficulties are responsible for 80-90 per cent of the overall imprecision. Examination of the probable location of the major difficulties in sample preparation indicates that the preliminary stage of grinding, mixing and extraction of a first aliquot (about 1/100 of the original sample) is generally perfectly adequate. The difficulty lies in the subsequent stages of sample preparation. Dry mixing techniques are unlikely to give good precision if the sub-samples actually examined by the analytical technique are less than 10 mg in amount. Solution techniques are less prone to sampling difficulty. Fusion techniques, unless conducted with great care, can produce more difficulty than dry mixing. Sample preparation is critical to the success of many analytical procedures. Selection of appropriate sample preparation techniques requires just as much care as the selection of techniques for the actual analysis.

Dec 1, 1971

By M. D. Pritzker

Shrinking-core models are used to describe the physico-chemical processes that are associated with many metallurgical gas-solid and liquid-solid reactions. The models can be used to evaluate rate constants and effective diffusion coefficients from experimental data. This work generalises the model for diffusion through a product layer to cases where the transport of more than one species is rate-controlling

Jul 1, 1991

By G Fakes

This paper describes the history of civil engineering tunnelling and developments in soft ground techniques during the 19th and 20th centuries, culminating in the design and use of high speed tunnelling machines for all types of ground conditions. Some of the problems encountered are outlined, and descriptions are given of some contemporary developments in rock tunnelling techniques, with comparisons of methods used in the mining industry.

Jan 5, 1996

By Winmill T. F.

Paper presented at the at the Institution of Mining Engineers' general meeting held in London on 8th June 1916: In a previous paper it has been shown that the rate of absorption of oxygen by coal is neither directly proportional to the surface area of the coal exposed nor to the percentage of oxygen in the air. Further experiments are now described supporting this conclusion

Dec 1, 1916

Two of the most important economies in coal-washing are in the actual washing of the coal and in a proper lay-out to reduce to a minimum the cost of labour for handling and washing. A guarantee is usually required for turning out a washed coal containing not more than 2% of free dirt and a resulting refuse with not more than 2% of free coal; any plant that gives results within such guarantees can he considered economical, provided that there are no other losses during the washing process. Various drainage arrangements and washery lay-outs are illustrated and discussed with respect to drainage, bunkers, sieves, settling tanks and conveyors and two further points considered: siding accommodation, which may become quite important with washeries of large capacity especially when the coal is brought in railway-wagons; and the irregularity with which the coal arrives. (Paper presented at the Manchester Geological and Mining Society's general meeting held in Manchester, April 11th 1916, with Mr. Leonard R. Fletcher, President, in the chair)

Dec 1, 1916

"Prior to the publication of the General Report of the Miners' Phthisis Prevention Committee of South Africa in 1916 little attention was paid to the dust hazard and the necessity for its suppression in the underground workings of the Broken Hill mines. Such precautions as were observed for the elimination of dust were related rather to the prevention of lead poisoning, which, in the early days of Broken Hill when large tonnages of lead carbonate ore were being won, was rather prevalent. Ventilation and hygiene followed the general practice in this and most foreign countries.This paper covers incidence and action since 1918, considering medical aspects and operating aspects. "

Jan 1, 1947

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

Jan 1, 1947

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 Garforth W.

The chairman announced the new government duties of the out-going President, Sir Thomas Holland, and the formation of a new standing committee on mining to advise the Advisory Council for Scientific and Industrial Research on suitable projects for grants. Some of the potential lines for investigation into the best methods of winning and presenting coal in the best commercial condition include wasteful practices in operating steam boilers, national loss due to neglecting recovery of coal by-products, and the leaving of large areas of coal for fear of spontaneous combustion or as boundary pillars and support

Dec 1, 1916

By J. P. Ress

In 1903, seventeen years after mining of the Witwatersrand gold-bearing reefs started, the findings erf the Miners' Phthisis Commission (Transvaal) resulted in the initiation of measures with the object of controlling dust production. The substance of these measures was as follows: Removal of persons from places where they would be exposed to blasting fumes; use of water to suppress dust made in drilling and in other operations; supply and control of air to working-places; filtration of dusty air; and determination of the amount of the dust in the air. Broadly speaking, progress in dust control has followed these four lines with increasing success as the nature of the problem has become better known. Complete success has not, however, been achieved, partly because increasing mechanization of mining has intensified the problem and partly because the application of these measures is not infallible, being subject, in many cases, to human control. A brief summary of the development of these measures will lead to a description of present-day practice.

Jan 1, 1947

The author's written response to previous discussion of his paper published in Trans. Inst. Min. Engrs.,1915, vol. L, p.51, discussion p.431, was presented at the Mining Institute of Scotland's general meeting held in Edinburgh on 12th February 1916 with D.M. Mowat in the chair

Dec 1, 1916

By B. Denby

sintered ores, to be removed by a pneumatic,

Apr 1, 1995

By J. Gough M. D.

There are many points still obscure regarding the nature of coal-workers'- pneumokoniosis, but the interpretation of the disease has been greatly clarified in recent years. It is now known that exposure to fumes or gases or other conditions peculiar to coal-mining are not necessary factors in the production of pneumokoniosis. The same disease occurs in coal-trimmers working in the docks, and it is thus established that the inhaled dust is the primary factor. On the other hand, there is no completely satisfactory explanation of the distribution of the disease. Geological and petrological studies have not given an unequivocal explanation of the difference in incidence in different parts of the coalfield. It is an open question whether the quantity of dust inhaled is more important than its chemical composition. However, there is ample evidence from the medical side that elimination of dust and of tuberculosis from the environment of coal workers will be required to prevent pneumokoniosis. Much is being done with regard to elimination of dust, and a similar energetic action is required in regard to tuberculosis.

Jan 1, 1947