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By A. Policard

The bodies of mammals possess a very efficient mechanism for ridding themselves of inhaled dust. When the lung is healthy this mechanism works very well, and dust is quickly and completely expelled from the lung either by the respiratory tract or the lymphatics. The mechanism, however, is easily upset, and slight alterations in the condition of the ciliated epithelium or the circulation of lymph are sufficient to interfere with it, therefore the second mechanism comes into play and the dust is fixed and immobilized in some part of the lung. This, however, is not a real cleansing process, since the lung becomes a dust-trap, and may become'pneumokoniotic. The mechanism is protective at first, but later, when the accumulation of dust is considerable, it gives rise to trouble. The lung cannot become, so to speak, a physiological dust-trap, and still retain its normal structure and function; pneumokoniosis begins, which is essentially a disease due to the mechanical presence of large amounts of inert foreign material.

Jan 1, 1947

By A Misra

In pursuit of solving the development rate problem the coal industry has investigated various development systems. While all the systems may improve the development rate they may not necessarily he cost effective. This paper carries out an economic analysis by developing cost models for present and future development systems for retreating longwall faces with particular reference to Australian longwalls. A critical cost analysis of various development systems is presented by taking into consideration all the costs associated with development systems. The costs have been divided into equipment, face and panel services, belt and structure, wages, roof and rib support, ventilation, consumables, power and maintenance. The annualised cost of various equipment has been obtained on the basis of depreciation rates prescribed by the Australian Taxation Office.

Jan 11, 1996

By Z. Sawlowicz

Finely dispersed, primary sulphide mineralisation in the Cu-Fe sulphide zones of copper-bearing shale of the Polish part of the Permian Kupferschiefer is mainly present in the form of framboids and spherules. This type of mineralisation is especially well preserved in organic-rich shale, where it often dominates over a later diagenetic mineralisation that consists of large grains and veins. In microscopic observations special attention was paid to composite grains of copper and iron sulphides. The results suggest that the Cu-Fe and Cu sulphides precipitated in the Kupferschiefer sediment before pyritisation of the framboids had ceased and that they replaced metastable precursors of pyrite. The precipitation of copper sulphides could have been delayed owing to the formation of Cu-organic complexes.

Jan 4, 1992

By Hickling G.

Discussion at the Manchester Geological and Mining Society's general meeting held in Manchester, February 8th 1916, with Mr. Leonard R. Fletcher, President, in the chair, of papers previously published in Trans. Inst. Min. Engrs.,1915, vol. L, p.322 and p.328. Included are a written contribution by Ollerenshaw W. and oral discussion by the author, Gerrard J., Paton J.D., Smith S.A., Stephenson H., Dixon H.O., Pickup W., Fletcher L.R. and Atherton H.S.

Dec 1, 1916

By W. J. Whiten, D. W. Grinsberg

Most cluster analysis techniques are not well suited to the analysis of engineering data as they have been designed for more qualitative data that tend to produce compact clusters. A clustering technique is described which develops and uses local cluster shapes to build clusters that are suitable for use in engineering applications. The technique is finding application in the analysis of many types of data, particularly where multiple trends and outlying points occur in multiple dimensions. Applications of particular interest are the calibration of on-stream analytical equipment and the analysis of data on plant performance. In both cases the multidimensional nature of the data renders manual analysis very difficult

Dec 1, 1991

"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

Discussion of the 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, included questions asked and points for discussion raised by Bramall V., Paton J.D., Fletcher L.R., Siddall F.N., Stoker A. and Stone T., in particular on how to eliminate dust

Dec 1, 1916

By G. Merrington, B. J. Alloway

Tailings from three historical mining areas in the UK were leached in columns under a simulated weathering programme which was chosen to represent periods of 1 and 2 years at 3 different ambient temperatures. The total concentrations of Cd, Cu, Pb and Zn in the primary ore minerals present in the tailings showed only a limited correlation with metal concentrations in the leachate. The leachate from columns of tailings that were maintained at a temperature of 25 (+/-3) degrees C contained, on average, 50% more Pb and 75% more Cu than leachate from tailings that were maintained at a temperature of 10 (+/-3) degrees C. The pH values of leachates from all three types of tailings at 25 (+/-3) degrees C were 0.2 units lower than those from columns maintained at 10 (+/-3) degrees C. The concentration of Cd and Zn in the tailings leachates showed no marked difference at the different temperatures. The composition of the leachate was found to be dependent on the type of gangue mineral, the presence of other sulphide minerals and the formation of secondary iron minerals. A comparison of the concentrations of heavy metals in the leachates produced in the laboratory with those in leachates that were collected in the field over a similar period of time from two of the mine sites showed that concentrations were of a similar order.

Jan 8, 1993

The mineralogical composition of the ore was determined and the mineral phases with which nickel is associated were identified. The ore was prepared by grinding to -420 micrometres and classification into granulometric fractions. Prior to the main series of experiments the effect of agitation rate on nickel recovery was investigated. The influence of sulphuric acid concentration, temperature and particle size on the kinetics of nickel extraction was then studied, both quantitatively and qualitatively, over fixed value intervals. Application of the initial rate method enabled determination both of the order of reaction with respect to sulphuric acid concentration and the activation energy for the dissolution of nickel. The results indicate that a physical mechanism can be ruled out as the rate-determining step in the extraction of nickel from the ore and that a chemical mechanism is more likely

Dec 1, 1991

By Fergusson E.

An account is given of the history and operation of the Straits Tin market and the Penang price. The procedure by which the official ruling tin price is determined is presented and the way in which bids are treated is outlined: the price declared in Penang is the result of a joint operation by the two Malaysian smelters and is arrived at by finding the highest price at which the whole of the day's offerings for sale can be sold, thus reflecting the marriage of the offerings of the individual mine producers with the demand for Straits Tin from the consuming countries of the world. A system of accurate weighing, sampling and assaying of concentrates delivered to the smelters' premises enables the various ore-buying agencies of the two smelters to notify their central offices promptly of the estimated tin content of the concentrates their customers wish to price that day, so that by 11.00 a.m. both smelters will have exchanged with each other figures giving the total quantity of metal they have for inclusion in the day's market, at the same time exchanging particulars of the bids they have received. Miners are encouraged to sell regularly for cash and an evenness is thus achieved which avoids large daily fluctuations in overall quantity.

Dec 30, 1971

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 L. Wade, R. Wang, M. A. Horton

Laboratory methods to find the mechanical properties of rock are inherently biased towards stronger strata, which best survive the sample preparation process. Geophysical techniques are not subject to such bias and may be used to predict mechanical properties rapidly and cheaply. Samples (151) were obtained from a borehole that had been comprehensively geophysically logged. The mechanical properties of the samples were established in the laboratory and correlated with the geophysical responses of the strata from which they came. The results indicate that, for homogeneous strata at least, it is possible to predict the unconfined compressive strength reasonably well from sonic travel time measurements made in the field. Predictions of static Young's modulus may also be made from this data source, but with a lesser degree of confidence. A multivariate regression equation is presented which relates down-hole sonic travel time to unconfined compressive strength, depth and the frequency of fractures in the rock mass. This equation may offer potential for the prediction of the mechanical rock properties of fractured and layered strata.

Jan 4, 1993

By P Cochrane

Our ability to generate information and transport it about the planet on super highways of optical fibre is about to change the way in which we communicate, work and live. There is not a single aspect of our future that will go untouched by the communication and computing revolution that Is now upon us. The change we are about to witness will overshadow the impact of the printed word, industrial revolution and physical transport. The next major wave of information technology (TT) development will focus on the delivery of information and experience on demand, in the right form, at the right time, at the right price, to fixed or mobile terminals anywhere, over networks of optical fibre, radio, satellite and optical wireless. Bandwidth, distance and time will no longer be significant cost elements as service and access become dominant.

Jan 7, 1996

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 Tawsaporn Nuchanong, Ian Nichol

Investigations of the dispersion of gold in soils and stream sediments associated with three gold deposits in Thailand indicate the existence of different geochemical dispersion patterns in the three areas, demonstrating the need for the adoption of a variety of exploration techniques. The three gold deposits which were investigated were the Phu Tham Phra-Phu Thong Daeng copper-gold prospect, the Doi Tung and the Huai Hin Lab gold prospects. Overall the investigations at the three localities demonstrate clearly that the chances of exploration success can be significantly enhanced if composite soil samples are analysed to ensure a more reliable estimation of the gold content in soils and if both the 63 micrometre fraction and the field-panned concentrates of stream sediments are analysed because of the variable grain size of the gold characterising different gold deposits and surface environments.

Jan 4, 1992

By A. D. Read

Selective flocculation was investigated as a possible method of recovering values from mineral slimes which are too finely divided to be treated by conventional mineral processing methods. It has proved possible to flocculate selectively either haematite or a silicate from a stably dispersed mixture by varying the anionic character of the high-molecular-weight, partially hydrolysed polyacrylamide employed. Different separation methods have been developed for hard and soft water media. Electrokinetic and infrared techniques have been employed to elucidate the mechanism whereby selectivity has been attained in the different cases. The following influences on the various selective flocculation parameters have been investigated: (a) the level of the different reagent additions and (b) the shear conditions during and after flocculant addition. A feature of the particular system studied was the high solids content at which it was possible to achieve good selectivity. Probable reasons for this are advanced, and the possibilities and potentialities of the process are discussed.

Dec 1, 1971

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

By R. Phillips

The low concentration of diamond in workable deposits requires very large samples for grade estimation, and results, even then, may be erratic and difficult to interpret. Although the Poisson probability distribution cannot accurately describe the occurrence of diamond, it is suggested that it gives a better estimate of grade than conventional methods, even from single samples. Examples illustrate the simple calculation required.

Dec 1, 1971

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

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

Jan 1, 1947