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By T. Sterry Hunt

In a paper presented to the Institute in 1881* I have discussed at some length the question of the " Hydrometallurgy of Copper," and among others, have noticed two methods, devised and patented by Mr. James Douglas and myself, for the extraction of copper

Jan 1, 1888

By J. H. Tylczak, R. Blickensderfer, D. J. Singleton

As part of its research on wear of mining and mineral processing equipment, the US Bureau of Mines evaluated the erosion-corrosion characteristics of 12 alloys in phosphoric acid waste water. Tests were conducted on 2- and 5-cm-diam specimen8 in 12- and 60-cm-diam ball mills by grinding phosphate rock in gypsum pond water with an initial pH of 1.6. For comparison, grinding tests also were conducted in tap water. Static corrosion tests in gypsum pond water also were carried out. For all alloys tested, the wear by erosion-corrosion was greater than the sum of erosion plus static corrosion. A low-alloy, high-carbon steel and a high-manganese, nitrided stainless steel were the most cost-effective materials

Jan 1, 1987

By Zhou Yanwen, Fudong Wang, Shing Liu

Mixed CrB2 and MoS2 powder (Cr:Mo=1:1 atomic %), without any further process, were used as the targets to be sputtered and deposited onto stainless steel and silicon substrates by pulsed DC power supply. The structures and properties of the CrBMoS films were then analyzed by using SEM, XRD, micro-hardness tester. The SEM morphology of the films showed dense, defect free structure, and the preferred orientations of the films were CrB2 (111) and MoS2 (200) according to XRD spectra. The thicknesses of the films were measured and the relationship between the deposition rates and pulsed factors was determined. The films, with the micro-hardness as high as 19GPa and friction coefficient as low as 0.02, could be considered to be the hard solid lubricant films.

Jan 1, 2015

By D. Hopkins, D. Türler, R. D. Giauque, W. B. Davis, M. Karaca

In a highly collaborative research and development project with mining and university partners, sensors and data-analysis tools are being developed for rock-mass characterization and real-time measurement of mineral content. Determining mineralogy prior to mucking in an open-pit mine is important for routing the material to the appropriate processing stream. A possible alternative to lab assay of dust and cuttings obtained from drill holes is continuous on-line sampling and real-time x-ray fluorescence (XRF) spectroscopy. Results presented demonstrate that statistical analyses combined with XRF data can be employed to identify minerals and, possibly, different rock types. The objective is to create a detailed three-dimensional mineralogical map in real time that would improve downstream process efficiency.

Jan 1, 2002

By L. P. Teas

The main facts brought out by the study of the blende-bearing ores examined are as follows: 1. Chalcopyrite as minute triangular or rectangular dots, or as

Jan 1, 1918

By S. T. L. Harrison, J. R. Amaral Filho, M. Smart, J. Broadhurst, J. Weiler

Technosol production from mine waste, following amendment with additional organic residues, to provide healthy and functional topsoil is an advantageous alternative to the long-term dump disposal of mine waste. Minimising the legacy of mine waste and supplying soil for mine site rehabilitation contributes towards more sustainable mining practices. Following the creation of the physicochemical structure of the soil from appropriate mixtures of coal waste with low sulfur content, physical ameliorants and nutrient sources, the inoculation of Technosols with active microbial suspensions may accelerate the decomposition of organic matter present and ensure nutrient availability for plant growth through active nutrient cycling, particularly of nitrogen, sulfur and phosphorous. In this paper, South African ultrafine coal waste was used as the main mineral matrix, and malt residue was used as source of organic matter and nutrients. In order to evaluate the effects of Technosol inoculation, five microbial treatments were used, including the addition of: commercial grade efficient microorganisms (EM Prosoil), anaerobic digested sludge supernatant from treating brewery waste, and ‘tea’ extracts prepared from compost, vermicompost and soil native to the mining area. Growth experiments were carried out using Eragrostis teff, commonly known as teff, a grass typically used for the rehabilitation of mined areas in South Africa. Preliminary results showed that Technosols inoculated with microorganisms performed better in terms of nutrient availability and plant growth. Varied performance was observed as a function of the microbial inoculation applied. This suggests that the inoculation of Technosols with appropriate microorganisms may be recommended to accelerate nutrient availability assisting plant growth during the initial establishing of the Technosols. Technosols continue to show promise as an alternative to both mine waste disposal and the burrowing of topsoils for mine rehabilitation. Keywords: Fabricated soil, mine waste, coal discards, malt residue, nutrient availability, soil microbiology, plant growth

Jan 1, 2020

By Bernie W. Martin, Paul MacLeod

The new St. Clair River International Tunnel Project presented unique challenges in planning, permitting and approval. The project straddles the border between the Province of Ontario and the State of Michigan necessitating the review of U.S. approval legislation that has not been used in 60 years. The preparation of an environmental impact report to satisfy the legislative requirements for the Federal laws of the U.S. and Canada as well as the Province of Ontario and the State of Michigan presented a daunting task. In all, over 200 external contacts were made in carrying out the environmental approvals and permitting work. The definition of the alternatives including the NULL option were documented along with the impacts and mitigation measures. A "Modified Delphi" technique, along with other methodologies, was used for alternative evaluation and selection. A formal and informal public consultation process was undertaken which involved over forty major presentations and external meetings. A unique alternative to the traditional design, tender, build contracting practice was adopted; The Negotiated Compressed Process (NCP).

Jan 1, 1993

By N Gkikizas-Lampropoulis

Selection of delay times to optimize fragmentation has been a controversial topic among researchers and blasting practitioners. This paper interprets previous experimental information on the effect of delay on fragmentation with the aid of some new experimental observations of the time of detachment of the free face of the blast as well as results of numerical modelling. It was shown that detachment of the burden occurs at delays shorter than the one which produced optimum fragmentation in the experiments, suggesting some fragmentation improvement due to gas action. In addition, at the spacing to burden ratio of the experiments, the damage zone from an earlier detonating charge extends the distance to the neighboring charge, essentially affecting the burden of some of the holes of the blast, at detonation time. Computer modelling demonstrated that increased spacing results is less overlap of stress induced damage zones meaning that there is less influence of delay on stress wave induced fragmentation. It was also shown that simultaneous initiation results in less back break, while increased back break may result even with short delay times.

Jan 1, 2016

By Mohan R. Srivastava

- OUTLINE - apologies and explanations - a quick bit of history - the wisdom of Wikipedia - ?Matheronian geostatistics continued to convert Bre-X?s bogus grades and Busang?s barren rock into a massive phantom gold resource?? - variogram analysis for Busang - would variogram analysis (or variance analysis) have revealed the fraud? - what went right, what went wrong

May 1, 2007

By O N. Antzutkin, W Forsling, K J. Pike an

The adsorption mechanism of three different O,OÆ-di-alkyl-dithiophosphate (dtp) collectors, K[S2P(OR)2] with R = Et, i-Bu and i-Amyl, on the surface of synthetic chalcocite (Cu2S) was studied by means of solid-state 31P CP/MAS NMR spectroscopy. The morphology changes on the conditioned Cu2S surfaces, in the collector concentration range 0.1 - 10 mM, were also monitored with scanning electron microscope (SEM). In order to assign Cu(I)-dtp species on the surface of Cu2S, the corresponding bulk Cu(I)-dtp compounds, which are clusters of the monovalent copper containing either Cu6(antiprismatic) or Cu8(cubic) cores, were synthesised, and characterised by means of solid-state 31P CP/MAS and static 65Cu NMR. Further investigations on the crystal habits of the bulk systems were carried out by powder x-ray diffraction and SEM. A comparative analysis of the 31P chemical shift and chemical shift anisotropy (CSA) data estimated from the experimental NMR spectra of the polycrystalline bulk Cu(I) dialkyldithiophosphate complexes was used for assigning the 31P resonance lines in the NMR spectra of the collector treated Cu2S powder samples. The species formed on the synthetic Cu2S surfaces were assigned to polycrystalline phases of: Cu6L6 with L = Et2dtpû, Cu6L6 and Cu8L6(S) with L = i-Bu2dtpû, and Cu8L6(S) with L = i-Amyl2dtpû. A heterophase autocatalytic step process of both formation and growth of solid CuxLy (L = R2dtp, x = 6 or 8 and y = 6) complexes on the collector treated Cu2S surface is proposed. A possible role of the oxidised form of dithiophosphate collectors, bis[di-alkyl-thiophosphoryl]-disulfane (disulfide), is discussed in terms of a specific self-redox reaction. The second order quadrupolar lineshapes in 65Cu NMR spectra were simulated and the interaction parameters, CQ and hQ, for the bulk dialkyldithiophosphato-copper(I) complexes were obtained.

Jan 1, 2005

By J. H. Klepinger, C. W. Goodale

I. Introduction....................567 II. Character oF the OrE................568 III. Old FluE System..................572 IV. Tests on Old FLUE System..............575 1. Aspiration Tests................. 575 2. Tests with Steel Settling Chamber........... 575 3. Test with Experimental Brick Flue........... 583 4. Testa on Blast Furnace Geses............. 591 V. Design of New FluE System.............. 597 VI. Main Dust Chamber................. 605 VII. Some DetailS of Construction ............. 609 VIII. THE Chimney.................... 616 IX. Operation of New FluE System............. 624 X. Temperatures and DraFTS............... 630 XI. Velocities and Volumes................ 632 XII. TeStS on the New FluE System............. 637 XIII. Conclusion..................... 643 I. Introduction. In the summer of 1909 the Boston & Montana reduction department of the Anaconda Copper Mining Co. completed a new flue system, at a cost of about $1,100,000, and as this includes the largest and highest chimney in the world, and some new features of flue construction, a description will be of interest. At the Spokane meeting of the Institute in September, 1909, a brief mention was made of this flue system, in discussing Mr. Brunton's presidential paper on the Progress of Metallurgy in the West, and a promise was given that when a long enough time had elapsed, so that operating results could be given, a paper would be offered. The smelting plant includes blast furnaces, MacDougall roasters, gas-fired reverberatories, and converters.

Jan 1, 1914

By A. Hussain

PAPER NOT SUBMITTED FOR PUBLICATION

Jan 1, 1987

By J. M. Armstrong

Jan 1, 1934

By J. C. McHardy

During 1980-2000, the Florida phosphate industry will deplete its central Florida Polk County reserves. As a result, new mines will be built in the so-called southern Florida reserve areas. These mines will require new mining, beneficiation, and tailings disposal technologies since southern reserves have different characteristics than have been encountered in the central Florida deposits. Furthermore, government regulations will necessitate development of new tailings and clay disposal methods. This paper reviews these challenges for the Phosphate industry and how these opportunities can be expected to effect plant design and plant operating practices.

Jan 1, 1984

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Jan 1, 1942

By C. R. Neary, R. A. Lord, H. M. Prichard

experimental results are compared and classifying

Aug 1, 1994

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Jan 1, 1942

Jan 1, 1943

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Jan 1, 1942

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Jan 1, 1942