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By Andrews Allen

WE all remember when, a few years ago the preparation of coal was nothing but a matter of having somebody at the face or somebody in the railroad car pick out the impurities; also the sizes were generally' made" over a bar screen. Anything that was black was coal; and the only matecia1 picked out was the slate or rock-impurities that could be distinguished by eye or by hefting. This was all right as long. & coal could be sold at. a good price. After all, we are all in business to -make the most money honestly out of a certain acreage of coal and a certain plant. For this purpose what is required is the greatest possible recovery of marketable coal and the highest market price.

Jan 1, 1929

An appropriate scale-up methodology is very useful for ball mill design and optimization of the grinding circuit. To date, the scale-up is based on the selection and breakage function method using lab mill data. However, a major drawback of that approach is that the charge motion in a lab mill is vastly different from that in a large industrial mill. Therefore, in the methodology proposed here, first the energy of individual collision in the mill is computed employing the discrete element method (DEM). Then the breakage of particles as a function of collision energy is studied in a separate experiment. Together, this information constitutes what is known as collision energy based population balance method. The appropriateness of this method is shown for 38-cm ball mill.

Jan 1, 1998

By H. NORTON JOHNSON

THE oil industry in California during 1929 reached new heights and new depths in the discovery and development of the oil resources of the State. The discovery of new fields, and more especially the discovery and development of deeper prolific sands in known fields has, for the first time in its history, brought the potential production of completed wells within the State to over 1,000,000 bbl. oil per day. Constant improvement in equipment and technique has made possible economic development to depths unheard of but a few short years ago. Commercial production from a depth of over 4000 ft. was considered quite an accomplishment in 1923 when the Meyer sand at Santa Fe Springs was developed, and when later oil was successfully raised from this depth.

Jan 1, 1930

By Sui Xue

A process has been developed from laboratory-scale experiments for the aqueous processing of various lead-bearing wastes. The process exploits the limited solubility of lead in sulfate-rich solutions to effectively separate lead from other metals. The lead sulfate is then completely converted to lead carbonate using sodium carbonate and ammonium carbonate. The effectiveness of this conversion was observed to be sensitive to the solution pH and carbonate concentration. The final stage of the process uses low temperature calcination of the lead carbonate to form PbO. Yellow lead oxide (massicot) is readily formed if calcination is conducted at a temperature at or iibove 50G°C, wlule red iead oxide (iitharge) is formed at temperatures near 450°?C. A complete economical analysis of the process will be discussed.

Jan 1, 1996

By Mousaab Majar, Nikolaus Schneider

The technical challenges for accurate drilling positions increase with deep underground structures in inner city areas. Designed for jet grouting, specific sensors have been developed to record the alignment of rods during drilling by integrating microchips into the drilling rods. By feeding the rod with constant electric current, microchips, integrated in special couplings, can be read during the drilling process and tracked on monitors installed in the operator’s cockpit. The orientation for the drilling rod is provided by magnetic points and a compass, positioned above ground on the drilling rig. In combination with asymmetric drilling bits, it is now possible to steer the drilling hole to predetermined positions to compensate for deviations in deep bores. This type of drilling rod for jet grouting has been used in Berlin since summer 2019.

May 1, 2022

By Edward H. Robie

THE registration badges gave out, there were not enough programs, the Pioneer Hotel's rooms were insufficient, and some hundred applicants for banquet tickets had to be turned down at the Institute's Regional Meeting in Tucson, Nov. 1-5. Minor inconveniences these, however, occasioned by the fact that, optimistic as they are in Arizona, about half again as many partook of the week's activities as were expected. For this, the local program committee can be blamed-both the technical and social features were too attractive in quantity and quality. Seriously speaking, though, the Institute has probably never had a more successful Regional Meeting than this one. It being the first that has been held in Arizona in 22 years, no effort was spared to make it the distinctive gathering that it was.

Jan 1, 1938

The National Mining Hall of Fame and Museum (NMHF&M) will celebrate its 25th anniversary on Sept. 22, 2012 when the 2012 class is inducted during a special ceremony in Las Vegas, NV in conjunction with MINExpo 2012. The NMHF&M will induct four men representing the equipment manufacturing, minerals exploration, copper and coal sectors of the mining industry. The diverse cross-section of mining industry giants joining the hall of fame include Glen A. Barton, J. David Lowell, Samuel Newhouse and John Cleveland Osgood. They will join 214 other mining industry pioneers when they are formally inducted into the National Mining Hall of Fame at the 25th Silver Anniversary Induction Banquet & Ceremony. These men were selected for being visionaries, leaders and ambassadors within their own sectors and across the industry at large.

Jan 1, 2013

By Gerald Zink

The work described in this paper is sponsored by the Bureau of Mines for the purpose of accelerating the drilling of roof bolt holes and reducing the quantity of materials needed to fill each hole. A high-speed small-hole drill has been fabricated and tested in the laboratory. High priority has been given to safety, reliability, and compatibility with underground coal mining practice. The combination of drag bits and erosion jets is designed for high penetration rate, long wear life, and uniform hole size in a variety of sedimentary strata. A reliable high-pressure high-speed swivel feeds water to the bit at about 4 1/min (1 gpm). The duplex hydraulic intensifier which drives the jets has a 40 kw capacity (30hhp) Results of recent full-scale laboratory testing are presented.

Jan 1, 1978

By S. J. Broderick

[The term "nonmetallic minerals? as commonly used is the mining industry, refers to those minerals of industrial importance that are mined essentially for uses other than for the metals contained. The field comprises several hundred rod minerals of industrial importance, of which 70 have can adequately described in the textbook Industrial Minerals and Rocks. A few o f the more important nonmetallic products are sand and gravel, salt, phosphates, clays, refractories, limestone, and cement materials. Some of the minerals, such as bauxite and pyrolusive, have both metallic and nonmetallic applications, but in this report only the nonmetallic mineral phases are considered. In the organic field of nonmetallics only coal is considered, as, the others - petroleum, natural gas, natural bitumens, and hydrocarbons - are of no importance in water softening.]

Jan 1, 1941

Good morning ladies and gentlemen of the AIME. I was doubly pleased when Toby Yu asked me to present to you my thoughts on the past, the present, and the future of bulk transportation by barge. My first pleasure comes from sharing with you the subject that has been my career for many years. I love this industry in the same way Mark Twain loved our rivers. Somehow, I can find in all of the activities that make up this crazy barge business the same sort of excitement that he found in "steam boating." The second reason for my enthusiasm is that Toby carefully pointed out that the presentation had to be kept to a maximum of 15 minutes. I can promise you that I will hold to his maximum time limit.

Jan 1, 1982

By Jae-Chun Lee

One of the main advantages of the supported liquid membrane(SLM) would be that different kinds of ions can be extracted selectively or simultaneously from multi-component solutions by parallel treatments with multi-SLM units. This distinctive feature of the SLM extraction is originated from its non-dispersive contacting operation between organic and aqueous phases. In this study, simultaneous and selective extractions of zinc and copper ions from their mixed solutions have been demonstrated using two parallel modules of SLMs. PC88A and LIX84 were used as the extractants for zinc and copper, respectively, and the Hoechst Celanese hollow fiber modules(Liqui-Cel Lab Module) as the supporters. The performance of the simultaneous system was compared with those of the system in which the extraction of each component was achieved by individual runs

Jan 1, 1998

By D. H. H. Quon

Results of a study conducted to determine the properties of iron ore pellets made from Mount Wright and Carol Lake ore concentrate fines with partial and full substitution of bentonite by several organic binders are presented. Carboxy methyl celluloses 7H and 6TL, hydroxy ethyl cellulose (natrosol) and modified guar gum all produce pellets of acceptable wet, green and dry strength. However, when fully substituted, an inorganic binder such as calcium carbonate is required for satisfactory strength development after induration. Mixing the Carol Lake ore with Mount Wright ore in a 50-50 ratio also achieves the same result. The failure of the Carol Lake ore in the pelletization process is attributed to the low hematite content of the ore. The results are very similar to those from the extrusion studies reported earlier (8).

Jan 1, 1989

By Charles W. Frey

OF all the machinery used in mining work, mine cars are probably the most abused. They are hauled through water and muck, up hill and down grade, whipped around curves, bumped and jerked, and exposed to the ravages of the weather. However, as a general rule their lubrication is not altogether neglected. The mine operator may not heed the extra drag that a frozen conveyor bearing gives, but he is all too aware of the increased load that faulty mine car wheels put on his power plant. When the circuit breakers begin to fly, and when his mine loco- motives come out with only half the cars that they were able to carry a month before, then neglected mine car wheel lubrication becomes apparent, and woe to the person responsible.

Jan 1, 1938

By A. Elsayed

Lightweight metals such as magnesium show potential in replacing aluminum alloy castings for engine cradles, cylinder heads and transmission cases. Unfortunately, magnesium alloys are susceptible to entrapping oxides and other impurities during casting that hinder strength and ductility. The current study examined various filter sizes and configurations with the aim of improving the mechanical properties of permanent mould cast AZ91E. The unfiltered casting had a yield strength, tensile strength and ductility of 93.3 MPa, 153.3 MPa and 2.2 % respectively and increased to 96.5 MPa, 167.0 MPa and 3.1 % with the use of a fine mesh filter within the well of the mould. The increased strength and ductility was likely due to the filtered castings containing fewer inclusions on their fracture surfaces as compared to the unfiltered castings.

Jan 1, 2011

Flexible hoses with rated working pressures up to 40,000 psi are used when high-pressure water jets are employed to cut rock or improve the performance of mining machines. Hose failures at such high pressures can result in serious injuries to workers. The Bureau of Mines used fatigue and burst tests to investigate the failure modes of high-pressure hoses at their rated working and burst pressures. Fatigue failure, at rated working pressures, occurred when the inner liner of the high-pressure hose broke, allowing water to seep through the wire wrapping, although the reinforcement wires did not break. At the burst pressure, all hoses failed catastrophically when the reinforcement wires broke. Low-pressure hoses placed over the high- pressure hoses for safety failed to contain water released by catastrophic failure.

Jan 1, 1987

By Donald H. McLaughlin

PRICES paid for goods and services in paper currencies are undoubtedly determined by many interrelated factors, but among them none is more specific in pushing prices toward higher and higher levels than the vast increase in debts and monetary obligations of our own and practically all major governments. There is nothing unorthodox in the situation in which the gold miners find themselves today. With wages and the prices of all materials required in the production of gold at the high levels characteristic of a period of prosperity, phony or otherwise, and with shortages of both men and machinery to contend with as well, the spread between the returns in paper dollars that must be accepted for gold in the United States and the cost of producing it is rather painfully small for most producers. Technical

Jan 1, 1948

By John B. Gayle

During studies of the various methods for determining and specifying the factors that indicate whether a particular coke is better or worse than other cokes for metallurgical uses, questions arose as to the precision of screen-analysis tests on coke. Although the usual index of precision, the standard deviation of the test result, gives a measure of the precision of these data, the experimental determination of the standard deviation for a particular set of conditions requires tests on a large number of duplicate samples. Because this procedure necessaily involves a great deal of labor, an equation for predicting standard deviations from theoretical considerations has been developed. Results predicted with this equation agree satisfactorily with the experimental values and are applicable to tests on coal, coke, gravel, and other bulk materials.

Jan 1, 1952

By Xiong Tong, Jiushuai Deng, Yingbo Mao, Lingyun Huang

Ammonium carbamate has been used as a reagent for the leaching of copper from the copper oxide ore found in the Honghe state, Yunnan province, China. In order to find the optimal conditions for the leaching of copper from this copper oxide ore,the effects of several processing parameters, including the concentration, time, temperature, particle size and stirring intensity have been investigated. The results of these optimization experiments showed that the leaching rate of copper reached up to 72.76% under the following conditions: liquid-to-solid ratio of 10:1, ammonium carbamate concentration of 2.5mol/L, leaching temperature of 45 °C, stirring speed of 300rpm, a reaction time of 1.5 h and 85% by weight thereof passes through a sieve having 0.074 mm.

Jan 1, 2015

By International geochemical

During the production of the Geochemical Atlas of Finland till samples were collected throughout Finland at a density of one sample per 300 km2. The material studied was the fine fraction of till (less than 0.06 mm). The geochemical mapping has shown that elements that are locally enriched in bedrock in the form of ore mineralisation are also enriched in a wide area of the surrounding till. These anomalous enrichments of ore elements take the form of rectangular or curvilinear zones that are some tens of kilometres wide and hundreds of kilometres long. The mineralised zones host ore deposits of different genetic types and can be termed "ore provinces". They stand out prominently on the geochemical maps and can be divided into sub-units of different chemical composition.

Jan 12, 1992

By Hartmut Rossel

VAW aluminium AG has built a "Recycling-Technikum" (Recycling Research Centre) to add a new arm to the company's Corporate Research and Development Department. The Recycling Research Centre, a pilot plant for scientific research, has been in operation since September 1993. These state-of-the-art facilities allow the investigation and optimisation of recycling techniques in 'a global way and in detail. Research is concentrated on the unit operations - processing, melting and waste-gas purification - with the available installations making it possible to compare different alternative process combinations on a 100-kg scale. One of the main targets of VAW research is the development of recycling techniques for packaging. The paper presents an approach to recover the aluminium contained in flexible packaging materials using an integrated melting and waste-gas purification system.

Jan 1, 1995