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By C. W. Purington

Jan 1, 1900

By O. E. Michaelis

The metal used at the Befors Works in gun-munufacture is unforged open-hearth steel, cast without blow-holes. It has from time to time been asserted that it is impossible to pro

Jan 1, 1888

Jan 1, 1922

By Feridun A. Albayrak

Jan 1, 1985

By P. Barnes

The complete and uccurate filtration of water (if the word accurste map be thus Used) for the feeding of boilers, and for many similar industrial purposes, although somewhat practiced both at home and abroad, has heal by no means common. Even if the exact line cannot be defined at which filtration begins to be called for, ad will be found profitable, it is certain that in a large number of cases it may be employed with real advantage in the economy of fuel, and also in the greater durability of the boiler or other form of apparatus in

Jan 1, 1882

By James Gayley

The paper presented to the Institute in 1910, by H. O. Hof-man, on Recent Progress in Blast Roasting,' has called the attention of the iron industry to the adaptability of these processes to the reclamation of by-products such as flue-dust and blue billy, and the better preparation of concentrates and fine ores for use in blast-furnaces. The waste of valuable iron-ore through the production of flue-dust has increased at an enormous rate, and much of it has in

Jan 1, 1912

By S. K. Ghosh

This paper discusses how the information on ash composition, ash-fusion temperatures, and ash-slag viscosity can be used to predict slagging and fouling potentials of a particular coal. A review of several empirical parameters that are commonly used for determining such potentials is given. Also, some guideline values for interpreting the relative propensity of slagging and fouling of various types of coal are provided.

Jan 1, 1986

By P. Barnes

THE complete and accurate filtration of water (if the word ,accurate may be thus used) for the feeding of boilers, and for many similar industrial purposes, although somewhat practiced both at home and abroad, has been by no means common. Even if the exact line cannot be defined at which filtration begins to be called for, and will be found profitable, it is certain that in a large number of cases it may be employed with real advantage in the economy of fuel, and also in. the greater durability of the boiler or other form of apparatus in

Jan 1, 1882

New Device Eliminates Blasting in Coal A non-explosive device developed by duPont utilizes the high pressure of a gas generated inside a steel tube which is inserted in a hole drilled in a coal seam to break down the face of coal. Chemical reaction is started by an electric current which produces heat to initiate the action. The same heat destroys the starter wire as soon as electric current is no longer needed. The tube containing the chemical is closed at the outer end by a plug with electrical connections, and at the other with a disk that is ruptured by the compressed gases formed. When the gas has been liberated in sufficient quantities to create a desired pressure the disk breaks and the released gas breaks down the coal face. The new device is called a Chemechol.

Jan 10, 1951

By P. E. Landolt

MILITARY necessities and economic scarcities, occasioned by the first and second World Wars, led to the search for substitute materials and new products to meet the demands of advancing technology accelerated by research development. Among others, lithium came to attention. Its chemistry had been studied for a long period, but its general use was quite restricted due to limited known sources of raw material. In World War I, Germany used lithium metallurgically for two principal purposes: 1-hardened lead alloy, B-Metal, for railway bearings as a substitute for lead-tin-antimony alloys; and 2-light strong aluminum alloys, Scleron, in which zinc was largely substituted for copper.

Jan 12, 1951

By Robert B. Hill

A history of gravity classification shows the development of many types of equipment with several prominent types continuing in use today. Part of the development and evolution is the spiral classifier. Data will be presented showing characteristic size separations in a closed circuit grinding operation. Comparisons with hydro- cyclone operation will be shown including operating cost comparisons. Effects of variables will be shown in spiral classifier operation. Finally, other uses for spiral classifiers will be described.

Jan 1, 1982

By S. A. Braley

THE first commercial production of bituminous coal in the United States was in 1820, and formation of acid in the areas from which the coal was removed began at that time. Thus it is 130 years since the development of mine acid began. The coal operator has had to deal with the acid water produced in his mines, and his losses from corrosion of pumps and equipment have been tremendous. Other industries and the public have been forced to spend large amounts for their water requirements because of the acid discharge from the mines. There are many contradictions in the literature on this subject probably because of variations in the analytical procedures followed and differences in the methods of calculation and reporting. The opinions previously expressed may be summarized as follows:

Jan 8, 1951

Jan 1, 1967

By I. M. LeBaron

The phosphate ore, or matrix, is a mixture of white pebbles of phosphate, of all sizes but mostly minus I to 1 1/4-in. diameter, in a matrix that varies from nearly all silica-sand gangue to a mixture of pebble, sand and clay. There is an occasional streak of hard pan of sand cemented with iron oxide, which can be drilled without much difficulty.

Jan 1, 1948

By I. M. LeBaron

The phosphate ore, or matrix, is a mixture of white pebbles of phosphate, of all sizes but mostly minus I to 1 1/4-in. diameter, in a matrix that varies from nearly all silica-sand gangue to a mixture of pebble, sand and clay. There is an occasional streak of hard pan of sand cemented with iron oxide, which can be drilled without much difficulty.

Jan 1, 1948

By A. Sainato, E. Baker, J. Cervik

In Europe, water infusion is used widely to reduce generation of respirable dust during mining. Its use in the US is limited to a few plow operations in the deeper parts of the Pocahontas No. 3 Coalbed. The technology for infusing water into retreating longwalls is described and results of a recent Bureau test in the Lower Sunnyside Coalbed demonstrated dust reductions ranging from 47% to 64%. Because water infusion increases moisture content of the coalbed, face air velocities in excess of 2.5 m/s (500 fpm) are possible, further diluting dust levels before dust entrainment occurs. An economic analysis shows a 23% reduction in operating costs when coal production is increased by changing from unidirectional to bidirectional mining with water infusion.

Jan 1, 1986

The Duluth Engineers' Club was formally organized on the evening of Aug. 5, 1918, at a meeting .attended by over l00 members of the several engineering professions. W. G. Swart, a member of our Institute, was elected the first President of the Club. At the organization meeting, an opportunity was given, to Alfred D. Flinn, Secretary of the United Engineering Society, to outline the assistance that is being rendered to the Federal Government in the present contingency by members of the engineering profession. Membership in the Duluth Club is to be open to mining engineers on the iron ranges as well as to the residents of the city of Duluth.

Jan 10, 1918

By Fred C. Bond

DISCUSSION Milton C. Shaw and Donald R. Walker (Massachusetts Institute of Technology)—For many years the two empirical rules of comminution bearing the names of Rittinger and Kick have been applied to grinding processes to account for the energy required to crush brittle materials. The basis for Rittinger's rule was the thought that the energy to grind a substance went largely into supplying the additional energy associated with the new free surface, while Kick's law was prompted by the concept of dimensional similarity and is a special statement of the concept of constancy of strain energy to cause rupture. According to Rittinger the energy to grind a given volume varies as the change in the square of the mean particle size, v - A (D2), while according to Kick this energy varies

Jan 1, 1953

By W. D. Faulkner, J. E. Urbanic, R. J. Jula

The process of treating granular activated carbon for return to service in the recovery of gold in carbon-in-pulp and carbon-in-leach circuits has been investigated. Carbons from two US mines, one Canadian mine, and a South African pilot plant operation were characterized before and after regeneration. Thermal regeneration of the carbon was investigated using factorial analysis to determine the effect of interaction of furnace temperature, retention time, and use of supplemental steam. The operation of acid washing the service carbon was investigated, including a comparison of the use of nitric and hydrochloric acids. The effect of quenching regenerated carbon was also briefly studied. Prom the data obtained, guidelines are given for effective regeneration operation.

Jan 1, 1986