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By Massimo Guarascio

Computer data processing and ore reserve evaluation techniques, mainly based on geostatistical methodologies, have been developed at Agip Mining Division with the assistance of the Department of Mining Engineering of the University of Rome. A number of computer programs are available when facing problems such as optimization of sampling patterns, minable reserve estimation, grade control of output, and so on. In the present paper, the aims and the criteria followed in developing these programs are discussed. Some recent examples of application are also cited.

Jan 1, 1977

By H. F. Walther

Basic electric-are furnace steel production mainly involves the use of two separate types of slags. The first, known as the "melt down" or oxidizing slag, which is in most cases removed from the furnace mechanically, and the heat finished under the second or deoxidizing slag, which is commonly known as the "finishing slag.'' The melt down slag is formed by the addition of lime or limestone to the charge, which combines with the oxides formed during the melting period and the product of any bottom erosion that may take place.

Jan 1, 1935

By D. R. Piteau, A. MacG. Robertson

Strength, permeability, and deformational properties of a rock mass are influenced and often controlled by the geological discontinuities within the mass. These properties are often determined by physical tests conducted within and on portions of the rock mass under consideration. Any extrapolation of these test results to other portions of the rock mass assumes that a similar pattern of discontinuities, having similar properties, exists throughout the region of extrapolaion. A survey in which various joint properties of interest are measured may be conducted to sample the joint population of the mass. Suitable data manipulation and handling techniques are developed to permit the definition of the joint population of the rock mass. The validity of the extrapolation of test results may then be assessed.

Jan 1, 1974

By H. F. Walther

Basic electric-are furnace steel production mainly involves the use of two separate types of slags. The first, known as the "melt down" or oxidizing slag, which is in most cases removed from the furnace mechanically, and the heat finished under the second or deoxidizing slag, which is commonly known as the "finishing slag.'' The melt down slag is formed by the addition of lime or limestone to the charge, which combines with the oxides formed during the melting period and the product of any bottom erosion that may take place.

Jan 1, 1935

By Oswald J. Heinrich

THIS question having been repeatedly raised, and particularly revived in a discussion at the last meeting of the Institute, I beg to submit the following remarks, based partly upon personal experience, partly upon the results of large works in Europe, establishing, years ago, the practicability of certain methods, which may therefore be considered to have passed the stage of mere experiment. Before entering upon the merits of one system or the other, it is indispensable to lay down some recognized principles, which ought to serve as guides, in arriving at fair judgments in questions of this character. In a profession like that of mining, locally so much influenced by combinations of circumstances too various to mention, it is difficult to do more than lay down the main features of a system based upon general laws and recognized facts, leaving the details to the sound judgment and experience of the engineer, who, by virtue of his education, ought to be able to make such choice and such modifications in the plans of a mine as the particular case demands. Mineral resources, in some countries the sole property of the owner of the soil, in others controlled by the strong hand of a government, are nevertheless a gift of nature, in which, indirectly, the whole of the human race has as real an interest as the immediate owner himself. This interest requires, at least, that no unnecessary waste of

Jan 1, 1874

Jan 1, 1913

Jan 1, 1913

The technique of hard facing can be a quick and economical means of prolonging wear-life of many metals, but maintenance personnel must first select the proper alloy from the hundred that are available. Even then, roper selection is effective only when it is properly applied by the welder. To complete the successful weld, several hints are offered:

Jan 4, 1978

By Robert W. Hunt

No matter how perfectly sectioned or skilfully manufactured the rails used may have been, or with what care the road-bed may he maintained, legitimate results from these important factors cannot be secured unless proper attention is bestowed upon the joint-fastenings. In this country, splice-bars of various patterns furnish the practically universal joint. Other forms have been used, and are now being experimentally tested, but the typical American rail-joint consists of angle-plates or splice-bars. At the same time, it is true that scarcely a railroad engineer is satisfied with his joint. He may consider it the best of which he has knowledge, but at the same time he is well aware of many of its weak points.

Jan 1, 1890

[ARTICLE I. NAME AND OBJECT Section 1. This Society shall be known as the Society of Petroleum Engineers of the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. Section 2. The object of the Society of Petroleum Engineers shall be to furnish a medium of cooperation among those interested in the petroleum-natural gas industry an to promote the advancement of this branch of mineral technology through meetings to stimulate the preparation, reading, discussion and circulation of papers connected therewith. ARTICLE II. MEMBERS Section 1. Any person who is a member of AIME may become a member of this Society by the specified process. Section 2. Local organizations may be formed by the Society of Petroleum Engineers as subsidiary units, the membership of which shall be subject to and in accordance with the by-laws of the Institute.]

Jan 1, 1961

By Edward J. Bagnall

The major raw material feed properties of size distribution and chemistry are examined in relation to their effect on sinter operating conditions, plant productivity, sinter physical quality, reduction- degradation characteristics and sinter texture and mineralogy. The resultant physiochemical properties of these sinters are related to their behaviour in subsequent ironmaking operations.

Jan 1, 1977

By F. C. Blake

THE test of the English cupellation furnace should be so supported that the cupeller can change readily the elevation of the test, and at the same time watch the litharge channel. It is also important to raise or lower either side, independently of the other, in me of uneven wear of the side walls or of the breast. If the refined silver is poured from the test, it is much better to control the lowering of the test from the front than to raise the back by screws or a lever. In order to enable the cupeller to manipulate the test with one hand, when the litharge is running, and to pour the refined silver from the test without aid, I have altered the common support to the test, as shown in the accompanying drawing. The common method of supporting the test is by four screws, working in cross-bar nuts beneath the test. The points of the screws set, into the test plate upon which the test rests. These screws are usually worked by pounding or pulling upon the heads, which may be either small pulleys or straight bars, as shown on the back screws in the drawing. The screws are also worked by turning a crank, which is

Jan 1, 1882

By Esteban Domic, Eugene O. Brimm

The Lo Aguirre ore deposit of Sociedad Minera Pudahuel is expected to have a life of 12 years, producing 16,500 mt per year of copper cathodes. The total copper content of the ore ranges from 2% in acid-soluble form to 2% as sulfides. Sociedad Minera Pudahuel chose TL leaching, solvent extraction, and electrowinning as the processing steps to give low investment and operating costs. Design and operating criteria of the TL leach plant have been obtained in an experimental program carried out since 1974. Bench scale tests indicated that 90% of the oxidic copper and 35% of the sulfidic copper could be extracted to give 5 gpl copper by treating crushed ore with acid, curing, and rinsing in a column with a dilute acid solution containing ferric sulfate which is requllred to solubilize the sulfides. These results were verified in a pilot plant which combined leaching, solvent extraction, and electrowinning. Raffinate was recycled to the leaching circuit after oxidation to regenerate ferric ion. Refinements in the processing have resulted in significant improvements in extraction to give 95% to 98% recovery of the oxidic copper and 55% and 60% of the sulfidic copper. The plant is expected to give this degree of recovery. As a consequence, the original plan to include a concentrator in the plant has been abandoned.

Jan 1, 1980

By Ronald R. MacDonald

There is an ongoing need for the abstracting and coding of new information in the energy and environmental studies field for addition to the BIRS system. There are approximately 3000 bibliographic entries coded into the BIRS system. The bibliographic retrieval system was designed to be run by the general data management System 2000. The information system with entries of coal research, land reclamation and other energy and environmental studies is up and on line. As more entries are coded they are loaded into the system.

Jan 1, 1977

By A. M. Gaudin

THIS paper presents, with the help of colored photomicrographs, the new method of mineral identification termed "selective iridescent filming." This method pertains to the field of determinative mineralogy, which it provides with tools for: (1) phase identification, (2) solid solution analysis. The method should be particularly useful in the applied fields of: (1) paragenesis of ore deposits, (2) mineral dressing, (3) mineral synthesis and study of phase equilibria.

Jan 1, 1938

By A. M. Gaudin

THIS paper presents, with the help of colored photomicrographs, the new method of mineral identification termed "selective iridescent filming." This method pertains to the field of determinative mineralogy, which it provides with tools for: (1) phase identification, (2) solid solution analysis. The method should be particularly useful in the applied fields of: (1) paragenesis of ore deposits, (2) mineral dressing, (3) mineral synthesis and study of phase equilibria.

Jan 1, 1938

By Donald A. Cumming

Since the first major mine development, the company has continually looked for ways of improving drifting methods. The planned increase in production to 60,000 tpd, and the lack of trained personnel, requires new development methods to maintain this high production rate. In order to finish the drifting on the 2015 and 2075 levels, a total of 59,000 ft is required, or two years at the present rate.

Jan 4, 1972

By G. Almgren

Swedish cut-and-fill mines are described with regard to location, production volumes, and grades. Development goals (such as higher productivity and better working conditions) are presented, and different methods of development, such as mechanization, new layouts, etc., are discussed. Development methods are described with examples from drilling, loading, haulage, and rock mechanics. Special attention is paid to filling techniques. Figures are given for productivity and relative costs.

Jan 1, 1977

By Walter Knox, J. D. Doherty

In 1939, at the request of The Koppers Coal Co., the Koppers Company Research Department established a Stoker Coal Research Laboratory for the purpose of investigating the performance characteristics of stoker coals in typical domestic stoker installations. Fig. I is a photograph of part of the laboratory. The material in this paper deals with the performance of one coal in a single installation. Presented are details of this installation, mechanical characteristics of the stoker, and the results of a series of burning tests in which adjustments were systematically varied. Summary OF Results Mechanical Features I. A large percentage of the total power consumed by a domestic stoker is used to operate the gear case and motor (Fig. 3)- 2' The power consumption per ton goes down with an increase in rate of coal feed (Fig. 4). 3. The automatic air control in this stoker showed advantages Over manual control (Fig. 5). 4. The air velocities through the retort tuyeres were uniform around the retort, but varied between the rows of tuyere rings (Fig. 6). 5. The crushing of coal with this stoker increased the minus 1/8-in. from 11.6 per cent to 19.2 per cent. There was a notice- able segregation of coal as it came from the retort and distribution was not uniform (Fig. 7). 6. Measurement of air entering over the fire showed that with some not uncommon adjustments this air may be a high percentage of the total air supply (Fig. 8 and Table I). Operating Performance ,. The, removal of clinker was shown to give a period of poor performance characterized by a high fuel-bed resistance and a high percentage of carbon monoxide in the flue gases (Fig. 10). 2. The fuel-bed resistance was found to decrease as the fuel bed built up in a normal response to heat demand after a prolonged hold-fire (Fig. II). 3. with intermittent operation the burning rate was almost always less than the feeding rate, The wide variations were found to be greatly dependent upon the length of the On period and the length of the intervals between On periods (Fig. 12). 4. The maintenance of a low furnace draft led to less fly ash, better clinker formation, and higher efficiencies (Fig. 13). 5. The maintenance of a minimum of excess air also resulted in less fly ash, better clinker formation, and higher efficiencies (Fig. 14). Guiding Principles In planning the investigations, the following principles were adopted: Selection of Heating Equipment.—Use only standard models of stokers and furnaces representative of those widely used.

Jan 1, 1942

By Walter Knox, J. D. Doherty

In 1939, at the request of The Koppers Coal Co., the Koppers Company Research Department established a Stoker Coal Research Laboratory for the purpose of investigating the performance characteristics of stoker coals in typical domestic stoker installations. Fig. I is a photograph of part of the laboratory. The material in this paper deals with the performance of one coal in a single installation. Presented are details of this installation, mechanical characteristics of the stoker, and the results of a series of burning tests in which adjustments were systematically varied. Summary OF Results Mechanical Features I. A large percentage of the total power consumed by a domestic stoker is used to operate the gear case and motor (Fig. 3)- 2' The power consumption per ton goes down with an increase in rate of coal feed (Fig. 4). 3. The automatic air control in this stoker showed advantages Over manual control (Fig. 5). 4. The air velocities through the retort tuyeres were uniform around the retort, but varied between the rows of tuyere rings (Fig. 6). 5. The crushing of coal with this stoker increased the minus 1/8-in. from 11.6 per cent to 19.2 per cent. There was a notice- able segregation of coal as it came from the retort and distribution was not uniform (Fig. 7). 6. Measurement of air entering over the fire showed that with some not uncommon adjustments this air may be a high percentage of the total air supply (Fig. 8 and Table I). Operating Performance ,. The, removal of clinker was shown to give a period of poor performance characterized by a high fuel-bed resistance and a high percentage of carbon monoxide in the flue gases (Fig. 10). 2. The fuel-bed resistance was found to decrease as the fuel bed built up in a normal response to heat demand after a prolonged hold-fire (Fig. II). 3. with intermittent operation the burning rate was almost always less than the feeding rate, The wide variations were found to be greatly dependent upon the length of the On period and the length of the intervals between On periods (Fig. 12). 4. The maintenance of a low furnace draft led to less fly ash, better clinker formation, and higher efficiencies (Fig. 13). 5. The maintenance of a minimum of excess air also resulted in less fly ash, better clinker formation, and higher efficiencies (Fig. 14). Guiding Principles In planning the investigations, the following principles were adopted: Selection of Heating Equipment.—Use only standard models of stokers and furnaces representative of those widely used.

Jan 1, 1942