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By AIME AIME

THE annual meeting of the A.I.M.E. was fittingly closed with a joint meeting of the Metropolitan sections of the four National societies on Feb. 18, at which this subject was adequately discussed by leading engineers before an audience that completely filled the Engineering Auditorium. The large amount of publicity that has been given the Diesel electric loco- motive, and the often garbled reports of its performance and possibilities that have been circulated, makes it particularly fitting that the facts should be given the profession as determined by those who have aided in developing and operating this latest form of prime- mover in railroad operation. C. A. Stein, general manager of the Central R. R. of New Jersey, opened the meeting with a discussion of the problem of electrification, and the relation of the short haul, switching, and terminal service to heavy electrification. Referring directly to the problem of the Central R. R. of New Jersey, some subtitution for the steam locomotive is necessary within the city limits of New York because of local ordinances against the smoke nuisance. While the improvement in the design of the steam locomotive has been marked-the efiiency today is over fifty times that of the locomotive of 100 years ago-it has now probably reached the point of maximum perfection. If anything, it is open to the criticism of having Coo many appliances to get out of

Jan 1, 1926

By Frank Hirthammer

The paper explains the procedure of implementing Track & Trace solutions for manufacturers of explosives based on customer experiences. By using concrete examples, the process from project start to implementation is described. Lessons learned from the experiences of European explosives manufacturers are presented.

Feb 1, 2020

By Sidney H. Haughton

FOLLOWING the discovery of diamonds in 1870 and the Witwatersrand gold fields in 1886 South Africa changed from a predominantly pastoral country with a scattered white population into a land whose economy came rapidly to be based primarily on mining. The total value of the mineral output of the Union in 1944 was approximately $493,000,000, to which gold contributed 84 per cent. Gold furnished some 33 per cent of the Union Government's total revenue in that year, and approximately half the country's population obtained its livelihood directly or indirectly from the gold mining industry. In any review of the Union's mining activities and in any consideration of the country's future, gold mining must occupy a prominent place. It is generally conceded that the present structure is not properly balanced and that an economy based on a preponderance of a single nonpermanent factor possesses potentialities of serious instability.

Jan 1, 1946

By Andreas Gaich

A new 3D fragmentation analysis method for muck piles is presented. It works with aerial imagery from UAVs (drones) and handles entire muck piles with minimum user intervention.

Feb 1, 2020

By Ian Coltrin, Steve Merrill, Dariusz Lelinski, Sudhir Kamath

Froth flotation has been the heart of mineral beneficiation for over a century. Over the years, developments have been made in flotation cell design, size, and in many other aspects of flotation technology. Despite the overall effectiveness of these improvements, valuable mineral particles are often lost along with waste material. These particles are lost when the froth recovery process within a flotation system is not designed for variable froth conditions seen in plant operations. Both the amount of froth generated and the type of froth in a flotation cell change as concentrate is removed down a row of cells. Traditionally, froth recovery has been designed using a froth carry rate averaged over the entire row of flotation cells with a static amount of open area at the top of the cell.

Sep 30, 2022

By G. L. Oldright

THE metallurgist is familiar with the rapid development of concentration -by flotation and smelting in the reverberatory in recent years, brought 'about chiefly by the exhaustion of' bodies of .rich, coarse, direct smelting ore. Geologically speaking, in many porphyry-copper districts, the richer contact or replace let deposits surrounding 'the main ore-forming igneous intrusion have been exhausted, and it is necessary to beneficiate the copper minerals disseminated throughout the mass of the intrusion itself. The organization of great companies to treat such low- grade ores on a large scale and the practices resulting from the necessity for an economic method of treatment 'are among the most prominent metallurgical developments of the past decade. It is interesting to note the effect of the present trend of practice on the inter-relationship of the concentrator and smelter, on the constituents of the smelter charge, and on smelting in general.

Jan 1, 1925

By Doug Harding

The Metropolitan St. Louis Water District’s Project Clear is a 28-year program targeting wastewater capacity throughout St. Louis, MO. The extensive program includes the Jefferson Barracks Tunnel, running parallel to the Mississippi River at 2 m ID and 5,400 m long. A rebuilt Robbins Main Beam TBM began boring but hit challenging conditions about 2,400 m in, including water inflows. A larger 4.1 m Robbins Main Beam machine will complete the remaining 3,050 m in limestone, dolomite, and shale. The TBM will utilize a high-powered, high breakout torque cutterhead along with enhanced 360-degree probing & grouting capabilities to detect any karst formations.

Dec 1, 2022

By T. Doshi, S. Ennis

The interactions of mineralogy, chemistry and mechanics in an ore concentrator are highly complex, so it can be particularly hard to measure the impact of a specific plant change. This paper describes a method for modeling a baseline metal recovery so that the value of a major process improvement can be measured. This method only considers variables that cannot be optimized, such as mineralogy or equipment availability. Linear regression, random forests, extreme gradient boosting (XGB), and simple two-layer neural network models of process value were tested as candidate baseline model types to assess the impact on throughput and recovery in a copper concentrator. XGB performed the best in terms of accuracy for both throughput and recovery models. Using an XGB model of nonoptimizable process variables provides an accurate, dynamic baseline that can be compared with continuous production data to determine the value added by major concentrator improvements in real time.

Mar 2, 2022

By PHILIP N. MOORE

IT is a pleasure to realize even at that day the dignity of the engineer's calling was upheld. May I also add my firm belief that today there be many engineers who will qualify to the specifications of our interesting author. Since that time, the development of the world has been chiefly due to the engineer, and so far as human brain can foresee, the material tasks of the future will continue to follow the directions of his judgment. Popular opinion says this is the age of the engineer; literature, which in the long run, voices public sentiment, shows it in the number of engineers who figure as characters of fiction. The engineer has been doing the big things necessary to increase the comfort and efficiency of mankind, but while a certain amount of fame and repute falls to him, too often he figures as the hired man of the entrepreneur, using that term not in the offensive sense of a mere promoter, but to mean the great visioned master of enterprise who has seen ahead of other men, recognized the coming needs of the world, and through ability to inspire others and to hire capital for his use has also been able to hire engineers as needed. Justly enough, therefore, to such men comes the fame as well as the prize of the game.

Jan 1, 1926

By Mark Rantapaa

Measurable improvements in throughput have been documented at Barrick Goldstrike due to increased ore fragmentation through efficient drilling and blasting techniques. A decrease in throughput at the Autoclave, due to increasingly hard ore, was identified in early 2002. A team of individuals from the Open Pit and Process areas worked closely on the Drill-to-Mill (D2M) Continuous Improvement initiative to ensure that it would address the needs of both groups, with the target of actually improving throughput in future years, despite the projected harder ores. A series of tests were conducted to determine if adjustments to drilling and blasting could positively influence throughput. Better fragmentation and a subsequent increase in mill throughput were achieved through the use of: 1) Electronic caps for more precision and flexibility, as well as for allowing extremely fast shots. 2) Explosives with a higher velocity of detonation (VOD), to provide for improved shock energy. 3) Improved distribution of the explosives by decreasing pattern spacing. Early tests indicated a significant increase in throughput when processing identified harder ore. It is anticipated that the total process throughput (hard and soft ore) will increase by six tph in 2003 due to the improved fragmentation of the hard ore. Barrick Goldstrike?s D2M initiative includes roaster ?hard ore? (BWI >17), as well as autoclave ?hard ore? (BWI >15). Approximately six million tons of D2M material is expected be shot in 2003, a relatively small amount compared to the 150 million tons to be mined. The benefit of additional ounces produced should far outweigh the additional drilling and blasting costs.

May 1, 2003

By P. B. Bucky

IN this day of steady progress in the mining industry, especially along mechanical lines, the question of whether to discard present equipment for that of a new type often engages the minds of many officials of mining companies. The rapid strides made from year to year sometimes cause this question to be brought up within a year after new equipment has been purchased and installed. It is a moot question whether a machine that has been purchased last year should be replaced by a new one put on the market this year. As I see it, the reasons for the replacement of present equipment may be summed up as follows: (1) because of increased safety; (2) because of legal regulations; (3) because of increased profits. I think all of us, as engineers, will endeavor to put in as safe equipment as it is possible to devise. The tendency of mining companies in that direction is very gratifying.

Jan 1, 1930

By JOHN R. SUMAN

IT SEEMS particularly appropriate that the Institute's Regional Meeting should be held in Minnesota this year. Whether we like it or not, we cannot help looking at things now in the light of the World War and the all-out effort we, as a nation, are making to defend our resources, our institutions, and our way of life. The ability to do this lies in large measure in the ability to forge weapons of defense-the machines of war. The basic ingredients of any defense system, or war machine, are the raw materials of industry-iron ore, providing steel for guns, shells, tanks, and warships; coal for stoking the nation's furnaces; oil to furnish power for war planes, ships, trucks, and mechanized weapons; and all the other materials that play a vital role in the operation of modern armies and navies. The tremendous requirements of full-scale defense programs are indicated by the large number of commodities that are now under priorities because the supply is not sufficient to meet both defense needs and all normal civilian consumption. But out of all these items two are of paramount importance-steel and petroleum. In this age no nation can hope to main¬tain a position as a first-class power in the world without a highly developed industry, particularly the heavy industries based on steel, and without access to the necessary resources for those industries. In 1918, 70 per cent of the iron and steel production of the United States was required for defense purposes. In 1940, 15 per cent of our iron and steel production was consumed for defense purposes, and with the acceleration of the defense program, it appears that the proportion of steel output required for defense purposes will reach 40

Jan 1, 1941

By T. B. Counselman

WHEN one thinks of Minnesota iron ore, one thinks of big open pits, where high- grade ore is simply scooped up with a power shovel, loaded into cars, and hauled away for shipment to the blast furnace. On the western end of the Mesabi range, however, are large tonnages of iron ore which contain too much silica to be used directly in the blast furnace, and these ores must first be concentrated to a purer form. The Mesabi range is about 100 miles long and a maximum of 3 miles wide. The iron formation, which in its unaltered form is called taconite: consists of a banded iron- bearing chert. Where the high-grade ore bodies occur, these have resulted from folding and cracking with sub- sequent leaching out of the silica, leaving the iron oxide behind. The big open pits and the underground mines are situated in these concentrations.

Jan 1, 1941

By B. A. Stainton, John D. Gill

OUR combined economic activities have as their goal the maximum of individual well-being and national security. In this age of intense international competition the two objectives are closely related. For many decades, the maximum of well-being and ability to maintain national security have moved generally upward. The best single measure-perhaps the only adequate measure -of the level of the rising goal is the per capita real national income (national income corrected for price changes). For centuries before the industrial revolution the income of the world's population changed little from generation to generation. In our country prior to 1800 the growth of national income was hardly measurable from decade to decade. Since 1850, perhaps since the "industrial revolution," the growth of per capita real income has been increasing geometrically. Of major importance is the accelerative growth of the productive ability of our economy. Inadequate consideration of its implications is partly responsible for periodic delays in solving our princi-

Jan 1, 1946

By Frank Schrama

The Steel Plant Model (SPM) is an advanced logistic simulation model for steel plants. With the SPM, bottlenecks can be solved and logistics can be optimized. Both existing plants and greenfield designs can be simulated. All movements and actions simulated, from hot metal to cast products. Not only all major equipment and their relevant components (like a sublance) are simulated, but also ladles, scrap boxes, transfer cars and cranes. The whole plant is simulated in 3D and actual distances and speeds determine transport times. The SPM includes process time deviations and equipment downtimes for maintenance or unexpected breakdowns. This ensures more realistic and reliable results. Logistic optimization is based on comparison of different scenarios. For a new scenario, equipment and practices, etc. can easily be modified, added or removed. At the same time the SPM produces all relevant data for every new scenario, which can be presented conveniently. This makes the SPM the ultimate tool to find bottlenecks or optimize plant logistics. The SPM is validated for several plants world-wide, with different characteristics and layouts. The SPM not only realistically simulates existing plants with all utilizations, crane movements and waiting times, but also to accurately predicts the influence of plant modifications or unexpected events like breakdowns. Given the flexibility of the SPM, any (new) steel plant can be simulated quickly when a layout and the requested data are provided.

Aug 16, 2017

By Christoph Sedivy

Industrie 4.0 is slowly but surely arriving in the melt shops. Furnaces are being equipped with more and more sensors, digital models are increasing the degree of automation, and information is being shared between different aggregates within the plant. Because the electrode control system plays a key role in electric steelmaking, it naturally assumes an important position in the melt shop’s Industrie 4.0 strategy. In addition to reliable, state-of-the-art core regulation functionality, monitoring and reporting tools and the ability to communicate with other equipment are also required. Therefore, the latest generation of our electrode control system, the Melt Expert, was developed based on Industrie 4.0 design principles. Intelligent plant condition diagnostics, performance monitoring, and user-defined reporting are essential modules in this new system. With these functionalities, electrode control systems are developing into the information and control center of the furnace. A newly developed software app brings most relevant process information to mobile devices. This feature allows steelmakers to keep an eye on the performance of their equipment anytime and anywhere. This paper describes the new features of the electrode control system and shares our customers’ operational experience. Our focus is on the practical aspects of plant status monitoring, KPI reporting, and diagnostic functionality as well as the improvements achieved.

Oct 30, 2017

By Shengli Wu, Mingyin Kou, Laixin Wang, Zhe Wang, Xinliang Liu

The sticking behavior of iron ores in the shaft furnace is one of the most important problems in the COREX melting progress, which directly influence the smooth operation and productivity of shaft furnace. Therefore, it is of great importance to study the sticking behavior of pellets in COREX shaft furnace. The results showed that porous metallic iron produced at the interface of pellets samples was the main reason for the sticking of pellets in the COREX shaft furnace. The SI (sticking index) and metallization rate increased with the reduction temperature and gas flow, and decreased with melting rate. However, the SI of pellets in the COREX shaft furnace could be decreased by the proper match of melting rate and reduction temperature, reduction temperature and gas flow, while the metallization rate of pellets were kept at a certain level. Furthermore, the matching of melting rate and reduction temperature was more effective than the matching of reduction temperature and gas flow.

Jan 1, 2016

By Bin Xu, Qian Li, Yong-bin Yang, Tao Jiang, Jian-jun Hu

It could significantly increase the leaching rate of refractory gold concentrate containing sulfur and arsenic by roasting pretreatment with adding certain amount of sodium sulfate, and the mechanism of that was systematically researched with DSC, XRD and SEM in this paper. Results indicated that the mechanism of Na2SO4 on double refractory gold concentrate at roasting pretreatment can be summed up in the following three aspects：Firstly, Na2SO4 can react with SO2 and SO3 which is produced by the oxidation of sulfides and generate Na2S2O7(l), which plays buffer effect on sulfides exothermic oxidation, avoiding the secondary-encapsulated of gold. Secondly, the liquid phase of Na2S2O7 can cover mineral particles' surface that possesses a sintering effect, it leads to internal cracks of the particles. Finally, mineral particles will gather with sodium sulfate particles as the center that can improve the permeability of the layer.

Jan 1, 2015

By H Lieberwirth, M Pfeifer, F Heinicke

HPGRs (high pressure grinding rolls) have been developed within the last decades for energy efficient processing of a wide variety of ores. Special interest has been raised by projects increasing the capacities of processing plants by installing HPGRs prior to ball mills. Bond ball mill tests have been used for decades as a base for ball mill dimensioning in mineral circuits. For final CAPEXOPEX considerations of the processing circuit, one key question is about the level of grinding energy split between HPGR and downstream grinding stages. This is especially interesting if the downstream process comprises multiple grinding stages combined with separation steps. The paper presents investigations on grinding energy consumption, size distribution and microfracturing of HPGR products, which affect the efficiency of the whole comminution and sorting process.

Aug 24, 2022

By Scott G. Giltner, Alex Schwenk

Blasting within 250 ft of a crusher was successfully executed through the application of electronic detonators, 3-D imagery, signature hole analysis, custom loading of blast holes. The blast was well contained, the vibrations were minimal, and there was no flyrock.

Feb 1, 2020