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By G. Demi, G. Belardi, N. Shehu, S. Cico

The physico-chemical interaction between minerals such as olivine, chromite and serpentine and the ions most commonly present in solution, like Ca and Mg and flotation reagents such as EDTA and oleic acid was investigated. The study was conducted via release tests, electrophoretic measurements and microflotation of selected minerals coming from the Kukes deposit (Albania).

Jan 1, 2003

By C. James, J. Siefke, D. Shumway

The Mojave Desert is a particularly fragile ecosystem that faces several significant impacts. These include rapid housing development, overdrafted water supplies, and loss of wildlife habitat as a result of mining, industrial activity and urban sprawl. Over the past three years, a diverse group of educators, natural resource managers and business leaders has been assembled under the auspices of a local college to provide unique natural resource education opportunities for the region. By leveraging the collective experience of these present generation natural resource professionals, the Mojave Sustainability Project hopes to provide the next generation of professionals with that knowledge and those technical skills upon which tomorrow’s community can rely. This paper is a case study of how partnerships between academia, government, industry and the community can serve to address the regional social, environmental, and economic needs of today, while investing in the development of those professionals who will balance these needs tomorrow.

Jan 1, 2005

By James R. Kunkel

The paper point out the use about of robust water-balance method for sizing heap leach solution ponds and water reservoirs. In this sense, using a robust water-balance method to size storage ponds and reservoirs as well as to calculate operational water demands is important to assess the interactions between operational and climatological variables for the project.

Sep 13, 2001

By Júlio C. Lúcio

Consider the case of a mining company with N investment opportunities in projects of different commodities. The problem is: since the company has limitation of capital, equipments, technical staffs, etc, what is the best portfolio of production projects in order to maximize expectations from shareholders? In the no-longer past, the traditional method for the selection of portfolio of projects was the rank-an-cut method. But, this does not properly account for the risk to which the company is exposed. The Markowitz?s Mean-Variance is an advance because the risk of the NPV can be estimated at the level of the company or even division of the corporation. The final product of the Markowitz?s model is the efficient frontier, in which, the manager can clearly understand the maximum return from existing assets and the associated risk level - but this model does not recommend which one is the best portfolio. In this paper we present a model to select the best portfolio considering not only economic indicators, but also requirements of production, constraint in investments, etc. We show that if investors are diversified, managers should select projects with highest return, regardless of risk. However, in practice, if bonuses of managers are tied to their performance, the choice for portfolio with lower return and risk can happen. Numerical application considering typical portfolio of large mining company is used as example.

May 1, 2009

By Linda Duncan, Trevor Yeomans, Chris Potorieko, Michael Fullam

"NVI Mining’s Myra Falls Operation is a 4,000 mtpd copper/zinc flotation circuit with by product gold of ~28,000 ounces per year. Gold recovery has historically averaged 40-55%, however, a portion of this was recovered in the zinc concentrate and received poor payment. Two Knelson CD-30 Concentrators have been operating in the grinding circuit since 1992, with gravity recovery averaging about 2-5% over that time period.The Myra Falls gravity circuit was one of the very first hard rock mining installations operating in the world with automated Knelsons. The mine has employed a unique and unusual upgrading method for the Knelson concentrate that had never been evaluated as to its efficiency. Recent Gravity Recoverable Gold Testing by McGill University, and mathematical modelling of the Gravity Circuit by Knelson Gravity Solutions indicated the gravity circuit was not living up to its potential. Myra Falls Personnel changed the upgrade system-operating regime, and a complete gravity audit of the grinding circuit was carried out, with the results confirming the initial suspicions. Gravity recovery increased from 5% to 15%, with overall gold recovery improving by 5%.INTRODUCTIONNVI Mining operates a 4000 tpd mine and mill complex on Vancouver Island. The milling circuit consists of open circuit rod milling, closed circuit ball milling, gravity recovery, copper flotation, zinc flotation, and tails disposal. There are two milling circuits, “A” circuit, and “B” circuit."

Jan 1, 2006

By R. W. Van Dolah

An attempt has been made in this investigation to define the conditions under which ammonium nitrate (AN) might detonate as a result of involvement in fire. The initiation of detonation by shocks derived from explosives or from projectile impact was investigated as a function of temperature and charge diameter. A new technique was devised to investigate the burning of raw and contaminated AN under pressure. No transition, to detonation in AN was obtained in the burning experiments. The critical diameter for detonation of fertilizer-grade AN was found to be quite small when the AN was at temperatures just below melting point; this indicates that initiation of detonation may be less difficult at elevated temperatures but such initiation by gas-phase detonation was shown to be unlikely. Transition from burning to detonation was obtained with AN intimately mixed with fuels that included polyethyl-ene, paper, and fuel oil when these were contained in vessels with restricted vents. However, the experimental results supported by an analytical study indicate that the initiation of detonation in AN from fire exposure in normal storage and from transportation incidents is quite improbable. The detonation of AN in recent incidents more likely may have resulted from the effects of adjacent explosions.

Jan 1, 1966

By C. C. Wright, R. J. Day

Although data on the exact tonnage of recoverable coal silt are not known, the quantity produced in 1943 was estimated to be over five million tons for the anthracite region of Pennsylvania alone. Since that time the recovery of the No. 5 buckwheat size previously included in silt estimates has increased greatly thus reducing the total silt tonnage. As a compensating factor, however, the methods of recovering silt previously escaping into the rivers and streams have been markedly improved so that the net figure may not have changed materially. Comparable estimates for bituminous coal are lacking, but undoubtedly the silt represents a significant tonnage. With the trend toward increased wet cleaning of the smaller sizes of bituminous coal, it is to be expected that even greater quantities of silt will be available in the future. The raw silt from anthracite collieries usually contains a high mineral matter content, but technological developments in fine coal cleaning have been making rapid advances and it appears probable that more extensive use of these methods will be employed in the near future. Bituminous coal silt in many instances contains a similar high mineral matter content. As with anthracite silt, however, the cleaning of this material, where necessary, appears both technologically and economically feasible. With a view to upgrading the size and value of silt, considerable laboratory and pilot plant work has been conducted by a number of organizations on what is commonly known as pelletization. Actually the process is one of extrusion in which the moist silt is extruded from a die in the form of rods, which usually break into relatively short lengths—a few inches long—as they fall from the die. Fig I is a photograph of some extruded 3/8-in. diam pellets and of the anthracite silt from which they were produced This technique of producing larger sized material from fines is by no means new, having been used extensively by the industrial carbon and clay industries for years.' The application of the process to coal silt appears, however, to be relatively new. The first major program of investigation dates back only to July 1945, when a group of engineers representing the Anthracite Institute, The Pennsylvania State College and the J. F. Pritchard and Co. conducted preliminary tests on the extrusion of anthracite silt at the Floridin Co. plant at Warren, Pa. Since that time these three organiza-tions—individually, together, and in cooperation with other interested groups— have actively pursued work on various phases of the problem. Much of the early history and details of the laboratory and pilot plant work by the Anthracite Institute, has been reported by Mulcey and Eckerd.2 It is the purpose of this paper to report additional information on the process, especially with respect to the factors influencing the quality and use properties of the product, and the current develop-

Jan 1, 1949

By W. W. Adams

[The s1xteeilth an.nual National Safety C mpeti t1on, concluc ted "by the Bureau of t4ine g, Un+ ~ed st tag' DepartIilent 0:1' the Interior, has jast been closed, and the results reveal t:'W.t. t_!e co~)eting comps.nies had fewer a.ccidents in proportion to the number. of !\1a..."1-h(J1J.l'~ :orkcd than in a:ny other yeex in the record of the contest. These annUk~l contestn are thus achieving the r purpose of promoting safety in tho minin induC'tr:r. ]

Jan 1, 1941

By Zhiqiang Zhou, Shengnan Zhou, Zizong Zhu, Yuchuan Ding

The effect of silicon on removal of phosphorus from high phosphorus Si–Mn alloy was investigated at 1673 K by CaO-based slag. It was found that the dephosphorization efficiency increases significantly as increasing the silicon content, which is due to the reaction between silicon and CaO at slag/alloy interface. The relation between silicon content with oxygen activity and phosphorus activity coefficient of Si–Mn melt was determined respectively as follows: lg aO = -1:55xSi - 1:67; ln rP = 9:26e xSi 0:0433 + 11:0839 The carbon content in Si–Mn melt decreases continuously with the increasing silicon content, meanwhile, the decreasing rate of carbon content becomes rapid when the mole fraction of silicon is about 0.32. Si addition is beneficial for both dephosphorization process and low carbon Si–Mn alloy production.

Mar 1, 2017

By T. H. Miller

An attempt has been mace in this publication to present annotated references to all articles pertaining, to ore dressing that were published during 1931 and 1932; in a few instances reference is made to articles published prior to 1931 where the articles have not been included in previous bibliography appended to the annual statistical discussions of ore concentration published by the Bureau of Mines. Articles have been taken from more than 75 periodicals, journals, serials, etc., and 423 articles are abstracted herewith. A number of these abstracts, particularly those appearing in foreign publications, have been taken from Chemical Abstracts (published by the American Chemical Society, Easton, Pa.), the general use of which the authors wish to acknowledge. Other annotations were taken directly from the original publications. The entire field of ore dressing has been included in the bibliography and articles dealing with crushing, grinding classification, concentration, thickening, and filtration have been included, as well as on amalgamation, cyanidation, leaching, magnetic concentration, washing, etc., and on theory and laboratory operation. The articles are arranged in alphabetical order by authors. Lack of printing funds prohibited the inclusion of a subject index.

Jan 1, 1934

This is what I term ... the graveyard end of any Conference. It's almost over. Those of you remaining are either all talked out or past the information overload stage. And some of the sensible? ones have left for more exciting field trips, or gone back to their work-site where they earn their daily crust, or headed off South to another Conference of interest to the Energy sector that is being held currently in Christchurch. But that's OK. I have a thick skin! And neither am I particularly Politically Correct! I am not a miner: I am not involved in the mining industry in a hands on way at all. I am not even an academic. I am not even too sure why I am here ... apart from the fact that I agreed to come! At various times in my life I have been a D istrict Councillor, Chairman of a Regional Council and even an MP. I am a supporter of responsible mining.  All of what I have to say is my own point of view rather than that of either the Coal Producers' Federation or the mining industry. That is not to say that we are often in agreement, but I thought I would clear that point right at the outset. And some of what I will talk about will not strictly be to the topic - it's hardly mind-bending riveting stuff. Well, is it? But obviously because you are still here you have some interest in the topic.

Jan 1, 1997

By Robert W. Geehan

"INTRODUCTION A preliminary examination of the Argentena mine was made in 'January 1945 by an engineer of the Bureau, who recommended investigation by diamond drilling. The Bureau conducted a core-drilling project at the mine from April 30 to August 4, 1946. Claims investigated are in sec. 33, T. 24 S., R. 58 E., Mount Diablo base and meridian, in southern Clark County, Nev., about 2.2 miles west of Goodsprings.The Argentena mine has been an intermittent producer of zinc-lead-silver ore since 1926. During the war years, ore was shipped to the Government stock pile at Jean, Nev., and to the International Smelting F. Refining Co.'s smelter at Salt Lake City, Utah. The mine has been shut down at intervals because of lack of a market for mixed oxidized zinc-lead ore.The 12 holes drilled by the Bureau totaled 1902 feet. The program was designed to test for faulted portions of the ore bodies know in the mine and to test favorable areas for similar ore bodies. As a result of this program, one faulted segment of the ore body was found, and it was established that no one was present in a second fault block. Similar blocks remain unexplored in the vicinity of the mine. Two holes drilled in favorable areas several hundred feet from the mine failed to discover new ore bodies."

Jul 1, 1947

By William R. Yernberg

The combined 80th Annual Minnesota Section of SME Meeting and 68th Annual University of Minnesota Mining Symposium was held April 17 and 18, 2007, in Duluth, MN. About 350 mining industry professionals attended the conference, including engineers, executives, mining managers and suppliers from the United States, Canada, Australia, Finland and Brazil. This year’s theme was “Consolidation – Growth – Technology.” The 80th Annual Minnesota Section of SME meeting included concurrent technical papers sessions, a keynote session that featured two distinguished speakers and a general managers session in which taconite mine operators provided updates on their operations. The Minnesota Section meeting also offered an SME short course titled “Control the Feed, Control the Mill.” More than 50 individuals at-tended the short course.

Jan 1, 2007

By Wen-Chieh Cheng

Two bored piles with base grouting are loaded axially and the results are used to compare with numerical analyses. One compressive pile with a diameter of 2 meters is drilled through clay deposit and into bedrock to a depth of 13.7 meters. One tensile pile with a diameter of 1.5 meters is drilled through the same clay deposit and into bedrock to a depth of 17 meters. Both piles are installed with monitoring system such as rebar strain meters, concrete strain gauges and extensometers. The monitored data during pile load test are used to obtain average frictional stress (t) a displacement (z) curve, pile tip bearing (q) as well as pile head load (p) and a displacement (s) curve. FLAC3D is used to simulate the pile loading and base grouting. The soil and bedrock are modeled with Mohr-Coulomb. The parameters of the constitutive law are established from soil biaxial tests and rock bore hole deformation tests. The pile is assumed as an elastic body. The interface element is used to simulate the pile/soil interface and pile/rock interface. The numerical results are compared with the pile load test in terms of t-z curve, q-z curve and p-s curve. Finally, the pile base grouting is simulated and the uplift is analyzed. The result from this study is promising and the numerical modeling is successful.

Jan 1, 2006

Two Variable Real-Time Algorithm for Cone Crusher Control

Sep 13, 2010

By P. Wearden, K. Bryner, K. Vrana, V. Castranova, R. Dey, R. Reist, J. Blackford

"Summary: Fibroblast proliferation and enhancement of collagen synthesis are key steps in the development and progression of pulmonary fibrosis. The current investigation presents a fibroblast proliferation assay to detect the release of competence factors from pneumocytes. The specific objective of this study was to define cell culture conditions for fibroblasts that would allow selective detection of competence factors in test media. The results indicate the following: (a) fibroblasts should be cultured for 2 days in plasma-free medium rather than 2% plasma to assure complete quiescence; (b) 1% plasma was optimum for producing progression activity for the bioassay of a competence factor, while 0.5% plasma did not produce sufficient progression activity (yielding false negatives) and 2% plasma often contained significant competence activity (yielding false positives); and (c) fresh plasma should be used since the progression activity of plasma was adversely affected by freezing and thawing. Under these conditions, this bioassay can be employed with either rat or human lung fibroblasts to detect competence factors such as platelet-derived growth factor (PDGF), at levels as low as 25 ng/ml.Fibrotic lung disease, as a consequence of occupational exposure to silica dust. is characterized by the development of concentric hyalinized nodular lesions in the lung and the progressive loss of pulmonary diffusion capacity. Proliferation of pulmonary fibroblasts and enhanced synthesis of collagen by these pneumocytes have been shown to be key steps in the development of chronic silicosis ( 1 ). The regulation of lung fibroblast proliferation by cytokines released from alveolar macrophages may be an important pathogenetic mechanism in the development of the fibrotic process (2). Some cytokines stimulate fibroblast proliferation by activating specific phases of the cell cycle (3,4). In particular, platelet-derived growth factor (PDGF) promotes fibroblast proliferation by inducing the movement of quiescent (G0 ) cells into the G1 phase of the cell cycle (5). Insulin-like growth factor (IGF) and transforming growth factor-P (TGF-P). on the other hand, regulate the rate of transition of fibroblasts from G 1 into the S phase (5,6). These two classes of cytokines have been termed competence and progression factors, respectively. One approach used to examine the release of cytokines from macrophages is the fibroblast proliferation assay in which quiescent fibroblasts are exposed to culture supematants from macrophages exposed to various stimuli. In most of these assays, the supernatant contains fetal calf serum (FCS), which provides the competence factor(s) necessary to facilitate the proliferation of fibroblasts (7-9). Recently, a fibroblast proliferation assay using platelet-poor .plasma [lacking competence factor(s)] as a substitute for FCS bas been described (I 0, 11 ). In this assay, the release of a competence-inducing PDGF-like growth factor from rat and human macrophages can be distinguished from other cytokines that act as progression factors."

Mar 1, 1992

By J. E. Spurr

"Zinc Industry in BelgiumBy March F. Chase, Consulting Metallurgist, Bureau of MinesBelgium for many years was the principal spelter producing country of the world. Gradually its production was surpassed by that of Germany, and Germany in turn lost first place by the production in the 77ti.tad States. For the ten years previous to 1914, 21.6 per cent of the world's spelter was produced in Belgium. Of this production approximately 40 per cent was exported. A large percentage of the balance was rolled and of the shoots thus produced a considerable quantity was also exported.From an economic standpoint even before the war, the Belgian industry was in a unique, if not praoarious, position. Dependent upon foreign countries for ore and foreign markets for sale of products, smeltor was at a distinct disadvantage when compared with some of those of other localities. These disadvantages were partly offset by cheap coal and labor and by whatever there is of value in experience and what we may term for want of a better expression smelting tradition. However intangible this latter may be, it did have and has today an influence on commercial operations.One must not overlook the effect it will have on the revival of the industry. It may not be the determining factor but the fact that for so many years this industry flourished in Belgium, and played such an important role in the industrial life of the country will decide many operators to attempt to re-establish their operations.In 1913 the Belgian spelter plants produced 204,220 long tons of spelter or approximately 20 per cent of the world's production. During this year 500,000 to of ore were treated. The actual value of all of the products derived from treating sine ore amounted to 225 million frames."

May 1, 1919

By David H. Searle

This paper will discuss the common trends existing in various Canadian jurisdictions for the closure and reclamation of mines. Included will be a discussion of the requirement to post security as well as its form and how security is calculated and refunded. Reclamation can no longer be left to the end of mine life. Progressive reclamation must occur throughout mine life and must be part of the mine plan from the beginning.

May 1, 2006

By A. C. Munro

This paper, which describes the milling practice at the Britannia concentrator, Britannia Beach, B. C., is one of a series being prepared by the Bureau of Mines. The concentrator treats copper ore at the present rate of 6,000 to 7,000 tons of dry ore daily and produces copper concentrate and pyrite concentrate by selective flotation methods. The copper concentrate is smelted and the pyrite product is utilized for acid manufacture.

Jan 1, 1932