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By Sara Jane Boles

The purpose of this Bureau of Mines investigation was primarily to isolate and examine the effect of liquid content upon the apparent porosity and bulk density of compacts pressed from high-purity, fused aluminum oxide, and, secondarily, to study the actual mechanism by which the liquid content affects the bulk density. No attempt was made to approach the theoretical maximum density of the oxide by introducing additives, particle packings, or similar variables; instead this study is an intercomparison of the bulk densities obtained as functions of the water contents of the compacting mixtures. Water content was varied from 7 percent to 25 percent, on a total-weight basis. The data gathered indicated a well-defined optimum water content for obtaining minimum apparent porosity and maximum bulk density, under the conditions of the experiment. During the course of this study, a number of additional variables in the forming process were discovered and are introduced in this report, although a thorough evaluation was found to be beyond the scope of this present investigation.

Jan 1, 1963

Magnetic separation is an age-old technique for mineral beneficiation operations. The existing mathematical models for magnetic separators are quite complicated, and it is very difficult to measure the theoretical separation efficiency. The connectionist approach of modeling, to establish the relationships of the inputs and outputs, is preferred for this kind of problem. Experiments were carried out on a high-intensity roll magnetic separator to develop a database using four input variables (magnetic flux intensity, particle size, splitter position and roll speed) and two output variables (weight recovery and Fe recovery). The artificial neural network (ANN) and statistical methods (MLRG) were used to model the magnetic separation process. For the ANN, the regression coefficient (R2) values between the predicted and measured results were 0.89 and 0.94 for Fe recovery and weight recovery, respectively. Compared to ANN, the multivariable linear regression analysis showed inferior performance in predicting the weight recovery and the Fe recovery. The ANN models for the roll magnetic separator can predict the separation efficiency up to an acceptable limit. These models can be used to modify the operational parameters at mineral beneficiation plants to minimize the effects of variations in the raw material characteristics.

Jan 1, 2009

By A. Krishnan

Keywords: Tantalum extraction, SOM Technology, inert anode, membrane stability The Solid Oxide Oxygen Ion conducting Membrane (SOM) technology offers great potential for environment friendly and energy efficient extraction of high-energy content metals. This work was performed to demonstrate the technical and commercial viability of the technology to produce tantalum metal directly from tantalum oxide and ore concentrates using a solid-oxide, oxygen-ion-conducting membrane (SOM). The process can be used to efficiently produce tantalum metal without expensive pre-processing of raw materials and without harmful by products. The work reported in this paper is: the proof that high purity tantalum metal can be produced, study of the electrochemical behavior of the cell and the method to increase membrane stability.

Jan 1, 2005

MFIRE is a computer simulation program that performs normal ventilation network planning calculations, and dynamic transient state simulation of ventilation networks under a variety of conditions. The program is useful for the analysis of ventilation networks under thermal and mechanical influence. MFIRE simulates a mine's ventilation system and its response to altered ventilation parameters, external influences such as temperatures, and internal influences such as fires. Extensive output enables detailed quantitative analysis of the effects of the proposed alteration to the ventilation system Network simulation using digital computers has become widespread throughout the mining industry in recent years. However, as the sophistication of the simulator increases (MFIRE, for example), the complexity of input data requirements and interpretations of results requires more skill and knowledge from the users. Perhaps the most difficult part of using MFIRE is to construct the data set describing the mine's physical layout and its ventilation properties. The initial attempts to get the data set running often reveal unknown or ignored aspects of the mine's ventilation. MFIRE was written in Fortran 77 and compiled with Microway1 Fortran for the Intel 80386 based computers with a 80387 math co-processor. The source code is portable and available for users who wish to modify the source code to operate on other computers. This user manual describes the development of MFIRE, the input format and requirements, the output, common errors, fire parameters, and examples MFIRE application. Valuable reference material is included in the appendices. Knowledgeable users may skip directly to the PROGRAM INSTALLATION AND OPERATION section to begin using MFIRE immediately.

Jan 1, 1995

The Effect of High Power Nanosecond Electromagnetic Pulses on Selectivity of Pyrite from Arsenopyrite

Sep 13, 2010

This manual provides instructions for installing, operating, and maintaining a protective canopy on the Galis Mfg. Co. face drill. The instructions are based upon an actual installation made in the mine on face drill model 460-S. The parts list and engineering drawings for the protective canopy are included at the end of the manual. And a discussion of some alternative design concepts is also included. The manual can also be used for retrofitting other face drills with similar protective canopies. Skilled mechanics can determine if the instructions herein would be applicable to the other face drills and can determine any necessary modifications if they are not.

Jan 1, 1973

Wastewaters from Mining Projects both gold mining and coal mining generally have minerals in solution or very fine material which does not settle out quickly. These waters in the past have been discharged into the nearest water course and caused extensive pollution.

Jan 1, 1986

By Jamal Rostami, Ebrahim Farrokh

Selection of tunneling method, specially the use of shielded machines for application in deep rock tunnels can be heavily impacted by presence of ground convergence and squeezing conditions. Tunnel convergence is a function of ground conditions (i.e., rock mass behavior, groundwater, in-situ stresses), size of the opening, and TBM operational parameters. The case study of Ghomroud water conveyance tunnel project in Central Iran, which is under construction using a double shield TBM, is used to examine the effect of rock parameters on tunnel convergence and hence on the need for over excavation and shield lubrication to avoid problems with the shield getting stuck. Although it is impractical to perform a continuous assessment of rock mass conditions within the shield or in the lined tunnel, results of field observations and subsequent studies show that the amount of the tunnel convergence has direct correlation with the percentage of fines and large rock fragments in the muck and TBM thrust/torque/ROP. These relationships have been examined and will be presented in this paper.

Jan 1, 2007

By James Tarr, Matthew Eichler, Brent Tardif

ANFO was being used as one of the blasting agents on a construction site in New England. Groundwater was encountered in numerous blast holes. The blasting contractor was employing typical explosives loading procedures for wet conditions. An abutter to the project complained that blasting caused her well water to have an odd taste and smell. Through testing, it was determined that there were hydrocarbons and nitrates in the well water. Several days later a second neighbor complained of foul tasting water; again it was determined that hydrocarbons and nitrates were present.

Jan 1, 2003

By Jim Sarvinis, Mark Berkley, David Clarry, Jason Berzansky

"Technologies developed to sequester CO2 or use CO2 for enhanced fossil fuel recovery are currently being utilized across the globe. Taxation regimes and CO2 credit trading are becoming drivers for a number of projects. Some mining companies have also identified ancillary opportunity to sequester CO2 in their by-products; recent work in the alumina industry is a prime example. In addition to process plant emissions, mining companies are becoming increasingly aware of their overall carbon footprint, including CO2 generated during the production of utility power. New power plant designs, in various stages of development, include CO2 separation and sequestration techniques. This paper summarizes the state-of-the-art for these technologies; including integrated gasification combined cycle (IGCC) power plants. A concept to use the gasification products as reductant in metallurgical processes is also described. The relevance of technology from power plant designs with post-combustion capture to the processing of off-gas generated in metallurgical facilities is also reviewed.IntroductionGlobalization and international economic growth have led to an increase in energy demand worldwide, and a corresponding increase in greenhouse gas (GHG) emissions. In 2005, 81% of global energy supply came from fossil fuels [1]; and while alternative energy technologies are emerging, it will require many decades to curb society’s fossil fuel dependence. Given the global concern of climate change and its scientific relationship with anthropogenic carbon dioxide (CO2), there is at present great interest in the development of techniques to reduce emissions of CO2. While most of these efforts are related to power generation and energy efficiency, the development of technologies for CO2 capture may offer opportunities in reducing emissions from industrial processes."

Jan 1, 2008

ALEXANDER, JOHN S, M,'74-6,'81-3 ASHBURNER, C A, M, '85-7 ASMUS, GEORGE, Dl, '78-80 BACON, D H , M, '00-2 BAYLES, JAMES C , M,'80-2,'91-3 P, '84-5, V,'88-9 BIRKINBINE, JOHN, M, '83-5, V, 'S7-J, P, '91-2 BLAIR, THOMAS S , M, '74-43 BLAKE, WILLIAM P , V,'71-4,'76-7,'05-6 BLANDY, JOHN F, V,'71-3,'78-9 BLOW, A A, C, '05-7 BOWIE, A J , JR, V,'93-4 BRAMWELL, J H , A1, '89-91 BROOKS, THOS B , M, '72 BRUNTON, D W , V, 97-8 BUCK, STUART M , M, '83-5 BURDEN, JAMES A, V,'80-1 BURNHAM, WILLIAM, M, '82-4. CAMPBELL, H H, M, '93-5 CHAMBERLAIN, H S , V, '96-7 CHANNING, J PARKE, V,'08 CHRISTY, S B , V. '91-2, '07-8 CHURCH, JOHN A, M, '79-8l,'94-6, V, '07-8 COGSWELL, W B, V, '74-5,'86-7

Jan 1, 1910

By Behrouz Tehrani

The size, complex issues, and requirements to construct large number of tunnels, for a single project, expeditiously, and without exceeding the overall project budget, a program Construction Management (CM) team is highly recommended to be selected early during design process to provide guidance/direction relative to contract packaging and scheduling. This paper is not focused on the project itself, however, the emphasis is on experiences gained from the project. Wishing that some of the strategies described in this paper will be of value to owners of underground project.

Jan 1, 2008

By Robert Boyd

The Diamond Markets ? Supply has continuously increased over the past 25 years ? However, global supply is expected to drop by 1 to 2% by 2015 ? Demand Driven Market ?Demand is expected to grow 3% annually through to 2015 ? Supply Squeeze Anticipated (2010 to 2015) ? Consumption is exceeding rate of discovery, mine development and reserve replacement ? These fundamentals are driving increased capacity and production at existing mines in South Africa, Botswana and Russia and new areas such as Canada ? Canada is now the third largest diamond producing country in the world ? These fundamentals are also driving record levels of exploration expenditures throughout the world with particular focus on Africa and Canada

May 1, 2006

By S. Tuttle, R. Sisson

"Suncor Energy Inc. has proposed a 2.2 billion dollar expansion to the current oil sands operation, which will more than double the productive capability of the facility. As part of the application for this expansion, a comprehensive closure plan had to be developed and filed.Closure planning includes a systematic evaluation of the area to be developed, the development activities planned, the goals and objectives of the corporation in re-establishing landforms and ecosystems at the same time as running an effective operation. As early as is practical during the mine development, surface contouring is completed, soil is reconstructed, and vegetation, surface drainage and wetlands are re-established. Once active reclamation is complete and vegetation has been re-established, Suncor monitors maturation of landscapes and ecosystems to provide the submission basis for reclamation certification"

Jan 1, 1999

By D. Strachan

Installation of support in known poor ground intersections during reaming operations requires rapid access to stabilize the shaft wall and thus to prevent the loss of the shaft through scaling. This is especially relevant to shafts of long dimension where the duration from time of exposure to time of support installation is lengthy This paper deals with the innovative methodology employed at Harmony?s No. 8 Shaft 17/24 level sub ventilation shaft to rapidly support a shale intersection between 23 and 24 Level by employing a single deck stage suspended from the reamer head by means of Skyjack winches.

Jan 1, 2009

ALEXANDER, JOHN S, M,'74-6,'81-3 *ASHBURNER, C A, M, '85-7 ASMUS, GEORGE, Dl, '78-80 BACON, D H , M, '00-2 BAYLES, JAMES C , M,'80-2,'91-3 P, '84-5, V,'88-9 BIRKINBINE, JOHN, M, '83-5, V, 'S7-J, P, '91-2 BLAIR, THOMAS S , M, '74-43 BLAKE, WILLIAM P , V,'71-4,'76-7,'05-6 *BLANDY, JOHN F, V,'71-3,'78-9 BLOW, A A, C, '05-7 BOWIE, A J , JR, V,'93-4 *BRAMWELL, J H , A1, '89-91 BROOKS, THOS B , M, '72 BRUNTON, D W , V, 97-8 BUCK, STUART M , M, '83-5 *BURDEN, JAMES A, V,'80-1 BURNHAM, WILLIAM, M, '82-4. CAMPBELL, H H, M, '93-5 CHAMBERLAIN, H S , V, '96-7 CHANNING, J PARKE, V,'08 CHRISTY, S B , V. '91-2, '07-8 CHURCH, JOHN A, M, '79-8l,'94-6, V, '07-8 COGSWELL, W B, V, '74-5,'86-7

Jan 1, 1910

By Thomas A. Davidson

The Bureau of Mines Helium Field Operations has developed a simple and accurate method for calculating the viscosity of gas mixtures. Only the composition of the mixture and the molecular weights and viscosities of the pure components in the mixture are required. The momentum fraction of a mixture is calculated from the composition. The fluidity is calculated as a quadratic function of the momentum fractions. The efficiency factor for transfer of momentum in collisions between bodies of different masses is derived and used with one empirical constant. The viscosity is the reciprocal of the fluidity. Results of the method are compared with 752 reported viscosities for 40 dilute binary systems at temperatures from -78 to 276.9°C. Using this method the average absolute deviation is 1.29%, the root-mean-square deviation is 1.99%, and the average deviation is -0.84%.

Jan 1, 2010

By H Kurth

Geoscan is used for multi-elemental analysis of conveyed bulk materials in real time. It has been used for coal analysis since the 1990s, in the cement industry, and since 2003 for measuring mineral ore quality. Geoscan-M has proven performance and demonstrated paybacks of weeks or months, in iron ore, manganese, copper, zinc-lead and phosphate industries. Geoscan-M measures continuously through the full bed depth and is unaffected by belt speed, particle size, layering and dust levels. Increments of two minutes (typically one to five minutes) are accurately measured and provide the plant operators with tonnage weighted results of each element within seconds.A Geoscan installed after crushing is able to measure quality shortly after mining. The analysis results can be used to divert the increments based on composition, such as diverting waste for disposal and diverting marginal material to a stockpile for processing at a later date. The bulk sorting process allows different qualities to be placed into relevant stockpiles for subsequent blending. Material meeting product DSO (Direct Shipping Ore) quality can bypass a beneficiation circuit to prevent unnecessary treatment costs. An analyser in a blending application enables proportioning of different quality feed materials from multiple stockpiles to achieve a desired compositional consistency for process feed. The parameter used for decisions may be; a) primary metal content, e.g. Cu, Fe, P, etc. b) deleterious component content, e.g. Mg as an indicator of talc content, c) process parameter content, or a combination of these. Process parameter content may be the elemental ratio between critical components, e.g. Cu:S ratio, Fe:Si ratio, basicity, Lime Saturation Factor, etc. or the content of an “indicator” element, e.g. Si as an indicator of material hardness or grindability.Measurement of the composition in real time enables prompt feedback to the mining operators and also feed forward to the process operators. Compositional variability can be critical in the process and advance warning enables appropriate reactions prior to processing. This may include modifying the feed rate, changing the feed blend (through additives), or modifying reagent dosing in anticipation of a change in feed quality. Benefits include, but are not limited to; reducing waste processing, improved feed grade stability, reducing energy, water and grinding media consumption, producing less tailings, increasing process efficiency, higher metal recovery, better plant utilisation, reducing plant downtime, better utilising mined material, all achieved using the same process plant throughput capacity.CITATION:Kurth, H, 2015. Optimising plant feed quality and process performance using Geoscan elemental analysis, in Proceedings MetPlant 2015, pp 373–380 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 7, 2015

Generating short- and long-term mine production schedules in isolation and independently from each other means that only a local optimum can be achieved when each scheduling phase is carried out. The globally optimal solution however, can be achieved when integrating scheduling phases and accounting for the interaction between short-term and long-term activities simultaneously. This paper addresses the task of integrating short- and long-term production plans by combining the short-term objective of minimising deviation to targeted mill feed grade with the long-term objective of maximising net present value (NPV) into a single mathematical model. A case study is presented which compares the present values of the same stope data set scheduled via separate long and short-term models and than by the proposed integrated model which applies a predetermined penalty for each tonne of metal deviation to target for the respective ore tonnage being processed. This allows an operation to obtain a globally optimal scheduling regime when taking into consideration the cost and loss of value resulting from fluctuations in grade to the mill over the short-term.

Dec 6, 2010

By Jos. R. Guiteras

This paper has been written to describe briefly the mining and milling of gold and silver ores in the Black Canyon and neighboring mining districts in Yavapai County, Ariz. The description of present operations is the result of a 10-day visit to the region by the writer in March 1936. Acknowledgments The author is indebted to earlier writers on the geology and mining in this regions and to the mine managers and their staffs, whose courteous cooperation has made possible the assembling' of material for this paper. Individual acknowledgments are made in the text.

Jan 1, 1936