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Development of Technology for Complex Uranium Ores Processing on the Flotation Process Basis

Sep 13, 2010

By J. A. Lamonica

The Bureau of Mines conducted an environmental noise survey to determine the noise levels to which underground coal mine employees are exposed, to evaluate noise survey techniques and equipment, and to compare noise exposures using two criteria, Walsh-Healey and CHABA, for determining allowable exposures that were under consideration for the Federal Coal Mine Health and Safety Act of 1969- Time study techniques and Bureau-approved standard sound level meters were employed. The shift exposures of 20 percent of the miners studied were in excess of the safe standards established by both criteria. The shift exposures calculated using the Walsh-Healey criteria were greater than those calculated using the CHABA criteria owing to the intermittent nature of the exposure. Ultimately the CHABA criteria were rejected, and the Walsh-Healey criteria were adopted.

Jan 1, 1971

A Study of Extracting Vanadium from Stone Coal Using Cyclic Oxidation

Sep 13, 2010

By Franciszek Letowski

"Recovery of precious metals associated with a sulphidic matrix has an important economic effect on complex sulphide ore treatment. Because a significant portion of the silver and gold associated with pyrite are rejected to tailings during the selective flotation of pyritic Zn-Pb-Cu ore, other ore processing routes have been investigated.Direct leaching of the ore with ferric sulphate solution followed by separation of different components of the solid suspension by flotation was applied. Such a process allows for: production of zinc sulphate solution; transformation of galena PbS to insoluble lead sulphate PbS04 and its accumulation in a non-floatable fraction together with precipitated geothite FeOOH and other insoluble gangue minerals; separation of sulphur and non-decomposed sulphides in the floatable fraction.Laboratory research carried out on the ore samples from an Alaskan pyritic deposit from the Delta region indicates that gold and silver are mostly concentrated in the floatable fraction.Total recovery of zinc from the ore attains 96.5% to 98.5% after ferric sulphate leaching. About 85% of copper was extracted from the ore during the ferric sulphate and subsequent ferric chloride leaching, and about 6% of the copper remained in the non-floatable fraction and mixed fraction during the leaching-flotation step. Extraction of lead from the nonfloatable fraction during leaching with calcium chloride solution attained 98% to 99%. Extraction of silver from the floatable fraction during leaching with ferric chloride solution reached 98%. Extraction of gold from the floatable fraction during cyanide or thiourea leaching reached 71% to 89%. The results of the laboratory research are presented."

Jan 1, 1987

By Dermot Winters

The Surface Mining Control and Reclamation Act (SMCRA, or the Act) was enacted on August 3, 1977. The Act was written, in part, to put an end to uneven environmental standards and to establish minimum national standards. Certainly, one of the motivating factors for passage of the Act was the success of the Federal Coal Mining Health and Safety Act of 1969 in reducing deaths and injuries in the coal industry nationwide. Section 516 (b) (1) of the Act requires *that subsidence be prevented from causing material damage to the extent technologically and economically feasible except in those instances where the mining technology requires planned subsidence in a predictable and controlled manner. Section 516 (c) of the Act authorizes the regulatory authority to suspend underground mining if there is imminent danger to inhabitants of urbanized areas, cities, towns, and communities. On December 13, 1977, the interim program, which applies a portion of the performance standards of the Act, was promulgated. Then on September 18, 1978, the proposed permanent program was published for public comment. Finally, on March 13, 1979, the final permanent program was promulgated and the States were given a period of time to submit their programs for approval.

Jan 1, 1986

By M. Slatter

The need for anti-corrosion coatings has existed for many years in the ground support industry, but the application requirements have made coating selection limited. Varying groundwater and chemical conditions continually challenge long term coating performance. Traditionally the industry coating preference has been hot-dip galvanizing due to its performance characteristics in highly corrosive environments and low cost nature. However, the galvanized coating has application limitations. This paper highlights some of these limitations and provides selection criteria for a new organic coating developed for one such difficult application, DSI?s Omega BoltPTM Pwhich is an expandable ground support. [ ]

Jan 1, 2009

By L Tolmay, L Nair

Investor confidence can be compromised when one observes large discrepancies between the SAMREC reserves and the mining plan. It is therefore up to the responsible persons to ensure that all contributing factors get taken into account when determining a reserve declaration. Confounding factors could be further aggravated by large oscillations in the commodity price thus resulting in major changes to the mining plan, if the accepted price was either too optimistic or pessimistic. Additional factors that must receive our attention are, uncertainty in geological facies type, mining practices, geology and grade estimation. The paper outlines (in the authors? opinion) some of the important factors that need to be taken into account, in order to ensure proper alignment between the estimates of the life of mine (LOM) reserve grades, and the corresponding actualisation of the mining plan. These parameters provide an historical insight into what actually happens when attempts are made to implement the mining envisaged in the LOM plan. In turn these allow judicious application of discount factors that enable a realistic estimate of SAMREC reserve classification and declaration. Some of the factors that will be covered are: - 1) Flexibility of developed reserves and the ability to maintain this. 2) Mining control mechanisms and their overall efficacy. 3) The ability to extrapolate facies types and its effect on grade control. 4) The ability to control the mining mix and value variation. 5) Finding a happy medium between optimism and pragmatism.

Jan 1, 2007

By J. Kortnik

Mining has always been, and still is, an activity which is vital for the development of mankind. This is because a predominant proportion of industrial products and energy is produced from raw materials that are excavated using mining methods. The need for environmental protection and the close proximity of urban settlements and mines in Slovenia have necessitated ever stricter requirements for the excavation of raw materials and introduction of more environmentally-friendly mining methods. This is achieved by implementing a closed eco-technological cycle of raw material excavation within the scope of mining methods. In surface mines, this means prompt reclamation of the degraded surfaces, and in underground mines the use of methods with minimized impact on the surface and on underground water. In underground mines, mining methods with backfilling installed according to the multi-barrier disposal system are the only ones that allow the possibility of implementing a closed eco-technological cycle of excavating raw materials. Various industrial waste materials are also included in the backfilling material in order to improve its strength properties. Backfilling consisting of several different waste materials is produced in the form of a composite. Before backfilling consisting of waste material composites can even begin to be used in mines, an environmental impact assessment of its suitability for mines needs to be made. In order to make such an assessment, a pressure leaching cell and an open diffusion cell were made, i.e. a pressure leachate test and a sorption test were developed. The two cells and the developed tests will enable the study of the influence of backfilling on the environment if installed in an underground mine. The pressure leachate test performed with the use of the pressure leaching cell simulates leaching from a consolidated backfill during the seeping of underground water into the backfilling material under pressure. The sorption test performed in an open diffusion cell simulates the flow of eluate leached from the backfilling material through the rock/geotechnical barrier. The two tests were developed in such a manner that they are performed either in succession immediately after one another, but they can also be performed separately at a certain time interval. The paper presents an assessment of the suitability of backfilling made of different waste material composites. Keywords: environmental impact assessment, multi-barrier disposal system, waste material composites, pressure leachate test, sorption test, pressure leaching cell, open diffusion cell, eco-technological cycle, mining methods with backfilling.

Jan 1, 2003

By J. B. Gwiazda

S.S. Peng The highlights of this paper are : • The shield supports with lemniscate links will exert a tangential force on the roof strata, causing unnecessary and harmful roof movements, thus damaging the roof structure. The principal source of the tangential force is the horizontal movement of the point O, the pivotal joint between the canopy and the caving shield. When the support height is changed during setting, the point O will move along a curve upward and rearward toward the gob. As a result, it produces a vertical movement, causing the roof to move up a distance of ?d, and a horizontal movement toward the gob, creating vertical fractures in the roof. • The major purpose for employing the lemniscate-link system is to protect the hydraulic legs against the action of the bending moments induced by the tangential force that causes deformation or destruction of the legs. • Based on these two points, the author suggested that, in order to eliminate the harmful effects of the lemniscate-link system and strengthen its advantageous features, a shield support with a new design of that mechanism has been developed. With the new design, the conventional rigid lemniscate links are replaced by hydraulic rams. When the pressure inside the rams reaches a certain level, the ram will yield.

Jan 12, 1986

By Pierre De Pasquale, Aquilino Antonio Alvarez-Castro

Greenhouse gas emissions are now an essential issue for extractive industries. Actually, lowering of quarry energy consumption and CO2 emissions participates to answer both environmental and financial issues. The “EE-Quarry” European project, supported by the European Commission (EE stands for Energy Efficient), develops a new and highly effective modelling and monitoring Energy Management System technique to improve Energy Efficiency and move to a low CO2 emission rate in the nonmetallic mineral industry.

Jan 1, 2016

By R A. Lynch, D A. Malovichko

The implementation of routine real-time micro-seismic monitoring of open pit mine slopes has been discussed. Some examples of seismic arrays have been given, and a recommendation of suitable seismic sensors made. Unfortunately near-surface sensors are required for good location accuracy, and the effects of reflection, mode conversion and surface waves must be accepted and compensated for during processing of the seismograms. It makes sense that mining at the base of a slope and levels of seismic activity within the slope should be related, and this is confirmed using both 2002-2003 and 2005 seismic data recorded at Navachab mine. An example of how seismic data can be used to gain information about seismically active geological structures has been described. The removal of broken rock, and not blasting nor the breaking of supporting rock, has been found to cause slope micro-seismicity. While the standard Brune source model is suitable for some 20% of the seismic events, unreasonable results are obtained for the rest. A moment tensor inversion has been performed after S-wave splitting and surface effects have been filtered out. This approach confirms a predominantly shear mechanism for a typical high frequency source.

Jan 1, 2006

By J. P. Morris

An experimental blast furnace in normal operation was quenched by substituting cold nitrogen for the hot blast air. More than 2,200 samples from the stack, bosh, and hearth were taken; 500 of these were selected for detailed analysis. Deductions are made as to the patterns of burden movement and gas flow; the reduction of iron oxides, including a comparison of ore and sinter; and the behavior of sulfur above the smelting zone. Metal and slag beads from the bosh were analyzed, as were samples from the hearth metal and slag. A brief description of a petrographic examination of the quenched burden is included.

Jan 1, 1963

Barrick Gold plans to have four new gold mines in production by 2006. Together, the mines would increase the company’s output by 40 percent. The projects include Veladero in Argentina, Alto Chicama in Peru, Cowal in Australia and Tulawaka in Tanzania. All of them are scheduled to begin production between the first quarter of 2005 and the first quarter of 2006. They are expected to drive Barrick Gold’s growth profile to a target of 211.5 to 217.7 t (6.8 million to 7 mil-lion oz) of gold production in 2007. The company’s projected output for 2004 is 152.4 to 155.5 t (4.9 million to 5million oz) in 2004. Overall, higher production and lower costs are expected in the early years from the new mines.

Jan 1, 2004

By J. O. Marsden

Part I in this series of papers considered the chemistry of medium-temperature pressure leaching of copper sulfide concentrates and reviewed the metallurgical testing and initial process development for this technology. This initial work resulted in the development of a process flowsheet utilizing superfine grinding (to a P98 of 12 to 15 µm and P80 of 6 to 7 µm), pressure leaching at 160° to 170ºC, followed by conventional solution extraction (SX) and electrowinning (EW) for the recovery of copper. However, this process required a significant amount of concentrated acid to be fed to the pressure leach vessel to meet the reaction requirements, representing a cost of between $0.03 and 0.05/lb copper (2006 basis) produced by the process. It was immediately recognized that the development of a process that did not require such a large acid addition would be advantageous. This paper, which is Part II in the series, describes the development of a process that incorporates medium-temperature pressure leaching and direct electrowinning (DEW) in a novel and innovative process flowsheet. Phelps Dodge (a subsidiary of Freeport-McMoRan Copper & Gold Inc.) refers to this as the ?MT-DEW-SX? process. Part III in this series covers the large-scale demonstration of the MT-DEW-SX process at Bagdad, Arizona; and Part IV addresses the development and design of a full-scale commercial application at Morenci, Arizona.

Jan 1, 2007

By F. A. Penning

Improved skips, with lightweight cylindrical bodies, have made a significant contribution to advancing mine hoisting technology. New concept skips of aluminum bodies with rubber lining; fiberglas bodies with polyurethane liners have been designed and fabricated for field testing at an operating mine. New design, adjustable guide rollers have shown improved ride characteristics with noticeably less wear. Major reductions have been made in stress levels and stress concentrations. Field experience has shown the practicality of the approach. Guide alignment has been measured using the Guide Alignment Measuring System (GAMS). Analysis has been applied to interpret the data. Field measurements in an operating shaft and a test tower have shown the agreement in data from GAMS and plumb wires. Reproducibility has been demonstrated. The data are useful to realign shafts, to use as s maintenance tool, and to evaluate the maximum safe hoisting speeds. The surveys are made at several hundred feet per minute and the system is self-contained. Dynamics of skip-guide interaction has been analyzed using the computer program SKIP II. The effects of speed, weight, type of guides, kind of misalignment have been studied. Resonance has been demonstrated and factors that eliminate resonance have been identified. Data from the GAMS surveys are applicable to the SKIP II program. Interaction between the hoist rope and the mine conveyance has also been studied. Computer programs and closed-form solutions are presented. Economic impact of lightweight skips is presented for an existing mine and for a new mine. Reduction in rope size has a profound effect when using a lightweight skip for the same capacity. Increased productivity can be realized by keeping maximum rope pull the same while increasing skip capacity. Examples and charts project the significant savings in capital expenditure for new installations.

Jan 1, 1985

A series of fault slip seismic events have occurred at Garson mine. The events have occurred during development advancement exposing faults, after the extraction of single stopes due to mining induced stress change, and due to time effects after delays of many days during which no mining had been conducted. This paper discusses the study completed consisting of a global or holistic approach aimed at mitigating some of the risks associated with the structurally controlled rockbursts at Garson. Background Garson mine is located in the south east area of the Sudbury Basin (Ontario, Canada). Mining occurs in two main ore bodies (the #1 Shear and the #4 Shear) which are copper-nickel-sulphide and occur within shear zones that (as well as the ore bodies) strike approximately east-west and dip steeply south. From the north (footwall), lithologies progress (Figure 1a) from norite (NR), to greenstone (GS), and finally to meta-sediment (MTSD). A generally WNW-ESE striking, bifurcated sub-vertical dyke of olivine diabase (OLDI) cuts the series. The current active mining block at Garson is between 4700L and 5100L (levels denote depth in feet below surface).

May 1, 2009

By R. Kaushik

According to the U.S Department of Energy (DOE), mineral processing activities including comminution (size reduction) uses 4% of the world electrical energy consumption. Such numbers reinforce the need to invest in energy savings initiatives in order to produce more using less. ENERGY EFFICIENCY OPPORTUNITIES AND CHALLENGES IN MINING OPERATIONS In addition, DOE, in its Mining Industry Energy Bandwidth Study, has identified huge potential for energy savings for the coal, metals and mineral industries. Even knowing the overall causes of energy waste and some potential tools for remediation, mining companies may struggle to apply such tools and get the desired results due to the following reasons: ? Limited staff ? Lack of accurate economic and investment analysis to justify energy savings projects ? Lack of knowledge to identify low or no-cost savings opportunities ? Internal competition for resources According to the workforce and talent management experts, the Talent Strategy Advisors, the demand for mining engineers is expected to exceed supply by 30% by 2013. Mining personnel are likely to be burdened with increasing and varied workloads with limited training. This will result in the need for automated and simple tools to support energy efficiency activities. Mining engineers will simply not have the time and resources to create such tools, collect and analyze the data to make decisions, and track results.

Feb 27, 2013

Whilst the wider community is both a large consumer of mineral products and relies on mineral exports for much of the wealth which sustains it, the community generally has a poor perception of the minerals industry.   The role of professionals and The AusIMM in the "New Economy" minerals industry is reviewed. The new structure of The Institute is vital as we move forward in times of globalisation, rationalism, increasing litigation, criminalisation of risk and increased focus on corporate governance. This address looks forward to ways The AusIMM and professionals of the future are positioning themselves for these and other challenges.

Jan 1, 2001

Three complete connector assemblies and six separate contacts were submitted to a series of tests to establish the connectors permissibility and compliance with U. S. Bureau of Mines research Contract #H 0110423 D.C. portion. Test Procedure TPC-0118 was coordinated, and the test plan approved by the Bureau as fully complying with the intent of the contract for the direct current connectors. The components and connector assemblies have been demonstrated in testing that they meet or exceed all the requirements of the test procedure.

Jan 1, 1974

The solvent extraction section of an old Uranium Plant in the Vaal River region (North West Province in South Africa) produced a substance called CRUD (Chalk River Unidentified Deposit) that formed within the aqueous/organic interface of the settler of the solvent extraction circuit. The CRUD was deposited together with gold tailings to the tailings dam many years ago. Previous research done on the CRUD confirmed that exposed CRUD leaches Mn and Ni at concentrations that are well above their acceptable risk limits as well as Zn that leaches at concentrations that are slightly lower than its acceptable risk limit. Soil washing and bioremediation technologies were employed to treat the contaminated soil.   Various laboratory test work and the pilot scale studies were conducted in parallel with each other and the results of the laboratory studies were used to determine critical parameters. Four lixiviants, ie sulfuric acid, acetic acid, oxalic acid and ethylene diamine acetic acid were tested at three concentration levels ie 0.001 M, 0.0001 M and 0.00001 M, respectively. Column tests showed that the leaching of the heavy metals increases as the soil porosity increases. Silica sand was added to increase porosity of the contaminated soil. Highest Mn removal was achieved mainly by sulfuric and oxalic acid at 0.001M at all soil levels. EDTA was significantly efficient in the removal of Ni and Zn. The recovery of heavy metals, particularly Mn, decreased as the depth of sampling increased.   Heterogeneous bacteria and filamentous organism plate counts were conducted to evaluate the growth of the bacteria and filamentous organisms in the soil. Results showed that more organism growth took place in the bioremediated soil with a fertilizer added to it. The leaching of metals from the soil that was bioremediated in the pilot study was generally higher than the extraction of the metals from the soil that was leached with no bioremediation carried out. The results from this study suggest that the leaching of heavy metals from the contaminated soil is to a large extent dependant on the pH of the leaching solution. By increasing the soil's porosity and bioremediating the soil, higher extractions of metals were achieved.

Jun 1, 2010