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By Z. Tshentu, M. Ngayek, P. Moleko-Boyce

This paper is focused on the development of iridium(IV)-specific quaternary diammonium cations containing electron-donating substituents in the benzyl group of methyl and electron-withdrawing substituents such as triflouromethyl and nitro groups. Quaternary diammonium cations used were tetra- 4-methylbenzyl-1,10-diammonium decane chloride (QuatDMDAMeBnz), tetrabenzyl-1,10- diammoniumdecane chloride (QuatDMDABnz), tetra-3-trifluoromethylbenzyl-1,10- diammoniumdecane chloride (QuatDMDACF3Bnz) and tetra-4-nitrobenzyl-1,10-diammoniumdecane chloride (QuatDMDANO2Bnz). Polyvinylbenzylchloride (PVBC) nanofibres were used as support material, and the functionalised nanofibres were used for separation of Ir(IV) from Rh(III). The sorbent materials were characterised by FTIR and elemental analysis. The efficiency of the quaternary diammonium cations was investigated in a column study under dynamic flow adsorption conditions. Column sorption of [IrCl6]2- and [RhCl5(H2O)]2- on nanofibres functionalised with diammonium cations showed [RhCl5(H2O)]2- was not adsorbed by the sorbent materials while [IrCl6]2- was loaded onto the column. The loading capacities of [IrCl6]2- on the quaternary diammonium sorbent materials increased in the order of F-QuatDMDAMeBnz (3.08 mg/g) < F-QuatDMDABnz (3.39 mg/g) < FQuatDMDACF3Bnz (5.46 mg/g) < F-QuatDMDANO2Bnz (7.10 mg/g). The loading capacity for Ir(IV) with quaternary diammonium cationic nanofibres increased with an increase in the electron-withdrawing nature of the substituent on the quaternising group. The charge delocalising ability of the 4-nitrobenzyl group resulted in the best interaction of the decamethylene diammonium cation with [IrCl6]2-. Keywords: Iridium(IV), rhodium(III), quaternary diammonium, polymer nanofibres, separation

Jan 1, 2020

By C. D. Rugen

Ground raw material as fed to the cement kiln generally is a mixture of two to four components, each of which may have widely varying physical and grinda-bility characteristics. Chemically similar materials found in the same or different deposits may also differ appreciably in physical properties, depending on their crystalline structure. The calcareous or principal cement raw material may vary from a soft chalky limestone or friable cement rock at one plant to a hard limestone or oyster shell at another plant. Argillaceous materials include clays, shales and granulated slag. Siliceous and/or iron-bearing material, including sand, iron ore and cinders, may also be required in addition for certain types of mixes. Frequently differences in grindability characteristics are not given the attention they deserve in comparing grinding results at one plant with those at another or in selecting suitable circuits or equipment. Many types of crushing and grinding units are used, with numerous open and closed circuit arrangements. Both wet and dry processes are used successfully. When rebuilding or installing a new grinding department, the choice of process or circuit in some cases may be dictated by the nature of the materials being ground but in other cases it may be the result of good salesmanship or a compromise. An over-all evaluation of wet process vs. dry process grinding should not be made without considering the effects on all other producing departments in the plant. In general, the more recent grinding installations, both wet and dry, have employed closed circuits, but many older open circuits are still in successful operation. In our experience, closed-circuit raw grinding pays, because of lower power consumption and less operating labor per ton of product. However, some dry open-circuit mills with improved equipment and operating methods compare favorably in performance with dry closed-circuit units. Character of Ground Raw Mix (Kiln Feed) Grinding in the cement plant in general requires a considerably her product than in most ore-grinding operations. A distinction between fineness of kiln feed and of cement may be made in that kiln feed preferably should be ground to a limiting size,whereas finished cement should include a range of size fractions including sufficient fine flours to give a product with satisfactory physical qualities. Grinding raw mix for kiln feed therefore is more comparable to ore grinding, although the limiting size is smaller. Most kiln feeds are ground from 85 to 95 per cent passing 200-mesh, depending on mix composition. Some cement chemists believe that raw materials cannot be too he, since finer particles theoretically combine more readily and intimately in the kiln. However, there are certain definite practical objections to extremely fine kiln feed, such as loss of kiln dust, unstable material flow through the kiln and greater dificulty in control of chemical composition due to dust loss, and the disproportion of fines from the more easily ground component. Our

Jan 1, 1947

By C. D. Rugen

Ground raw material as fed to the cement kiln generally is a mixture of two to four components, each of which may have widely varying physical and grinda-bility characteristics. Chemically similar materials found in the same or different deposits may also differ appreciably in physical properties, depending on their crystalline structure. The calcareous or principal cement raw material may vary from a soft chalky limestone or friable cement rock at one plant to a hard limestone or oyster shell at another plant. Argillaceous materials include clays, shales and granulated slag. Siliceous and/or iron-bearing material, including sand, iron ore and cinders, may also be required in addition for certain types of mixes. Frequently differences in grindability characteristics are not given the attention they deserve in comparing grinding results at one plant with those at another or in selecting suitable circuits or equipment. Many types of crushing and grinding units are used, with numerous open and closed circuit arrangements. Both wet and dry processes are used successfully. When rebuilding or installing a new grinding department, the choice of process or circuit in some cases may be dictated by the nature of the materials being ground but in other cases it may be the result of good salesmanship or a compromise. An over-all evaluation of wet process vs. dry process grinding should not be made without considering the effects on all other producing departments in the plant. In general, the more recent grinding installations, both wet and dry, have employed closed circuits, but many older open circuits are still in successful operation. In our experience, closed-circuit raw grinding pays, because of lower power consumption and less operating labor per ton of product. However, some dry open-circuit mills with improved equipment and operating methods compare favorably in performance with dry closed-circuit units. Character of Ground Raw Mix (Kiln Feed) Grinding in the cement plant in general requires a considerably her product than in most ore-grinding operations. A distinction between fineness of kiln feed and of cement may be made in that kiln feed preferably should be ground to a limiting size,whereas finished cement should include a range of size fractions including sufficient fine flours to give a product with satisfactory physical qualities. Grinding raw mix for kiln feed therefore is more comparable to ore grinding, although the limiting size is smaller. Most kiln feeds are ground from 85 to 95 per cent passing 200-mesh, depending on mix composition. Some cement chemists believe that raw materials cannot be too he, since finer particles theoretically combine more readily and intimately in the kiln. However, there are certain definite practical objections to extremely fine kiln feed, such as loss of kiln dust, unstable material flow through the kiln and greater dificulty in control of chemical composition due to dust loss, and the disproportion of fines from the more easily ground component. Our

Jan 1, 1947

By Kari Niiranen

LKAB (Luossavaara-Kiirunavaara AB) is operating iron ore mines, concentration plants and pelletizing plants in Northern Sweden. The largest of the apatite magnetite deposits and the mines are Kiirunavaara with annual production rate of approximately 27 Mt crude ore underground. LKAB produces two varieties of pellets: blast furnace pellets and direct reduction pellets (LKAB DR Oxide Pellets). Meanwhile the concentration process in a sequence of the low intensity magnetic separation (LIMS) and flotation at the concentration plant. In spring 2007 there were noticed great fluctuations of SiO2 grade in the crude ore. The high SiO2 grade is particularly problematic in the case of direct reduction pellets. In consequence, a project was started (called Silica in the Mine) to define exactly the problem related with silica and to find out, if possible, the reason for the great fluctuation of SiO2 grade in the crude ore going to the processing plant. A further target of this project was to develop a simplified method at the laboratory scale, to predict SiO2 grade in the magnetite concentrate in the future, but also predict the physical properties of the ore with respect to mineral processing. The essential stage of systematic characterization of the ore body for mineral processing properties is the estimation and simulation of different parameters from the laboratory scale to the large scale at the concentration plants using empirical data collected at the mineral processing by LKAB in Kiruna. Further a target was also to find useful physical parameters for mineral processing and implant those parameters into the existing geological 3D-model of the deposit. This information will be used for making prognosis of the future mining and the quality of the crude ore. It will also give better control and improve the production planning in the mine and the performance at the concentration plant in Kiruna concerning the decrease of the SiO2 grade of the magnetite concentrate.

Sep 1, 2012

By Richard E. Otoo, Evan J. Owen, Virginia T. McLemore

Disruption in critical minerals supply chains has resulted in the evaluation of various types of mineral deposits for critical minerals potential. Much of the study on critical minerals focuses on occurrence and characterization, but little research has addressed what concentrations of critical minerals in a mineral deposit are required to make an exploration target into an operating mine. Understanding the cut-off grades of ore deposits being actively mined is one criterion to determine if concentrations in an exploration target are high enough. Cut-off grade is defined as the minimum amount of mineral contained in a ton of ore that is sent to the processing plant. Among many factors, cut-off grade depends upon the size and type of the deposit and mining operation, the processing technique, and market prices. This research does not aim to define cut-offs for determining if a mineral deposit is economic. Rather, it defines estimates of concentrations of critical minerals that could be considered good enough for further exploration. For example, ~2% total rare earth oxide (TREO) is the cut-off grade for Mt. Pass carbonatite, but 500 ppm TREO could be an exploration target for coals.

Feb 1, 2025

By Patricia R. Devine

This report expands an earlier study by Jack Faucett Associates (OFR #40-88) of the same title. Both reports are based upon an interindustry analysis from 1963 through 1982, during which time U.S. metals consumption and production did not keep pace with economic growth. The report discusses three sources of change: technological change, economic growth, and composition of final demand, as well as the relative importance of the individual components of final demand for metals. The results show investment and personal consumption to be the most metal-intensive components of final demand, and technological change to be the major cause of decline in consumption growth during the study period. Technology change is defined as alterations in production processes resulting in more or less consumption of metal per unit of output, often because of material substitutions and design changes. A trade analysis shows the significance of import growth, particularly indirect imports (metal contained in imported goods) as a factor contributing to the reduced growth rate of domestic metal production. The effect of import growth is partially offset by indirect export growth, suggesting that continued increase of all U.S. exports can have a strong effect in reducing the negative trade balance in metals.

Jan 1, 1988

By A G. Noble

Tunnelling for hydro-electric power projects can be a very challenging component of the overall development. In contrast to urban transportation tunnelling where the logistics for access and supply of power, water and other essentials are readily available, hydropower projects are usually in very remote locations and all necessary plant, equipment, spares and materials need to be brought in and the site must function as a self sufficient unit.For a large scheme the river diversion tunnel(s) are usually on the initial phase critical path in order to meet the non-negotiable deadline of river diversion before the onset of the wet season. A newly formed tunnelling crew, once mobilised to the site for the project, will face the first major learning curve of the project’s systems and logistics during this critical tunnelling activity.Power tunnels convey the water to the turbines in the powerhouse and are usually on the critical path for the main works, especially if the scheme comprises a powerhouse located within an underground cavern. A modern cavern arrangement requires a complex warren of various openings: access adits, ventilation/cable tunnels, shafts, surge tunnels, etc.Hydropower tunnel construction tends to be dominated by tunnel boring machine (TBMs) or drill-and-blast excavation techniques and each has its challenges in very remote locations. TBMs still have long lead times as for any type of project, but additionally require a thorough roads and bridges infrastructure assessment of the country from the port of entry to the site to ensure a problem-free delivery. In some cases the project also requires the establishment of a complete precast concrete segment production facility and the space for creation of laydown areas; there is no ‘just-in-time’ delivery mechanism applicable to typical remote hydropower sites.This paper highlights the technical and risk management considerations in the planning, design and construction of tunnels for hydropower projects. It contrasts the typical factors that govern the design of urban transportation tunnels with those for remote hydropower tunnels. The perspectives of stakeholders are provided including those of international lenders. With examples from large and small scale projects across the globe it provides an insight to all parties and in particular, those tunnellers that are working in the hydropower field for the first time.

Mar 8, 2011

By R. Mensah-Biney

The aqueous biphase separation process (ABS) has been used to separate ultrafine industrial minerals. The partition behavior of TiO2, Al2O3, Fe2O3 and kaolin was not pH dependent. The partition behavior of SiO2 was, however, pH dependent. The partition coefficient of kaolin in PEG 3400/ Na2CO3 biphase system was = 150 and that of the silica in the same system was = 0.02, resulting in a separation factor of = 8500 between kaolin and silica. The aqueous biphase separation system was used to separate free silica from kaolin in a raw clay sample from Mexico. The partition behavior of mica, feldspar and clay from North Carolina was also evaluated.

Jan 1, 1999

By A. Mei, F. Amadini, F. Cernera, D. Baliani, A. Flor, M. La Morgia, F. Sassi

The risk of TBM jamming because of squeezing rock mass or excessive caving (instability of the cavity) conditions is always a focal point while boring long and deep tunnels with shielded TBMs. Mechanized excavation provides a large amount of real-time data, for each machine’s parameters. Several analyses have been executed to assess the correlations between different sets of TBM parameters for the exploratory tunnel. Instead of analyzing the full dataset, a different approach is proposed, with data processed sequentially to simulate the real excavation situation. The probability distributions are recalculated together with their statistical parameters while advancing. This approach is extended also to the training of a Machine Learning model able to foresee the behavior at future rings based on past rings (using a Recurrent Neural Network). The predictions show a promising first step toward creating practical tools that can assist contractors and designers to correlate and predict TBM excavation data. These tools will assist to predict and quantify high risk situations that could arise during excavation.

Jun 13, 2023

By S. Gopalan, J. D. Milshtein, S. N. Basu

Production of syngas is proposed utilizing the W/W03 redox system and employing a solarpowered two-step thermochemical cycle. Three chemical reactions occur in two chambers. Assisted by a solar concentrator, a high temperature reaction reduces W03 powder to metallic tungsten in both chambers. Subsequently, the temperature in one of the chambers is lowered and H2(g) is produced via re-oxidation of the tungsten powder using steam. The temperature in the other chamber is simultaneously lowered to an intermediate temperature and CO(g) is produced via oxidation of the tungsten powder using C02(g)· The gas streams coming out of the two chambers result in the syngas production. A complete thermodynamic analysis of the system is described. The W/W03 redox cycle offers greater gravimetric fuel productivity compared to previously proposed systems, and the entire cycle can be operated below 1273K.

Jan 1, 2013

By Dr. Zach Agioutantis, Elliott Morgan

The explosives, mining, and heavy civil industries consistently battle the uncertainty that is associated with working with a heterogenous medium like rock in blasting. This has led to studies to increase fundamental understanding of material response under dynamic loading that is associated with blasting. This study looks at the dynamic strain associated with blasting the lab Split-Hopkinson Pressure Bar (SHPB) testing while also building off of previous studies with the goal of better understanding the dynamic forces that are enacted on a geologic body during a blast loading event. This is required in order to advance geologic blast response modeling. This is achieved through analyzing the stress and strain values for each specimen that are calculated from strain data collected with a SHPB. Based on this data, the dynamic material response characteristics are able to be determined. Tests were conducted on five Berea Sandstone specimens with a rough length to diameter ratio (L/D) of 1.0. The strain data from these tests were then used to create stress strain curves as well as charts depicting failure stress to both strain rate and failure particle velocities. The tests conducted returned similar results to previous tests results on Berea Sandstone while also showing a correlation between strain rate at failure and failure particle velocities. While further research is needed, there is evidence that SHPB test data could be used in conjunction with the MBF model. The MBF model states that the peak particle velocity (PPV) of blast vibrations can be correlated with deformation (strain) at a given point. With a further understanding of dynamic material response correlated to PPV measurements, further refinement could allow for better prediction of blast performance.

Jan 21, 2025

By Ryan Sullivan, Lisa Smiley, Jewels Stover

The Westerly Storage Tunnel (WST) Project is part of Project Clean lake, the North East Ohio Regional Sewer Dist years. When completed in 2020, WST will be nearly 2 miles of 25-ft diameter tunnel 200-250 ft below ground. The storage tunnel will manage higher flow volumes, keeping stormwater out of the combined sewer system reducing overflow occurrences. Three deep shafts provide access to the tunnel at the tunnel boring machine (TBM) launch and retrieval sites, as well as a vent shaft. Support of excavation for the access shafts was constructed utilizing unreinforced concrete diaphragm walls. This innovative, value-engineered alternate design significantly reduced risks associated with conventional secant piles combined with a rib and liner plate system. Implementation of the diaphragm wall technology resulted in a water tight, continuous shaft keyed into rock. This case study examines the design, methodology, and installation challenges unique to each shaft, as well as the benefits of the final product to the overall project.

By P. R. A. Andrews, R. K. Collings

"SUMMARYIn cooperation with the Ontario Ministry of Natural Resources, selected deposits of Potsdam sandstone in the Ottawa-Kingston area were core-drilled and evaluated by CANMET as potential glass and foundry sand. Analyses of cores ranged from 84.6 to 98.5% Si02, 0.09 to 0.65% Fe203&apos; and 0.07 to 2.10% A12°3&apos; The cores were largely composed of white to grey, relatively tough sandstone. Impurities included iron as pyrite, iron oxides and staining on the quartz grains; carbonates as calcite; and aluminum oxide as feldspar. Beneficiation included size reduction to grain size, about 600 um, by jaw, roll and cone crushers, and grinding in a muller-mixer. Removal of fines was achieved by attrition scrubbing and washing. Further removal of impurities was achieved by reverse flotation of pyrite, iron oxide, feldspar, and carbonate minerals employing both anionic and cationic collectors. Flotation resulted in a substantial improvement in the quality of most samples; analyses of quartz concentrates showed 98.5 to 99.7% Sial> 0.022 to 0.156% Fe203&apos; and 0.07 to 0.62% A1203. Further reduction of the iron content by wet magnetic separation and acid leaching also was investigated. On the basis of the samples submitted, sands/ones from six of the seven deposits studied have potential as sources of glass sand. Foundry sand tests were inconclusive because of the small quantities available for study."

Jan 1, 1986

By L. C. IlsLey

"The maintenance of permissible equipment which is tested and inspected at the Pittsburgh Experiment Station of the United States Bureau of Mines is dependent to a surprisng degree upon the voltage at which the equipment is operated. The difficulty of maintaining 500-volt equipment is frequently brought to the bureau's attention, and it is quite possible that if the bureau had appreciated at the beginning the full hazard involved, it would never have undertaken the approval of equipment operating at voltages greater than 250 volts.In this connection, the following statement from State mine inspection departments and other sources are of interest as showing the general feeling in safety organizations with respect to voltages higher than 250. These statements, although obtained as a result of a questionnaire sent cut several years ago, still apply very well to present conditions.A. I have not had time to consider seriously the proposed change from every angle, but looking at it from a standpoint of hazard, feel that the danger would be greatly increased. I have always occupied the position that underground voltage on portable equipment should never exceed 250 volts.High voltage of course would mean smaller transmission lines, which would be more economical and no doubt would require in several instances smaller equipment; notwithstanding, if this statement is true, the writer is still favorable to low voltage on underground portable equipment.B. I believe 500 volts should be the limit on the best equipment ender the best conditions and that the U. S. Bureau of Mines should do all in its power to limit the voltage to 500 volts on permissible equipment, as any increase in voltage means increased hazard.C. I will refer you to a section of our mining law, entitled ""An Act to Regulate the Tine of Electricity in the Mines of the State of ----"" which reads in part, as follows: Trolley wires, or other exposed electrical wires, shall not carry a voltage above 275 volts.You may readily see by this that we are not permitted to operate mining machines under ground in -----, with more than 275 volts at the terminals, except that we are permitted to install transforming stations throughout the mines, after complying with certain regulations at the mine.However, as we have had to date, within the calendar year of 1925, six men electrocuted in the mines of the State, using a voltage of 275 volts, I am of the opinion that if this voltage was increased, the hazard would also be increased in proportion.D. I do not care to make a statement for publication: however, I am referring you to our mining laws. On page 27 and 28 you will find what the laws of -----¬require relative to the installation of electricity in the mines.""Hereafter where electricity is installed no higher than two hundred seventy-five (275) volts shall be used underground, except for transmission, or for application to transformers or other apparata, where the high-voltage circuit is stationary. High-voltage motors, and transformers, shall be installed in suitable chambers, built of fire-proof construction, and well ventilated, and shall not be placed on intake, or between intake and return air courses. All high-voltage lines lines and apparata must be clearly marked, to indicate their danger. Main and distribution switchboards for high voltage shall be made of insulating and incombustible material, such as marble or slate, and to be free of all metallic veins, or of material equivalent thereto. Same shall be installed in a dry place. All switches or other instruments used in connection with high voltage shall be installed on suitable switchboards, with at least a three-foot passageway in front and rear properly floored, and kept looked by a door at each end that can be opened from the inside without a key. With higher than medium voltage, there shall not be any live metal work on the front of switchboard, and the entry circuit must be protected by an oil breaker s"

Apr 1, 1932

By C. J. Walker, J. S. Miller

This work was done in an attempt to find a simple solution to the problem of simultaneously changing terminal rate and terminal pressure under conditions of unsteady - state flow in porous media . Although the original aim was not realized , a method for encasing a sandstone core that would permit high - pressure ( 200 to 980 psi ) flow tests and the use of electronic equipment to measure pressures at points along the core during unsteady - state gas depletion was found to be feasible . The sandstone core used in this study was from the Bandera formation of Pennsylvanian age , Redfield , Kans . The core , cylindrical in shape with a 3.5 - inch diameter and 6- foot length , had a porosity of 15 percent and a permeability of 9 millidarcys .

Jan 1, 1963

By Brent K. Nelson, D. Lee Petersen, Charles R. Nelson

INTRODUCTION Tunnels are commonly constructed in the very weak St. Peter sandstone in the Twin Cities area of Minnesota. Historically, core recovery in this weak sandstone was very small in the critical weaker strata resulting in little preconstruction information on the ground conditions. Improved core recovery techniques have been utilized for recent projects, allowing rock quality rating methods to be developed for the recovered core. Down-the-hole tests, and the use of combination ratings between different types of core data provide for more detailed characterization of ground conditions. THE ST. PETER SANDSTONE The 45 m thick St. Peter is an unusually pure quartz sandstone. It underlies all the Twin Cities area, except where it has been eroded by the present day Mississippi River or by pre-glacial rivers. It forms conspicuous steep bluffs along the Mississippi River where the upper Platteville limestone formation protects it from erosion. Where the Platteville formation is missing, the sandstone slopes are often more gentle. Natural case hardening of the exposed sandstone bluffs often forms a resistant crust and reduces sloughing. This case-hardened surface is not representative of the sandstone back from the bluff.

Jan 1, 1987

By Cleo Griffith Rall, D. B. Taliaferro

The method for determining oil and water saturations described herein has been used successfully for several years in the core laboratories of the Bureau of Mines. The apparatus constructed according to the original specifications has proved very satisfactory; in fact, it has been widely adopted by core laboratories throughout the petroleum industry. The writers have found that the method gives reproducible results, the degree of accuracy depending largely on the attention to details given by the operator. The relative importance of these details of procedure and the design of the apparatus are discussed in this report. In September 1940, the Bureau of Mines published a report describing a method used in its laboratories for the determination of the water content of oil-field cores. The procedure was essentially the same as that adopted by the American Society for Testing Materials for the determination of the water content of petroleum products, although the apparatus and technique were altered slightly to increase the precision of the method and to adapt it to the characteristics of the material to be tested. The report also contained a description of the method used at that time in the Bureau’s core laboratories for measuring the oil content of a core, utilizing the sample on which the water-saturation determination had been made. The procedure involved the transfer of the weighed sample, from which the water had been distilled and measured, to a Soxhlet extractor and the removal of the remaining oil by means of a suitable solvent. Soon after the report was published, the water-determination apparatus described therein was modified so that both the oil and water contents of a core sample could be determined simultaneously. This method, which has been described by Yuster, is now widely used throughout the industry.

Dec 1, 1946

By J. B. Salsman

As part of the research effort on investigating the effects of microwave energy on the chemical and physical properties of minerals and ores, the U.S. Bureau of Mines (USBM) Tuscaloosa Research Center has conducted research to measure the dielectric properties of these materials. The objective was to establish a reliable database for use in predicting the effects of microwave heating on a wide range of minerals. The dielectric constants and loss factors of minerals, commonly referred to as the dielectric properties, were determined utilizing the theory of microwave propagation through an open-ended, air-filled coaxial line that was terminated at its open end with the particular mineral under investigation. In this phase of microwave research, the USBM measured the dielectric properties of powdered minerals with medium to high electrical conductivities in the frequency range of 300 MHz to 3 GHz and as a function of temperature from 25 to 325 °C. Since the minerals were prepared as powders, techniques were used to relate the measured dielectric properties of the powdered minerals to the dielectric properties of the mineral at its theoretical or natural density.

Jan 1, 2010

By D J. Hill

"Mining companies routinely invest in improvements to their processing operations, but often these enhancements do not work to full effect.Improvements can be ineffectual because underlying process problems are not identified or prioritised for correction or repair.This is frequently because ‘black box’ solutions deployed to implement process control improvements typically rely on instrumentation to provide data for algorithms to work effectively, and these solutions are often ineffective or disabled at mineral processing sites.There are three key reasons they can fail to deliver: vital instrumentation is not calibrated or functioning as required basic process control and loop tuning was not implemented correctly or is in need of tuning there is an inability to support the ‘black box’ solutions on-site.Many of these problems can be overcome by implementing operational analytics that identify where problems are occurring and prioritise where improvements need to be made.Incorporating operational analytics into process improvement is not a new methodology. It is more a back-to-basics approach to make more efficient use of capital and systems already deployed.Data collection systems, such as the OSIsoft PI System, provide real-time and historical process information for process control experts to analyse and identify areas for improvement. However, most systems are not used effectively. With some simple enabling, data collection systems can provide evidence for prioritising investments in improvements and determining an investment’s effectiveness.MIPAC advocates that the initial step, with analytical evidence, is that clients review the control strategies and implement small influential instrument repairs/calibrations and operator training. This can significantly boost process productivity without the need to spend large sums of money on new capital or employing expensive, difficult to maintain ‘black box’ solutions.A simple Stage-Gate®-style approach ensures that small investments in evidence-based process improvements deliver significant benefits to mining operations.CITATION:Hill, D J, 2014. How to prioritise process improvements, in Proceedings 12th AusIMM Mill Operators’ Conference 2014, pp 307–314 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Sep 1, 2014

By A. V. Kuznetsov, R. I. Kamkin, V. M. Paretskiy, A. Y. Mamaev, V. P. Bystrov, A. S. Vernigora

"Vanukov furnace technology is an efficient, proven pyrometallurgical injection technology, used extensively in Russia and Kazakhstan for a number of different applications. The technology was most widely adopted for processing copper sulfide concentrates for matte in smelters in Norilsk, Revda (Russia) and Balkhash (Kazakhstan). The following applications also were developed and tested at industrial scale: treatment of sulfide lead and lead-zinc concentrates, laterite nickel ore, production of cast iron, treatment of antimony gold-containing ores, and municipal solid waste. In this paper, current experience of Vanukov furnace application to these technologies is described with a number of general development trends and new areas of application.IntroductionAt the present time, the Vanukov process, developed at the Moscow State Institute of Steel and Alloys at the Department of metallurgy of non-ferrous, rare and noble metals with collaboration with other research organizations, is a highly efficient technological solution for processing different kinds of raw materials. The process was invented by Professor Andrey Vladimirovich Vanukov, whose research work began in 1949. From 1956 to 1975 test runs of the technology were carried out at the smelters in Norilsk and Balkhash. In 1976 a pilot Vanukov furnace was built in Ryazan. Furnace designs was modified to suit the various test programs. A major objective of each experiment was the determination of optimal working conditions for processing different types of raw materials such as copper, copper-nickel, copper-zinc, lead or pyrite concentrates, and materials containing secondary lead and zinc. After the death of Andrey Vladimirovich Vanukov in 1986, this technology and furnaces based on the technology were named after him: “Vanukov process” and “Vanukov furnace”. Today, the following furnaces based on Vanukov technology are either working or were tested at semi-industrial scale: three in Norilsk, two in Revda (Russia) and two in Balkhash (Kazakhstan) for treatment of copper sulfide concentrates for matte, one in Orsk (Russia) for processing laterite nickel ore, one in the Buruktal plant (Russia) for antimony gold-containing ores for antimony oxide sublimates and gold-containing metallic antimony, and one in China for processing sulfide lead and lead-zinc concentrates for production of black lead and zinc-containing sublimates."

Jan 1, 2011