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By Michel Ruel

"This paper describes how to make advanced control choices when difficult processes need improvement. The decision-making process involves choosing between a rules-based approach and a model-based approach as well as weighing benefits and drawbacks, complexity and simplicity, investment and results. This paper will present briefly each solution: basic control, advanced regulatory control, model predictive control, and expert systems such as fuzzy logic controllers and neural networks. The article then proposes a decision tree for selecting the most appropriate approach. A table will compare usage, development, commissioning, maintenance and lifecycle costs for each approach. Finally, conclusions and suggestions will summarize the methodology.INTRODUCTION Advanced process control (APC) is a popular topic. How can one decide whether advanced control should be added to an existing system? Advanced control is used to improve performance, stabilize production, handle constraints, protect equipment and manage grade changes. Most plants use feedback controllers, usually PID (proportional, integral, derivative) controllers. It is common to develop special control schemes to handle more complex processes. In classic PID process control, a controller brings a single value close to a set point using a single manipulated variable. On the other hand, APC brings several values close to optimal targets simultaneously using several manipulated variables. APC's four main strategies are advanced regulatory control, model predictive control (MPC), fuzzy logic and neural networks. Simple solutions are always preferred. Complexity will be increased if performances (production, quality, etc.) are below par. Profitability analyses should be conducted to validate project viability. Needs—not trends—should dictate choices! Before increasing complexity, it is important to define needs, goals, technical support, budget, etc. All these approaches entail strengths and weaknesses. Building a project based on technology rather than needs spells trouble."

Jan 1, 2014

By James Westfield

Following is a brief resume of the Division's activities that have had a favorable effect on health, safety, and the reduction of injuries at coal mines: 1. The Federal Mine Safety Code for Bituminous Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines on July 24, 1946, after consulting with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors while inspecting bituminous-coal and lignite mines as a basis for determining the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior on October 8, 1953, after further consultations with representatives of management and mine workers and was incorporated by reference in the 1952 and subsequent bituminous-coal wage agreements. The agreement of May 29, 1946, between the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bituminous-coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. Federal coal-mine inspectors also had temporary authority to close mines found to be imminently dangerous, but such authority under Executive Order 9728 was removed on June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1961

Same-batch and non-blind as well as blind pulp duplicates are often submitted as quality assurance/quality control (QA/QC) control samples to a routine laboratory along with routine assays (and other control samples such as reference material samples). The current ways of interpreting the results of duplicate assays to derive QA/QC conclusions and decisions, however, has not yet been formalised in a scientific manner. The current, prevailing approach and its limitations are reviewed and a new method is proposed as a substitute tool. This new tool should allow for operational error detection on a batch per batch basis (ie batch rejection) as well as laboratory performance assessment with time on reproducibility.

Jan 1, 2008

By C. Hosten, K. V. S. Sastry, D. J. Kawulok-Englund

Introduction Since the last decade the iron ore processing industry has undergone drastic changes from supplying screened and natural ores to manufacturing tailored concentrates and pellets. Increased need for the beneficiation of lower grade iron ore deposits and the increased demand for higher grade concentrates necessitate finer grinding of iron ores before concentration. The normal filtration stations used in the past are experiencing difficulties in dewatering the finely ground concentrates to moisture levels acceptable for balling. In addition to finer grinding, applications of complex beneficiation techniques has decreased the filterability of the concentrates and create problems in filtration of iron ore concentrates. An overview of the filtration literature indicates there are few research reports on the dewatering of iron ore concentrate slurries. There exists a need to understand the principles and mechanisms involved in the filtration of iron ore concentrate slurries with a goal of developing more efficient filtration techniques. This paper presents the results from the first phase of our research program that included the development of a reproducible benchscale filtration technique and the investigation of the filtration behavior of eight iron ore concentrates.

Jan 10, 1983

By D. Vogt, T. Hattingh

"This paper argues that the technology change to mechanization is also going to require a change in people. It presents a model for technological progress and adapts it to the mining industry. It then goes on to motivate the need for mines to become learning organizations in order to achieve maximum value from their people as they become less labour-intensive. In an important sense, mechanization is as much about knowledge as it is about technology.The change when a mine introduces mechanization or a level of automation is not simply one of technology but also a stage in the development of mining from ‘art’ to ‘science’. ‘Art’ describes a state of technology characterized by tacit knowledge, an understanding that comes only from experience, and has no formal procedures and little structure. In contrast, ‘science’ represents a state of technology where all the component processes are understood in detail, all knowledge is explicit, and processes and structures are formal.Studies of other industries, including metal part manufacture and aviation, show that each stage in the progression from art to science changes the nature of the organization and requires a different mix of skills from the workforce. Perhaps the most important change is the increase in knowledge and decision-making required as the technology gets closer to science.There is anecdotal evidence that South African underground hard-rock mines are not learning organizations. Mines by their nature are capitalintensive with long lead times from investment to returns, so there is reluctance to change from the original plans or to encourage staff to think independently. Particularly as mines move from art to science, this reluctance must be overcome.The important lesson for engineers involved in introducing mechanization is to understand that success or failure will be determined by the people involved, and not solely by the technology. The process will almost certainly require a culture change on the mine. We recommend that the mechanization team includes an expert in human and organizational behaviour to ensure that a receptive workforce and management are in place to accept the new technology when it arrives."

Jan 1, 2016

By D. W. Alexander

Researchers from the Office of Mine Safety and Health Research (OMSHR) of the National Institute for Occupational Safety and Health (NIOSH) completed field trials during coal mine rescue contests using simulated gas detectors in place of placards. The gas monitor simulator (GMS) devices replaced static, paper placards to deliver gas concentration data. Eleven teams were observed during the field contest, which was approved by the Mine Safety and Health Administration (MSHA). GMS devices were given to three team members, the captain, and both gasmen. Observation of teams revealed that team members changed behavior by acknowledging and sharing information more often while using the GMS. As a result of this research, it has been demonstrated that under the existing contest format, the newly developed GMS device may be used with no adverse impact on team contest performance. Furthermore, when GMS technology advantages are used, contest realism is improved. In the future, competency assessment may be incorporated.

Jan 1, 2011

By R. E. McElvain

"Hydraulic transportation of solids in suspension with water or other carriers, such as oil is becoming more practical as economic situations develop with respect to the railroads and other carriers. Of significant importance, is also the increased size of the major operations and the total impact of larg- er tonnages and more critical sources of supply.There are several means of imparting energy into the solids and directing the material down a pipeline, but the centrifugal pump is emerging as the most practical piece of equipment when considering relatively large flows and recent development. We can now handle relatively high densities without interruptions. This provides the mining and transportation fields a more economical means of lifting and transporting coal and other mineral products.Equipment & MethodsWarman International has developed several methods of alternate PDP against high heads. We have, at least for the present time, shelved our pump which uses clear water to slurry method and have placed our major emphasis on the full development of the centrifugal pump. I personally see several similarities on the alternate reciprocating devices as compared with the steam piston type engine versus steam turbines. The centrifugal pump comes into its most advantageous position at about 2000 GPM and can also show advantages by means of increased mobility, when driving tunnels and in other difficult operations when considering the total economic results. We now have some interesting d<:ta on one 5 mile raw silica sand line designed for pumping at 200-400 tons per h:mr. This is a separate subject on a ""simplified approach to slurry transport"" and paper has been prepared for the Hydrotransport 5 proceedings in Germany this Spring. Reference 1 may be of interest to those who want to delve into the subject further, and I also have some advance copies of this paper."

Jan 1, 1978

By P. J. Bethell

Background Increasingly complex geological conditions, with the presence of high ash binders in the mining horizon were encountered at the A.C. I. Dugout Mine near Price, Utah. This led to the production of high ash coal from the Dugout Mine during 2003 and 2004. This material had poor marketability and posed operating issues for the utilities burning the coal. Ash levels increased from typical levels in the 9-12% range to between 15 and 25%. etween 15 and 25%. Reviews of the mine plan and expected geological conditions indicated that further periods of high ash production could be expected. Action Plan Detailed sampling of the mine high ash production was carried out. The majority of the coal from the Dugout Mine is trucked to the Savage Coal Terminal (SCT) at Wellington, Utah where it is stored in multiple piles by quality. Coal at the mine is segregated by a CoalScan 2600, on-line analyzer into high ash, low ash and rock chute (waste material). From these piles, the material is crushed prior to shipment to SCT. The samples obtained from the various high ash piles were subjected to detailed sizing and washability analysis. Once this information was obtained, alternative circuit configurations were evaluated to process this material into a salable product. Water supplies in the arid terrain where the plant is located are scarce. This factor played a part in the final circuit design.

Jan 1, 2008

By Mark Davis

As a follow-on to previous investigations, reduced treatment levels for the optimum fire retardant/preservative system were evaluated. An impregnation of 3.5 lbs/ft3 of Fyreprufe followed by 3.5 mils of Albi 107A plus an Albi 144 top coat provides adequate flammability and flame spread protection. However, there is a significant loss in compressive strength at this retention level, particularly parallel to the grain. A pilot-size pressure impregnation cell was installed for use in treating larger quantities of wood. Based on the optimum fire retardant/preservative treatment system - Fyreprufe/ACC impregnation followed by Albi 107A/144 intumescent paint - a model treatment pro¬cess was developed, capable of handling 3 million board feet per year. Associated annualized costs per thousand board feet (K bd. ft.) for treating 12" x 12" timber were calculated to be: Impregnation: $-63.00/K bd. ft. Coating: $112.00/K bd. ft. A literature search was conducted to identify materials and techniques suitable for a localized stench warning system for heated mine timbers. Based on this review, a number of stench warning concepts were developed. Those based on surface coating were given a preliminary laboratory evaluation.

Jan 1, 1982

By Dave Stefanuto

Voisey?s Bay Project Components ? Mine/Mill Port In Labrador ? Mini Plant in Mississauga ? Demonstration Plant in Argentia ? Supply Vessel (Umiak1) ? Transshipment Facility (Quebec) ? Concentrate Handling & Transport to Sudbury/Thompson ? Cobalt Refinery Upgrade (Thompson) Project Setting ? The Project is on the traditional lands of the Labrador Inuit and the Labrador Innu ? Canadian courts have held that Aboriginal peoples in Canada possess special rights to traditional Aboriginal lands Those rights can include requiring resource developers to enter into Impacts and Benefits Agreements (IBAs) on traditional lands to set forth how lands can be used and benefits to be received by Aboriginal people

May 1, 2006

By Joseph M. Kurtak

The Bureau of Mines is currently conducting a four year mineral assessment of the 5.7 million acre Valdez Creek Mining District in Southcentral Alaska, as part of its ongoing statewide mining district evaluation program. This report is a summary of the 1987 field work, which included the examination of mines, prospects, and mineral occurrences in the study area. Placer gold has been the most important metal produced in the area, and production totaled 161,131 oz, with the majority of the production coming from the Valdez Creek Mine. Lode gold and silver production totaled 1,581 oz and 8,617 oz, respectively and came mainly from the Golden Zone Mine. Varying amounts of other metals, including copper, lead, zinc, molybdenum, antimony, chrome, nickel, cobalt, tin, tungsten and platinum exist in the study area. Occurrences of industrial limestone and coal are also located in the area.

Jan 1, 2011

By M. Didyk

In this report, the application of the PHU/MVS program is demonstrated through the use of a simple but realistic mine ventilation program. The report details, the problem description, the input data required and the various output features of the simulator. The PSU/MVS program is written in Fortran IV for use with IBM 370/168 computers. A version of the program that can be used in CDC computers is also available. A ventilation network consisting of 531 branches, 300 nodes and 5 fans took 48 seconds for solution on The Pennsylvania State University&apos;s IBM 370/168 computer. Appendix I of this report is the User?s Manual for the program. Appendices II and III contain the input data listing, and selected output listing for; the application. Appendix IV provides tables for leakage, friction factors and shape factors.

Jan 1, 1977

By P. L. Woolf

Blast furnace coal injection tests conducted by the Bureau of Mines in cooperation with a consortium of 22 steel companies in 1963-1964 are described. These tests were part of a program of extensive investigation of auxiliary fuel injection in the Bureau&apos;s experimental blast furnace located at Bruceton, PA. Seventeen coal tests are described on various coals ranging from anthracite to subbituminous. Factors affecting maximum rates of injection were studied. These included coal size, coal type, and oxygen enrichment. The effect of high sulfur content coal and the means to control metal sulfur were investigated. An epilogue briefly describing the commercial experience with coal injection from 1960 to the present has been included.

Jan 1, 1985

U.S. Minerals Coordinating Council Advised. -The Critical Materials Act of 1981, H. R. 4281, introduced on July 27, would create a Council on Critical Materials in the White House Executive Office to oversee Federal materials programs involving $1 billion committed to research by 14 agencies, and to serve as the President&apos;s focal point to evaluate materials policy. It was introduced by Congressman Fuqua (D-Fla.) whose Committee on Science and Technology has over-sight over the implementation of P. L. 96-479, the National Materials and Minerals Policy, Research and Development Act of 1980. Bulgaria&apos;s Mineral Bank. -Recently Bulgaria established a mineral bank to facilitate receipt of foreign credits for exploiting Bulgaria&apos;s mineral raw materials. The bank has wide powers to enter into business arrangements with foreign creditors. Bulgaria&apos;s main interest in trading with the West is to import the technology for developing energy and mineral resources.

Jan 1, 1981

By R. H. Hiltz

The Coal Mine Health and Safety Act of 1969 legislated maximum dust levels for the working place. As the law was implemented, extensive efforts were undertaken to provide the technology necessary to control dust generation. One approach to dust control was the use of high expansion foam in place of the usual water sprays on coal cutting equipment. At the time of the act, high expansion foam had already seen considerable testing for the suppression of dust in underground coal mines. Work by MSA, several coal companies and the Bureau of Mines itself had provided data which showed foam to have some merit as a dust control mechanism. It suffered in a few areas, however, which limited its practical application. Its principal difficulty was persistence which hampered operations due to foam buildup, but problems were also encountered due to equipment size and form.

Jan 1, 1975

The first mention of gold in Western Australia was in 1848 when some specimens of copper ore, which are believed to have come from the Murchison district, were sent to Adelaide for assay. Gold was present in these specimens, but no particular interest seemed to be attached to this fact as the search at that time was mainly concentrated on base metals and coal. Interest appeared to be shown in gold in 1852 when several parties moved out eastwards from York looking for goldbearing country. Though these parties inmany cases were very near to what is now known as the Yilgarn Goldfield, nothing was found.The next record of gold was reported in some specimens which were brought in from Cardup, some 25 miles from Fremantle. Though this area was investigated, it would appear that all the gold had been contained in the specimens and nothing further was found, though the report had been the cause of a small rush of people interested in gold.From time to time specimens had been brought in by various people from the district east of Northam, and in 1861 a reward emanating from private sources was offered for the finding of gold within a radius of 150 miles from Perth. The Government at this stage took an interest in exploration for gold and in the same year supplemented this privately offered reward on a &#163; for &#163; basis. The Government also, about this time, commissioned a practical miner, with prospecting experience in the Eastern States, to examine the country between Albany and Northam with a view to the possible existence of goldbearing veins in that area. His report, however, was entirely unfavourable and nothing further was done. In 1873 a quartz lode was discovered near Albany arid a company was formed to work...

Jan 1, 1956

By E. J. Gleim

A list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1942, was published in Bureau of Mines Information Circular 7207.3/ The list of that date was complete as to equipment then available and in current use. Information Circular 7240,4/ published as a supplement thereto, listed equipment approved curing the calendar year 1943. The present list is another supplement covering approvals issued during the calendar year 1943. The items are numbered to indicate the consecutive order in which each type of machine or device was approved in its particular classification. Thus, Information Circular 7207 gave 19 drills and drilling machines on the Bureau&apos;s active list. No additional approvals were given in 1942, but the three issued in 1943 bring the total to 22. Item 102, under Loading Machines and Conveyors, also appeared in Information Circular 7207, and items 120 and 124 appeared in Information Circular 7240. These numbers are repeated here to show that approvals were granted during 1943 for additional voltages on machines previously listed for one voltage only. Equipment listed in these circulars is approved by the Bureau of Mines only when found upon inspection and test to comply with minimum standards of safety as outlined in schedules prepared on the basis of many years of experience in dealing with safety problems of the coal-mining industry. The use of such equipment in mines known to be gassy, as well as in those that may become so, is earnestly recommended in the interests of safety. This circular is published so that the industry may be kept

Jan 1, 1944

By Andrey V. Tarasov

To carry out a physicochemical substantiation of a transition to ?soft? modes of reduction of calcine obtained by desulfurizing roasting of nickel concentrate produced as a result of copper-nickel converter matte separation in a nickel anode production circuit, an analysis has been conducted of the macrokinetic behavior of actual calcine samples in the presence of gaseous H2-CO mixtures and solid reductant additives. Within a temperature range of 900°C to 1100°C the main regularities typical of the calcine reduction process with individual gases (H2, CO) also take place when using a gaseous mixture. Under the conditions of low-temperature (900°C to 1000°C) nickel oxide reduction with products of fuel oil conversion in the presence of coke, the role of the latter is insignificant from the technological viewpoint. As a result of the present investigations, we have obtained analytical expressions of macrokinetic parameters of the reaction interaction within the [NiO] calcine-H2-CO-C-CO2-H2O-O2-N2 system.

Jan 1, 2005

By P Grieve, J L. Mauk

The Central Maratoto Valley in the Coromandel Peninsula contains a sequence of veins in pervasively altered dacite + andesites of the Waipupu Formation. We recognise at least eight different vein types: (1) pyrite stringers, (2) quartz + carbonate veins, (3) crystalline quartz veins, (4) carbonate veins, (5) chlorite + carbonate veins, (6) siderite veinlets, (7) siderite + carbonate veins and (8) carbonate + pyrite veins. The overall temporal trend of the veins is from early pyrite to quartz and then to late carbonate veins. Carbonate veins and pyrite stringers both form planar and irregular veins, whereas some carbonate veins have diffuse contacts with the wall rock. Gold and base metal sulphides are associated with some of the quartz + carbonate veins. Textures within the veins reflect open space filling and multi-phase reopening. A partial record of hydrothermal activity has been preserved by vein crosscutting relationships, hydrothermal alteration minerals and fluid inclusions. Hydrothermal alteration minerals display zonation from south to north. The alteration increases from unaltered to weak propylitic alteration of andesite in the south (MVRCDC1), to sericitic alteration of andesite and dacite in the north (MVRCDC3). The alteration assemblage is dominantly sericitic, with no adularia present, drawing parallels to the Thames region where there is no adularia.

Jan 1, 1999

By C. P. Bowie

For years many oil producers have believed that often low-pressure oil- and gas-bearing strata have been over coked in fields where the rotary system of drilling has been used. Collom3/ gave as a reason for this condition that because the mud fluid was thick, the oil or gas stratum was plastered and sealed as the tools passed through it and no oil showed at the surface. Although this observation was made 15 years ago, it may often still be true notwithstanding modern developments in coring and electrical logging. Operators have believed, also, that mud fluid does not solidify behind the casing. Lewis and McMurray4/ stated: "All the evidence obtainable from practical experience points to the fact that the mud fluid properly mixed and employed does not solidify behind the casing, even in deer wells and after long periods."

Jan 1, 1937