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By John C. Machisak

THE INJURY data and experience at quarries and related plants of the United States are presented in this publication under the following general sections (A) General injury experience: Tables 1-3: Current data on number of injuries, injury-frequency rates, location, accident agency, degree of injury, and related employment data. (B) Injury experience at different kinds of quarries: Tables 4-5: Current data on number of injuries, injury-frequency rates, location, accident agency, degree of injury, and related employment, data. (C) Injury experience by States: Tables 6-20: Current data on the number of injuries, injury-frequency rates, accident agency, degree of injury, and related employment data. (D) Selected injury data: Tables 21-30: Current data on various selected factors of operating conditions at different kinds of quarries, including employment size-groups, length of shifts, comparative severity of injuries, and injury data and related employment experience at dimension-stone and nondimension-stone quarries and at underground quarries. (E) Historical injury experience: Table 31: Injury and employment data on the quarrying industry for 1911 through 1957. Statistical data on injuries and related employment in the quarrying industries have been collected annually from the operating companies since 1911. Reporting to the Bureau of Mines is voluntary; there is no Federal law compelling operators of quarries and related plants to supply such data. Data presented herein may not be complete for the entire industry. They are however, believed to be representative of the hazards common to all quarry and related workers. Moreover, the figures are comparable as between States-a significant fact in view of the lack of uniformity among the States with regard to the classes of injuries covered by State reports and other factors that tend to make it impracticable or impossible when using State records to

Jan 1, 1960

By Karl D. Libsch, Modesto E. Erneta

Both battery design and environmental pressures are forcing the secondary lead industry to consider new and different processes. Trends in battery design are making normal decasing increasingly difficult. Lead in air, sulfur dioxides, and solid/liquid waste heavy metal restrictions are tightening. There is no clearly defined industry trend toward a given process, but it is clear that plants will be larger, less labor-intensive, and automated.

Jan 1, 1977

By S. W. Zoldok

"ERRATUMFor paragraph 1, page 1, read the following:The Cle Elum nickeliferous iron deposits occur on an unconformable contact between the serpentine and overlying Swauk sandstone formation and extend about 2 miles along the Cle Elum River in Kittitas County, Wash.The linear extent of the deposits and their proximity to a large source of,electric power and coal supply indicated that a development program was in order to determine the probable grade, extent of the ore bodies, and a suitable metallurgical process for recovering the iron, nickel, and chromium from the ore.The northern portion of the serpentine formation was investigated by the Bureau of Mines from August to December 1943 and from August to October 1944. The investigation consisted of road building, diamond drilling, sampling, and metallurgical tests.The Geological Survey assisted with logging of cores and made geologic and topographic maps."

Feb 1, 1948

By J. Iannicelli

Kaolin, normally an inert filler when compounded with polymers, is converted into a strongly reinforcing pigment by prereaction with certain functional silanes. Modification of kaolin with amino and mercapto silanes allows it to form crosslinks and confers significant improvements in modulus, abrasion resistance, compression set and other physical properties of a broad range of polymers.

Jan 1, 1990

By D. Pawelus, J. Butra, R. Debkowski, M. Szpak

Impact of horizontal stresses on stability of underground workings in mines is a very important issue in underground mining. Identification of the initial state of stress in the rock-mass should be one of the main actions taken into account while designing and carrying out the mining activity in underground mines. The paper presents the tests on three dimensional stress pattern in Polish copper mines, owned by KGHM Polska Miedz S.A. Group, carried out in 2012. The research program covered 7 measuring stands in two mines; their average depth was about 1000 m. The main aim was to identify the values and directions of horizontal stresses in order to optimize the extraction and to improve the safety. The overcoring method with the use of CSIRO HI type probe was applied. The paper also describes the measuring technique which was developed for the purpose of specific mining and geological conditions of KGHM mines, taking into consideration the natural hazards encountered there as well as technical and operational capabilities with regard to drilling equipment. The experience gained during the underground measurements and the issue of making such measurements in underground copper mines in Poland are presented in the paper. The stress patterns obtained during the underground measurements are of application importance for the process of designing the spacing of mine workings and improving their stability and mine support selection.

Jan 1, 2015

By Redman P. G, McMahon B. K

A simple technique for evaluating the field stress ratio is presented, based on the results of extensometer or convergence tape measure- ments taken in an advancing tunnel. This tech- nique also yields a value for the rock mass modulus, provided Poisson's Ratio is assumed. The results of two case studies are presented illustrating the effectiveness of the method.

Jan 1, 1981

By R. T. Dec

A review is undertaken of existing mathematical models of compaction process in roll press. The example of plane-strain, plane-stress model is presented together with comparisons between computed and experimentally recorded pressure distribution in roll nip region. Next, the discrepancies between predicted and measured values are discussed and practical method based on experimental optimization of compaction process using laboratory roll press is proposed. Examples of the selection of optimum roll press operating parameters for calcium oxide fines, sodium chloride and iron oxide dust are presented to illustrate advantages of the method. Finally scale up procedure is discussed for estimating the performance of commercial size roll press based on the data collected on laboratory size equipment.

Jan 1, 2000

By J. A. Herbst, R. Zaragoza

Conventional control schemes in use today are not able to produce satisfactory control when high-frequency disturbances are present in the flotation feed. An advanced model-based control scheme is presented here as a promising solution to this control problem. The main feature of this control scheme is the real time identification of the unknown disturbances in the first few cells of the flotation circuit. This information is used to control the rest of the flotation plant in a feedforward fashion. This control scheme also provides flexibility to meet any metallurgical, economical, or management objective.

Jan 1, 1987

By S. M. Pickering, L. T. Gregg

Appraisal of industrial minerals beneath privately owned land requires a different approach and mindset from valuation of base and precious metals or energy minerals, and from valuation of government-owned mineral lands. First, is it the value of inground minerals or of mining rights that is being sought? Second, value to whom, the mining company, a potential investor, the mineral landowner, a lending institution, the property tax assessor, or a condemnor? Third, how should mineral value be apportioned between the land and mineral owner, and a mining company with limited years of lease-hold interest? These and many other questions must be addressed before a valuation method and Discount Rate are selected. For various reasons the Income Method is most often used, with Net Present Value calculations made for long term predicted mining income. Choice of an appropriate Discount Rate is critical.

Jan 1, 2000

By Tim Suljada, Mary Stewart, Jim G. Petrie, Damien Giurco

"The minerals industry is being challenged to reduce the amount of virgin ore that is mined, and to replace this material through the recycling of used commodity items and scrap, or by the reprocessing of waste materials. It is argued here that the existing technology base of minerals processing and refining offers real potential for handling these secondary resources. The challenge is to develop tools by which the most preferable recycling routes (both economically and environmentally) can be identified from a list of feasible alternatives, taking into account any operational constraints of these technologies.This paper describes an heuristic approach to developing the family of all technically feasible flowsheets to address this challenge, from which a preferred option may be selected according to a set of decision criteria (economic and environmental). Our approach uses conventional flowsheeting techniques of selecting flow variables and splitter functions, supported by design performance information for each unit operation. This set of design decision variables is augmented by knowledge of the suitability of a particular waste or scrap stream for a given unit operation within a flowsheet. We achieve this by comparing the composition of the scrap stream with the range of mineral streams for which the unit operation was designed initially. This is inspired by the “overlap” approach proposed by Legarth, where an “overlap” of 1 would suggest that there is high degree of compatibility between a given secondary resource stream and a primary mineral stream as inputs to a specific technology. The “overlap” concept has been extended to include information about the physical characteristics of secondary resource streams, as well as information relating to synergistic / antagonistic influences of minor elements present in the waste stream. A flowsheet which delivers a product of acceptable quality from a given secondary resource material is built up from a progression of unit technologies. The exercise is repeated to generate the family of all feasible flowsheets from combinations of acceptable unit technologies."

Jan 1, 2003

By Charles E. Parsons

One of the greatest factors in our industrial development is cheap and convenient power. Long-distance electrical transmission has now reached such a stage that it is feasible, and practicable, to utilize the water-power of the country which was heretofore too remote for consideration. In all of the changes of energy from its various sources to its electrical applications, water-power stands pre-eminent in point of economy. Power-users the world over have endeavored to utilize this force in preference to any other, and until long-distance transmission was found practicable it seemed that every available water-power in this section of the country was doing its full share for the benefit of mankind. The success of each great industrial development has been clue in a greater part to some one man one who is just a step in advance of the rest in his particular field; one who is able to grasp a situation and foresee possibilities; and, above all, one who has that indomitable pluck and perseverance which sees in each obstacle one more step toward success. Such a mail is Eugene L. Ashley, for it was through his efforts that the development of the greatest power on the Hudson river was made possible. For several years prior to 1897 the various properties along the river between Glens Falls and Palmer Falls were in the hands of speculators. These men knew the value of waterrights, but they had not the ability to assemble the properties and finance such an undertaking. In 1897 Mr. Ashley began buying these water-rights, and, after two years of litigation, title mas secured to all of the properties along each side of the river, and the Hudson River Water-Power Company was organized to construct a dam and transmit power to the surrounding cities and villages. A contract was let for a dam

Jan 1, 1904

By H Kurth, L Balzan

On-belt analysers have been used since the early 1980s in the coal sector to measure ash content in real time for diverting material on conveyors to remove waste, bypass beneficiation and allow suitable material to proceed to the wash plant for processing. Since 2008, a GEOSCAN-M elemental analyser has been used on an overland conveyor in South Africa to divert direct-shipping quality iron ore to bypass a jig plant. This paper focusses on recent evaluation work to determine the suitability of an on-belt analyser to upgrade the processing plant feed in a copper-gold operation.Copper-gold ore samples from New Gold’s New Afton Mine near Kamloops, BC, Canada were tested to assess measurement accuracy over short time increments. A two-minute measurement increment has been used in the minerals sector as a compromise between good measurement accuracy and a useful tonnage (haul truck equivalent size or smaller). At New Afton, this increment represents approximately 35 t of material. Segregation decisions are currently made after visual and sometimes analytical determination, at increments of approximately 500 t to designate material as ore or waste at the drawbell in the cave.Results of test work including the composition range and expected accuracies by element are shown. The operation, which is not mine constrained, was evaluating the potential for ore upgrading through waste and low grade increment diversion to upgrade ore quality feeding the mill. Prompt-gamma neutron activation analysis (PGNAA) was considered as the company recognised that it would measure through the full conveyed cross section continuously and produce multi-elemental measurements unaffected by particle size, dust, moisture content, layering and segregation, mineralogy and belt speed.GEOSCAN analyses over various analysis periods will be collected to identify variability in the conveyed material quality and used to generate tonnage-grade curves so that an optimal diversion (bulk sorting) tonnage increment can be determined. Measurement increment time can be customised to suit site requirements. CITATION:Kurth, H and Balzan, L, 2017. Assessing bulk sorting suitability at the New Afton mine, in Proceedings MetPlant 2017, pp 315–323 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 11, 2017

By J. P. Baur

The sensitivity of radiochemical techniques makes possible the study of the initial-stage sulfuric acid leaching kinetics of chalcopyrite and other copper sulfide minerals. This Bureau of Mines study of the initial leaching of chalcopyrite used techniques to evaluate the molecular and electrochemical processes. High-grade Transvaal chalcopyrite was neutron-irradiated in a TRIGA reactor4 to produce radioisotopes copper-64, iron-59, and sulfur-35. Dissolution rates were measured in the time interval zero to 60 minutes, during which time significant anomalies were observed. First was an initial period of rapid dissolution lasting a few minutes; second, an arrest or ?plateau? region usually lasting from 6 to 10 minutes; third, a second period of dissolution of lesser rate than the first. The effects of solution variables such as pH, oxygen partial pressure, and ferric ion concentration at different temperatures were measured.

Jan 1, 1974

By J. Kou

The adsorption process, density and structural property of the oleate layer adsorbed onto a hydroxyapatite (HAP) surface at six different concentrations and three pHs (pH 8, 9 and 10) have been studied using the technique of quartz crystal microbalance with dissipation (QCM-D). The present study demonstrated the versatility and accuracy of the QCM-D for surface adsorption characterization. The real-time measurements of frequency and dissipation shifts with a hydroxyapatite-coated sensor revealed changes in the hydroxyapatite surface during the entire adsorption process. Chemisorption and surface precipitation of sodium oleate were also observed on the surface of hydroxyapatite through the use of Fourier Transform infrared spectroscopy(FTIR). Chemisorption dominated at low concentrations and high pH values and formed a rigid and thin adsorption layer. Surface precipitation of calcium oleate and micelles dominated at concentrations higher than critical micelle concentration (CMC) and lower pHs and formed a thick but dissipated adsorption layer with a high hydration level. Three distinct adsorption behaviors were identified from the different slopes of ?D-?f plots. The adsorption density was less than a monolayer at concentrations <0.164 mM, but increased significantly at concentrations higher than 0.821 mM at all three pHs. The critical concentration at pH 8 was 0.33 mM, which was lower than at pH 9 (0.821 mM) and pH 10 (3.3 mM).

Feb 1, 2012

Anaconda Aluminum Co. began production from a new 60,000-ton-per-year potline at Sebree, KY, which brings the total capacity of the plant to 180,000 tons per year. A strike by workers at Alcan Aluminium Corp. primary aluminum smelters at Arvida, Que., Isle Maligne, Que., and Beauharnois, Que. shut down the plants and the company announced force majeure on part of its ingot supply commitments. Kaiser Aluminum and Chemical Corp. announced plans to increase its price for primary aluminum from 60.0 cents per pound to 63.0 cents per pound effective July 1.

Jan 1, 1979

"Above ground, elevated belt conveyors that span more than 200 m (656 ft) between support points can cross valleys, rivers, forests and buildings with a minimal footprint. The cable bridge conveyor (CBC) is a new type of suspension bridge based belt conveyor system that has long spans between support points. It combines a typical belt conveyor and an improved simple suspension bridge to form a conveyor bridge. The improved simple suspension bridge places a widened bridge deck directly on suspended cables, without the need for high truss towers. The benefits include reduced cost and increase aerodynamic stability compared to conventional suspension bridges. The CBC’s compatibility with current belt conveyors allows versatility in application.A belt conveyor is a ubiquitous material handling system. Conveyors can be placed directly on ground or elevated above ground by support structures. Considerations of cost, design, environment, civil work, safety and process requirements are all factors in choosing the ground-based or elevated conveyors (Zhang, 2014). The ground-based conveyor has the lowest structural cost when the conveyor is placed on an existing road. Maintenance access is easy and straightforward. Compared to the groundbased conveyor, the elevated conveyor can cross existing buildings and structures, give passage to traffic beneath the conveyor, has a smaller footprint and requires less civil work to pass mountainous areas. The drawback of the elevated conveyor is higher structural cost, which can be compared with savings in civil work and other benefits. Conventional elevated conveyors are supported by rigid truss-type structures, with a typical span of 15 to 25 m (50 to 82 ft) between concrete support bents or steel trestles. Triangular truss, using steel pipes instead of hot rolled steel sections, is more efficient. The typical span of a triangular truss-supported conveyor is around 30 to 40 m (100 to 130 ft), while the weight is about 10 percent less than conventional box truss with a shorter span (Jennings, 2013).Long-span elevated structures based on suspension bridge is another step forward in increasing the distance between support bents, reaching 100 to 400 m (330 to 1,312 ft) and beyond. The wide distance between the support points of an elevated conveyor offers unique benefits. The conveyor can cross rivers, valleys, highways, forests and other obstacles with minimal footprint and reduced civil work. The versatility from long-span conveyors makes bulk material transportation over previously impossible terrains now a feasible option."

Jan 1, 2014

By K. Irmscher

During the last years, using modular computer models on the software and distributed computer capacities on the hardware side has become quite common in the mining industry. When tackling real mining problems under the condition of heterogeneous systems, however, some problems become obvious: the incompatibility of the heterogeneous platforms in connection with the heterogeneously structured information and the necessity of interpreting the data. Knowledge based approaches are employed for solving different planning problems in the field of mining industry. The main problems here consist in the knowledge representation and data acquisition. Starting point of the investigation form classifications of mining planning problems and the corresponding models which can be transformed into information models for evaluation. With help of an expert system a practical solution is represented. Distributed systems with mobile computing and communication facilities for immediate access can be used as an additional support for planning and processing. On the base of public or private computer networks (including mobile networks) the foundation is given for a computer supported treatment of planning tasks. Additionally the use of teleworking scenarios in regions of mine planning and data collection in geological applications is prepared. Foundation forms a workflow system on an object-oriented distributed platform.

Jan 1, 1996

By M Ljunggren, M Lundh

Dissolved air flotation (DAF) in wastewater treatment as a separation process of submillimetre biological flocs is based on the generation of bubble/floc aggregates. DAF is a complex process but has got advantages, such as allowing a high hydraulic load, compared to sedimentation. A thorough knowledge of the physics of the DAF process is, however, still lacking. This paper will present results of experimental studies on three aspects of significance to the separation process û the flow structure in the flotation tank, rise velocities of aggregates, influence of floc size on the separation efficiency. Flow structure. Measurements were performed in a pilot plant mapping and visualising the velocity field. The dispersion water (bubbles) had a decisive influence on the flow structure due to the effect of the bubbles on the bulk water density. Stratified conditions with a less dense, bubble-containing upper layer and a clear water, denser bottom layer were important for a good separation. A simple model of the stratified flow structure was elaborated making it possible to interpret the function of the aggregate rise velocities. Bubble/floc aggregates. The dynamics of single flocs, bubbles, aggregates were visualised using a borescope + CCD video camera + digital recorder + image analysis. Sequences of video frames made it possible to determine the rise velocities of the single aggregates. These velocities were found to be in the range 1 - 9 mm/s with a tendency for large flocs to have higher rise velocities. Separation versus floc size. The floc size distribution was measured in the DAF process. Data from three different DAF cases showed, that large flocs (> about 100 ¦m) were entirely separated, whereas small flocs experienced a less good separation. It was, moreover, found, that a very significant separation of flocs took place in the very upstream end of the separation zone in a pilot plant case.

Jan 1, 2005

By M. F. Vancas

The advantages of using vertical pulsed columns as replacements for conventional mixer/settlers in the uranium industry have been known for some time. The advantages of the columns offer include a reduction in real estate for the plant, elimination of diluent evaporation and crud formation. This paper presents the findings of laboratory tests of pulsed columns extracting copper from pregnant leach solutions and also discusses potential advantages of the pulse column in copper solvent extraction.

Jan 1, 1999

By G. R. Hopkins

[A new record in fuel efficiency at petroleum refineries was established in 1939, when a the average e B.t.u. requirements per barrel of crude oil processed declined to a new low of 557,000 B.t.u. (see fig, 1).]

Jan 1, 1941