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By M. Moss Stanley, Ronald P. Klepper

The objective of this chapter is to provide data that will assist in the selection and sizing of equipment utilized in the filtration method of separating solids from liquids. It should be recognized at the outset that in some situations more than one option may be available to achieve the target desired. In some cases purely technical objectives may be sacrificed because of cost considerations, design factors or other elements in order to satisfy optimization within the flowsheet and/or to provide bottom line results. Before considering available options, and prior to the next step of sizing out the selection, the operating criteria should be set down. The test work to develop selection and sizing data will be based on this data and the final products desired. This will help to establish initial parameters. A. GENERAL DATA 1. Material to be filtered: a. Solids b. Mother liquor 2. Feed rate of slurry in GPM 3. Density of slurry: Sp. Gr. Solids 4. Slurry: Temp. pH Viscosity 5. Source and method of feed 6. Valuable product: Solids Filtrate Both 7. Details on: Volatility Toxicity Stability 8. If flocculant is indicated, what has been used? 9. Describe product: (i.e., fibrous, cor 10. rosive, abrasive, inflammable, explosive, pasty, 11. Does product alter or require special environment during transport? 12. What type of filter media has been used successfully? 13. Is there any objection to use of a filter aid? If not, is there any preference? B. SOLIDS DATA 1. Sp. Gr. Bulk density 2. Screen analysis 3. Desired percentage moisture in cake 4. Solubility (state conditions): In mother liquor In wash water 5. Description of cake: (i.e., amorphous, fibrous, crystalline, colloidal, gran¬ular, thixotropic, 6. Special requirements for moisture de¬termination? 7. Can solids be compressed during dewatering? 8. Proposed product handling 9. Subsequent thermal drying or other pro¬cedure C. FILTRATE 1. Is separation of wash water and mother liquor desirable?

Jan 1, 1986

The need for an integrated approach to optimization of unit operations in both the pit and the mill has long been recognized, but the complexity and nature of the overall problem has up to now resisted solution. This paper reports on a modeling methodology which couples symbolic and numeric computing to unify operations in both the pit and mill. The ultimate goal of this work is to optimize all operations that are influenced by blasting. Blasting plays a key role in all facets of operations. Obviously, drilling and blasting costs are determined by blast design, but the down-stream costs that are closely related to blasting results are often treated as separate functions: loading, hauling, cleanup, and crushing and grinding are all heavily influenced. Diggablilty and bucket fill factor are a function of fragmentation, the condition of the floor and uniformity in the shape of the muck pile. Likewise, cycle times and loading delays partially determine haul cycles, while fragmentation distribution and size determines the efficiency of truck loading. Removal and breakage of oversize causes loading delays and increases cleanup costs. The influence of blasting doesn't stop at the crusher. Mill productivity, power consumption, and maintenance are a function of the feed. Even at the SAG mill a reduction of a critical particle size during blasting can increase throughput. Thus, a bottle-neck for production far removed from unit operations in the pit can be alleviated by a modification in blast design. The question is: how do we optimize blasting with respect not only to itself but to al\ related mining and milling operations? For that matter, how do we even model blasting so that we can control the results of a blast?

Jan 1, 1991

By G. E. Erdman

The total attitude of the industrial minerals producing company is a most important factor in how they regard quality control, technical support for their customers, and procedures used in mining their minerals products. This philosophy of the producing organization directs their action along certain courses. For instance, one producer might see itself as a mining company with its major goal mining efficiency to make it exceedingly price competitive in the market place. Another producer might see itself as a wide spectrum multi-mineral producer that furnishes a reputation for a complete line of products. Another producer might see itself as a specialist in one specific industrial mineral and bet its whole bankroll on providing the very best of quality with the goal of becoming the largest producer of the mineral commodity. Each perception can have a different impact upon the producer's operations and its regard for quality control. Minerals Being Produced The specific markets being served will have their own influence on how mineral product quality is regarded. Ceramic raw materials, for instance, have a very low tolerance for iron which is the cause of low fired color. Thus, industrial minerals for use in glass and ceramic markets must be won from deposits with a very low iron content. A high iron silica sand might be sold to a manufacturer of good old beer bottles. That is a solution to one particular quality facet, but eliminates selling to a significant market in clear glass, porcelain enamel, ceramics whiteware bodies and hobby glazes. Thus, there is a need for sound research in the industries expected to be served before the product is brought to market.

Jan 1, 1987

By W. V. Bluck

Higher coal quality is being recognized in potentially lowering the cost of power as measured at the bus bar. Assessment of potential coal supplies for most any given power plant is now going beyond buying at the lowest delivered fuel cost and is now taking into consideration other factors such as handling, storage, pulverization cost, boiler fouling, post combustion cleanup, and waste disposal costs. New measurements of quality are being considered now by those producing and those consuming the fuel by assessing numerous variables in the total fuel cycle to achieve the lowest possible power costs.

Jan 1, 1983

By James L. Whitlock, Amy E. James

During the past twenty years, numerous advances have been made in the technologies used to pretreat sulfidic refractory gold ores. These advances have included improved equipment design, increased gold recoveries, and reduced operating and capital costs. More recently, treatment of refractory gold ores has primarily been accomplished by pressure oxidation (POX), roasting, chlorine oxidation, or biooxidation. In addition to improving the time-proven processes of pressure oxidation and roasting, new and innovative approaches to biooxidation pretreatment of both concentrates and whole ores have been developed. Selecting the appropriate biooxidation technology depends on the nature of the refractoriness in the ore, economic gold recovery, plant design operating parameters (such as desired tonnage), site climatic conditions, and operating and capital costs, as well as several other deciding factors. The objective of this paper is to outline the biooxidation processes and technologies currently available for the recovery of gold from refractory sulfidic ores, to discuss the critical factors that affect plant design and operation, and to provide the metallurgist with a practical guide to choosing the appropriate biooxidation technology for a particular ore or concentrate.

Jan 1, 1999

By A. M. Marabini, G. Belardi, V. Alesse, M. Acosta

Sotiel mine is situated in the Iberian Pyrite Belt in southern Spain, some 40 km north of the port of Huelva. Although mining operations at the site date back to Roman times, the present mine came into production in 1983 and 5.6 million tonnes of ore had been extracted by 1993. The orebody is volcano-sedimentary and consists of fine grained copper, lead and zinc minerals in massive pyrite surrounded by slates and volcanics. Prior laboratory research had resulted in the synthesis of a new collector, belonging to the MercaptoBenzoOxazole (MBO) class that acts selectively towards Cu and Zn minerals after activation with CuS04. The MethylMercaptoBenzoOxazole (MMBO) version of this collector had been used for the laboratory flotation of Cu minerals and sphalerite activated by CuS04. This resulted in identification of the optimal physicochemical conditions for laboratory-cell flotation of the two minerals from samples of complex sulphide ores, and subsequently the reagent has been tested in the Sotiel plant (Spain). The plant has three flotation sections. With conventional re-agents, the first section yields a Cu concentrate grading 21% with a total recovery of 29%, and the second one yields a 40% Pb concentrate with total recovery of 34% and a 47% Zn concentrate with total recovery of 78%. Application of the new synthetic reagent in the copper and zinc circuits produces a more selective process with a decrease in re- agent concentration grade and recovery are increased by 2 and 9 points respectively in the case of Cu and by 1 and 3 points where Zn is concerned. Moreover, the penalty elements in the Cu concentrate are halved.

Jan 1, 1995

By P. Grotjohann

In processing heavy mineral sands, the low feed concentration and respective high value of the desired minerals require high capacity production and sharp classification/separation techniques to reduce the specific production costs. The allflux® separator, a new process system introduced to the heavy mineral industry, meets these criteria in an economical way. Its two-stage process, a combination of rising current and fluidized bed technology, allows the treatment of extremely high massflows in a single unit. Using concepts that have proven successful in processing concrete sands for many years, testwork in coal, iron ore, and heavy minerals looks very promising.

Jan 1, 1998

By C. N. Bailey

Let's review the economic factors in mill design. Talking about engineering economics in mill design reminds me of an old' saying "There are several ways to handle women but nobody knows what they are." I'm sure that the same economic factors do not apply to each of our mill designs, but for the sake of emphasis, it is well to review a few of them. They are so simple that we are apt to feel they are not important. Other speakers today are talking about the engineering factors of mill design, but I'm asking the question "Have we checked the economic factors involved in these designs? Have we checked the obvious? Many great discoveries have resulted from analysis of the things that appeared to be obvious all the time. What are some of these economic factors? Perhaps the most basic one is simply the value of minerals in place if minerals have value in the ground, they have value only because many important and different considerations add up to the probability that the minerals can be mined, beneficiated and disposed of profitably. The size formation and quality of the ore body, the distance from market, and the transportation available to the market area, depreciation rates, taxes, and the ownership interests involved are but some of the factors that must dovetail into the answer of profit, an answer prerequisite to hoped-for financing.

Jan 1, 1961

By Viacheslav Lyakhov, Cornelis H. Iestra, Victor I. Beloborodov, Vitaliy Bogdanovich

The results of a study and effective use of flotation for processing of ores with complex mineral composition containing fine-disseminated minerals with high specific density are presented in the paper. The object of research was complex baddeleyite-containing ore from Kovdor deposit (The Kola peninsula, Russia). Baddeleyite is a valuable, rare mineral, natural Zirconium dioxide with 5.8 - 6.0g / cm density, grade content 0.15 - 0.17 and dissemination less than 0.2 mm. The authors carried out a thorough investigation of baddeleyite- containing products selected in different sites of gravity flowsheet. It was determined that due to similar specific weight some sulphide minerals (pyrite, pyrrhotite) come into concentrate together with baddeleyite and, also, minerals of pyrochlores group (hatchettolite). The results obtained revealed the possibility of use the flotation for retreating rough baddeleyite concentrate. he given gravity concentrate has a number of specific features, e. g. high density of its minerals which, in its turn, provides for high speed of sedimentation of solid phase in pulp, and for the presence of large amount of sulphide minerals (up to 10%) having good flotability. With these features being taken into account a technology for flotation of baddeleyite-containing products after their preliminary gravity concentration has been developed (up to 5 - 10% Zirconium dioxide). The technology has three flotation stages. At the first one the reverse flotation of baddeleyite is carried out during which "light" minerals (forsterite. apatite and carbonites) come into froth product and at the second one flotation of sulphide minerals and at the third one direct flotation of baddeleyite is performed from the underflow product. The following reagents were used for flotation: of phosphate type (sodium tripolyphosphate, mono and diethers of alkylphosphpric acid) and sodium xanthate as collector for sulphides. The given set reagents provides for high effectiveness of flotation due to selective of collectors and presence of froth layer with high carrying ability. New flotation technology of recovering of baddeleyite from complex ore was developed and applied at the Kovdor Mining Plant, using AKER flotation machines.

Jan 1, 1995

By James A. Morrison, Stephane Carayol, Paul H. Madsen

The Rio Piedras Alignment Section 7 of the Tren Urbano is currently being constructed beneath a historic commercial section of San Juan. Different portions of the section are being constructed using open cut, cut-and-cover, New Austrian Tunneling Method (NATM), Earth Pressure Balance Machine (EPBM), and as tacked drift mined support system. The combination of complex geology, low ground cover, and several innovative construction methods present many challenges to the ground control program. Mining and construction sequences were first developed to minimize ground movements and risk of damage to structures. A unique compensation-grouting program was developed to improve the ground, limit settlement, and recover settlements incurred due to mining.

Jan 1, 1999

By W. H. Langer

Around the beginning of the 20th Century, annual aggregate production in the United States amounted to about 50 million short tons. Today annual aggregate production is nearly 2.5 billion tons. Over a third of the States in the country produce more aggregate than the Nation did at the turn of the century. I would like to describe some of the historical events that allowed this nearly 50 fold increase in aggregate production. You might wonder why I want to talk about history. Some of our best ideas lie buried in the past, waiting to be rediscovered in the present. Almost every issue that the aggregate industry experiences today has been recognized for at least a decade; many of those issues have been recognized for a half a century; and a few of them have been recognized for nearly a century. The main reason for this article is to save the past from the forgetful indifference of the present-to faithfully preserve the past, to illustrate the insights of our predecessors, and to demonstrate how little of what we know today is really new.

Jan 1, 1998

By B. A. Filas

Stabilizing fine coal refuse ponds for reclamation at Monterey Coal Company's No. 1 Mine has been difficult. Entrained water in the stored refuse causes liquefaction as reclamation caps are placed, resulting in additional material requirements than originally projected to stabilize the pond surface. Laboratory results indicate that in-place refuse densities may be substantially improved at No. I Mine by converting from a single-point to a managed slurry distribution system. Increased densities result in improved storage efficiency, less entrained moisture and a more stable refuse mass, thereby providing an improved working surface for reclamation and improved post-closure cover stability.

Jan 1, 1993

By A. J. Rergis

During the past ten years a number of papers have appeared describing zeolite occurrences in the western United States in Mesozoic sedimentary rocks, altered bedded Tertiary pyroclastics, playa lakes, hot springs, and amygdaloidal basalts. With the emergence of natural zeolites as economic industrial minerals it appears, useful to develop a system of classification to delineate those zeolite deposits of economic interest which were not discovered until the middle 1950's. The first attempt at a classification of naturally occurring zeolites was made in 1914 by Lindgren l when he classified the zeolites into eleven groups based on their mode of occurrence. The zoned zeolites in the Mesozoic rocks of New Zealand and elsewhere were classified according to the mineral assemblages by Fyfe, et al.2 in 1958 as a zeolite facies corresponding to low grade regional metamorphism. In 1966, Hay suggested as an alternative to the preceding classification one which would "classify as diagenetic all mineral assemblages produced in sedimentary rocks under conditions in which zeolites are formed." In this paper a classification is proposed with the objective of providing an overall perspective of the zeolite occurrences in the western United States.

Jan 1, 1967

By Jacob Grasmick, Bill Newns

Despite ongoing digitization and “hardware” technological advances, geotechnical uncertainty remains the most significant risk in underground and tunnel construction. And, whilst they are commonly held up as an example of the sophistication of the industry, the practice of drafting and using geotechnical baseline reports is subject to a wide range of influences, not all of which support good risk management. Uncertainties in predicting ground behavior, the gap between the pre-construction assumptions, and the systemic response to construction remains a significant technical and communication challenge. Accordingly, this paper presents a framework to quantify geotechnical uncertainty using geostatistics and translate these into practical tools for ground risk management throughout planning, procurement and construction. Adopting even some of the principles of this framework should provide improvements to contract risk management and should assist to minimize the potential for commercial losses.

Dec 1, 2022

By L. S. Rubin

The efficient and acceptable disposal of fine coal refuse (28MxO) is one of the highest priority problems facing the coal industry today. For many years the established system for the disposal of this fine refuse slurry has been to concentrate the solids in a static thickener and pump the resulting 20-40% solids underflow to lagoons or impoundments. Although this technique has served the coal industry well, increasing environmental concerns and refuse related disasters, such as Buffalo Creek, West Virginia and Aberfan, Wales, Great Britain have resulted in federal and state regulations which now control fine refuse disposal methods. As a consequence of these regulations, the capital costs of constructing, maintaining, and operating regulatory complying impoundments has become in many cases economically unattractive. Areas processing topologies similar to those coal preparation plants of the Appalachians are particularly burdened by these regulations and are consequently turning to alternatives for handling and disposal of their fine coal refuse. The basic requirements of impoundment alternatives as defined by environmental and plant demands are: (1) A relatively solids-free liquid (1000 ppm or less) to serve as plant make-up water in a "closed circuit" system, and (2) a sufficiently dewatered solids product which can be combined with the coarse refuse to form a compactable stable land-fill.

Jan 1, 1978

By M. B. Haggerty, Joe Welna

The Minnesota Department of Transportation is constructing a stormwater storage facility (SSF) along Interstate 35W (I35W) south of downtown Minneapolis, MN. The project will provide storm surge capacity reducing the frequency with which major precipitation events result in flooding of I35W. The design consists of six, 42-foot diameter, 90-foot deep, adjacent underground shafts providing 14.7-acre feet of storage. Construction challenges include high groundwater with variable glacial outwash deposits. Constructability and ground variability were managed using construction manager general contractor (CMGC) project delivery. CMGC provides an environment for collaboration and innovation starting in the design phase and carrying through construction. This paper provides an overview of key efficiencies and collaboration examples implemented on the I35WSSF project which were aided by CMGC delivery.

Jun 13, 2023

By Warren N. Warhol

The mutual growth of the rare earth industry and the Mountain Pass Operations was no coincidence. It was the commercial availability of rare earths on a scale first made possible by the capacity of the Mountain Pass Operations that spurred research and development efforts toward new applications for rare earths. The first important demand on Mountain Pass was europium oxide for the activation of red phosphor for color television tubes in 1964. Since that time, other rare earths have become even more important, and Molycorp is continuing to supply an ever widening variety of rare earth concentrates and compounds. We enjoy saying that rare earths are not really rare, and that they are not earths, either. Of course, we are talking about the 15 metallic elements with atomic numbers 57-71, called the lanthanides, which occur in nature always together in very similar proportions. Their scarcity can be gauged by the fact that there is more cerium in the earth's crust than there is tin, and more europium than cadmium. The word "earths" comes from the early chemical term for oxide. The rare earths were discovered as oxides, and the term has persisted.

Jan 1, 1980

The world's largest hydraulic excavator was recently introduced at Syncrude's North Mine at Fort McMurray, Alberta, in Canada. O&K's 826t (910-st) behemoth RH400, with a 42-m3 (55-cu yd) bucket, is capable of loading 72.5 t (80 st) in one pass. Syncrude's Alberta operation is the nation's largest single source of crude oil. It is also the world's largest producer of oil from oil sands. Syncrude produces 205,000 bbl/day, expects to increase production to 225,000 bbl/day by 1999 and to 320,000 bbl/day by 2005. That translates to 73.5 million bbl of Syncrude Sweet Blend (SSB) produced in 1996, 82 million bbl in 1999 and 114 million bbl in 2005. The North Mine is a new development that will replace the current East Mine, to be depleted of oil sand by the end of 1999. The North Mine will feature hydrotransport, a new and unique method of transporting oil sand from the pit to the process plant. Oil sand from the truck-and-shovel operation will be processed through a double-roll crusher and placed in a cyclofeeder where it mixes with hot water. The material is then screened and transported by pipeline to the extraction plant. Hydrotransport will replace conventional conveyor transport for moving raw product from the pit. Mine development will also use two 290-t (320-st) haul trucks to compliment the fleet of existing 218-t (240-st) trucks.

Jan 1, 1998

By G. Gillet

The conventional magnetic separators used in the mineral industry are equipped with traditional magnetic circuits or with permanent magnets (rare earth). However, when processing minerals with low magnetic susceptibilities or minerals of very small particle size, these separators are inefficient. In addition, a conventional magnetic circuit consumes considerable amounts of electricity to generate a relatively low magnetic field (~2 Tesla). The equipment is also heavy and bulky. Only a separator having a superconducting sole-noid can contribute in solving most of the problems, and only such a separator can produce high magnetic fields with low energy consumption. New developments and the experience acquired in using these superconducting magnets have resulted in new uses for magnetic separation, especially in the environmental area. This paper presents and describes a separation system that uses superconducting magnets that are completely automated and able to treat raw materials (concentration or purification) or liquid industrial effluents containing heavy metals in solution. Several industrial sectors, including the surface treatment, petroleum and chemical industries, are generating effluents containing heavy metal ions. The main metal ions found in such effluents include zinc, copper and vanadium. The purification of such effluents by magnetic separation is performed by adding a certain proportion of iron salts. The treated effluent passes through a superconducting separator where the flocs are retained in a matrix of steel wires. The efficiency of supraconducting high-gradient magnetic separation (HGMS) by this method exceeds 95%. Mineral separation and industrial-waste purification results are presented.

Jan 1, 2000

By John D. Kalasky

Ventilation is necessary in coal mines to supply fresh air to the working faces for the health, safety, and comfort of the miners, and for the circulation of air to the extent that it will dilute, carry off, and render harmless the noxious or dangerous gases generated. Adequate ventilation depends upon good face control, as well as upon a well designed and properly controlled overall ventilation system. Generally, this includes fans, airways, overcasts, air locks, regulators, checks, and canvas or plastic stoppings near the working places to prevent short circuiting of air, and effective bleeders to maintain a continuous flow away from the working places along the pillar lines at all times and to prevent diffusion of methane back to the pillar line in case of temporary interruptions in ventilation. In the development of a new mine, or the virgin area of an old mine, the main headings should properly be considered a construction project, designed with, only the number of permanently supported (roof) headings required to conduct the necessary air volume to and from the major panels in which mining is conducted by room and pillar or longwall methods. Although subject to hazards from methane quite frequently and requiring constant and careful attention at all times, development of headings has some built in safeguards which make it a less difficult problem in control of methane than exists in pillaring.

Jan 1, 1973