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By James K. Kindig

Solvent extraction as a method of purifying and concentrating metal values from solution has become a standard hydrometallurgical operation for recovery of both uranium and vanadium, and within the past two years it has been put into operation in a commercial plant for recovery of copper from leach solutions. In this first full scale solvent extraction plant for recovery of copper operated by Ranchers Exploration and Development Corporation near Miami, Arizona, a kerosene solution of an organic compound, LIX-64® is used to selectively extract the copper from the dilute acidic copper sulfate leach liquor obtained from heap leach operations. The copper is back extracted from the solvent into a stripping solution which is fed to an electrolysis circuit producing cathode copper for sale.

Jan 1, 1970

By A. H. Balch

A physical elastic seismic model, based on the Peoria oil field was constructed and used to produce multi mode cross-borehole seismic data. Because this was a physical model, it was necessary to deal with a complex wave field consisting of compressional waves, shear waves, and converted waves. The recorded raw data were complex, have no resemblance to the inter-well geology, and were difficult or impossible to interpret. These unintelligible data sets were extensively computer processed. Detailed, accurate, images of the inter-well structure, and reflecting horizons were obtained as a result of this processing. This investigation demonstrates that excellent, accurate images of the inter-well geology can be obtained by skilled seismic cross-well data acquisition and extensive careful computer processing.

Jan 1, 1993

By Ed L. Schrader

Kaolin of the Georgia-south Carolina "Clay Belt" are used in a wide variety of filler and extender applications. Sane applications specifically require the performance enhancement delivered by incorporating kaolin into the product formulations. Other applications are less specific in requirements for an inert mineral filler. In order to be a feasible candidate for filling and extending, a mineral or mineral product must be generally inert (except where specific interaction with the filled medium is desired), inexpensive, easily handled and transported in a variety of forms, accessible to a broad segment of the desired market, and must exist in sufficiently large ore reserves as to assure production for many years. Of course, more precise requirements are necessary in specific applications of a prospective filler material.

Jan 1, 1985

By J. Iannicelli

An entirely new level of magnetic filtration technology was put into full commercial production by the kaolin industry of Georgia, U.S.A. during 1973-1974. At present, four kaolin producers in Georgia are operating large magnetic filters each capable of processing over 1000 gallons of kaolin slurry per minute or over 65 tons of kaolin per hour on a dry basis. A fifth large filter will go on stream in August, 1975. Four of these units are 84" machines manufactured by the Pacific Electric Motor Company of Oakland, California. When operated at the maximum 1000 g, p. m. rate, these five large magnetic filters have a combined capacity approximating the entire waterwashed coating and filler kaolin produced in the U.S.

Jan 1, 1976

By S. C. Termes

This paper discusses recent Federal Bureau of Mines research on the selective flocculation of various minerals with insoluble crosslinked starch xanthate (ISX). ISX is insoluble, has a shelf life of over a year when kept cold, and has a higher molecular weight due to cross linking than the soluble noncrosslinked starch xanthate used in previous flocculation studies on nonsulfide minerals. ISX readily flocculates a number of sulfide mineral fines but not silicious gangue. Floc formation, floc size, and settling rate are strongly dependent on pH, with the pH dependence differing for each mineral. Bornite has been selectively flocculated from bornite-quartz mixtures, and the bornite-containing flocs were separated from the unflocculated quartz using decantation and washing procedures.

Jan 1, 1982

By James S. Browning

The principal uses of fine ground mica are as filler in wallboard joint cement, as a filler and surface coating for roofing, as an ingredient in paints, and in oil well drilling mud. The mineral has other uses in the manufacture of rubber, wallpaper, plastics, welding rods, electric insulation, house insulation, and textiles, and as an annealing agent in metal treatment. In recent years, more than 999 percent of the domestic mica produced has been scrap and flake mica (mica which does not meet specifications for sheet mica and is used for producing fine ground mica). There has been a continued increase in mica production for, several years, the 1963 production of scrap and flake mica totaling 117,251 tons.

Jan 1, 1966

By William F. Hahn

It is a pleasure to speak to this group about special crusher installations which are in the bauxite and phosphate rock processing industries. The installations to be discussed demonstrate the variety of conditions, materials, and results desired which must be evaluated before a selection is made from the specialized crusher technology available today. Those of you who are closely involved with phosphate rock and phosphate products processing will find some of this information a bit interesting and perhaps alien to your own descriptions or every day references. It is given from a "crusher" manufacturer's viewpoint and therefore is infused With our flair and language. General features of six (6) different crushers will be shown in cross-section With slides and will be discussed in the same order.

Jan 1, 1978

Lack of selectivity in mixed mineral flocculation can be attributed to one or more of the following factors: dissolved ion interference, heterocoagulation, mechanical entrapment in flocs and entrainment of fines between flocs. In a study of apatite- dolomite system, it was determined that dissolved ions do not have a significant effect on selectivity. Heterocoagulation was minimized by choosing proper process conditions and addition of a dispersant. Mechanical entrapment was proved to be insignificant and efforts were made to reduce entrainment by choosing an appropriate method of separation of flocs from fines. A new factor termed "polymer induced entrapment" which occurs due to limited affinity of the polymer to the mineral which is not flocculated is postulated to be the cause for the loss of selectivity.

Jan 1, 1986

By W. C. Smith

Even with the most conservative mine plan, rib instability can occur unexpectedly, and if not adequately dealt with, can progress from a nuisance to a major safety hazard. This Bureau of Mines paper examines the mechanisms of progressive rib failure in high mine openings and discusses techniques to control rib slabbing. A field test site in a longwall mine was instrumented to investigate rib behavior during mining. While data analysis showed minor pillar dilation, sporadic zones of progressive rib instability were detected which culminated in eventual rib failure. The failure occurred despite conservative pillar dimensions and shallow depth. Physical and computer models were used to demonstrate the mechanisms of rib failure and then evaluate the influence of support and other mine-related parameters on rib behavior.

Jan 1, 1989

Residential and commercial plumbers in the United States were introduced to Viega?s copper press technology in 1999. In short, the technology allows plumbers and installers to join copper pipe securely in four to seven seconds on pipe sizes of 1.2 to 10 cm (0.5 to 4 in.) by pressing the connections with specialized tools and fittings rather than through sodering or welding. The water- and air-tight technology, first introduced in Germany in 1989, includes three different sealing elements, a variety of materials and a selection of configurations. By eliminating the need to thread or solder pipe, connections and repairs can be made quickly and securely. Installations are also much quicker and as secure as traditional methods.

Jan 1, 2012

By R. K. Singhal

In open pit mining every effort is made to maintain as steep a pit slope as possible. Pi t slope angles are influenced by numerous factors some natural that are amenable to limited or no control at all and other mining technology related where a greater degree of influence can be exerted by the engineer. One such area where control is possible is the method of drilling and blasting in the pit. This paper discusses the influence of blasting techniques on the economics of pit slopes and demonstrates how balanced blasting can be used with advantage to pit wall control and improve fragmentation (thus reducing material handling costs). Microprocessor based instrumentation to monitor drill and blast performance has also been described.

Jan 1, 1988

By F. G. Miller

Over the past 30 years, the coal industry has been continually striving to perfect methods for cleaning fine coal to acceptable ash and sulfur contents while maintaining maximum product yield. The flotation process has been part of this effort and its importance is expected to grow as new utilization technology demands finer and purer coal products. The work outlined in this paper is part of a larger effort aimed at development of new and improved flotation systems for removing sulfur and ash from as-mined coal as well as for producing super-clean coal for future markets. The concepts and data presented are now serving as a basis for designing fine-coal circuits in which improved efficiency is obtained by optimum use of flotation.

Jan 1, 1986

By N. Cruickshank

Gas outbursts occur as sudden eruptions of gas and minerals from the face of a mine heading as the heading approaches potentially burst-prone (or anomalous) zones of rock. Such outbursts have resulted in considerable damage to equipment and in some cases lives have been lost. Characterizing these anomalous zones and detecting their presence is therefore vital to safe mining. Certain significant characteristics associated with the outburst-prone zones are: (1) the presence of fluid inclusions, (2) unstable stress conditions, (3) characteristic geologic structures, (4) certain physical properties of the rock, and (5) micro-seismic activity. Geophysical and engineering methods for detecting these characterisitcs are discussed and are considered with respect to their past success and future potential for predicting gas outbursts.

Jan 1, 1985

By L. A. Khan

This paper first discusses the physicochemical cleaning methods used to process fines followed by an analysis of the subprocesses of froth flotation and the adverse effects of slimes and particle oxidation. These subprocesses include the phenomena of interception, contact, adhesion and levitation. Preventive and corrective measures to combat the generation of fines and their effects are suggested. Preventive measures include controlled grinding, limited liberation, flotation at coarser sizes. Means of preventing oxidation and/or removing oxidation products are a1 so discussed. Corrective measure to increase recovery include intensive aeration, aggregation of particles, intensive mixing, increased retention time, and reduction of detachment. Measures leading to improves selectivity involve means to reduce slime coating, achieve selective mineralization of bubbles and minimize entrapment.

Jan 1, 1986

By Luis Yacher

CONTAC Engineers is a Chilean based company which works on process control and automation, principally for the minning industry. Jointly with other local and international engineering firms, CONTAC has participated in most of the last expansion and modernization plans being carried out at the Chilean pinning industry. At presente, CONTAC is involved on a research and development plan for the design and implementation of new instrument and process control procedures for mineral process automation. One of these efforts is the design of an ore size analyzer for coarse ore being transported over a conveyor belt. A feasibility and prototype study was made at a SAG Mill Plant and currently a high resolution, high speed analyzer is being developed. It will became available on early 1986.

Jan 1, 1986

By M. J. Hart

There are no formulas that guarantee success when it comes to obtaining zoning approval for mineral aggregate mining. Local land use decisions often times represent the most controversial issues faced by community. Public awareness, concern, willingness to get involved, sensitivity to the environment and probably most importantly fear of change only begin to describe the atmosphere in which local land use decisions are made. Add to this the public hearing process which is quasi judicial, adversarial, and unfortunately not designed for resolution of disputes and it is not difficult to see the need for an alternative to present methods. Hopefully, some day we will have a process that will do away with or at least minimize unnecessary, unproductive and unmanageable community conflicts.

Jan 1, 1984

By Erle I. Shobert

In the comparison and consideration of synthetic and natural materials, graphites represent a situation in which natural graphites amount to less than 10% of the total carbon and graphite production by weight, and less than 5% in dollar volume, There are few applications where it could not be re- placed by synthetic graphite. On the contrary, synthetic graphite materials can be engineered to cover an extremely wide range of applications. These include electrographite brushes for rotating machinery, pyrolytic graphite, graphite-impervious pipe, nuclear moderators, high purity spectrographic graphite, power tube anodes, graphite rotary shaft seals, and rocket nozzles. The special qualities of natural graphite and its limitations are delineated and the almost unlimited possibilities in artificial graphite materials are discussed.

Jan 1, 1964

By James E. Palmer

Geologic constraints on mining and recoverability include the following: coal seams too thin or thick for conventional mining methods; coal seams with insufficient stratigraphic separation; unstable roof or floor strata; discontinuous or lenticular seams; coal seams that have high dips or are intensely faulted; water problems due to proximity of aquifers; and coal quality problems such as excessive sulfur, ash, chlorine, sodium, etc. The demonstrated reserve base for western coal of 220 billion tons is considered misleading as it does not adequately incorporate the above parameters in estimating procedures. Current reserve base estimating procedures involve an abstraction of data from generalized resource estimates. The authors believe the reserve base should be determined independently beginning with well-known deposits, with all mining and recoverability constraints fully incorporated.

Jan 1, 1981

By R. J. Pruett, J. Yuan

Kaolin clays from five different commercial deposits in Georgia were studied to understand the variations of zeta potential and related fundamental properties. The results suggest that higher negative zeta potential is related to exchangeable or soluble calcium ions in the clays.

Jan 1, 1999

By Daniel McConvey

Who is the Investor? -Mainly institutional, including resource funds, other mutual funds and pension funds. -Some hedge funds. -Retail investors. -How important is the reserve disclosure to these investors? -Do these investors know the difference between a reserve and a resource?

Jan 1, 2003