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By F. J. Chernosky

In the past, a number of papers have been written on the use of various reagents as coal flotation frothers. For the most part, these papers have attempted to correlate the intrinsic chemical and physical properties of the reagents or reagent groups to the floatability of various fine coals. Because of the type or nature of evaluations made, chemically pure reagents were normally used. Generally, these reagents are unavailable in commercial quantities. Therefore, the results obtained with these reagents were usually limited in usefulness to the plant operator or metallurgist. This paper presents the results of a study in which commercially available forms of various reagents were used as flotation frothers. Flotation procedures which would conform in general to those employed in a large number of commercial coal flotation plants were utilized. The objective of the test was to compare these reagents on yield-selectivity-cost basis, that is, (1) the yields obtained, (2) the ash levels obtained, and (3) the reagent cost relating to these results.

Jan 1, 1962

By James A. Commins

Accurate engineering predictions of energy needs for pollution control equipment used in surface mining operations is critically important to sound management selection of control alternatives. This paper will describe a procedure for evaluating two control alternatives with different energy needs. Three steps are involved: an analysis of the pertinent regulations, a determination of the size distribution of the particles being emitted, a calculation of the energy needs and costs of the candidate control systems as a function of these regulations and emission characteristics. The principal air pollutant to be controlled in surface mining operations is particulates, or dust, some of which is already on the material introduced into the primary crusher and other dust which is generated by the various steps in the subsequent processes. The requirement for control stems both from regulations concerning workers at the operating site, and the community surrounding the operations. In order to speak quantitatively about the need for control we will use regulations that pertain in Pennsylvania although it must be borne in mind that such regulations vary according to juristiction.

Jan 1, 1975

By George W. Parker

The ever increasing costs of labor and supplies have made it imperative that operators of open pits look for some way in which to cope with these increases. One of the most logical ways to increase the efficiency of an operation is by the introduction of larger haulage equipment, as generally haulage costs are the greater portion of the over all expenses. These larger haulage units require larger shovel units. In the late 1930's and the early 1940's large mining, quarrying and heavy construction operations had more or less standardized on the 4 to 6 cubic yard shovels. During this same period the haulage units were generally 22 to 27 tons. Some ten years ago 9 - 13 cubic yard shovels along with plus 50 ton haulage units were introduced by manufacturers in an effort to enable operators to decrease costs.

Jan 1, 1962

By S. C. Sun

The grinding of coals for coal preparation has been studied extensively by previous investigators, but no similar work has been done on coal lithotypes (l-4). However, the different natural breakage characteristics of coal lithotypes have been recognized and utilized by the coal industry (5,6) to develop the Longway Burstlein process (7) for the concentration of macerals(8). The specific objective of this research was to determine the relative grindability of lithotypes, obtained from both anthracite and bituminous coals. An attempt was made to relate the findings, wherever possible, to the chemical and physical properties of the tested lithotypes. Another aspect of this research was to ascertain the size distribution and grindability of lithotypes ground at a various number of revolutions in a Hardgrove mill.

Jan 1, 1970

By John B. Jones

New concepts in shaft kiln processing are included in the design of two large diameter shaft kiln plants now under construction. One kiln will be used to produce cement clinker at the Boettcher plant of the Ideal Cement Company at Fort Collins, Colorado. The other kiln is for the semi-commercial oil shale plant for Petrobras, the Brazil National Oil Company at Sao Mateus do Sul, Parana, Brazil. Investigations on application of the new concepts are proceeding in a portable pilot kiln. The shaft kiln has long been recognized as a method of gas-solids contacting having the following principle advantages: l. High thermal efficiency 2. Ability to handle a variety of feed materials with a wide range of particle sizes 3. Minimum investment and operating cost

Jan 1, 1963

By V. D. Hanson

When maintenance of a plant or operation is under discussion immediately three "M's", all in short supply, are brought to mind - money, men and markets. This paper will present what currently is being done at our plants and its effect on the 3 "M's". Examination of coal realization figures (F.O.B. Mine) from 1945 to the present reveals the fact that open and free competition can and will meet market conditions. The industry, without benefit of advantages afforded tax and transportation wise to oil and gas, remains the backbone of the energy market of United States. Figure No. 1 shows the realization figures from 1945 through 1962 compared to the hourly earnings. Note that through 1945 to 1948 F.O.B. prices increased $1.93 per ton while hourly earnings increased $.66 per hour. Since 1948 (with the ex¬ception of 1957) F.O.B. prices have declined $.45/ton, while hourly earnings have increased $1.23 per hour. Basically the maintenance men possibly represent the highest increment rate in the overall hourly earning.

Jan 1, 1963

By Andrew J. Regis

Resource figures for bentonite clays are generally based on stratigraphic, sedimentary geologic data and drilling and sampling. Estimates of bentonite resources and/or reserves commonly found in the literature report on bentonite occurrences in specific localities or areas but none on any documented comprehensive estimates of bentonite resources. From 1974 thru 1977 the Bureau of Land Management conducted extensive studies of the resources of commercial grade bentonite in the three state region. These investigations consisted of: 1. Stratigraphic and geologic sampling with supplemental drilling data, followed by geostatistical analysis. 2. Data compiled from a systematic search of county and state records on mining locations, leases and acreage filed for bentonite. Estimates of resources of commercial grade bentonite using industry parameters were calculated from these data sources. It is concluded that there exists from 1.5 to 2.4 billion tons of in-place bentonite in Wyoming, Montana and South Dakota. Assuming a 5 percent annual growth rate for the industry, this would indicate a life of 62 to 73 years.

Jan 1, 1979

By J. A. Wallace

U. S. Steel's coal mining research activities are directed toward providing new or improved hardware and techniques to increase productivity or reduce cost. Because more than 80 percent of U. S. Steel's coal production is obtained from continuous miner sections, most of our research efforts are focused upon that mining system. Current and historical time study data show that our continuous miners only operate about 30 percent of the available face time. This limited equipment utilization is the result of the delays or interferences imposed by the non-coal-cutting phases of the continuous mining cycle. The most time consuming of these delays are: waiting-on-roof-support, tramming between alternate work locations, waiting-on-haulage-capacity, and in some mines waiting for excessive methane concentrations to clear. Because waiting on roof support is our most time consuming delay, several programs are underway simultaneously to address this problem. In one of these we are developing a patented microprocessor-based control method and apparatus to improve roof drilling performance. This increase is attained by using the microprocessor to adjust electrohydraulic valves which control drill thrust and rotation speed. The microprocessor is designed to continuously search for an optimum combination of thrust and drill rpm to maximize penetration rate at all times.

Jan 1, 1979

By John P. Cummings

Glass is the most unique substance which man has made. It is understood that Phoenician sailors playing on the beach in Mesopotanmia around 12000 BC, produced glass by the fusion of sand and soda in their campfire. Glass is unique for many reasons. However, let us consider the following. It is made of materials which are opaque and yet glass can be translucent, transparent, or opaque. It can be as soft as cotton or stronger than steel. It transmits light readily and yet is totally impervious to gases and liquids. It is chemically an inert, creates very little pollution in its manufacture. It is made of the most abundant raw materials on earth. It is readily recyclable and has little pollution in its disposal. Glass containers are made principally from sand (that is, silica), soda, which is sodium carbonate, and lime, which is calcium carbonate, plus decolorizers or colorants and cullet. The proportion of cullet, broken glass, in most glass tanks today is roughly 10 to 20% of the glass product. In most cases, the cullet used in the plant is glass from off-ware, or broken ware, which is a waste product within the plant. Cullet has the following advantages. It contains all of the raw materials normally used in a batch. It tends to melt at a lower temperature than batch, thus saving some fuel, and, finally, by forming a crust above the normal melting system, there is a tendency to cut down air pollution.

Jan 1, 1975

By Paul Eimon

In the world of minerals exploration, computer-oriented data storage and retrieval methods are being talked about, studied and researched. The goal is to facilitate the recording, collating, indexing, recovery, and analysis of mineral deposit-prospect data. A survey has been made of the various report forms, suggested outlines, and computer coding forms that are currently used in mineral exploration to index and/or describe mineral deposits and prospects. These forms have a number of common characteristics: location, commodities, type of deposit, host rock, etc. Such basic mineral deposit-prospect "data units" are part of most exploration programs. "Data units" may be comprehensive bound published descriptions of mines or mining districts or 3x5 file cards or elaborate computer coding forms being developed in Canada. Initial attempts to develop computer-oriented information systems have run into the same roadblock: the lack of a body of organized, processible data describing the basic qualities of mineral deposits and prospects. To solve this problem, international committees are considering coding forms, world-wide semantics, and rules or standards for data collection and description. It appears that mistrust and lack of understanding of the computer; fear of loss of proprietary information; and disagreements over terminology are distorting the picture of what has to be done if the mining industry is to grow into more meaningful information systems for mineral exploration.

Jan 1, 1969

By Kirk Carlton

This paper deals with a group of subjects so familiar to all of us that we might question the need for discussion. Even so, nearly every day's business turns up expensive examples of differences in understanding, misdirected assumptions and incomplete technical purchase documents. As our international activities increase, so do these problem areas. Their expense in both money and embarrassment gives rise to this attempt to focus a little extra attention on technical criteria and specifications. The two terms ?criteria? and "specifications" are, we believe, worth separating with respect to meaning. They should not be used interchangeably, although they often are. Criteria are by definition "standards for judging", whereas specifications are "enumerations of particulars". In relation to plant or project engineering, the criteria are the general rules and data which apply to the whole project and the specifications are the further listing of detailed requirements for specific contractual items or pieces of equipment. We'll look a little more closely at specifications after we give another minute or two to this "criteria" subject,

Jan 1, 1973

By R. Cohen-Alloro

Classical apparatus for granulometric separation generally have limited applications which are found either in the level of the size of separation or in that of the accuracy and the efficiency of the separation or in that of the rate of feed. In industrial practice, the classification of the products of coarse dimensions generally poses no problems. On the contrary, the separation of fine particles presents some difficulties, however the apparatus is used (mechanical classifiers, curved screens and sieves, hydrocyclones, etc...). These difficulties are due to hprfections of separation, rather high cost prices, and sometimes large amounts of recycled materials.

Jan 1, 1970

By Hans E. Tausig

The economics of transporting minerals by sea in less than full cargo lots encompasses an analysis of production costs, sale and inventory calculations and a careful comparison of ocean freight costs all of which when pieced together will usually definitively indicate which of the ocean freight alternatives is the correct one for the economic factors involved. To illustrate: Let us assume that a production to be marketed yields 60,000 metric tons of copper concentrates over a twelve month period. Shipment is geographically viable through Vancouver, B.C. The production has been sold to a Japanese Smelter and the mine produces at a rate of 5,000 metric tons of concentrates per month. The copper has been sold CIF FO. The Seller has carefully investigated ocean freight rates Vancouver, B.C./Hibi, Japan and finds that he could obtain a twelve month freight contract at $15.00 per metric ton FIGS based on a loading/discharging speed of 4000/ 2000 metric tons per WWDSHEX (weather working day, Sundays and Holidays excluded) this freight rate being predicated on shipping in lots of minimum. 15,000 tons. A further freight investigation reveals that to ship at the same terms and conditions but in lots of 5,000 tons, and shipping each month (in accordance with the mine's actual production) would cost $20.00 per metric ton FIOS. The calculation that is now made is whether it is more desireable to pay a higher ocean freight by shipping in 5,000 ton lots or to pay the lower freight where here the ocean freight involves a difference of some $300,000.00.

Jan 1, 1979

By Robert Stefanko

The importance of underground stress instrumentation cannot be minimized. It was Lord Kelvin who said that unless you can assign a number to a quantity,, you know very little about it. Most engineers will agree although this kind of statement is resented by our friends in non-technical fields. Mining is undergoing a revolution from art to science. But how can mining methods be optimized if there is no way of measuring the effectiveness of a given mining method? Do we know how effective a' support is unless we can determine its reaction to the mine structure? How do we assess the need for modifications to existing systems and supports, and how do we measure the effectiveness of such changes? Cut and try techniques are too wasteful of time and energy, and rarely provide solutions to a given problem. The purpose of underground stress instrumentation is to provide answers to some of the above questions -- answers that cannot be obtained otherwise This does not mean that laboratory studies are not valuable -on the contrary. Laboratory and underground studies supplement one another. Rock mechanics had its conception with the study of stresses in homogeneous, isotropic, and elastic models subjected to various force systems. These analyses were valuable inasmuch as they pinpointed possible sources of trouble due to stress concentrations. If the results observed underground did not always agree with the experimental analysis, it was not an indictment of the latter. More probably, the discrepancy could be attributed to the lack of similitude between model and prototype. The more nearly one can simulate underground conditions in a model, the more apt one is to produce results which correlate well-with underground observations. It is impossible to completely simulate underground conditions because all of the significant design parameters have not been recognized and evaluated. What better way can one evaluate these parameters than by underground stress instrumentation?

Jan 1, 1963

By Phil Allen

A synthetic fiber manufactured by one chemical company has been treated by another chemical company to produce a cloth fabric capable of performing ion-exchange functions. Only a few delimiting parameters have been established. This paper will discuss briefly the highlights of a functioning ion-exchange cloth. Throughout the paper this fabric will be referred to as "Fabric Z".

Jan 1, 1970

By T. A. Vivian

The use of heavy media organic solvents to recover coal from its attendant gangue is hardly new. DuPont built a pilot plant using pentachloroethane in 1936 at Weston Coal Company, Weston Breaker, Shenandoah, Pennsylvania. That's almost half a century ago. Since that time, it has become common practice to utilize similar classes of chemicals in laboratory separations of coal samples. It is the objective of this paper to discuss some specific separations on both pilot and laboratory scale on samples representing different classifications of coal. These separations have been carried out on coarse (+4 M), middling (4 x 20 M), and fine (-20 M) coal samples. The coal samples tested include Pennsylvania anthracite; Pennsylvania, Indiana and Colorado bituminous; Wyoming sub-bituminous; and Texas lignite. Other chlorinated solvents were used to vary the specific gravity of separation.

Jan 1, 1984

By L. F. Moran

Rod Mill Grinding is an important and fundamental step of the concentrating process in Marcona Mining Company's plants at San Nicolas Bay, Peru. This Paper summarizes experience in regard to consumption and specifications of grinding rods based on twelve years operation of the grinding circuits. Marcona operates a Plant complex producing 10 million tons per year of beneficiated iron ore products including pellets, sinter feed concentrates, high grade concentrates as slurry and filter cake. Processing capacity is 15 million tons per crude ore per year of which 13 million are around in rod mills. A continuous testing program was carried out over the years. Initial studies of daily production operations gave indications of poor grinding rates in relation to mill size and power consumption, with a high rate of broken liners and rods. The broken nieces of rod were not automatically expelled and further interfered with grinding efficiency, while replacement of liners caused unwarranted do n tire. Objectives were to improve all phases of the Process by studying the effects of changes in rod diameter, length, alloy constituents, and volume and weight of rod charge.

Jan 1, 1975

By Karen M. Kessen

The isotopic variations of lead from Mississippi Valley galenas have long been used to place constraints on the sources of the lead, and on the residence the of the lead in crustal reservoirs prior to its emplacement in the Mississippi Valley province. Similar studies based on strontium isotope variations in gangue minerals associated with the lead-zinc sulphides have been neglected until Haden's (1) study of such minerals from several localities in northwestern Ohio. His work revealed two things about the mineralization. Firstly, it shoved that the average isotope composition of lead from galenas from northwestern Ohio lies on the anamalous lead line characterizing Mississippi Valley-type leads, albeit at the least radiogenic end of the entire data array. This confirm earlier assignments of the Ohio mineralization as Mississippi Valley-type (Hey1 and others (2)). Secondly, Haden (I) showed that the strontium in the calcite, strontianite and fluorite is broadly similar in isotopic composition to the strontium in the host Silurian to Devonian marine carbonates within which these minerals arc emplaced. He concluded that the mineral strontium my have been very locally derived, from the carbonate hosts.

Jan 1, 1979

By Robert J. Neubauer

I was asked here today to discuss the first long-term freight rate contract ever signed by a U.S. railroad and shipper. That was ICG's contract with the hoosier energy company to haul coal from southern Illinois to an Indiana power plant. I?ll also talk about why you can expect to see more such contracts in the future But first, let me tell you a little bit about the Illinois central gulf railroad and why coal contracts are so important to us. ICG is a principal mid-American freight carrier. We are one of the ten largest railroads in the united states and one of the ten largest coal-hauling railroads. ICG links the industrial great lakes region with the warm weather ports of the gulf coast. Some of the major points on our route map are Chicago; Indianapolis; Omaha; Kansas City; Memphis; St. Louis; and, of course, baton rouge and new Orleans.

Jan 1, 1981

By James R. Jones

The Surface Mining Control & Reclamation Act is a complex piece of legislation signed into law on August 3, 1977. It is the culmination of more than six years of debate by the Congress over the need for a national regulation of surface mining as opposed to the prior concept of regulation by each concerned state. It departs from the more normal type of law in that it includes very specific requirements, limitations and performance standards. In its procedural aspects, it is somewhat similar to the Clean Air Act and the Water Pollution Control Act in that it places primary responsibility at the state level, provided the state meets minimum national requirements. At the time of writing this paper, in late December 1978, the Interim Regulatory Program has been in effect for seven months. The proposed regulations for the Permanent Program, the draft Environmental Impact Statement, and the draft Regulatory (Economic) Analysis ware available for eight weeks before the close of the comment period on November 27. We are now awaiting issuance of the final versions of these documents. The states in which coal is mined, for the most part, have made sere revision to their state laws and are in the process of revising their regulations, or have just completed the revision, to comply with the Initial Regulatory Procedures. They are now faced with another new major effort to analyze and plan for compliance with the Permanent Regulatory Program, which is expected to be promulgated by the Office of Surface Mining of the Department of Interior by the time this paper is presented.

Jan 1, 1979