• Application of hydrocyclones for recovery of fine gold from placer material

      Rao, P.D.; Wolff, E.N.; Maneval, D.R. (University of Alaska Mineral Industry Research Laboratory, 1982)
      Alaska and other gold areas have seen a sharp resurgence of placer mining in the last few years. Mines using sluice boxes usually recover gold down to 100 mesh, but recovery of gold finer than this size is a function of particle shape factor, sluice box design and operating parameters. It is felt that a concentrating device is needed to recover gold finer than 100 mesh that may not be recoverable in a sluice box. The device should be capable of processing a large volume of water and solids discharged from the sluice-box. Compound water cyclones, successfully used in the coal processing industry, seem to offer solutions. A system using these devices could recover a concentrate which would be one twenty fifth the size of the original solids in a two stage process. It is not intended to produce a finished product with cyclones, but to reduce bulk so that the reduced concentrate, free of slimes, could further be treated by flotation, gravity methods, or cyanidation to isolate the gold. This report addresses only the application of hydrocyclones for concentrating gold from placer material.
    • Applications of trend surface analysis and geologic model building to mineralized districts in Alaska

      Heiner, L.E.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1967)
      The Mineral Industry Research Laboratory, University of Alaska, has investigated the application of computers and statistics to mineral deposits in Alaska. Existing programs have been adapted and new ones written for the computers available at the University. The methods tested are trend surface analysis and geologic model making. An existing coeffecient of association program was converted to Fortran IV , but was not applied to an Alaskan problem. A trend surface is a mathematically describable surface that most closely approximates a surface representing observed data. In geologic model making, regression analysis is used to determine what geologic features are significant as ore controls. Coefficient of association compares samples to each other on the basis of a variable being present or absent. Trend surfaces were computed for dips and s t r i k e s of geologic features ( v e i n s , f a u l t s , bedrock) for Southeastern Alaska, the Chichagof district , and the Hyder district . Results for the f i r s t two are presented as maps. Trend surfaces and residual maps were prepared for geochemical data from the Slana district, Alaska. A mineral occurrence model was made for a portion of the Craig Quadrangle, and potential values were computed for c e l l s in the area. Appraisals of potential values by five geologists are compared with those of the model. An IBM 1620 multiple regression program is included.
    • Characterization and evaluation of washability of Alaskan coals

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1980)
      This report is a result of the second part of a continuing study to obtain washability data for Alaskan coals to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals.
    • Characterization and evaluation of washability of Alaskan coals - phase i - selected seams from Nenana, Jarvis Creek and Matanuska coal fields

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1979)
      This report covers the results of a study conducted to obtain washability data for Alaskan coals to supplement the efforts of the U.S. Department of Energy (formerly U.S. Bureau of Mines) in its ongoing studies on washability of U.S. coals.
    • Characterization and evaluation of washability of Alaskan coals - phase iii, selected seams from the northern Alaska, Nulato, Eagle, Nenana, Broad Pass, Kenai, Beluga, and Chignik coal fields

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1982)
      This report is a result of the third part of a continuing study to obtain washability date for Alaskan coals, to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals. Washability characteristics were determined for fifteen coal samples from the Northern Alaska, Nulato, Eagle, Nenana, Broad Pass, Kenai, Beluga and Chignik coal fields. The raw coals were crushed to 1-1/2 inches, 2/8 inch and 14 mesh topsizes, and float-sink separations were made at 1.30, 1.40 and 1.70 specific gravities.
    • Characterization and evaluation of washability of Alaskan Coals - phase iv, selected seams from the northern Alaska, Chicago Creek, Unalakleet, Nenana, Matanuska, Beluga, Yentna, and Herendeen Bay coal fields

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1982)
      This report is a result of the fourth and final part of a study to obtain washability data for Alaskan coals, to supplement the efforts of the U.S. Department of Energy in their ongoing studies on washability of U.S. coals. Washability characteristics were determined for fifteen coal samples from the Northern Alaska, Chicago Creek, Unalakleet, Nenana, Matanuska, Beluga, Yentna and Herendeen Bay coal fields. The raw coal was crushed to 1 1/2 inches, 3/8 inch and 14 mesh top sizes, and float-sink separations were made at 1.30, 1.40 and 1.60 specific gravities.
    • Conference on Alaskan placer mining, focus: gold recovery systems

      Beistline, E.H.; Cook, D.J.; Thomas, B.I.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1979)
      Alaska Miners' Association and the School of Mineral Industry, University of Alaska, Fairbanks conference proceedings of the Alaskan Placer Mining conference on Gold Recovery Systems.
    • Constraints on the development of coal mining in arctic Alaska based on review of Eurasian arctic practices

      Lynch, D.F.; Johansen, N.I.; Lambert, C., Jr.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1976)
      Arctic Alaska's enormous reserves of coal may be a significant future source of energy for the United States and for the Pacific Basin. Large coal reserves have been developed in the Arctic portions of Eurasia, where problems similar to those that might be encountered in Alaska have already been faced. To determine the nature of these problems, the Mineral Industry Research Laboratory of the University of Alaska, under contracts S 0133057 with the U.S. Bureau of Mines, has conducted a literature review on Eurasian coal mining and visited mines in Svalbard, Norway; Carmacks, Y.T.; and Healy, Alaska. The purpose was to establish the most significant physical constraints which may apply to the eventual development of Northwestern Arctic Alaskan coal.
    • Copper mineral occurrences in the Wrangell Mountains-Prince William Sound area, Alaska

      Heiner, L.E.; Wolff, E.N.; Grybeck, D.G. (University of Alaska Mineral Industry Research Laboratory, 1971)
      On January 9, 1970, the U.S. Bureau of Mines entered into an agreement with the University of Alaska based upon a proposal submitted by the Mineral Industry Research Laboratory. Under the terms of this agreement, the Laboratory undertook to compile information on copper occurrences in eight quadrangles covering what are loosely known as the Copper River, White River, and Prince William Sound copper provinces. If time permitted four other quadrangles would be added, and this has been possible. Information was to be obtained by searching published and unpublished records of the Bureau of Mines, the U.S. Geological Survey, the State Division of Geological Survey, the University of Alaska, and the recording offices.
    • The effects of placer mining on the environment in Central Alaska

      Wolff, E.N.; Thomas, B (University of Alaska Mineral Industry Research Laboratory, 1982)
      Within the Tolovana Mining District, as a result of placer mining, 800 acres of land have been disturbed (0.25% of the land area) and 4 million cubic yards of much have been transported down the Tolovana River through the subsiding Minto Flats. This has increased the rate of sedimentation of the lakes adjacent to the Tolovana River. Mine tailings are about 50% revegetated by natural species. Approximately 60 million cubic yards of muck must be removed to mine the Livengood deposits. A large area of settling ponds will be needed if the deposit is stripped by hydraulic means, or a large area for stacking overburden if mechanical stripping is required. The Crooked Creek area, mined for 80 years has 1,900 acres disturbed (0.7% of the land area) and 200,000 cubic yards of much has been stripped. No correlation is apparent between mining and the non-anadromous fish population, although sport fishing is considered by some to be not as good as a result of mining. Portions of the stream system observed to be impacted with mud showed evidence of having been periodically flushed out. Slave analysis and trace element analysis were applied in an attempt to trace sediments back to their sources, but were not successful. Mining is the pioneer industry around which much of the State of Alaska developed. The transportation network required by the mining industry benefits sportsmen, the tour industry, and directly increases the value of adjacent land. The profit from mining brought much of the early population to the state, and will be a steady source of revenue in years to come.
    • Final report - mineral resources of northern Alaska

      Heiner, L.E.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1968)
      PURPOSE. This is the final report on the work authorized on July 29, 1967, by the NORTH Commission. The purpose is to inventory mineral resources in northern Alaska and to delineate favorable mineral areas, insofar as possible. Later, a mineral policy study was added and a survey of available airborne geophysics. The Alaska Railroad made possible the large scale dredging at Fairbanks and became a feeder to all interior districts. It allowed the building of military bases during and after World War II. Freight moves predominantly north.
    • Focus on Alaska's coal '75, proceedings of the conference

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1975)
      Interest in Alaska's coals has increased greatly in the last few years partly as a II result of the public's realization that we are in a real energy shortage and partly because the building of the Alaska pipe line has demonstrated that transportation for Alaska's raw materials can be supplied if needed. Both President Ford and Secretary of Interior Kleppe have pointedly stated that Alaska must furnish much of the nation's energy needs in the next few decades. During the years 1974 and 1975, industry also showed greater interest as indicated by the large scale exploration activities in the Nenana, Beluga and Susitna coal fields. As a result of all of this interest it was decided that the time was right for an exchange of information on Alaska's coal; to bring people together and bring them up to date, and this conference was the result. Focus on Alaska's Coal, the first conference of its kind, attracted wide participation and apparently an enthusiastic response. The papers and the audience questions showed an overriding concern for the nation's energy needs and the possibility that Alaska can help alleviate those needs with its enormous solid fuel resources along with its oil and gas resources. As a result of the conference, the following points were brought into focus: Alaska's coal deposits are much more extensive than hitherto known. The development of a coal industry in Alaska to supply west coast markets is no longer a dream, and will in fact be a reality before long. Additional research on characterization and upgrading of coals is needed to further evaluate the potential of the enormous reserves. Alaska's coals are low in sulfur and thus are environmentally more acceptable. It is hoped that this conference brought into focus the opportunities Alaska offers to the nation and as a result, that work will be stimulated leading to the further development and utilization of its coal resources.
    • Focus on Alaska's coal '80, proceedings of the conference

      Rao, P.D.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1980)
      The principal objectives of the conference were to bring together current knowledge on Alaska's coal resources, mining methods, utilization and marketing, and every interested party to share this knowledge. The excellent papers presented and the large number of participants indicates that the objectives were accomplished.
    • Fourth annual conference Alaskan placer mining

      Campbell, B.W.; DiMarchi, J.J.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1982)
      An abridged format of papers, presentations and addresses given during the conference held on March 30-31, 1982, compiled and edited by: Bruce W. Campbell, John J. DiMarchi, and Ernest N. Wolff.
    • Geochemical-geophysical investigations, Fairbanks district

      Heiner, L.E.; Beistline, E.H.; Moody, D.W.; Thomas, B.I.; Wallis, J.E.; Loperfido, J.C.; Peterson, R.J.; Wolff, E.N. (University of Alaska Mineral Industry Research Laboratory, 1967)
      Trace element distribution in a subarctic valley in the Cleary Hill area of the Fairbanks gold district has been studied. Zinc and arsenic have been found excellent pathfinder elements for auriferous deposits. Methods of analysis for copper, lead, zinc, molybdenum, silver and arsenic as well as heavy metals are discussed. The University of Alaska method #2 has been improved, Terrain, slope, and frozen ground have little effect upon the distribution of trace elements associated with the Cleary H i l l vein. A new method for the determination of zinc using dilute acid is proposed. Analysis of geochemical data by trend surface procedures proved effective for localization of anomalies.
    • Mineral resources of southeastern Alaska

      Wolff, E.N.; Heiner, L.E. (University of Alaska Mineral Industry Research Laboratory, 1971)
      This report is part of a series by the Mineral Industry Research Laboratory describing the mineral occurrences of Alaska. Thus far reports have been issued on Northern Alaska (No. 16) Seward Peninsula (No. 18) and the Wrangell Mountain - Prince William Sound areas (No. 27). All of these reports contain tabulations of all deposits described in the literature. Report No, 27 also has computer drawn maps showing locations of mineral occurrences and a computer printout of certain data about each property. The magnetic tape which produced this printout was made as part of the project under which the report was written, It is capable of printing several options, as described in M. I.R. L. Report No. 24. The present report, M, I, R. L. Report No. 28, also contains a printout, and is also backed up by a magnetic tape. The location maps contained in the back pocket of this report have already been published in limited edition as M. I .R. L. Report No. 25, because it was desired to disseminate the information contained on them as fast as possible. It i s hoped that reports such as this eventually will be issued for all of Alaska.
    • Natural resource base of the Fairbanks North Star Borough

      Wolff, E.N.; Haring, R.C. (University of Alaska Mineral Industry Research Laboratory, 1967)
      This report on the natural resource base of the Fairbanks North Star Borough is one of several continuing research projects related to community planning in Alaska. It represents an interdisciplinary effort of the Mineral Industry Research Laboratory and the Institute of Social, Economic and Government Research at the University of Alaska. The result is a synthesis of the economic development potential of natural resources in the greater Fairbanks region.
    • Optimum transportation systems to serve the mineral industry north of the Yukon basin in Alaska

      Wolff, E.N.; Lambert, C.; Johansen, N.I.; Rhodes, E.M.; Solie, R.J. (University of Alaska Mineral Industry Research Laboratory, 1972)
      In 1972 the U. S . Bureau of Mines awarded a grant (No. G 01 22096) to the Mineral Industry Research Laboratory, University of Alaska, for a research project to determine optimum transportation systems to serve the mineral industry north of the Yukon River basin in Alaska. The study was conducted during the period May 1 - November 1, 1972. The study assesses the mineral potential of the region and selects two copper deposits: a known one at Bornite, and a potential one on the upper Koyukuk River. Two possible mining sites within the extensive coal bearing region north of the Brooks Range are also selected. A computer model was developed to perform an economic analysis of technically feasible transportation modes and routes from these four sites to Alaskan ports from which minerals could be shipped to markets. Transport modes considered are highway, rail, cargo aircraft, river barge, winter haul road and air cushion vehicles (A.C.V.). The computer program calculates the present worth of tax benefits from mining and transportation and revenues based on the value of minerals at the port, as well as the auxillary benefits derived from the anticipated use of the routes by the tourist industry. Annual and fixed costs of mining and transportation of minerals are calculated, and benefit-cost ratios determined for each combination of routes and modes serving the four mineral sites. The study concludes that the best systems in terms of a high benefit-cost ratio are those utilizing a minimum of new construction of conventional highways or railroads. The optimum system as derived from this study is one linking together existing transportation systems with aircraft or A.C.V. These modes are feasible only for the shipment of a high value product, namely blister copper produced by a smelter at the mining site, Of the several alternatives considered for the shipment of coal, only a slurry pipeline to an as yet undeveloped port on the Arctic coast showed significant promise. The study recommends that: 1. More government support should be given to mineral exploration in Alaska. 2. Potential mineral industry development should be considered in transportation planning at state and federal levels. 3. Additional research pertinent to mining and processing of minerals in the North should be conducted, and the feasibility of smelting minerals within Alaska explored. 4. Alternatives for providing power to Northwestern Alaska should be investigated.
    • Preliminary report mineral resources of northern Alaska

      Wolff, E.N.; Heiner, L.E.; Lu, F.C. (1967)
      This report is a preliminary report by the Mineral Industry Research Laboratory to the NORTH committee on the subject of mineral resources in the region to be traversed by a proposed railroad.