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Since mid-July, most domestic producers have been marketing 99.5 percent unalloyed aluminum ingot at 53-57 cents per pound. Dealers in the United States have recently quoted ingot at 52.3-52.8 cents. On October 2, London Metal Exchange will trade aluminum, selling contracts on a cash and a 3-month basis. New York dealers were quoting August ingot at 52.3 52.8 cents. The Bonneville Power Administration announced that, effective December 20. 1978, electric power rates charged primary aluminum producers in the Pacific Northwest would be increased The increase (equivalent to about 4 cents per pound of aluminum produced) will raise the average rate to about 8.7 mills per kw-hr compared to 3.2 mills per kw-hr.

Jan 1, 1978

By S. I. Saif

The Key Anacon deposit lies about 6 miles northeast of the Brunswick NO.6 mine of Brunswick Mining and Smelting Corporation. Geological mapping, especially in the well-exposed Nepisiguit River section, geophysical data, and information from extensive underground and some surface drilling show that the rocks at Key Anacon are similar in many aspects of stratigraphy and structure to those of the Brunswick Mine area. They include narrow beds of fine acid volcanic material interpreted to be metatuff and volcanogenic metasediments. The massive sulphide ore body at Key Anacon lies immediately above these acidic rocks, in association with other chloritic, sideritic or magnetic iron-rich metasediments. The iron formation, which is similar to that associated with other orebodies in the district, is overlain by massive andesitic material. Four phases of structural deformation have been recognized in the Key Anacon area; they are similar in intensity and style to those of the Brunswick No. 6 mine area. The orebody lies in a zone of complex isoclinal folding along the flank of a major F2 fold (Key Anacon Syncline) and in general appears to be stratiform. The ore occurs in probable F2 parasitic folds, and this suggests a complicated structural geometry superimposed on the original beds. The general similarity of the mineralization at Key Anacon, together with its occurrence with other iron-rich metasediments between a footwall of acid volcanic material and overlying andesitic rocks, is suggestive of stratigraphic time-equivalence with the Brunswick zone . If so, the metavolcanics at Key Anacon might have been derived either from a center within the main volcanic pile to the west or from a smaller local center active at the same time. Alternatively, the Key Anacon ore could have been formed during a much older volcanic cycle. The solution to this aspect of the problem is the subject of a continuing study.

Jan 1, 1978

By John S. Lagarias

When ore bodies are faulted or mill feed turns refractory, mining managers and engineers act vigorously to convert imminent failure into eventual success. The recent proliferation of onerous "environmental" regulations and restraints is likewise a threat to successful mining enterprise, in some ways more insidious and dangerous than the problems presented by natural obstacles. The regulatory burden has become so heavy that a pall of pessimism covers much of the mining enterprise. In this paper we frankly recommend a Pollyanna approach, making not just "the best of it" but directing the whole environmental process: first, to improve our planning, engineering, and operating procedures; and, second, to demonstrate the need for modification of laws and regulations which are intolerably burden-some to both the mining industry and the public. It is customary for government officials and environmentalists to point out how great are the new environmental regulations and how successfully these have improved the natural environment in particular and the quality of life in general.

Jan 1, 1978

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

By W. N. Wallinger

The mine and concentrator of Cyprus Anvil Mining Corporation are situated in south-central Yukon, some 120 miles north of Whitehorse. The large lead-zinc concentrator employs conventional crushing and grinding , followed by differential flotation, to produce selective lead and zinc concentrates, as well as a mixed lead-zinc (bulk) concentrate. Since the commencement of operations in 1969, the concentrator has undergone expansions and modifications which have increased the capacity to 10,000 tons per day, and afforded some metallurgical improvements.

Jan 1, 1978

Entering June, U. S. producer pricing of 99.5 percent unalloyed aluminum ingot was divided at 53-57 cents per pound. The Kaiser Aluminum and Chemical Corp. took the initiative and raised its June 1 ingot values by 4 cents to 57 cents. Consolidated Aluminum Corp. announced plans to increase ingot prices by 4.5 cents per pound to 57.5 cents per pound effective May 15. Dealers increased their May ingot quotes by 1.5-2 cents to 50-50.5 cents. CADMIUM While producers in the United States kept May cadmium at $2.25-$2.50, dealers increased their quotes by 15-30 cents to as high as $2.15.

Jan 1, 1978

By K. W. Grubaugh

The recently enacted federal surface mine law (P.L. 95-87) will increase further the complexity of securing a reclamation permit. This law intensifies the need to present the required reclamation plan in a thorough and comprehensive manner. One plan format, that used in construction performance contracts, offers promise of filling this need. Reasons for using the format of expressed, bilateral, negotiated contracts common to the contruction industry, and the salient aspects of an application which uses this format are reviewed. Advantages of this procedure are seen to be improved mine planning, awareness of the total design job, potential for improved speed of permit acceptance and improved cost control.

Jan 1, 1978

By P. J. Noakes

Remote and isolated, located in a frigid, hostile environment, the Black Angel mine in Greenland had to create a warm social environment which would help attract and retain a stable work force of miners and support staff. The high cost of personnel turnover plagues many mines and, when the mine is inside the Arctic Circle, accessible by helicopters which are highly vulnerable to unpredictable weather conditions during the long, dark winters, the potential costs of personnel turnover become critical factors in the success or failure of the mining venture. Manpower planning should start from the date the engineers begin the technical design of the new mine. The plan should include provisions not only to ensure an adequate, skilled work force, but also to ensure a stable work force of people who are happy enough in the mining environment to want to remain, take their vacation and return to work at the mine. The skilled work force was assured with training courses of four months, designed to produce highly specialized underground workers from unskilled Danes and Greenlanders supported by trained Swedish and other Scandinavian miners. The stable social unit was assured by plans the primary attribute of which had to be flexibility. The accommodation changed from shared accommodation with communal washroom facilities to single accommodation with private washroom facilities. A recreational director was hired to help the workers make use of elaborate recreational facilities. A closed-circuit TV and radio system was installed to operate as a private broadcasting system using taped programs originally broadcast on European TV networks or developed by the mine personnel themselves. The liquor rules were changed and the mine manager became a licensed innkeeper responsible for the orderly operation of the Black Angel Bar in accordance with the Danish laws governing the services of a public bar. The result is a relatively stable work force. Some 35% of the people have more than two years' service with the company, Greenex A/S, and some 62% complete 10 months of service.

Jan 1, 1978

By Joseph W. Leonard

In a recent publication in the SME Transactions of September, 1975, Volume 258, entitled "Potential for Further Lowering Sulfur in Intensively Cleaned Coal at Mines", the writer discussed: (1) technical findings useful for the management of reserves to further lower sulfur in intensively cleaned coal, and (2) a future coal preparation plant concept for the intensive cleaning of sulfur. The purpose of this technical note is to ( I ) illustrate the nomographs that can be formed when recovery is phased in with previous work, (2) make note of the powerful potential for predicting future cleaning performance in unmined areas, and (3) discuss resulting mathematical interrelationships.

Jan 1, 1978

By Parsons AE, Lewis IE

Selenium is a minor constituent of the raw materials processed by the Cockle Creek smelter of Sulphide Corporation Pty. Limited. Certain proposed raw materials contain higher levels of selenium, and these will create a problem with regard to the composition of liquid effluent discharged from the smelter. A method has been developed for removing selenium from the smelter circuit by the sulphation of the fume collected in the Acid Plant electrostatic-precipitators. It is planned that by treating 10-20% of the total dust arisings there will be a substantial reduction in the levels of selenium reporting in effluents when treating selenium-bearing raw materials. The selenium is recovered in elemental form.

Jan 1, 1978

By J. A. Irvine

In 1972, a cooperative program to map and estimate the quantity of Tertiary coal resources in southern Saskatchewan was initiated by the federal and Saskatchewan governments. More than 700 exploratory boreholes were drilled over a two-year period, and data were obtained from other organization s on an additional 1500 boreholes in the area. Stratigraphic data and data on each coal seam penetrated in the boreholes, along with technical and location data for each borehole, were stored in a computer data base for convenience of retrieval, modification and manipulation. Programs and program packages were developed or adapted to: (1) select borehole information defined by variable retrieval parameters from the data base; (2) calculate derived information , such as overburden ratios. cumulative net coal thicknesses , mean weighted center of gravity of coal seams in each borehole, etc., from the selected data ; (3) produce posting maps of either selected data or calculated information in various combinations at variable scales on a plotter or CRT display; (4) produce contoured structure, isopach or ratio maps , and perspective diagrams as appropriate , utilizing plotter or CRT display; (5) calculate and categorize quantities of coal in place within user- defined "mineability-economic-reliability" limits. The emphasis in computer utilization was placed on geological credibility of the results and ease of operation by relatively untrained geological personnel, resulting in extensive use of interactive methods. The single most important benefit derived from using computer-assisted procedures is the ability to produce new maps and quantity estimates rapidly and inexpensively as a result of availability of new data or/and changes in external criteria which impose economic or mineability constraints.

Jan 1, 1978

By Roberto Pimentel de Souza

CURD started producing pellets in 1969, with one two-million ton straight grate plant. In the beginning of April '73, the second unit came on stream with an additional capacity of 3 million TPY of pellets. In January '77, the third unit started, bringing the annual capacity to 8 million TPY. For the present year 3 more units, 3 million each, are expected to begin production. CVRD's experience is given about the use of different binders and additives. Over the years several kinds of pellets have been produced to satisfy the market requirements. General quality information is given regarding each.

Jan 1, 1978

By Robin P. Gardner

The development and use of short-lived radioactive tracer methods for the on-stream determination of residence time distributions in large-scale ball mills is described. Tests are reported on a pilot-plant ball mill with 0.43 m diameter and 0.86 m length and on an industrial mill with 1.83 m diameter and 2.74 m length. Tests with different tracer feed sizes indicate that the residence time distributions on both mills are independent of charge particle size. Similar tests are planned for a-large ball mill of 4.57 m diameter and 9.30 m length. No safety problems were encountered in these tests and none are anticipated in tests of the larger mill.

Jan 1, 1978

Reduce accidents associated with handling of the electrical trailing cable and the water hose on mining equipment. Approach Two reels were mounted on a loading machine to store and release the lines as required during face operations. How It Works A hydraulic motor, which is actuated by a treadle valve in the operator's cab, controls the reel on which 50 feet of electrical power cable is stored. A spring motor resists unwinding of the other reel on which 50 feet of water hose is stored. Both reels are mounted on the right rear of the loading machine. See Figure 1. Following common mining practice, the cable and hose are anchored to fixed points at the first intersection outby the face. Tramming forward causes the cable and hose to be pulled from the reels. Depressing the treadle valve causes the electric cable reel to turn and wind-in any slack in the cable. The spring tension on the water hose reel automatically rewinds the water hose when the loader is trammed in reverse.

Jan 1, 1978

Prospectors were digging silver in the Ray mine area in 1873, and by 1880 high-grade copper ore was feeding a 30-ton copper furnace. In 1910, D. C. Jackling and his associates organized the Ray Consolidated Copper Company, known in mining circles as Ray Con, to exploit the Ray orebody. For 50 years, all mining was underground and the Ray mine was known the world over for innovations in mining methods. It was the first to mine important tonnage (8,000 tpd) by block caving methods. The mill at Hayden, 26 miles (41.6 km) from the mine, kept pace with the new mining methods developed at Ray and in the early 1920's flotation replaced gravity concentration by the vanner machines. First mining by open pit methods began in 1950 and in January 1955 all underground mining was discontinued. The new primary crushing plant, installed in early 1967, featured design simplicity with a low capital cost. The 54 in. gyratory crusher was installed within a total height of 6 1 ft (18.65 m) from the truck dump road bed to the floor beneath the feeder-conveyor under the surge pocket. The crusher is fed by 120-ton trucks dumping from one side only into a 200-ton hopper equipped with a horizontal splitter bar to protect the crusher spider. The crushed ore pocket, of 120 -ton live capacity underneath the crusher, discharges to a 0 to 200 fpm (61.2 mpm), variable-speed, 72 in. by 80 ft long (1.83 m by 24.4 m) sloped belt feeder, probably a first in the industry. Wood-picking stations are provided on either side of the belt so that old mine timbers and tramp iron can be removed from the crushed ore and the wood can be dropped into Dempster containers located below the belt. Counter-weighted finger gates control the bed depth on the belt at 14 in. (356 mm) and a low- level radiation unit automatically maintains a minimum of a 3 ft bed (900 mm) of material on the belt directly under the surge pocket. The conveyor is skirted for its full length and is approximately 60 in. (1.52 m) wide inside its metal skirt liners. Ten impact idlers at 12 in. (305 mm) spacing are provided under the loading pocket and remaining idlers are spaced at 18 in. (457 mm). The belt is 1 ¼ in. (31. 8 mm) thick; and, while it has occasionally been damaged by tramp material, belt life averages 11 million tons. When the belt is changed, the coiled new belt is lowered into position onto one of two belt stands mounted over the feeder, the old belt is cut, and one end is attached temporarily to the new belt. The other end of

Jan 1, 1978

[Consider a square block W in an ore body S2, to be valued from one centre sample w, and one corner sample w2 (Fig. 9.1). The sample set is ws = Iw,;w21. We can estimate the block average µw by the average of the sample values x, and x2: µw = 'z (x, + xz). (9.1) The error made is measured by the estimation variance: o' (ws to W) = 2 - (ws; W) - - (ws;ws) - - (W; W). (9.2) However, we know that the centre sample w, gives more information about the block value than the corner sample w2. In the example studied in § 8.4, where w, and w2 were considered to be points, we found that of (w, to W) was nearly one third smaller than o2E (w2 to W), therefore when estimating W one should give more weight to w, than to w2. In general, when evaluating a block W from a set of n samples ws, where WS = l w;w2; ... wn1, a better estimator of µw can be obtained if we give different weights to the sample values, depending on the size and the positions of the samples. Some desirable properties of such an estimator µw are: ? It should be a linear function of the sample values xi: n µw = bi xi (9.3) =t where bi = weight given to sample x . ? It should be unbiased, i.e. its expected value should be equal to the true block value: E [µw - µw] = 0. (9.4) ? The mean squared error of estimation of µw should be a minimum E [(µw - µw)2] = a minimum. (9.5) The estimator which satisfies these properties is a minimum variance, linear and unbiased estimator, and is known as the kriging estimator. The corresponding error of estimation is the kriging error. This estimator is also known as the BLUE (for Best Linear Unbiased Estimator) estimator. This was named by Matheron in acknowledgement of the early work of Krige's in the optimization of the evaluation of the South African gold mines. The following notations will be used: µK kriging estimator. o2k = o2K (w,, to W) kriging error.]

Jan 1, 1978

By Lloyd W. Trevoy

Titanium and zirconium heavy minerals occur in the tailings streams from processing plants which use the hot-water extraction process for recovery of bitumen from tar sand. In a research program conducted by Syncrude Canada Limited, the crude tailings stream was upgraded to produce quality zircon and titanium mineral products. To process the tailings through conventional upgrading equipment, bitumen residues must first be removed from the mineral grains. Then, by gravity separation, fines and coarse sand grains were removed and a 71% heavy minerals concentrate was prepared which was further separated by high-tension equipment into zircon and titanium minerals concentrates. The zircon concentrate was upgraded by gravity, magnetic and high-tension cleaning to produce a high-quality 98% zircon product. The titanium minerals concentrate was separated into rutile, leucoxene and ilmenite fractions. Heavy minerals distribution in tar sand drilling core samples has been evaluated for various locations on Syncrude Lease 17, and expected annual production levels of heavy minerals have been estimated. A preliminary evaluation has been made of the potential for zircon, leucoxene and rutile production and for further upgrading of ilmenite and leucoxene to synthetic rutile for titanium dioxide pigment production.

Jan 1, 1978

By D. S. Speakman

The copper-zinc orebody at Sherritt Gordon's Ruttan Mine occurs in a structurally complex area of the Rusty Lake greenstone belt in northern Manitoba. Problems in interpreting drill results indicated a large deviation, and the structural complexity an erratic deviation, of drill holes. This was confirmed when a surface hole was intersected 420 feet to the left of line on the 800 level. This problem acted as a catalyst in promoting a search for a suitable down-hole survey method. The instruments investigated included magnetic multishot and gyroscopic units as well as the ABEM Reflex-Fotobor. Only the Fotobor came close to meeting the company's needs of simplicity, reliability, accuracy and ownership. In this paper, the methods of operating this instrument, as well as the data extraction and reduction techniques, are described. Data on the accuracy and repeatability of the instrument are presented, and a tabular presentation of the results of surveying on 86 holes totalling 64,000 feet of drilling is made. Preliminary statements of the results of ongoing research on causes of hole deviation are presented and recommendations for minimizing deviation are given. The use of the survey device is recommended in areas of structural complexity, for very steep or backsight holes and where expected ore intersections are missing.

Jan 1, 1978

By J. W. Scott, G. G. R. Falkenberg

"The Syncrude project is an integrated complex designed to mine, extract and upgrade bitumen from the Athabasca tar sands to produce 129,000 barrels per day of synthetic crude oil. This paper provides a brief general description of the location, history and geology of the tar sands and the overall organization and structure of the project. The major emphasis and the bulk of the detail presented deals with the extraction plant; a material handling and mineral processing installation designed to treat 312,000 tons per day of tar sand feed.History of the Tar SandsThe Athabasca tar sand deposit was recorded in 1788 by Peter Pond, however the first serious geological mapping and exploration did not begin until 1915. Little interest was taken in the deposits until the Second World War, when the governments of Canada and Alberta conducted an extensive exploration program. In addition a number of pilot plants were sponsored during the 1940 -1950 decade. The hot water separation process was successfully demonstrated on the pilot plant scale during 1948 -49, and was established commercially in 1967 in the G.C.O.S. plant. The Syncrude plant, due to come on stream in April 1978, also employs the hot water separation process."

Jan 1, 1978

By N. A. White

Whereas the ultimate world supply of energy minerals-defined as fossil fuels and fissile materials - is controlled by geological factors, the actual supply at any particular time is controlled by economic feasibility, technological innovations and /or political decisions. This paper identifies and discusses the principal uncertainties surrounding the international availability of energy minerals from now until the end of the century. A brief comparison is also made between energy and non-energy minerals. Genuine shortage s of energy minerals are now of a very long-term nature, whereas artificial ones may occur at any time and have a serious effect on the world economy due to the dependence of most OECD countries on imports of energy mineral . This paper argues that events over the last decade, such as the demand for a New International Economic Order, the OPEC increase in crude oil prices and the growing international lobby on environmental issues especially relating to nuclear safety - will progressively lead to a major, long-lasting transformation of the energy scene world wide. This transformation will encompass demand, in terms of conservation and efficiency, the supply mix of the various energy minerals , the supply system and the structure of the different energy industries . It is already affecting the role of governments and reaching into the question of national sovereignty both of developed countries, such as the U.K., Norway and Australia, and the developing countries, thereby making energy minerals a key area of international relations.

Jan 1, 1978