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By G. M. Lee

SEVERAL improvements have been made in Granby smelting practice since the company abandoned the direct smelting of raw ore in the blast furnaces in June, 1927, in favor of sintered concentrate. These improvements have been made in several fields, but the most novel and outstanding change was the development of a process of concentrating most of the gold, and a somewhat smaller fraction of the silver present, in a small portion of the blister copper produced. The practice of making "copper bottoms" is usually associated with the reverberatory smelting of copper ores containing high percentages of impurities, or of copper matte high in precious metals. It has for its object, in the one case, the production of a major part of the copper relatively free from impurities and, in the other case, the production of a small per¬centage of the copper carrying the major part of the precious metals. Although the blister copper produced at the Anyox plant of the Granby company is remarkably free from deleterious impurities and normally contains no great amount of precious metals, certain economic considerations made it advisable to concentrate the existing precious metals into a relatively small percentage of the blister copper produced. The process devised took advantage of principles and reactions of the usual bottoms processes, but was carried out in the converters instead of in a reverberatory furnace.

Jan 1, 1935

IN addition to the gold and silver that b drawn, a certain kind is also prepared that is called spun; not that it is spun as the word says, but because a linen thread is covered with it so that it seems a spun thing, and it is called spun silver or gold. To make this, a desired quantity of fine cupeled silver is taken-the batch used is customarily [I4I] fifteen pounds. A square bar is made with this, a braccio or more long. Then the quantity of gold that you wish to put on is taken, that is, a ducat for every pound, and of this another bar is made, sufficiently thin, long, and wide exactly to cover on one side the

Jan 1, 1942

By A. K. Gangopadhyay, J. J. Moore

The effect of grinding media composition, mineral type, and slurry environment on the wear rate of various grinding media (balls) are discussed. Sufficient wear data have been obtained and correlated. Modes of wear were determined from examination of the ball surfaces using scanning electron microscopy. Five modes of wear have been identified to be operative under certain slurry conditions for the various ball compositions studied.

Jan 1, 1986

By AIME AIME

No democracy such as ours, can ever be prepared for war, because we could never conceivably be the aggressor. The aggressor prepares in secret, designs his new tactics, and invents and makes new equipment and selects the time to strike. If a democracy prepare done year and the war came later, all that it had one would have to bed one over. All that England has today in the way of effective armament has been invented, designed, made, and the crews trained since the war began, because the totalitarian aggressor introduced new types of equipment and new techniques.

Jan 1, 1941

By Francis Peabody

THIS paper will not be a technical paper, because, although I have been in. the business of mining and selling coal for 30 odd years, I am neither a mining engineer nor a practical miner. If I digress from time to time from my thesis, I must be forgiven by the expert engineers and highly technical gentlemen for whose proceedings this article is written. Waste of the wonderful store of power that the Creator placed at our disposal appears to have been the theory and the basis of our methods of extracting this power-waste from the time the coal is mined to the time it is consumed. Let us consider the prime causes of this wastage which has been the heritage of the coal mining industry. In the early days-about 150 years after "Stone Cole" was discovered in Illinois by Joliet and Marquette, and Father Hennepin noted a, "sole" mine on his map-the mode of mining prevalent among farmer land-owners, on whose property coal was discovered near the surface or outcropping on the hillsides, was to enter the seam by a shallow shaft or drift into the hillside and remove the coal by wedging it down until a large room was left. The roof without support would fall and our primitive coal operator would then sink another shaft or drive another drift. In these early operations only the large lumps were taken and all small pieces and screenings were left to be covered by the fall of the roof-in fact this condition prevailed in Illinois up to about 1885. Gradually the method of mining changed from the open chamber, to a single entry with rooms turned to the right and left. Later, as the demand for coal increased and the necessity for larger mines became evident, the "room and pillar" system grew to be regular practice.

Jan 5, 1917

Objective stockpile goals have been met for antimony, bismuth, fluorspar, and iridium, while those for bauxite, cadmium, copper, lead, zinc, manganese, mercury, platinum, tin, and vanadium have not, according to a report by the Munitions Board. Total materials under inventory and contract represent about 78 pct of entire stockpile goals, the report stated. Frobisher, Ltd., of Canada has been given permission to survey power possibilities in certain lake and river basins in the Yukon believed to have a potential of 5 million he. Canadian Resources Minister, Robert Winters, also announced that his Government has rejected a bid by Aluminum Co. of America concerning use of Canadian waters to power a proposed Alaska aluminum project. Alcoa is reported hopeful of resuming negotiations.

Jan 3, 1953

By S. W. Ihle, L. J. Warren

A sample of garnet from the scheelite ore body on King Island, Tasmania, Australia, was upgraded and ground to produce an ultrafine portion suitable for micro-electrophoresis. X-ray and chemical analysis identified the garnet as andradite with some admixed grossular. At neutral pH the garnet particles were negatively charged, their zeta potential becoming rapidly more negative with increasing pH. An iso-electric point was found at pH 3.5. The effects on the zeta-potential of various electrolytes, hydrolyzable metal ions, and flotation collectors were also studied.

Jan 1, 1976

By Heinrich Ries

In another place,* the writer has called attention to the modern methods of the laboratory investigation of clay, and it is desired here simply to discuss one branch of the subject, which, though of considerable importance, has heretofore received little attention in this country, viz., the rational analysis of clay. In order, however, the better to point out the bearings and advantages of this procedure, it is necessary to refer briefly to the ultimate analysis as well. The remarks in this paper refer only to the use of clay for the manufacture of clay-products. Pure clay or kaolin-f is extremely refractory, possesses little plasticity, and usually shrinks aud warps considerably in burning. Even the smallest proportion of impurities changes these properties, so that the kaolin exhibits variations in shrinkage, plasticity, tensile strength, fusibility, and often color when burned. The majority of nearly pure kaolins consist of kaolinite (A1,O2 2SiO,, 2H20), undecomposed feldspar, and quartz. The kaolinite generally forms the finest particles of the clay and is known as the clay-substance, while the rest of the clay-particles are collectively spoken of as sand. In the ordinary or ultimate analysis, the substances generally determined are silica, alumina, ferric oxide, lime, magnesia, alkalies and water. An analysis of this type simply regards the clay as a mixture of elements or oxides, but gives no clue as to the actual condition in which these substances exist, i.e., whether as silicates, oxides or carbonates, etc., a point which it is of the highest importance to know; for the individual components of the clay influence its properties not only according

Jan 1, 1899

Jan 1, 1947

By Gary A. Kordosky

Winning copper from oxide ores usually involves hydrometallurgical techniques. The processes involved are the leaching of copper from the ore and the recovery of the leached copper from the aqueous solution.

Jan 1, 1981

By Frank C. Schader

JOHN CARTER ANDERSON, Kingman, Ariz. (communication to the Secretary *).-From an extended study of the Oatman and Secret Pass districts of Mohave County, Arizona, I believe that the genesis of the ore deposits, in most cases, is directly connected with rhyolitic intrusions later than the Tertiary flows; and that the developments of, the future will prove these intrusives to be the primary source of the ore. In support of this opinion I will instance the Wilhelm-Eclipse dike in Secret Pass and the Murdock, Nellie, Black Range dike and ledge in the southern part of the Oatman district. The Wilhelm-Eclipse dike is a very fine-grained light-colored siliceous rhyolite dike with a strike of N.45W. traversing the full length of the Secret Pass district about midway between two major faults which mark the easterly and westerly boundaries of the district. These faults .have lifted the block between so that erosion has exposed the pre-Cam-

Jan 4, 1917

By E. C. Lee

THE safety of mine workers has received more attention from both State and Federal law-making bodies than any other industry, a fact that shows clearly the hazardous nature of the industry. The last, but by no means the least, of the measures adopted for the protection of mine workers, is workmen's compensation legislation. This is proving to be a powerful instrument for greater safety in the industries, from the fact that special stress is laid not on how the accident happened or who may have been responsible for it, but on how badly the employee is hurt by it. The injured person does not have to employ lawyers to prove his case, because the mere fact of his employment is proof of his right to compensation. The immediate effect of such legislation is the certainty confronting the mine operator that he must pay out large sums for every accident, regardless of its cause, thus adding materially to the cost of the production of his coal. This fact furnished to the operator the strongest incentive to reduce the causes of accidents; not that the operator has ever lacked reasonable consideration for the welfare of his employees and a proper humane interest in their safety, but his engrossment in earning his daily livelihood has been so great that he has not felt that he had the time to devote to the safety of the operation. This time he must now find because of the actual-cash value of the prevention of accidents in his mines. This agency alone proved inadequate to bring about a material improvement because operators have always been willing enough to improve safety conditions when possible to do so within reasonable limits of their financial ability. The requirement in the Workmen's Compensation Laws of several of the States, that the mine operator shall insure as a guarantee of his ability to meet his compensation obligations, has furnished the needed incentive, moral and financial, necessary to the prompt and effective dissemination of a more general knowledge of the causes and

Jan 10, 1917

By Frank Firmstone

IN the early decades of the past century the method of starting iron blast-furnaces by "scaffolding-down" seems to have been in universal use for coke-furnaces and, at least in this country, for charcoal-furnaces also. It was likewise used at some of the early anthracite-furnaces, as is stated in the important "Reminiscences" printed by the late Samuel Thomas. I It had been generally superseded in Great Britain as early as 1850, by some variations of the plan now used, and was rarely used when Percy wrote.' On the Continent it was still followed in the 60's,3 and was elaborately described by Valerius in 1852. I have never read any statement as to when and by whom '4 scaffolding" was first dispensed with, but the following extracts from journals of my father seem to fix an authentic date for an instance in this country:

Mar 1, 1907

By Walter Weeks

CONSIDERABLE difference of opinion seems to exist as to whether the rate of air flow when a fan is placed on a given duct should be determined by the use of static pressure or total pressure characteristics. A little study will show that both methods are correct. Assume that a fan is connected to a duct by an expansion piece as shown in Fig. 1, and that steady flow is established. Considering the atmospheric pressure as zero pressure, let the static head at the outlet of the fan be h and the velocity at this point be v1. The total head at the outlet is then h + v1/2g? The total head at this point must be equal to the total head at the end of the duct plus the losses that have occurred between the two points. Let f be the friction loss in the straight duct, s the shock loss in the dif- fuser, and V2 the velocity at the end of the duct. Then h+ v12/2g=v22/2g + f + s FIG. 1.-FAN ON DUCT. A curve showing the value of the left-hand side of the equation for different rates of flow is the total pressure characteristic of the fan, while a curve showing the value of the right-hand side is the total pressure characteristic of the duct. If these two curves are plotted on the same chart, the intersection indicates the rate of flow when steady flow is established.

Jan 1, 1930

By Edward Ernst, Richard Runvik

AT the U. S. Gypsum Co. mine in Oakfield, N. Y., a flat-lying vein of rock gypsum is mined by the room and pillar method. Averaging only 4 ft thick, this vein is 1200 to 6000 ft in mineable width and many miles in length. Overlying the vein throughout the mine is a 2-ft thickness of distintegrated gypseous shale and fractured limestone which parts easily, falling with little or no warning. This shale, known as ash, varies in thickness from less than an inch to more than a foot. Small veinlets of selenite cut this shaley material, which breaks around timber props. The 18-in. limestone over-lying the ash is fractured vertically into blocks of varying size and will fail if any but the shortest unsupported spans are permitted. Above these two members is a thick layer of competent limestone.

Jan 6, 1957

New Products Equipment

Jan 4, 1953

By Fred T. Greene

Most of the recent discussion of the mineral land law published in the Transactions is in the abstract—an exception being Mr. Goodale's paper, The Apex Law in the Drumlummon Controversyll which illustrates in concrete instances many of the practical disadvantages of what Dr. Raymond has called "The Law of the Apex." The present paper, it is hoped, may serve a similar purpose, emphasizing the necessity for a change in our mining laws, and bringing home to mining engineers some of the defects and dangers of our present code. There are many storm centers of "apex litigation" in the Rocky Mountains; and not the 1east. of them is the Wardner camp, where such litigation has been almost continuous since 1892, and the end is not yet. In their decisions, the courts have accepted the claims of the litigants that the "Wardner vein" is a broad zone varying from 250 to 500 ft. in width at the surface. This is the simplest theory which could have been advanced, and probably decreased, rather than augmented, the number of contests; in fact, every one of the claim owners seemed to feel that the greatest advantage would accrue to him if this theory were adhered to. The dominant structural feature of the Wardner vein is a persistent fault, striking N. 40' W., dipping about 40" to the southwest and called the "Wardner foot wall." Fig. 1 is a composite of two adjacent cross-sections of the vein and is a fair representation of the relative size and shape of the orebodies and their relation to the "Wardner foot wall." The country rock is a comparatively thin-bedded sericitic quartzite which has an average strike of N. 80" W. and dips at high angles to the north and south. The movement on the Wardner foot wall is apparently normal, and there has been more or less brecciation on either side of it; but as the moving mass was that above the foot wall, the brecciation has been more complete on that side, and has extended farther from the plane of movement. Many minor faults, generally of insignificant extent, resulted from the movement along the Wardner foot wall. Most of these were

Jan 1, 1916

By Stanly A. Easton, H. M. Childs

Methods evolved at Kellogg have had primarily in view the safety of workmen and complete recovery of the ore; it is believed that these results have been secured at a minimum cost. The ore in the Bunker Hill mine is of good grade, relatively speaking; much of it is quite rich and no mining method would be successful which did not recover all of the ore. It would be possible to work certain of the orebodies by shrinkage methods, or some form of top-slicing, at probably lower costs than by the methods now applied, but the shapes of the orebodies are so irregular that satisfactory extraction of the ore in all its ramifications would be extremely difficult. In past years, much high-grade ore has been lost in blasting, due to the unskilful use of powder in a galena ore, which, by reason of its brittle-ness and great weight, tends to scatter widely. Any method by which large masses of ore and waste are broken together will result in an imperfect recovery of the ore, and whenever large masses are broken, ore and waste will unavoidably fall down together; ore and waste thus become entangled and, although a pile of broken material may seem to have been well picked over, quantities of ore will inevitably be lost. This fact has been shown by persons reworking the filling in stopes that were mined by methods defective in the foregoing particulars. Safety of the men is secured by avoiding large openings, and by working mainly under timber, and at small faces at close range and easily inspected. In former years the principal source of serious accidents was "falls of ground;" it is now over seven years since a serious accident has occurred from this cause. The most prolific source of accidents during recent years has been "timber and tools," workmen being struck by timbers passed into the stope from the level above; this danger has been greatly reduced by compressed-air warning whistles and the fencing in of dangerous areas. The lead-silver ore of the Bunker Hill and Sullivan and affiliated mines is found in bodies of almost every shape, although vertical or nearly

Jan 1, 1925

By Cyril Stanley Smith

METALLURGISTS - or at least metals - have been of central importance in most of the inventions that have shaped the course of man's history. From the first Bronze Age tools to the iron armor of the Roman soldier, the cannon, cast type for printing, the steam engine, the electric motor and modern electronic devices, technological progress has revolved around some particular property or comb nation of properties selected from the metallurgist's repertory. The recent utilization of the energy of the atomic nucleus (currently for military purposes alone but with great constructive implications for the future) is no exception to this, although the use of uranium and plutonium in metallic form is of secondary importance, since the significant properties are those of the nucleus and not of the electrons responsible for metallic behavior. THE METALLURGIST AND ATOMIC ENERGY The metallurgist has a role of central importance to play in the future development of atomic energy. Not only must he make and shape the fissionable materials themselves, but he must also develop auxiliary materials to withstand the extreme conditions imposed on nuclear reactor components by the high heat-transfer rates needed for efficient utilization of the fuel and by the perplexing but interesting effects of radiation on the structure and properties of materials. It is doubtful if there is currently any other field potentially more rewarding to a young metallurgist. Quite apart from the all important but relatively short-range considerations of national security is the vision of the effect on civiliza-

Jan 1, 1953

ADVANTAGES OF LIFE MEMBERSHIP The Institute calls the attention of members to the following advantages of obtaining life membership: 1. One payment avoids the trouble of future payments. 2. The interest on $150 is less than the annual dues. 3. Provision is thus made early in life for the less productive years. 4. In case of in increase of clues at any time in the future life members are exempt from increased payments. Excerpt from, By-Laws. Article III. Section 3 Any Member or Associate not in arrears may become, by the payment of one hundred and fifty dollars at one time, a Life Member or Life Associate, and shall not be liable thereafter to pay annual dues. The money thus received shall be invested and only the income thereof used for current expenses of the Institute.

Jan 1, 1916