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By C. G. McLachlan

Abstract This paper deals with the application of the cyanide process to recover gold from a pyrite concentrate produced by means of differential flotation. This concentrate before cyanidation contains from 0.09 oz. to 0.14 oz. gold per ton, of which only about 60 per cent is recoverable. The rest is so fine that it remains interlocked in the pyrite and therefore is not acted on by the cyanide. The concentrate also contains about 15 per cent pyrrhotite and 0.4 per cent chalcopyrite, both of which are cyanicides. The cyanicidal effect of the pyrrhotite is inhibited by preacracing the pulp with lime, and maintaining a high lime alkalinity during cyanidation. The effect of the chalcopyrice is reduced as far as possible by removing those particles which are free by means of a further flotation step immediately prior to cyanidation. This involves the flotation of some very fine material. After nullifying as far as possible these two cyanicides, the concentrate is cyanided directly, i.e., without being roasted. This leaves the pyrite available for subsequent sale as a source of sulphur dioxide and sulphuric acid, and the entire residue of the cyamde plant, amounting to about 500 tons per day, 1s now being disposed of in this way. Prior to deciding on direct cyanidation, a number of laboratory roasting tests were made. These showed chat, 1f proper control were exercised, a better recovery of gold could be effected from the roasted product than by the direct method of treatment. The tests also showed that the capital cost o the plant would be much higher than that needed for the procedure adopted. The possibility of subsequently selling the pyrite for its sulphur content would also have been eliminated. Introduction A previous paper has described in considerable detail the application of the flotation process to improve gold recovery from Noranda's milling ore, and in so doing has covered the production of an auriferous pyrite concentrate. The present paper deals with the recovery of gold by cyanidation from that concentrate. This gold, though intimately associated with the pyrite, can, for metallurgical purposes, be considered as all occuring in the native state.

Jan 1, 1946

By Arno C. Fieldner

The objectives of the coal-research activities of the Bureau of Mines are very well expressed in the organic act of Congress establishing the Bureau. It reads as follows: That it shall be the province and duty of the Bureau of Mines, subject to the approval of the Secretary of the Interior, to conduct inquiries and scientific and technologic investigations concerning mining, and the preparation, treatment and utilization of mineral substances with a view to improving health conditions, and increasing safety, efficiency, economic development, and conserving resources, through the prevention of waste in the mining, quarrying, metallurgical and other mineral industries; to investigate explosives and peat; and on behalf of the Government to investigate the mineral fuels and unfinished mineral products belonging to, or for the use of, the United States, with a view to their more efficient mining, preparation, treatment, and use; and to disseminate information concerning these subjects in such a manner as will best carry out the purposes of this act.

Jan 1, 1946

By R. S. Dean

Boron compounds have been considered for many years as possible additions to iron and steel. A very recent use of boron-steel rods was for the control of neutron intensity in the graphite-uranium pile at the Clinton plutonium plant(130).4/ Norris(129) reports that slags containing boric oxide reduce the ferrous oxide content of steels and thereby the aluminum required for deoxidation. Boron is not considered an alloying element, but minute amounts produce what is often called a "needled" steel. The study of a series of iron-boron alloys by convenient steps, starting with iron containing no boron, indicated that boron was a hardening agent and made the iron very difficult if not impossible to forge. Then came the discovery that very minute traces of boron are quite different from the smallest amount previously thought worthy of study.

Jan 1, 1946

By Charles L. Harness

The barite industry has made notable progress since the days when barite was used only as an adulterant in white-lead paints and the only method of mining it was with pick and shovel. The following chronological record may serve to show how this heavy white mineral has grown in importance in the national exonomy and at the same time to indicate development of methods for obtaining it. 1845. - Barite first, mined in Fauquier County, Va., for use as an adulterant in white-lead paints. 1850 (approx.). - French settlers 60 miles southwest of St Louis, Mo., discovered barite; called it "'tiff;' meaning white. It was mined and shipped to St. Louis for use in paint.

Jan 1, 1946

By H. A. Kramer

The Flin Flon mine is at present hoisting 5,000 tons of ore daily. In 1943, a peak production of 6,188 tons daily was maintained. Before discussing secondary blasting, it is felt that a short review of stoping procedure will be of value. A list of papers dealing with various phases of the mining operation is appended. Stoping Practice Stopes vary in width from 30 to 150 feet, in length from 200 to 450 feet, and in height from 200 to 500 feet. A typical stope would be 300 feet long, 300 feet high, and 90 feet wide. The dip of the orebodies varies from 60° to vertical, with an average of 82°. The ore is heavy, having a specific gravity of 4. Both sub-level benching and radial drilling are practised. Blast-hole diamond drills are responsible for 85 per cent of the total production. Two sizes of hole are drilled at present, 11 7 6 -inch and 1%-inch. For bench drilling, the burden on the 1 7/16-inch hole is six feet, with holes on 8-foot staggered centres; in radial drilling, the burden is six feet, with nine feet between the toes. The burden on the l 5/8-inch hole is eight feet with holes on 11-foot centres, or 13 feet on the toe of fanned holes. Holes are blasted with two No. 8 instantaneous electric caps per hole, using 403 Polar Forcite. A powder charge of 0.15 pounds per ton is used, with a tonnage factor of 5 and 6.4 per foot drilled for the two sizes. Two rows of holes are blasted together. Fragmentation is satisfactory with the above drilling pattern and powder charge. However, some overbreak and fall-off locally results in oversize material. It is estimated that, after primary breaking, 75 per cent of the ore will pass through the grizzly openings and 15 per cent will pass the draw points, leaving 10 per cent that must be broken further to pass the draw points.

Jan 1, 1946

By Will H. Coghill

The scope of this paper is such that it was deemed advisable to group the contents into several main sections. They are: Section 1. Geography and Geology. Section II. Historical Review. (a) Mining and Smelting in Alabama. (b) Milling. (c) Summary of Milling Research. These two sections are primarily a bibliography and summary of the research on the Birmingham Red Mountain ores up to the middle 1040's. Section III. Status of the Birmingham Iron Industry. This sect ion points out the extent to which the findings of the iron-ore research have been applied on a commercial scale. Also, a very brief description of the dependent and allied industries is included. The value of the Birmingham iron ore is greatly enhanced by the proximity of coal and dolomite. Thus the coal and coke industry and the dolomite industry are closely allied with and to a large extent dependent upon the possibilities of economic utilization of the Red Mountain iron ores. Section IV. Beneficiation Investigations of the Red Mountain Iron Ores. This is a record of the most recent, hitherto unpublished work of the Southern Experiment Station of the Federal Bureau of Mines, Tuscaloosa, Ala., on the chemical and physical composition not only of the Big seam but of most of the iron-bearing rock strata of Red Mountain.

Jan 1, 1946

By G. G. Oberfell

THOUGH the largest volume use of natural gas has been, is. and in all probability will continue to be as a fuel for domestic and industrial heating, it has various market outlets, both as a fuel and as a raw material for the chemical industry. Natural gas is a preferred type of fuel where ease of control, fuel uniformity, and freedom from ash are of primary importance. Other industrially important uses are as a source of carbon black and as a fuel in various low-cost heating operations. Many other uses are of varying importance and new potential uses are continually being uncovered, some being of economic importance to the gas indus¬try as a whole, but most of them involve such small volumes of gas that they are only of passing interest. Since various products extracted from natural gas and recovered as by-products from petroleum refining, such as liquefied petroleum gas and fuel oil, are being utilized in many industrial and domestic heating applications, some consideration will have to be given such materials in order to present a reasonably complete story of the importance of natural gas. Some of these materials may prove to be transient competitors and will not be available when more profitable uses are found for them. Meanwhile, however, the potential volumes of such materials available, the current volumes being marketed, and the nature of the utilization are considered as constituting an essential part of the over-all fuel picture.

Jan 1, 1946

By AIME

VERSATILITY is perhaps the outstanding characteristic of the subject of this sketch. He is author, golf-player, musician, public speaker, philatelist, German scholar, and has been a school teacher; but these are incidental. Oliver Ralston's professional forte might be described as beneficiating solid minerals and he has dealt in an important way with practically all of them. To this work he has brought a fertile mind stimulated by keen imagination but kept on the track by a sense of economic balance. An indication of his versatility is evidenced by his career with the Bureau of Mines, which he first joined in 1912, when the Bureau was just one year old. Except for two excursions into industry-Hooker Electro Chemical Co. (1917-20) and United Verde Copper Co. (1928 to 1935)-his entire professional career has been with the Bureau.

Jan 1, 1946

By E. V. Murphree

CREATION of atomic energy, aside from its influence on war or peace, has posed these basic questions for the world: How soon can energy from atoms be harnessed to do man's daily work? How much of this power will there be, to what degree will it supplant present fuels, and what does it imply for the future of civilization? Answers to these questions may be found in part in analysis of just what atomic energy is and how far its development has come. The answers are encouraging. One of the first questions encountered in considering the application of atomic reactions is whether such reactions can be controlled. Fortunately, this has been adequately demonstrated by the operation of the Government plutonium plants at Hanford, Wash. Here nuclear reactions are carried out on a large scale involving liberation of about a billion B.t.u. per hour. This hourly heat liberation is equivalent to that obtained from about 7100 gallons of fuel oil. It has been possible to operate these plants day in and day out with the reaction controlled at the intensity desired. There should therefore be no question that, under proper conditions, reactions involving nuclear fission can be controlled.

Jan 1, 1946

By NEWTON B. KNOX

THE Guianas region is a geological unit, consisting of the northern lobe of the Brazilian Shield, but political accident and the fact that rivers act as the principal means of transportation have divided the region between five separate sovereignties. Brazilian and Venezuelan Guiana have already been considered. The French, Dutch, and British colonies consist of a coastal plain some fifty miles wide, which, together with the lower reaches of the principal rivers, support the greater part of the population. Inland from this tidewater region is a wide area of low, forest-covered hills, under-lain by gneisses, schists, granites, and pegmatites of the Shield. As in Venezuelan Guiana, these rocks are overlain by a thick series of horizontal continental sediments intruded by moderately basic magmas. Gold, bauxite and diamonds have been the principal products of the colonies. The first metal is quite widespread in the hill country. The quartz mines are small, though occasionally rich; probably the greater number of veins remain undiscovered because of the thick mantle of decomposition product that covers the schists and gneisses. The greater proportion of the gold, therefore, is derived from placers which are exploited in all three colonies. Some geologists claim that they occur in two belts parallel to the coast; whether this feature has its origin in the location of the primary mineralization or in the gradients of the rivers is not clear. In some instances the river gravels grade into auriferous laterite. The laterites are well developed in the Guianas and represent the weathering products of the more basic rocks.

Jan 1, 1946

By C. E. Julihn, Lowell B. Moon

"INTRODUCTION To increase the supply of ore needed to produce steel the Bureau of Mines has explored 187 mineral deposits containing chromium, iron, manganese, cobalt, nickel, fluorspar, tungsten, vanadium, or coal during the fiscal years. 1940-44, the deposits thus explored were selected from several thousand that were first examined to appraise their possibilities. The objective of the exploration was to determine the tonnage and grade of ores upon which mining, operations might be based, and the metallurgical processing that was most suitable for their utilization.Most of these deposits were sub-marginal by pre-war standards; hence there had been no incentive for their exploration, yet many such deposits were known to exist that probably contained ore sufficient in grade and amount to be utilized as war reserves.Some of the Bureau's exploration projects have disclosed substantial or even very large amounts of ore, much of which is fairly high in grade. In a few of them bodies of high-grade ore have been found, though in others the tonnage has proved to be too small or too low-grade for utilization."

Mar 1, 1945

By H. Foster Bain

The war has brought about many changes in the Western States, and some have deep pr sent or potent al economic significance. The West has been feeling severe growing pains for a number of years. Especially since the beginning of preparation for national defense and through the period of

Jan 1, 1945

By Lowell B. Moon

Regardless of how a mineral deposit in first discovered or by whom, any mining enterprise based upon it must pass through a preliminary stage of exploration. The common understanding of ?exploration? among mining engineers is well-expressed by Jackson and Knaebel:3/ Exploration work ranges from that performed by the individual prospector employing only the simplest tool, and equipment to elaborate campaigns involving the expenditure of largo stuns of money end the use of churn- car diamond-drilling equipment, large test-pitting crews, or sometimes a regular mining organization. In any event, the object is to determine as accurately as possible, with the funds available, the size, shape, and other characteristics of the ore bodies and their average value or grade.

Jan 1, 1945

By R. F. Evans, J. M. Avery

MUCH has been written of the glamour of magnesium from sea water, the Aladdin-like creation of a huge magnesium plant in the Nevada desert using cheap hydroelectric power from Boulder Dam; the marvels of the Hansgirg process for the electrothermal reduction of magnesium oxide by carbon, and the ferrosilicon process for producing magnesium from dolomite. This is the story of the production of -magnesium by the electrolytic process, using steam-electric power supplied by a public utility, in a plant at Painesville, Ohio, 30 miles east of Cleveland on the shore 'of Lake Erie. The story is not without interest, since it involves several unique developments that provide the answer to a question frequently asked: How is it possible to produce magnesium metal economically at such a location as Painesville, Ohio? Basically, the answer lies in making use of facilities already in existence for the production of soda ash, which makes it possible to manufacture magnesium chloride, the principal raw material, cheaply enough to offset the high cost of electric power. To this is coupled the successful conversion of by-product chlorine into a product required for the war program. The source of magnesium for this operation is the enormous surface deposit of high-grade dolomite in the region south of Toledo, within reasonable freight haul of Painesville. This same geological stratum underlies the Painesville plant, but unfortunately at a depth of about 3000 ft. apparently too great a depth to permit underground mining to compete with the delivered cost of rock from surface quarries in other areas. The cost of dolomite obviously is an important factor, since the rock contains only some 12 per cent magnesium (20 per cent MgO) so that one dollar on the cost of stone means more than $8 in terms of its magnesium content, and more than that in terms of recoverable magnesium metal. PRODUCTION OF MAGNESIA FROM DOLOMITE In the summer of 1941, the Diamond Alkali Co. was well along with construction of a plant intended for the commercial production of refractory and other grades of magnesia from dolomite. The process to be used was designed to make maximum economic advantage of existing plant and operations by tying the production of magnesia in with the manufacture of soda ash in such a way as to make use of the lime (CaO) value of calcined dolomite. The process finally adopted after a lengthy research and development program has much in common with the old Clerc-Nihoul process, but includes certain innovations found to be necessary or

Jan 1, 1945

By Henry F. Hebley

THE solid fuel industry, especially that branch represented by bituminous coal, is gradually becoming aware of its ? paramount importance in a world where there is an ever increasing demand for the products of a mechanical age. In practically every process of manufacture, the necessity for energy in some form is being multiplied. Some of that prime energy is derived from water power-hydro-electric schemes, flood control schemes, etc. - but often the electrical energy thus developed is generated at great distances from the load centres, requiring long transmission lines with consequent transformer and transmission losses. A few plants have harnessed the tidal power of the seas and one has harnessed the energy of the wind in a modern manner. All of these schemes are dependent on certain natural geographical, hydrographical, and physical advantages of terrain, as well as an adequate area of consumption of the energy developed. If flood control is the primary object, then power generation is a by-product; and the economics of large capital expenditure on power generating equipment must be considered in that light.

Jan 1, 1945

By W. J. Kroll

The production of beryllium metal and its alloys is one of the most difficult tasks in metallurgy. In this report we shall examine the progress made in this work- in the last 15 years; taking into account the outstanding publications, including; those of the patent literature, and the information obtained during our 20 years? experience with this metal. The difficulties experienced' in producing elementary beryllium derive from the physical nature as well as from the chemical behavior of the metal and its compounds. Its oxygen affinity is about the same as that of calcium and a little higher than that of magnesium. Its chlorine affinity is much lower than that of magnesium, about equal that, of manganese, and little higher than that of aluminum. The sulfur and nitrogen affinity is probably almost the same as that of calcium for these elements, and beryllium carbide is probably more stable than aluminum carbide, A14C3. The intermetallic affinity of beryllium may be given in descending order, as follows: Nickel - copper - iron. It forms eutectics with -aluminum and silicon as well as with silver. It does not alloy with magnesium and only partly with calcium. Its oxide melts at 2,570° C., but CaO and BaO form readily fusible eutectics with BeO(65).3/ No igneous solvents are known for BeO, which behaves id this regard like Mgo. The beryllium silicate is a strong compound, the aluminete much less so; however, CaO easily displaces Be in the heated mixtures. The Anhydrous chloride hydrolyzes, and it cannot be made from aqueous liquors. It sublimes at 488° C, and melts at 405° C., The fluoride, which, is very Soluble in water, hydrolyzes also, but a kind of oxyfluoride of the approximate formula 2 BeO?5 BeF2 can be made from solutions by dessication. The fluoride melts at 800° C, and boils above 1,100° C. It forms very stable double fluorides with alkalifluorides, which have very low melting points and are fairly soluble in water. They are more stable than the analogous fluosilicates and the sodium fluoaluminate cryolite.

Jan 1, 1945

By Ernest W. Johnson

Diamond, drilling of some blast holes in stoning operations is practised in at least two iron mines in the Lake Superior district - the Soudan mine of the Oliver Iron Mining Co., on the Vermilion range at Soudan, Minn., and the Anvil-Palms mine, operated by Pickands, Bather & Co., on the Gogebic range at Bessemer, Mich. Diamond drilling, at the Soudan nine has partly replaced percussion drilling because of the extreme hardness of the ore and of the lean formation. According to Wolff,4/ the jasper or lean formation in this mine is the hardest rock regularly drilled in any commercial operation.

Jan 1, 1945

By C. W. Van Law

WE have just heard a very able presentation, by Mr. J. C. Cameron, on the subject of Recent Trends in Labour Relations, as they exist today in Canada (l). With minor changes, what he said applies equally to the situation in the United States. Direct negotiation between employer and employee on a man-to-man basis, wherein good faith and mutual esteem was at least sometimes a factor, has almost entirely given way to a mass struggle in which each side is represented by highly trained specialists in a new jurisprudence, built up on vote-getting labour laws, decisions in analogous cases by Boards whose members may have had very little personal acquaintance with the specific case, etc., etc. Membership in a labour union has become almost an essential requisite to a job; once in, the individual workman loses his identity and dares not act on his own initiative or even express any idea not handed him by his Union head. An honest workman cannot turn in an honest day's work, because his Union will not allow him. Leadership in the Unions has become so powerful an instrument, both politically and monetarily, that Union policies are drafted primarily to build up that power, and may have little relation to the equities of the individual case. ?While both sides still render lip-service to the doctrine that Capital and Labour can advance best by co-operation to mutual benefit, that doctrine has in effect given way to as bitter and as legalistic a struggle as any in our civil courts. There are many reasons to believe that we are, industrially, in a situation much like the European situation from 1935 to 1939; an impending war to the death with 'appeasement' as the only, unavailing, policy

Jan 1, 1945

By A. C. Fieldner

The past full year of war has increased greatly the demand for virtually all kinds of fuel, and the Bureau of Mines research and service facilities have been extended to meet these unprecedented requirements. Liquid fuels, such as aviation and motor gasolines, are fundamental to modern warfare. Bituminous coal and anthracite are needed, not only to servo the expanded industrial program for which coal normally is used but also to replace natural gas, wherever possible, and fuel oil in the Eastern States, New England, and the Pacific Northwest. Railroad transportation with energy derived from coal is replacing much of the motor-vehicle transportation that has been stopped or curtailed to conserve rubber. Pulverized coal hoe been sound to be a satisfactory and cheaper substitute for fuel oil in metallurgical heating furnaces. Celloidal fuel - a mixture of coal dust and oil - may offer a partial substitution for curtain coal-burning equipment. Several industrial experiments have been made with this type of fuel. The expansion of the steel industry in connection with the war program has required a corresponding increase in the production of metallurgical coke and its associated byproducts - light oil, tar, ammonium sulfate, and surplus gas. If the war is of long duration and new reserves of petroleum are not discovered, wartime trends from fuel oil to coal probably will not be reversed.

Jan 1, 1945

By R. S. Dean

REQUIREMENTS for war materials have led to large scale experimentation upon metallurgical innovations. It is of interest to inquire what this may contribute of permanent value to our existing technology, as innovations adopted during war are apt to be discarded promptly at its end. This is because utilization of substandard ores usually requires a new technology for ore treatment, and a new use-pattern for employment of the products. Thus two very different problems are involved: first, devising a process; then, adopting its products by industry, with readjustments of the use-pattern if necessary. A new process may be as good or better than an old one, but the readjustments required for use of its products may prevent its general adoption if this implies scrapping existing plants and investing much additional capital. Metallurgical innovations are of three kinds: I. The use of substandard material in processes already established; 2. The grading-up of substandard material to render it more suitable for established processes; 3. The adjustment of technology and use-pattern to the raw materials that we have.

Jan 1, 1945