Search Documents

By R. W. Raymond

At the Pittsburg meeting of the Institute, in March, 1910, the death of Mr. Metcalf was announced, and Col. H. P. Bope, of Pittsburg, delivered in memory of him a brief but eloquent address, which, though expressing the Norrow of Mr. Metcalf's friends, and, in general terms, the debt of gratitude which his country and his profession owed to him, was not intended to be a complete survey of his life and work. With Colonel Rope's permission, and with the aid of some of the statements in his address, I substitute for it, in our Transactions, this more cletailed, yet still inadequate memorial. As Colonel Rope justly remarked, the men who could do justice to this theme—such men as Jones, Chalfant, Bennett, Oliver, and Park—passed away before Metcalf, leaving him almost the last of the generation of great steel-makers who made Pittsburg the Sheffield of America, and who discharged a double function, as the rearguard of the old metallurgical practice and the ran-guard of the new. I knew many of them; would that I were better qualified to celebrate their achievements. William Metcalf was born Sept. 3, 1838, at Pittsburg, Pa., where his father, Orlando Metcalf, was an eminent member of the bar. At the age of sixteen, he entered the Rensselaer Polytechnic Institute, at Troy, N. Y., from which he was graduated in June, 1858: Returning to his native city, he became an assistant engineer in the Fort Pitt Foundry, of which he was made Superintendent in 1859. This famous establishment produced the largest castings and heaviest machinery then knolrn in the United States; and Mr. Metcalf's intense, intelligent and incessant study of his business prepared him as a manufacturer for a patriotic service to his country more valuable than, as a soldier, he could have rendered in the field. The call came in 1862, when the government needed, above all things, a supply of field, naval and siege artillery. The

Jan 1, 1911

By Kenneth Cottingham

The year 1941 brought a considerable increase in drilling activity in Ohio. In 1940, the total of wells completed was 1228, whereas in 1941 it was 1561, or an increase of approximately 27 per cent. Of the 1561 wells, 333 were oil wells, 701 gas wells and 527 dry holes. The completions for the past five years are shown in Table I; the number of productive oil or gas wells for the year 1941, arranged by producing formations, are given in Table 2; the number of wells, oil, gas or dry, completed in each county in 1941, in Table 3, and wells by sands in Table 4. The production of oil increased by about 500,000 bbl. in 1941, nearly all of the increase being in Pennsylvania grade. In 1940, the total production was 3,052,000 bbl. from 25,500 wells. In 1941 the total production was 3,547,534 bbl. from 24,801 wells. The increase in production is chiefly due to the Clinton pool in Clayton township, Perry County, which is briefly men- tioned later in this review. The number of oil wells, by grades of oil, and the total quantities produced are shown in Table ;. Annual oil production for five years is listed in Table 6. The average prices paid for crude in 1941 were slightly higher than in 1940 These 1941 prices, with dates of change, are shown in Table 7. The maximum production of natural gas in Ohio was in the year 1915, when the total was just under 80 billion cu. ft. The maximum consumption occurred in the year 1916, and was approximately 169 billion cu. ft. For the past several years, Ohio has ranged from eighth to eleventh, in order of gas production for the different states, being in tenth place in 1940. In the matter of consumption, however, Ohio remains in fifth place. Preliminary figures for 1940 indicate that production of natural gas increased II per

Jan 1, 1942

By Walter Miller

The focus of attention during 1939 was on increasing the octane number of gasoline. The "octane race" resumed full swing. The averagc octane number of house-brand gasoline by the end of the year had easily reached two numbers higher, with several companies in the field actually purveying house-brand gasoline of 78-80 "research" octane number, equivalent roughly to from 74 to 77 A.S.T.M. octane rating, compared with the 70 A.S.T.M. ceiling of two or more years ago. Whether this trend toward much higher octanes is the result or the cause of the many t,echnical developments in the motor-fuel field of recent, years, progress has really been startling. In addition to the advance in catalytic cracking and catalytic re-forming, other important contributions to the technical ability to produce higher octane values include: installat>ions involving increased capacity in thermal re-forming, with improved economic status both as to yields and octane number, by coupling with catalytic polymerization; more widespread adoption of catalytic and thermal polymerization, and a surge toward extensive installations of newly developed alkylation processes for making iso-octane, neo-hexanr and other high antiknock products; and greater use of improved desul-phurization processes, and application of superfractionation methods for segregation of practically pure hydrocarbons with superior octanr qualities from gas and highly volatilc liquids. The approaching of practical limits in the use. of tetracthyl lead (t,hr well-known "law of diminishing returnsn coming into the picture at the higher octane levels being approached) has given impetus to development of the methods listed above. In particular, processes that improve the octane rating and also increase ethyl lcad sc.nsitivity have had considerable study durirlg the year. CatSlytic Re-foRming Although the interesting report on the Houdry catalytic cracking process presented at the annual meeting of the American Petroleum

Jan 1, 1940

By B. M. Loring, I. R. Krame, F. M. Walters

NO observations on the mechanical properties of man-manganese alloys have been published since pure manganese became readily available, either distilled manganese or electrolytic manganese. The purpose of this investigation was to determine whether iron-manganese alloys are essentially brittle, as reported by Hadfield,' or whether the lack of ductility observed was due to impurities in the alloys that he studied. Experimental Methods The alloys were melted in a roo-lb. high-frequency induction furnace with a magnesia crucible, using ingot iron and electrolytic manganese. The heats were split, the first giving six 18-lb, ingots and the second three. Each successive heat was higher in manganese and about 0.3 per cent silicon was added as ferrosilicon. The alloys forged without difficulty and were given a 9' per Published by permission of the Navy Department. Manuscript received at the office of the Institute June 28. 1941. Issued as T.P. 1369 in Metals Technology. September 1941. * Division of Physical Metallfirgy Naval Roscarch Laboratory. Anacostia Station Washington. D. C. 1 References are at the end of the paper. 4 cent reduction to ¾-in. rounds. The chemical analysis of the alloys is given in Table I. The forged rods were homogenized for 224 hr. at r150°C. (2100°F.) and air-cooled. The alloys were tested in two conditions of heat-treatment: (I) as normalized from 870°C. (1600°F.) and (2) normalized from 870°C. and tempered for I hr. at 540°C. (Iooo°F.) and air-cooled. The tensils specimens were 0.505 in. in diameter with a 2-in. gauge length, and the impact specimens were v-notch Charpy. The proportional limit and yield strength were taken from the stress-strain diagrams drawn by a Peters recorder. The data obtained from the tensile test and the hardness measurements are given in Table 2. Specimens that were normalized are designated by N; those that were normalized and tempered by T. Alloy G was tempered after forging (D).

Jan 1, 1942

LATEST estimates of Russian steel production for 1951 give rise to the belief that on at least one vital front, the Western bloc of nations has maintained a definite advantage. On the surface, we are outproducing the Eastern bloc by more than twice. The United Nations Economic Commission for Europe estimates Russian output at 31.30 million tons, a 15 pct increase over the previous year. Production for the entire Iron Curtain is figured at 40.93 million tons. Western Europe alone produced 17 pct. more steel during the same period. The figures are misleading in one sense. We have no precise idea of how much steel is being used for arms. The Western nations are still expending much of their production for consumer goods, and you cant throw washing machines in a shooting war. It is significant to note that Russian production is well, beyond estimates made by world authorities prior to the current international situation. INTERIOR Secretary Oscar L. Chapman warns that the United States must make use of the resources of other nations or face mineral impoverishment once the time of struggle is over. He pointed out that the present struggle between two ideologies can leave the United States in such a state as to preclude anything but political' victory-with an accomp anying economic loss that will be irreparable. Chapman scored the attitude whereby conservation programs are looked upon as a luxury, pointing out that the nation faces an ever increasing need for action on that front. He also announced that the Bureau of Mines doubled its facilities for producing pure zirconium during 1950-51 at the request of the Atomic Energy Commission. Zirconium may be an important structural metal for atomic power devices. The Interior Secretary also said that the AEC has provided the Bureau with funds for the study of radioactive minerals and to help test and evaluate about 9000 ore samples believed to contain uranium.

Jan 1, 1952

By B. M. Loring, I. R. Krame, F. M. Walters

NO observations on the mechanical properties of man-manganese alloys have been published since pure manganese became readily available, either distilled manganese or electrolytic manganese. The purpose of this investigation was to determine whether iron-manganese alloys are essentially brittle, as reported by Hadfield,' or whether the lack of ductility observed was due to impurities in the alloys that he studied. Experimental Methods The alloys were melted in a roo-lb. high-frequency induction furnace with a magnesia crucible, using ingot iron and electrolytic manganese. The heats were split, the first giving six 18-lb, ingots and the second three. Each successive heat was higher in manganese and about 0.3 per cent silicon was added as ferrosilicon. The alloys forged without difficulty and were given a 9' per Published by permission of the Navy Department. Manuscript received at the office of the Institute June 28. 1941. Issued as T.P. 1369 in Metals Technology. September 1941. * Division of Physical Metallfirgy Naval Roscarch Laboratory. Anacostia Station Washington. D. C. 1 References are at the end of the paper. 4 cent reduction to ¾-in. rounds. The chemical analysis of the alloys is given in Table I. The forged rods were homogenized for 224 hr. at r150°C. (2100°F.) and air-cooled. The alloys were tested in two conditions of heat-treatment: (I) as normalized from 870°C. (1600°F.) and (2) normalized from 870°C. and tempered for I hr. at 540°C. (Iooo°F.) and air-cooled. The tensils specimens were 0.505 in. in diameter with a 2-in. gauge length, and the impact specimens were v-notch Charpy. The proportional limit and yield strength were taken from the stress-strain diagrams drawn by a Peters recorder. The data obtained from the tensile test and the hardness measurements are given in Table 2. Specimens that were normalized are designated by N; those that were normalized and tempered by T. Alloy G was tempered after forging (D).

Jan 1, 1942

By A. M. Stone

INTRODUCTION In ore beneficiation one of the simplest methods of mineral concentration is hand picking to remove either the ore or the waste material from a moving table or conveyor belt. Ore Sorting Equipment may be defined as equipment for mechanized picking. This type of equipment has been used successfully over the past thirty years or so to beneficiate ores of various types in particle mesh sizes between 1mm and 200mm.. at throughputs of up to 150 tonnes per hour. In general for ore sorting to be a consideration the ore and the waste material must be well liberated in the feed to the sorter (that is into practically discrete particles of ore and waste). The larger the liberation size the more likely sorting is to be cost effective. Correct selection of ore sorting equipment is most important and often special machine features are developed for an individual application. Sorter performance can be best determined by extensive testwork of representative ore at design tonnage on prototype or preferably on production model sorting machines. ADVANTAGES OF SORTING ORE The four main advantages of sorting ore are: Reduced milling cost. Reduced processing cost. Higher overall recovery. Reduced transportation costs. Reduced Milling Cost With sorters installed the milling plant following the sorter is generally smaller and hence less costly to install and operate as it only has to handle the sorter product. However this benefit is somewhat offset by the increased cost of the screening and washing plant prior to the sorter and the cost of the sorting plant itself. Reduced Processing Cost As there is less material of higher grade presented to the concentrating plant following the sorter, this plant will generally be smaller and less costly to construct and operate than a plant treating the total quantity of material. Higher Overall Recovery The economic recovery is often misunderstood by plant operators when evaluating the advantages of sorters

Jan 1, 1986

By Angela L. Paveley

Economic viability of base metal mining is complicated by a volatile market that can cause fluctuations in the growth and stability of the mining industry. Nickel is mined primarily for use in manufacturing industrial stainless steel and plating materials. It is essential that nickel production be sufficient to respond to current and future market demand. A Post-Pillar cut and fill mining complex is currently producing nickel sulfide in Northern Manitoba. From 2006 this area has shown a steady increase in the annual production, rising from 11 million pounds to 25 million pounds in 2010, and accounting for 33% of the total production for the Manitoba Operations. It is expected that fine-tuning the mining process can safely enhance ore recovery, improve production consistency, and increase economic viability of the deposit. The Post-Pillar Optimization study was initiated by the local technical and operational departments at the mine and analyzed from July 2010 to March 2011. The purpose of this study was to determine if portions of non-recoverable pillars can be slashed without jeopardizing pillar strength. This ideal case would optimize ore recovery and reduce variability in the ore mining rate. Numerical modeling and geo-mechanical material properties analyses, completed by the rock mechanics group, define the maximum drift width at 32 feet and the minimum pillar width at 18 feet. Thus, it was suggested that up to 3 feet could be slashed from two sides of the standard 24 foot pillars without damaging ground integrity. The field data collected indicates that additional ore could be recovered without compromising the safety of the workplace and the integrity of the complex. Consequently, technical and operational groups work jointly to achieve pillar optimization. Approximately 500,000 pounds of nickel was extracted from the complex via pillar optimization from July 2010 to March 2011. Economic analyses show the pillar optimization method developed for the mining complex is a proven, value-added opportunity. The mining complex remains a safe workplace and has retained ground integrity.

Nov 1, 2011

By David B. Morris, Paul I. Eimon

Computer-assisted data storage and retrieval in the geosciences is coming of age. A growing awareness of the need of the geological and mining community for effective access to existing data has triggered studies and development programs on many levels; governments, professional societies, industrial concerns, and the academic world are all active in this field. Developments in the past decade in computer hardware and software lend hope to the geoscientist searching for a means of expediting the flow of data. The new concern of the earth sciences coming together with the blossoming child of technology, computing, has led to serious study of the geoscience information problem. Active system development is under way in several areas. The papers presented at this Symposium effectively sample the spectrum of present day activity in machine-based geologic data storage and retrieval. These papers show the reader where the action is in this field today. Both long-range studies and plans and operational systems are discussed. Several studies and research efforts have been undertaken on a national or international scale. Robinson discusses the activity of the international geological community in these Proceedings. He speaks from a position of authority as Chairman of the International Union of Geological Sciences' Committee on Storage, Automatic Processing and Retrieval of Geological Data. A study of a "coordinated information program for geological scientists in the United States" documented by Smith, et al.1 proposes a "long-range information program ... responsive to the entire geosciences community . . . (to) draw on the best of large-scale information systems technology." The European geologic community is embarked on project Geosemantica 70, started at the Ecole Nationale Superieure des Mines de Paris. Dixon discusses some results of this work in a following paper. The Canadian study of geological data storage and retrieval on a national scale is reported in a volume edited by Brisbin and Ediger.2 The Canadian report presents detailed recommendations for recording and coding geologic data for automatic process-

Jan 1, 1969

By Kenneth Cottingham

The year 1941 brought a considerable increase in drilling activity in Ohio. In 1940, the total of wells completed was 1228, whereas in 1941 it was 1561, or an increase of approximately 27 per cent. Of the 1561 wells, 333 were oil wells, 701 gas wells and 527 dry holes. The completions for the past five years are shown in Table I; the number of productive oil or gas wells for the year 1941, arranged by producing formations, are given in Table 2; the number of wells, oil, gas or dry, completed in each county in 1941, in Table 3, and wells by sands in Table 4. The production of oil increased by about 500,000 bbl. in 1941, nearly all of the increase being in Pennsylvania grade. In 1940, the total production was 3,052,000 bbl. from 25,500 wells. In 1941 the total production was 3,547,534 bbl. from 24,801 wells. The increase in production is chiefly due to the Clinton pool in Clayton township, Perry County, which is briefly men- tioned later in this review. The number of oil wells, by grades of oil, and the total quantities produced are shown in Table ;. Annual oil production for five years is listed in Table 6. The average prices paid for crude in 1941 were slightly higher than in 1940 These 1941 prices, with dates of change, are shown in Table 7. The maximum production of natural gas in Ohio was in the year 1915, when the total was just under 80 billion cu. ft. The maximum consumption occurred in the year 1916, and was approximately 169 billion cu. ft. For the past several years, Ohio has ranged from eighth to eleventh, in order of gas production for the different states, being in tenth place in 1940. In the matter of consumption, however, Ohio remains in fifth place. Preliminary figures for 1940 indicate that production of natural gas increased II per

Jan 1, 1942

By Walter Miller

The focus of attention during 1939 was on increasing the octane number of gasoline. The "octane race" resumed full swing. The averagc octane number of house-brand gasoline by the end of the year had easily reached two numbers higher, with several companies in the field actually purveying house-brand gasoline of 78-80 "research" octane number, equivalent roughly to from 74 to 77 A.S.T.M. octane rating, compared with the 70 A.S.T.M. ceiling of two or more years ago. Whether this trend toward much higher octanes is the result or the cause of the many t,echnical developments in the motor-fuel field of recent, years, progress has really been startling. In addition to the advance in catalytic cracking and catalytic re-forming, other important contributions to the technical ability to produce higher octane values include: installat>ions involving increased capacity in thermal re-forming, with improved economic status both as to yields and octane number, by coupling with catalytic polymerization; more widespread adoption of catalytic and thermal polymerization, and a surge toward extensive installations of newly developed alkylation processes for making iso-octane, neo-hexanr and other high antiknock products; and greater use of improved desul-phurization processes, and application of superfractionation methods for segregation of practically pure hydrocarbons with superior octanr qualities from gas and highly volatilc liquids. The approaching of practical limits in the use. of tetracthyl lead (t,hr well-known "law of diminishing returnsn coming into the picture at the higher octane levels being approached) has given impetus to development of the methods listed above. In particular, processes that improve the octane rating and also increase ethyl lcad sc.nsitivity have had considerable study durirlg the year. CatSlytic Re-foRming Although the interesting report on the Houdry catalytic cracking process presented at the annual meeting of the American Petroleum

Jan 1, 1940

By W. H. Adams

Inasmuch as] the mining of phosphate rock and its transportation has so general a bearing on the great industries of this continent, entering as well into the problem of our trade with foreign countries, it may be useful to place on record the following list of localities from which certain products of a like nature are received by us in a business way, or in which we are interested more or less either by ownership or by competition. As a ready means of comparison, the percentages of the mine products and the deteriorating constituents are given : Coprolite (Cambridge).—This material is obtained from the Upper Greensand formation in Cambridgeshire. The phosphate runs from 50 to 60 per cent., and averages 64 per cent. It contains much carbonate of calcium, but little iron, in the ferric condition. The superphosphates manufactured from the material are permanent and little liable to a revert." They contain from 28 to 35 per cent. of soluble phosphate. Coprolite (Buckingham).—From the same formation as the Cambridge variety, and very similar in composition.. It averages 60 per cent. phosphate. Coprolite (Suffolk).—These coprolites are not so valuable for the manufacture of superphosphate as the two previous varieties, as the iron they contain is in the ferric state, and liable to "revert" the soluble phosphate. The phosphate varies from 48 to 60 per cent., but averages 54 per cent. They are of Tertiary formation. Coprolite (Potton or Bedford).—The average amount of phosphate in these coprolites is about 50 per cent. In some cases they may, however, run up to 60 per cent., and in others may not exceed 45 per cent. They belong to the Lower Greensand formation. The ferric iron frequently is as high as 4 per cent., and the alumina as much. Russian phosphate comes from the chalk, and occurs in carious rounded masses. It contains from 28 to 35 per cent. of phosphate, but may run up to 69 or 70 per cent. Curacoa phosphate is also of very high class quality, giving 80

Jan 1, 1890

By C. E. Meissner

THE need for a practical method of deciding upon new alloy steel analyses to widen its markets was the problem facing the Chrome Steel Works at the beginning of 1927. In addition to determining the physical properties of the alloys under consideration, it was necessary to test their value in service. Small melts of steel in a crucible, from which test specimens could be made, were insufficient to determine more than physical properties, therefore actual castings and ingots had to be made before the products could be placed in service. Furthermore, to save further experimental work, it was desirable that these heats should be made on a "pilot" basis; that is, actually duplicating regular open-hearth furnace practice. Therefore a one-ton (2000-lb.) acid open-hearth furnace was built. FURNACE DESIGN There are no special features in the design of this furnace. Standard acid open-hearth practice is followed, with the reproportioning of the dimensions necessitated by its small size; notably, a considerably increased length in proportion to width in order to get proper flame propagation. After the first heat was made it was found that the checkers were insufficient. The checker chambers were increased in size and the checker openings were made much smaller. The furnace was started late in March, 1927, and made 65 heats. Experimental work was then stopped until the data accumulated could be worked up and summarized. The run was resumed in November and the furnace is still operating, having made at this writing 60 additional heats. For the last series of runs, there was some rebuilding of both the furnace itself and the checkers. Slag pockets were added. Fig. 1 shows details of construction; Fig. 2, the, general appearance. All designing was done by the operating and engineering staff. Construction materials were those available around the plant. The reversing valve is a standard butterfly type taken from an old furnace.

Jan 1, 1928

By M. J. Friedel, D. E. Scott, T. J. Williams

Rock masses in deep level mines are subject to high stresses, which can result in unexpected failure of rock into mined-out openings. Historically, various independent methods have been used to discern the causes of rock bursts and to evaluate stress conditions in rock masses susceptible to violent failure. Personnel from two research centers of the former U.S. Bureau of Mines, Spokane and Twin Cities, investigated a rock burst that occurred in May of 1994 in a rock mass between the 4400 and the 4600 levels of the Sunshine Mine, Kellogg, ID. The team evaluated the current state of stress in the pillar and the most likely cause of the rock burst by studying the seismic history of the pillar, examining the geology, analyzing the available in situ stress data, calculating possible fault-plane solutions for the burst, and performing a seismic velocity tomographic survey. The results of the study showed that post-rock-burst seismicity was concentrated about 15 to 30 m west of and about 15 m above the rock-burst location. The pillar is composed of a very hard sericitic-to- vitreous quartzite of a type rarely found in the mine, but that is often found in other district mines having a history of seismic activity. In situ stress analysis of the pillar and the surrounding rock mass showed a probable stress rotation from northwest-southeast to east-west. Of four fault plane solutions, the most probable was either a left-lateral, strike-slip movement with a compressive principal stress oriented nearly north-south, or a right-lateral, strike-slip movement oriented east-west. Finally, tomographic images showed low-velocity areas (interpreted as areas of low stress) associated with the crosscuts and haulageways, and high-velocity areas (interpreted as areas of high stress) associated with the rock-burst location. High velocities were also found in a planar area oriented in an elongate northeast-southwest direction.

By Kenneth Cottingham

The number of completions in 1944 in Ohio was only slightly greater than completions in the preceding year, but the initial daily volumes both of oil wells and gas wells declined considerably. The dry-hole ratio was a little lower than in 1943, even though in the year under review considerable effort was made to find new production. No new areas of consequence were discovered. Thirteen new gas pools, the largest of which was 1000 acres and the average 565 acres, were opened during the year. Eleven of these pools were in the Clinton sand, one was in the Oriskany, and one was in the Berea. Approximately 15 small pools might also be rated as discoveries, but because only one or two wells have thus far been completed in each, they cannot at present be properly evaluated. The latter pools average about 120 acres each. Some extensions were made to existing gas pools. The number of oil wells drilled was only one less than in 1943, yet compared with the year 1941, when twice as many oil wells were drilled, the difference is startling. Effective Aug. I, 1944, a blanket subsidy was granted of 35¢ per barrel on all Cleveland-Chatham, Coming, and Lima grades of oil, and 75¢ per barrel on Pennsylvania grade crude. The subsidy was authorized by the Office of Price Administration, with reimbursement to purchasers of the various grades made through the Defense Supplies Corporation, a branch of Reconstruction Finance Corporation. For several years the small operator, particularly the owner of stripper wells, was in a serious position. The subsidy has been a means of real help and, in addition to aiding the operator, it has prolonged the life of many small wells that otherwise would have been abandoned, with consequent loss of daily production and unre-covered reserves. It is questionable whether the price increase is sufficient to revive production of Corning grade, which has

Jan 1, 1945

By V. Lessels, D. J. Buckwalter, D. H. Rose

A cyanide leaching process developed at Michigan Technological University was tested in a 12 to 24 tpd pilot plant. Flowsheet layout and equipment are described. Cyclic operation of leaching, copper precipitation by acidification, and regeneration of the cyanide leaching solution are discussed. Copper extraction and reagent consumption were as predicted by laboratory tests, and the process was proven to be technically feasible. The White Pine Copper Co., a wholly-owned subsidiary of the Copper Range Co., produces copper in the Upper Peninsula of Michigan. Production in 1965 amounted to 138 million pounds of metal. An expansion program now under way will increase this by approximately one half. The highly mechanized room and pillar mine produces 18,000 tons of ore per day, which is treated in a flotation plant. The concentrate is smelted in a reverberatory furnace, the matte is blown in converters to blister copper, and the blister copper is further refined to a uniformly high-quality Lake copper, which is 100% conductive and has a silver content of 25 to 40 oz per ton. The run of the mine ore averages 22.5 lbs of copper per ton with the ore mineral occurring in the form of chalcocite. The nature of the mineralization is such that the sand tailings average a little over 4 lbs of copper per ton. Intensive research has improved copper recovery in the flotation operation to some extent, but at the scale of present operation about 12,000 tons of sands containing over 48,000 lbs of copper go to the tailings pond daily. When the plant expansion is completed, the loss of copper will be somewhat greater. In 1959, the White Pine Copper CO, initiated a study of the recovery of copper in the sand tailings. Inasmuch as the flotation operation was considered to be optimized, a logical approach seemed to be leaching. For various reasons ammonia, ferric chloride, acid, and biological leaching were ruled out as impracticable. This led to a consideration of cyanide leach-

Jan 1, 1968

By Reuben B. Ellestad, Fremont F. Clarke

In the early days of the lithium industry most of the production was from lepidolite, zinnwaldite, and amblygonite. Nearly all the early extraction processes described in the literature involve heating the finely ground mineral with sulphuric or hydrochloric acid. On subsequent water leaching most of the bases present in the mineral (especially aluminum) are dissolved as sulphates. As a result, the leach solution required extensive chemical purification before the lithium could be precipitated as carbonate. Following the remarkable growth of the lithium industry to its present size, zinnwaldite and amblygonite ores must be considered of minor importance only. Attention is now focused on spodumene, abundant enough in North America to be a major source of supply, and there are important supplies of lepidolite and petalite in Africa. The extraction processes described below all apply to spodumene, although several will also operate on other lithium minerals, such as petalite. Base Exchange with Alkali Sulphates: A distinct advance was made with the disclosures of Wadman and von Girsewalt. In these methods the finely ground silicate ore (spodumene or lepidolite) is intimately mixed with an excess of alkali sulphate (usually K2S04) in at least a 1 to 1 proportion, and the mixture was heated to a relatively high temperature. Base exchange results, with the formation of lithium sulphate. A water leach dissolves the lithium sulphate, together with the excess potassium sulphate. Successful operation of this type of process requires very thorough grinding and mixing, as well as careful temperature control. The use of K,SO, is objectionable from cost considerations since purification of lithium carbonate re- quires the use of potassium carbonate, if the K2S04 is to be recovered and recycled. The lower solubility of K,SO, as compared with Na,SO, is also objectionable, since it limits the concentration of the Li,SO, solution to be precipitated by K,CO,. Early laboratory-scale investigation of this process by Lithium Corp. was not encouraging

Nov 1, 1955

By F. E. Marcy

It is not my purpose to write a lengthy article or to attempt the solution of the problem I am presenting, but to call attention to what I believe an important issue, hoping that it may arouse in some one, or in some company, a sense of responsibility. I am referring particularly to modern up-to-date milling plants discharging tailings which under existing conditions cannot be further treated or from which a recovery cannot be made at a profit, but where a quantitative and qualitative analysis shows that a portion of these tailings might profitably be treated at some future time when our metallurgical knowledge has advanced, when we have cheaper power, chemicals, labor or other advantageous conditions. Early Methods In our early milling methods very little attention was given to the care of tailings. It was thought that if the mill could be located by a stream or a river where the final disposal of the tailings could be forever lost sight of, it was highly desirable. We can now see and estimate what was lost in these rich tailings, not recoverable from the streams and the great rivers. Fortunately for many, the depositing of tailings in these streams and rivers was objected to by the farmers and finally prohibited by the State Legislatures. In looking back over our past milling methods, it seems that the first endeavor was to make the maximum amount of money for a particular period, or year, regardless of the future, the depletion of the mine, or the conservation of the total mineral content. The dumping and sluicing of 3000 tons per day, for a period of many years, of a copper tailing carrying 12 lb. of recoverable copper together with its portion of precious metals, the thousands of tons of valuable metal contained in the tailings that have been carried away by Silver Bow Creek, the streams of the Coeur d'Alene, the Flat River and Colorado districts, the enormous quantities

Jan 1, 1918

J. S. UNGER,* Pittsburg, Pa, . (written discussion?).-The author of the paper has given an excellent description of the appliances used to cool parts of an open-hearth furnace, and some of the reasons why the refractories fail in service. Personally, I favor water-cooling, but to a limited degree. At one time I advocated more universal cooling than is now practised, but believe I must change my mind. Water-cooled, thin-lined blast furnaces have not proved as satisfactory as anticipated. While this may retard the building of many such furnaces, it will not prevent the use of regular tuyere- and bosh-cooling appliances. Water-cooling any furnace may be easily carried to the extreme. In an open-hearth furnace, excessive port or roof cooling, or cooling the working floors may preserve the lines of the furnace, lower the cost of refractories, acid to the comfort of the workmen, and necessitate fewer shutdowns for repairs, but it may not be good economy on account of the high first cost, the cost of cooling water, maintenance of cooling appliances, and the immediate reflection in a higher fuel cost. The question becomes a financial one, and is answered by using water-cooling devices up to the point at which they cease to show true economies. Open-hearth furnace bulkheads, roofs, and ports fail rapidly in about the order named. If they could be made to last indefinitely by water-cooling, the furnace would still have to be shut clown periodically for cleaning the slag pockets, regenerator chambers, and flues. Extra, or spare, pockets and regenerator chambers have been advocated to permit of continuous operation, but the space required, the cost of installation, and the fuel required to initially heat such cold chambers will largely prevent their adoption. Some particular fuels, as high-ash powdered coal, require frequent stoppages for cleaning, but for this particular fuel a special provision can' be made.

Jan 5, 1919

By T. Bednarski, L. Thomas, G. Banza, D. Muteba, P. Cole, M. Soderstrom

"In copper solvent extraction, aqueous-in-organic entrainment results in the carry-over of unwanted species into the electrowinning process with negative cost implications. The need to bleed is increased and the purity of the copper cathode is potentially compromised, depending on the impurities being transferred (Cl, NO3, Fe, Mn). In some cases, entrainment results in elevated levels of manganese in the electrolyte which can cause oxidative conditions to develop and degradation of the organic phase. Degraded organic phase detrimentally affects the physical performance of the copper solvent extraction process, contributing to even higher aqueous-in-organic entrainment. Aqueous entrainment may be minimized through good operating practices and maintenance of the organic quality, but the accurate measurement of entrainment remains a challenge. This paper presents coalescing devices designed to provide more exact measurements of aqueous-in-organic entrainment. IntroductionMany copper solvent extraction (SX) plants experience high aqueous-in-organic (A-in-O) entrainments but are unaware of the extent of the problem because entrainment is often not measured. Aqueous entrainment results in the carry-over of unwanted species into the electrowinning (EW) process and the need to bleed to maintain acceptable concentrations in the electrolyte. The costs associated with the bleed are exacerbated in copper plants where aqueous entrainment levels are high. Other than these direct costs, there are operational consequences of the build-up of certain species in the EW circuit that can have deleterious effects on plant performance.Minimizing aqueous entrainment in operating plants requires an understanding of the factors that affect entrainment levels. Both chemical and operational influences are discussed in this paper. The difficulty of obtaining a representative sample makes it challenging to obtain an accurate measure of aqueous entrainment from a continuous process like SX. Coalescing devices used to get a more precise measurement of A-in-O entrainment are useful to complete mass balances around the SX circuits. Alternatively, mass balances can be used to estimate aqueous entrainments and are helpful as a tool to troubleshoot operations with a view to improving plant performance."

Jan 1, 2016