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By Archer Wheeler

Introduction. THERE are two general methods in use for the production of metallic copper from matte which are worthy of consideration : (1) the Welsh blister process, and (2) the converter process.1 As practically all of the copper produced to-day is made in converters, we will give a brief outline of that process before proceeding with the special subject of this paper. Matte may be roughly defined as a mixture of the sulphides of copper, iron, nickel, silver, etc. In the converter process this is blown up to metallic copper in a modified type of Bessemer converter. The conversion of matte consists mainly in, (1) the removal of sulphur in the form of SO2, and (2) the slagging of the iron. With this brief statement we come to the two subdivisions of the process of converting mattes: Converting with acid linings. Converting with basic linings.

Jan 12, 1913

By R. G. Robins

The processing of gold bearing sulphide minerals which contain arsenopyrite and various complex arsenic sulphides results in arsenic containing emissions and effluents which are suspect in relation to clean air and clean water standards. Removal of arsenic from gaseous emissions is briefly reviewed. The use of lime to stabilise aqueous residues as either calcium arsenate or calcium arsenite is shown to be inadequate for long term disposal since both compounds are converted into calcium carbonate due to the influence of carbon dioxide in the atmosphere. Mixed calcium arsenate-phosphate residues are similarly unstable, but present better stability than the straight calcium compounds. Alternative disposal methods are reviewed whereby the arsenic is converted to more stable compounds, such as barium arsenate, titanium (IV) arsenate, and arsenic sulphide.

Jan 1, 1984

By L. P. Teas

ALTHOUGH 1927 in the Arkansas-Louisiana territory will probably pass into history as a year of small profits and little new production, nevertheless during this period two large gas fields were developed; two new oil fields were discovered, and two new oil horizons, hitherto of minor Annual Production in Millions of Barrels FIG. 1.-PRODUCTION OF NORTH LOUISIANA AND ARKANSAS BY FIELDS FOR 1926 AND 1927. importance, were developed; In spite of the "hard times" some of the leading, supply houses did more business this year in this. district than in any year since 1920.

Jan 1, 1928

By T. Cuscino, D. D. Lane, C. Cowherd, T. E. Baxter

Three types of commercially-available dust suppressants, commonly used in the surface mining industry to control fugitive particulate emissions from unpaved roads, were tested in the laboratory for cohesive strength and resistance to reduced effectiveness by large water addi¬tions. Results indicate that each product tested varies in cohesive strength with a range of 34-300 kPa (5-44 psi). Total cohesive strength depends on the aggregate moisture content and the means by which the sample is dried. Results show that laboratory testing can be used as a decision¬making tool concerning the type of dust suppressant for a particular mining operation. Also, the road surface aggre¬gate moisture content u critical to successful dust suppres¬sant performance. Large water additions to the aggregate road surface after initial suppressant application can pro¬duce nondesirable results. A modified wet sieving analysis is presented to test the effect of water addition.

Jan 1, 1984

By N. Rowlands, J. A. Finch, R. Espinosa-Gomez

The sulphation roast-leach process for complex sulphides results in phase changes due to roasting and leaching. The phases in the calcine, and in the neutral and hot acid leach residues were identified and their degree of liberation determined in order to design and Interpret separation tests on the residues. The hot acid leach residue was composed of hematite, silica, and lead sulphate with some associated silver. Magnetic separation was selected as the process for producing a lead concentrate, as the non-magnetic product. Separation was limited by -1 pm hematite reporting to the product, and hematite/lead sulphate agglomerates reporting to the magnetics.

Jan 1, 1984

By F. S. Knoll

The expanding role of electrostatics as applied to minerals and related fields is covered in this paper. New and existing forms of electrostatic separation are classified into two broad groups: separation of charged particles and separation of neutral particles. The basis for each form of separation is discussed along with particle examples and results obtained.

Jan 1, 1986

By K. I. Savage, L. G. Austin, S. C. Sun

The comminution environment - the physical, chemical, and solid state - was studied for silicon carbide ground wet in a laboratory vibratory mill. The relative importance of these variables on the grinding rate of producing a material 50% passing 5µ from a powder feed of 50% passing 19µ was established.

Jan 1, 1975

By W. B. Devereux

The special mriditions under which gold occurs in the Potsdam formation of the Black Hills prew~lt features worthy of a more systematic pesentation than they have heretofore received. The notes

Jan 1, 1882

By U. K. Custred

To the layman, the term "strip mining" usually applies to the appearance of mined-over land after an operation is completed, not to the technique. This attitude, however, is becoming pass6 in the central Florida pebble phosphate field as eight mining companies in the area pursue a mutual program of land reclamation. The Florida phosphate industry is fortunate in this respect because it occupies an area favorable to reclamation. The terrain is flat; overburden is sand and clay which will support vegetation fairly readily; a high ground water table naturally converts mine pits into lakes. Too, this is water which readily supports marine life, not the acidic water so frequently found in the coal industry.

Jan 4, 1963

By C. Wegert, L. E. Paulson, S. A. Cooley, R. C. Ellman

The Grand Forks Energy Research Center (GFERC) and Commonwealth Edison of Chicago jointly conducted tests in which 400 tons of subbituminous and lignite coals were dried in a commercial scale dryer, oil sprayed and cooled, then shipped from Pekin, Ill., to Grand Forks, N.D., and stockpiled. Cars containing raw coal and dried coal which had not been sprayed, were also transported for comparative purposes. During transit, observations were made of changes in the coals' moisture content, dust losses, and temperature.

Jan 1, 1977

By T. Cantwell, N. C. Rasmussen, H. E. Hawkes

Beryl is a mineral that may be difficult to distinguish from quartz by casual field inspection. The easily recognized green color and hexagonal crystal form of coarse-grained beryl are by no means universal, even in beryl from pegmatitic deposits. If it occurred as a fine-grained accessory mineral in an igneous rock, it would almost certainly escape detection unless samples were submitted for petrographic or chemical analysis. There may be substantial deposits of some beryllium mineral, other than beryl, that has been overlooked because that mineral also closely resembles the common rock-forming minerals. A reliable and simple method of identifying beryllium minerals and determining the beryllium content of a rock would be helpful in exploration. This article describes preliminary experiments in applying nuclear reaction to the qualitative identification of beryl and to the semiquantitative determination of the beryllium content of rock samples.

Jan 9, 1959

By Carlos Kovacs-Figueroa

Complying with air pollution regulations created the need to dispose of increased sulfuric acid production by the Morenci smelter. As a result, a two-module leaching plant was constructed to leach Morenci flotation tailings. The leaching plant was equipped to perform the following operations: leach feed pumping, agitated leaching, two-stage countercurrent decantation, neutralization of leached tailings, and copper precipitation. Ancillary facilities were provided for neutralizer and flocculant preparation as well as precipitant handling and recovery of precipitates. Plant control is automatic from a central control panel supervised on a shift schedule by one operator and two helpers. Construction of the first module was initiated in April 1973 and leaching of tailings commenced in November 1974. Construction of the second module began in January 1975 and was completed in November 1975.

Jan 1, 1977

By D. Collins, B. Pina, G. Snell

The conversion of moisture and ash free (maf) coal to pyridine solubles and gas was investigated in a microautoclave batch reactor. Two washed Kentucky coal samples (KY # 9 and KY #11) were studied in liquefaction solvents of various donor strength. The liquefaction solvent hydrogen donor strength was varied by changing the tetralin content of a mixed 1 -methylnaphthalene-tetralin mixture. Primary liquefaction conversions in excess of 90 wt% in 10 minutes of reaction time @ 700° K (427OC or 800°F) were achieved with liquefaction solvents of moderate donor strength, i.e. 40% tetralin. A modified irreversible first order rate expression (eq. 1) described the experimental data:

Jan 1, 1986

Fred D. DeVaney (Magnetic Roasting of Iron Ores, P. 1219) has presented several other AIME papers, all of them concerned with grinding and concentrating problems. He is chief metallurgist, Pickands Mather & Co., at Hibbing Minn., after working for the U. S. Bureau of Mines at Tuscaloosa, Ala., and Rolla, Mo., as a junior metallurgist and a metallurgist. DeVaney started as a research metallurgist with Pickands Mather in 1942. He set up the first laboratory in the Lake Superior district devoted to taconite concentra¬ [ ] tion, his major interest. He has been an AIME member since 1923, holding various offices, including the first presidency of the Minnesota Section. DeVaney has a Bachelor's in Mining, and Master of Science earned at the University of Alabama in 1924. He is a member of the Engineers Club of Northern Minnesota and plays golf for relaxation and enjoyment.

Jan 1, 1952

By K. A. Natarajan, I. Iwasaki

Electrochemical measurements were made wing chalcopyrite and pyrrhotite electrodes in aqueous solution containing a xanthute collector and ground ore mineral particles. The purpose was to investigate the electrochemical reactivity of ozone with respect to dissolved xanthute, surface adsorbed xanthute, and the sulfide mineral itself. Electro-chemical evidence for the removal of xanthate coatings from chulcopyrite, pyrrhotite, and platinum surfaces by ozone is presented. The oxidizing power of ozone is compared with that of oxygen and other common oxidizing agents to portray the superiority of ozone as an oxidant.

Jan 1, 1986

By P. R. Gage, R. W. Bartlett

SILICIDE coatings on refractory metals are often applied by transporting a silicon halide vapor to a hot metal surface where dissociation or hydrogen reduction occurs. The subsequent chemical reaction to produce the coating requires diffusion of silicon or the refractory metal through the in situ silicide layer. This solid-state diffusion process step is often slower than the vapor-transport step and, therefore, rate controlling. This situation is analogous to the parabolic oxidation of metals in which the oxidation rate is controlled by diffusion through the oxide layer. The purposes of this study were to 1) measure the rate of formation of MoSiz and MoSi2 coatings under conditions such that the silicide diffusion process is rate controlling and lower silicide compounds are not formed and 2) determine by a marker experiment whether silicon or the respective refractory metals are the principal diffusing species in the disilicides.

Jan 1, 1965

By Ta M. Li

Application of an hydraulic mining system to a troublesome overburden removal project has unlocked an estimated three million tons of ore reserves at Caland Ore Co., Ltd.'s open-pit iron operation in Ontario, Canada. The mine, operated by Caland under a 99-year lease and royalty agreement with Steep Rock Iron Mines, Ltd., would have been forced to curtail its mining operations later this year as the economic limits of the original pit design were being reached. As a result of the stripping program, which uses a tandem set of Marconaflo jet slurry systems, Caland officials now estimate that mining will continue into 1977. These reserves, added to existing ore stockpiles, are expected to sustain the firm's pelletizing operation well into 1981. In addition, Caland engineers are initiating studies to continue mining since the ore body, to date, has yet to bottom out.

Jan 10, 1976

The old single-jack may have been portable- but it left much to be desired in drilling speed and depth of hole. Portable compressors for drilling can be snaked into tough spots. However, that calls for more men, equipment, and money, with corresponding loss of mobility. The drills listed in this notebook sheet meet three requirements: They are light. They are self-powered. And all are reported proven in practice. Undoubtedly there are other units filling the requirements that are not listed. Extreme mobility for far-flung exploration teams is always an acute need. The drills listed here help solve the problem. Canadian Longyear, for instance, reports that the Porta drill has been parachuted into wilderness spots and helicopters have lofted light core drills onto mesa tops in the Colorado Plateau uranium country.

Jul 1, 1955

By J. C. Holm

Although the main constituents of Portland cement are the oxides of calcium, silicon, aluminum, and iron, characteristics of the cement are seriously affected by such contaminants in the raw materials as magnesium, phosphorus, sodium, potassium, sulfur, and others of lesser importance. Sources of cement raw materials comprise a long list of minerals occurring in nature in various degrees of purity. The calcareous raw materials are generally limestone of purity varying from calcite to cement rock (a low-grade limestone of natural, almost correct chemical composition), chalk, marl, seashells, coral, and coral sand. The argillaceous raw materials supplying silicon, aluminum, and iron are mainly various forms of clay and shale, to which may be added silicious sand, iron ore, bauxite, or kaolin for minor adjustment of the chemical composition.

Jul 1, 1956

By Frederick N. Clark

These tests were made under the writer's supervision in the mining and metallurgical laboratories of the Massachusetts Institute of Technology, in the winter of 1888-89, by Mr. Robert C. Williams, of Marquette, Mich., assisted by Mr. J. B. Seager, of the

Jan 1, 1890