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By M. Ye. Shulgina, M. L. Bolotin, S. A. Prokopev, Ye. S. Prokopev

Iron ores concentration at Russia’s operations is carried out using conventional flow sheets. They comprise the two-four stage grinding followed by one-two stage magnetic separation. This results in the maximum recovery of magnetite to concentrate and the tailings generation. The final concentrate is generated only during the last stage of magnetic separation. Technologically, this flow sheet layout is not effective at recovering the liberated magnetite grains during grinding to the resulting concentrate. Advanced models of magnetic separators do not allow for the selective separation of the tailings and the portion of the resulting iron ore concentrate. Magnetic product which is the ore mixture of the liberated magnetite grains, high grade and low grade intergrowths is directed to the next grinding stage. In this case, regrinding of the liberated magnetite occurs. In addition, the performance of hydrocyclones during classification in closed grinding circuits is poor. Their classification efficiency does not provide the material separation in accordance with the size. In this case, simultaneous separation in accordance with the density occurs. The quartz particles with the size of 300 mm have similar velocity and trajectory like the particles of magnetite with the size of 60 mm. As a result, light and coarser intergrowths report to the overflow and free heavy magnetite grains report to underflow and return to regrinding (“the density effect”). This resulted in a significant increase of a mill circulating load, the decrease in the feed throughput and higher power consumption. In this connection, the development of iron ore concentrate stage recovery with the focus on gradual liberation of the intergrowths is getting much attention. Gravity concentration technique, particularly, spiral separation is effective at solving the problem of stage recovery not only the dump waste product but also high grade magnetite concentrates at the early concentration stages. This can be attributed to a significant difference in magnetite (4.9-5.2 g/cm3) and host minerals (quartz 2.7 g/cm3) densities, which is the principal during gravity concentration. The test work on concentration of various products samples from current operations (the mills discharges, concentrates from various stages of wet magnetic separation and cyclones underflows) was carried out. Spiral separators SV-500 and ShV-500 manufactured by Spirit LLC were used for the test work. High grade iron ore concentrate (69.05% Fe) was generated during primary wet magnetic separation concentrate concentration using a spiral separator. During the concentration of mills discharges the content of iron in the resulting concentrates and middlings of wet magnetic separation II stage was 64.5% and 64.6%, respectively. The recovery of iron to the concentrates of spiral separation was 33.6-42.0%. The studies presented demonstrate that by using spiral separation for iron-bearing ores concentration, you can separate magnetite liberated grains at the early concentration stages, decrease their regrinding and circulating loads in grinding circuits. This process is able to improve the overall recovery and economics of iron ores concentration process.

Jan 1, 2016

By E. Mataradze

Statistics shows that the majority of accidents with fatal outcome are caused by methane and/or coal dust explosion. This leads to assume that contemporary counter-explosion systems of various designs cannot be considered effective. Considering the growing threat of methane explosion in the coming years along with the development of deeper levels, the improvement of a system for protecting people in underground opening appears urgent. This paper presents the results of the testing of the Automatic System from Methane Explosion in Coal Mines. The protective system consists of: i) a wireless device for the detection of explosions and activation of a protective system, and ii) an absorber with a pyrotechnic device ensuring the discharge of dispersed water. The protective system, at the command of the initiation signal, produces tailored dispersing water mist with droplet sizes in the range of 25?400 ?m along selected tunnel sections.

Aug 1, 2013

By G. Barrasso

REACH was proposed by the EU Commission in October 2003 and stands for the Registration Evaluation, Authorisation and Restriction of Chemicals. It requires that all substances identified as persistent, bio-accumulative and toxic, whether the risk of those chemicals being released is real or perceived, require registration prior to them being allowed to be imported into the European Union. An internal investigation by the metals industry indicates that almost all primary raw materials streams would be classified as hazardous due to the potential health or environmental hazard properties of one or more of their ingredients. REACH uses a wide definition for chemicals and metals and as such its implications greatly impact the entire supply chain of the metals industry. The process of registration would require the producer/ importer to produce a dossier. Initiatives along the same lines as the EU REACH are also coming up in other parts of the world. REACH requires registration of at least four substances manufactured by the aluminium industry: aluminium metal, including powder, aluminium oxide, and aluminium hydroxide. The proposed legislation permits the affected companies to band together to form a consortium to develop certain aspects of the registration application. The aluminium industry has established a consortium and testing is currently underway.

Jan 1, 2006

By Shigeomi Nishigaki

This paper presents quantitative indexes to evaluate operator?s bearing, difficulty in a task, and machine operability when an operator remotely controls a backhoe, and reports the use cases. The quantitative indexes would give her/him the opportunity to reflect on her/his works, and enable us to gain in-depth insight into the teleoperation, and furthermore give us with promising hints to improve it.

Aug 1, 2013

By K. Ihara, R. Akiyoshi, Y. Takaki, S. Kang, H. Shishido

"Tensile tests and scanning electron microscopy-electron backscattered diffraction (SEM-EBSD) analysis were performed in an Al-Mg-Si alloy to clarify the effect of annealing and cold-rolling reduction on the texture formation. The hot-rolled specimens were cold-rolled with the reduction of 58-75%(CR1), followed by annealing at 773 K for 5 min(IA). The secondary cold-rolling(CR2)for the IA specimens with the reduction of 33–66%, followed by the solution heat treatment(ST), were performed. Focusing on the CR1 and CR2 specimens, the average r-values increased with higher primary and lower secondary cold-rolling reduction, respectively. This was considered to be due to the increase of r-values measured in the direction of 45 degree with respect to rolling direction, caused by the formation of the ß-fiber components (Brass {011}<211>, Copper {112}<111> and S {123}<634>) with high density. Based on the texture analysis of annealed specimens it was suggested that the high density of the ß-fiber components after IA and the small amount of stored strain energy of CR2 introduced by the lower cold-rolling reduction remained the ?-fiber components even after solution treatment.INTRODUCTION Al-Mg-Si alloys have been applied to automobile body applications, due to their excellent paint-bake hardening (age-hardening) and corrosion resistance compared to other aluminum alloy. On the other hand, the mechanical properties and deep drawability of Al-Mg-Si alloys are inferior to those of steels. Thus, it is important to improve the mechanical properties and deep drawability in order to expand the application components. One of the best methods to improve the deep drawability is to increase the Lankford coefficient (r-value). Previous studies reported that the increase of the average r-value ( ) improves the deep drawability. The relationship between the r-value and texture of the alloy is also well known. Inoue et al. reported that the ß-fiber components, such as Brass ({011}<211>), Copper ({112}<111>) and S ({123}<634>), increase the r-value measured in the direction of 45o with respect to the rolling direction. r"

Jan 1, 2018

By Kenneth Blower

This paper gives a detailed coverage of the ore flow through the primary crusher, cobbing plant and concentrator, including equipment sizes, recoveries, reagent consumptions and product descriptions. Special features, such as rubber chutes, rubber-lined mills, pebble-mill grinding, steam-hooded filters and process control instrumentation, are also discussed.

Jan 1, 1968

The 14MW SAG mill at Tarkwa, Ghana, experienced a frozen drop charge incident on 10 February 2010. This caused downtime of 112 hours, a repair cost of $200k and production loss of 162,000 tons, corresponding to a loss of $8.9M. A new locked charge protection system was installed on the two Tarkwa mills on 30 July 2010, mitigating this risk. This system calculates the ore angle in real time while the mill is starting up and trips the mill if the ore angle exceeds a trip angle setting. The calculation of the ore angle is derived from the mill motor rotor currents only - no mechanical transducers are required. The head of Gold Fields West Africa, Peter Turner, says of the new system: "This is excellent work and the type of technology that has had and will continue to have, major opportunity cost impacts on our business."

Jan 1, 2012

By J. E. McMenamin, R. B. Hall

"With the emphasis in the past decade on larger and more efficient equipment for open-pit operations, the Normandie mine of the Asbestos Corporation has followed the trend, switching from the smaller type of percussion drills to down-the-hole rigs. One 5 Y2 -in. percussion drill is still in use, but is limited to a ""smooth blasting"" role or to the control of the slope on final benches.In keeping with the times, an attempt was made to eliminate, as much as possible, the use of high explosives and to maximize the percentage of ammonium nitrate -fuel oil mixture. As the concentration of ground water increased with increased mining depths, small pumps were initially employed for the dewatering of boreholes. This proved unsuccessful, and a hole-blowing rig was built and a conversion to plastic liners made. The acquisition of a bulk-mix AN-FO truck has permitted the changeover from an AN premix to an ammonium nitrate prill -fuel oil combination at the borehole."

Jan 1, 1966

By F. Richards

"The property of the Cariboo Gold Quartz Mining Company; Limited; is in the Wells-Barkerville district of Cariboo mining division. It consists of a group of 106 Crown granted mineral claims and fractions; and extends for over 6 miles along what is termed the Barkerville gold belt. The main portal and mine camp are half a mile south of Wells; which lies at the northeast end of Jack of Clubs lake and is reached by a 55-mile motor road from Quesnel; the northern terminus of the Pacific Great Eastern railway.Gold-bearing quartz veins were discovered on the surface in various parts of the property by different prospectors as far back as 1877, but the work that led to the formation of the present company was performed by Al Sanders in the year 1926. Sanders dug trenches and drove small adits on quartz veins containing gold above what is now known as the Sanders zone. Very little underground work has been done beneath the earliest known discovery-the B.C. vein. The Cariboo Gold Quartz Mining Company was formed in the autumn of 1926. The total production of gold from its beginning in 1933 to the end of 1944 has been as follows:"

Jan 1, 1954

By Mory Ghomshei

Pebble Creek Geothermal Power project is associated with a massive recent volcanic eruption in Southwestern British Columbia Canada. Slim holes drilled to depths 1100 m in the prospect area, show very high temperature gradients around 80?100?C/km. The temperature and chemistry of the Pebble Creek hot springs indicate the possibility of a steam reservoir in the prospect area. In addition to high temperature gradients, presence of host rocks with high permeability, along with abundance of recharge waters (from the Lillooet River) provides clear signature of a high-grade geothermal power reservoir at depth 2000 to 3000 m. Data show that over five hundred Megawatt of green power can be generated from the prospect area in a commercially viable manner. The generated power will be base-load, which in comparison with large hydro has the advantage of lower capital costs and a significantly smaller footprint. The final hurdle to overcome, before starting the development phase, is deep exploratory drilling for resource confirmation. This paper is a summary of the data available on the Pebble Creek geothermal power prospect, presented in the context of viability of the resource for large-scale commercial power generation.

Aug 1, 2013

By Joseph F. Daniels

In recent considerations of the utilization and beneficiation of coal, the chemise and the chemical engineer have been occupying the centre of the stage with their presentation of the picture of new fuel forms. The stage hands and supernumeraries of the cast, the miners and the consumers who carry the brunt of the present-day burdens, are apt to be forgotten in the glorious settings and the climaxes. With no thought of disparaging or of minimizing the efforts of our fellow scientists, let us remember that economic considerations as well as technical difficulties will limit these chemical applications, which must develop and move slowly before reaching the stage of industrial application at some later day. In the meantime, the coal-mining industry must live on hard faces rather than rosy dreams. In these brief notes it is my purpose to call attention to some of the physical advances in the utilization and beneficiation of coal which have been of interest to the industry in the State of Washington.

Jan 1, 1928

By John F. Gartner

"Traditionally, the geologists of Canada have been occupied with the tasks of finding new mineral bodies, locating gas and oil fields or hunting for economic deposits of industrial minerals. A very minor percentage of graduate geologists have applied their skills to solution of the ""urban blight"" or employing their understanding of ""Nature"" for the optimum use of land by mankind. However, things are changing quickly. The role of the geologist in the planning process is being established. It is an exciting time! Geologists are now being consulted on a wide range of urban planning problems. These vary, tor example, from assessment of the geological environment for the new communities of Erin Mills and Meadowvale, which will have total populations in excess of 100,000 people (truly a satellite city), to a complete geological/ geohydrological assessment of the new sanitary landfill for the city of Guelph.Use of geologic techniques and methods for urban studies must be enhanced with certain skills not taught, in the past, to the geologist. These include airphoto interpretation, soil mechanics, geohydrology, municipal engineering and highway engineering to mention a few. The geologist has the unique training to assess the natural environment and to discover, warn and explain the implications of man's attempt to command his environment."

Jan 1, 1972

By C. W. MacLeod

LOCATION The Goudreau gold area in Ontario extends from a point a short distance south of the main line of the Canadian Pacific railway, at Lochalsh, in a south-westerly direction to the Magpie river. It crosses the Algoma Central & Hudson&apos;s Bay railway at Goudreau station, 177 miles north of Sault Ste. Marie. The area is roughly 25 miles in length by 6 miles in width. The potential gold formation is much more extensive but little prospecting has been done outside of the limits mentioned. The actual continuous area of Keewatin formation, in which gold has been found, is one of the largest in Ontario. ACCESSIBILITY Probably no mining area in a similar stage of development has had the excellent transportation facilities which Goudreau enjoys. This field is traversed in part by the main lines of the Canadian Pacific and Algoma Central railways. The Provincial Government has constructed 22 miles of road through the heart of the camp. Sixteen miles of this road is suitable for motor car traffic and several cars and trucks are in constant service.

Jan 1, 1926

By George Langford

Introduction The manufacture of ductile beryllium is one of the most interesting problems confronting the metallurgist today, and one which becomes more acutely in need of resolution as the uses for beryllium increase. Beryllium belongs to the hexagonal group of metals along with zinc, magnesium, and cadmium. The melting point of the metal is about l,280°C. ± 5°C. Due to its brittleness, the metal&apos;s chief use is as an alloying agent in copper and iron. The very low absorption coefficient of beryllium for x-rays makes the metal ideal for x-ray windows, and, similarly, because of its low capture cross-section for neutrons, the metal holds a preferred position in the field of nuclear physics. Modern x-ray diffraction methods were responsible for explaining the mechanism whereby zinc metal, although brittle when cast, could be made ductile at room temperature. The diffraction patterns of zinc and magnesium indicated the importance of the parts played by recrystallization and preferred orientation in this mechanism. It was with this in mind that an Investigation into the recrystallization and preferred orientation of beryllium was undertaken. The investigation, after a series of experiments were conducted involving cold-working and annealing, yielded the recrystallization temperature curve for beryllium. Both the texture of preferred orientation and the effect of recrystallization on this texture when subjected to compressive stresses were also determined. W. A. Alexander, J. K. Swinton and L. M. Pidgeon, in their investigation on The Recrystallization Temperature of Beryllium (C.I.M., Trans., Vol. L, 1947, pp. 657-664), utilized the Brinell ball as a means of cold straining the metal. Sufficient strain was developed to estimate the recrystallization curve for the metal. However, in order to determine the lowest recrystallization curve, as well as to develop a preferred orientation structure, larger deformation than that possible with a Brinell ball was required. The plastic deformation of beryllium can be carried out at an elevated temperature above 700°C. Above 850°C., the metal is quite ductile and can be readily compressed or extruded.

Jan 1, 1948

By Rhual L. Guerguerian

MINING has been practised by mankind for over sixty centuries (1). In 1876, the "ball mill" was patented, and during the century that followed rotary grinding developed to the state where individual machines are treating tens of thousands of tons of ore per day. This paper gives a brief description of design practices prior to the availability of advanced facilities, followed by modern analytical design development at Dominion over the past ten years.

Jan 1, 1978

By Ronald B. DeDiemar

This paper will present the intrinsic factors of a cone crusher that affect performance, develop and define an ideal feed gradation for a cone crusher and, finally, bring out an important new development in computer design of crushing chambers and show an ability to predict crusher performance without trial-and-error methods.

Jan 1, 1979

By R. J. Fruehan

Oxygen steelmaking (OSM) is not only the dominant steelmaking process but defines the structure of the industry. There are a number of myths regarding the future of OSM, which are false. These myths include that the EAF will become the dominant process in the near future, it is less costly to produce steel in an EAF and OSM is a mature technology and no new developments are occurring. These myths are shown to be false. Selected new developments are discussed such as post combustion, recycling of waste oxides, slag splashing and sensors.

Jan 1, 2004

1. Scientific prospecting has had a profound and some-what unexpected effect on the world&apos;s supply of raw materials over the past twenty years. Where shortages were recently anticipated, abundance now prevails. It seems probable that, for the foreseeable future, adequate metallic resources will be found at costs well within the world&apos;s economic means. 2. The amount of research devoted to scientific prospecting has been extremely small in relation to the possible importance of the problem and to what could be done. It has been dominated by the thought of a dozen brilliant men, and true research expenditures have not amounted to more than a few million dollars. 3. An undue proportion of the expenditures have been for so-called geological research -mostly of a petrologial character. The results have essentially been of historic interest only. However, there has been some in-crease in genetic understanding, and this is of great importance for future resources. 4. Basic advances in mineral exploration have been made in detection techniques, generally called geophysics and geochemistry.

Jan 1, 1964

By C. J. Sullivan

Many metalliferous ?provinces are co-extensive with particular groups of sedimentary, volcanic, or :basic plutonic rocks. Deposits may be truly syngenetic (Rand, Rhodesia-Katanga, Mans-field, Blind River, White Pine); re-. concentrated by circulating waters (Colorado Plateau, Red Bed Coppers) ; or re-concentrated thermally during metamorphism and granitization (most uranium and lead-zinc provinces ?and some copper and gold provinces). Basalts may yield important cop-per provinces when folded and re-heated. Granitization of basalts which have not reached the chlorite-carbon-ate phase of metamorphism may produce copper provinces. If they reach ?the chlorite-carbonate stage, granitization may result in a gold province. Copper and copper-nickel provinces may result if gabbros are granitized, and a ?similar alteration of per-idotite may result in asbestos or nickel ores. Many similar associations are known. Granite is not a source of ore, but a result of heat. A classification of ?ore with respect to source rocks is of greater prospecting value than are classifications based on magmatic differentiation and hydrother-mal solution theories. Volcanic centres are important ore foci because the thermally unstable metallic sulphides may be concentrated here by a distillation process. The ores found in the hot spring deposits, viz., mercury, mercury sulphide, sulphur, and the compounds of ?antimony and arsenic, are not those which are soluble in water at low temperature (epithermal sub-division of hydrothermal class), abrut those which are unstable thermally at comparatively low temperatures . Water is one of the most common thermally unstable minerals, and generally accompanies the thermally activated ore-forming sulphides.

Jan 1, 1957

By M. Ye. Shulgina, M. L. Bolotin, S. A. Prokopev, Ye. S. Prokopev

Iron ores concentration at Russia’s operations is carried out using conventional flow sheets. They comprise the two-four stage grinding followed by one-two stage magnetic separation. This results in the maximum recovery of magnetite to concentrate and the tailings generation. The final concentrate is generated only during the last stage of magnetic separation. Technologically, this flow sheet layout is not effective at recovering the liberated magnetite grains during grinding to the resulting concentrate. Advanced models of magnetic separators do not allow for the selective separation of the tailings and the portion of the resulting iron ore concentrate. Magnetic product which is the ore mixture of the liberated magnetite grains, high grade and low grade intergrowths is directed to the next grinding stage. In this case, regrinding of the liberated magnetite occurs. In addition, the performance of hydrocyclones during classification in closed grinding circuits is poor. Their classification efficiency does not provide the material separation in accordance with the size. In this case, simultaneous separation in accordance with the density occurs. The quartz particles with the size of 300 mm have similar velocity and trajectory like the particles of magnetite with the size of 60 mm. As a result, light and coarser intergrowths report to the overflow and free heavy magnetite grains report to underflow and return to regrinding (“the density effect”). This resulted in a significant increase of a mill circulating load, the decrease in the feed throughput and higher power consumption. In this connection, the development of iron ore concentrate stage recovery with the focus on gradual liberation of the intergrowths is getting much attention. Gravity concentration technique, particularly, spiral separation is effective at solving the problem of stage recovery not only the dump waste product but also high grade magnetite concentrates at the early concentration stages. This can be attributed to a significant difference in magnetite (4.9-5.2 g/cm3) and host minerals (quartz 2.7 g/cm3) densities, which is the principal during gravity concentration. The test work on concentration of various products samples from current operations (the mills discharges, concentrates from various stages of wet magnetic separation and cyclones underflows) was carried out. Spiral separators SV- 500 and ShV-500 manufactured by Spirit LLC were used for the test work. High grade iron ore concentrate (69.05% Fe) was generated during primary wet magnetic separation concentrate concentration using a spiral separator. During the concentration of mills discharges the content of iron in the resulting concentrates and middlings of wet magnetic separation II stage was 64.5% and 64.6%, respectively. The recovery of iron to the concentrates of spiral separation was 33.6-42.0%. The studies presented demonstrate that by using spiral separation for iron-bearing ores concentration, you can separate magnetite liberated grains at the early concentration stages, decrease their regrinding and circulating loads in grinding circuits. This process is able to improve the overall recovery and economics of iron ores concentration process.

Jan 1, 2016