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By Hans Lundberg

Introduction Today, geophysical exploration is recognized as a special science wedged between geology and mining. Universities and technical institutes have special professors teaching geophysics applied to oil and ore prospecting. The list of literature on geophysical exploration has grown from practically nothing at all some twenty-five years ago to ~ several thousands of books, some of them very imposing volumes. Most of the methods now used have been developed since the first World War, and very large systematic exploration campaigns have been carried out in many places, in many countries. It has been rather difficult to obtain enough information as to what is going on in Canada. However, since the Associate Committee on Geodesy and Geophysics of the National Research Council became more actively engaged in promoting geophysical research, it may be easier to obtain information and, in the future, the quarterly issued Canadian Geophysical Bulletin may throw considerable light on the current geophysical activities in Canada. Some twenty crews have been engaged the last few years in geophysical prospecting for ore. In the United States, between 500 and 600 crews are employed exclusively in geophysical prospecting. Most of these, however, are engaged in oil exploration. During the winter 1942-1943, the German Government employed some fifty crews on geophysical exploration, and some ten crews were working for private enterprises.

Jan 1, 1948

By L. Gutierrez, M. Pawlik

The rheology artificial mixtures of bitumen with fine quartz of varying bitumen content, as well as actual oil sand ores, was investigated under different physicochemical conditions (pH, temperature). All rheological measurements were conducted using a Haake Rotovisco VT550 rotational viscometer, connected to a fixture specifically designed to measure properties of settling suspensions. It was found that at low bitumen contents (1 %, wt.) the pH of the slurries was the most important parameter that controlled the rheology of quartz-bitumen slurries. At higher bitumen contents (10%, wt.), it was a combination of high temperature and high pH that gave the lowest apparent viscosities and yield stresses of the model mixtures. These model observations correlated well with the rheology data obtained for slurries of actual oil sand ores. The overall results were discussed in terms of aggregation-dispersion phenomena between bitumen and mineral particles.

Jan 1, 2009

By S. Avalos, J. M. Ortiz, W. Kracht

Semi-autogenous grinding mills are intensive energy consumers. Current models base their energy consumption inference on operational variables and feeding ore characterization. While they provide adequate design guidelines, they are not suitable for real-time energy forecasting dealing with gaps in operational dataset and up/downstream process bottlenecks. This work explores the capability of Gated Recurrent Units to learn the semi-autogenous grinding mill consumption behaviour. Gated Recurrent Units are trained to forecast different time-support consumptions under a time-series operational dataset. The results show high performance on small supports (30 minutes) to capture local variability and long-trends while larger time supports (8 hours) can only capture time-trends but not local variability. The proposed technique seems promising for further research and implementation on real mine cases since the input variables are low-cost and easy to obtain. INTRODUCTION Current changes in the Chilean energy matrix (Román-Collado, Ordoñez, & Mundaca, 2018), from fossil fuels to renewable energies, have impacted different industries and particularly the mining sector. Solar energy incorporation into greenfield/brownfield projects will help reducing costs and will lead to rethink foundational paradigms (production and processing strategies) (Pamparana et al., 2017). Also, integration of new space-time predicting tools together with automated real-time updating models are some of the main challenges in the geometallurgical framework (Ortiz et al., 2015; van den Boogaart & Tolosana-Delgado, 2018). Those contexts encourage and demand the development of tools capable of predicting the energy consumed by mining systems, being comminution the greatest energy consumer with an average close to 50% of the entire mine consumption (Cochilco, 2013). In comminution, the semi-autogenous grinding mill (SAG) represents the largest energy consumer (~10 nominal each SAG). Theoretical and empirical energy consumption models (Jnr & Morrell, 1995; Morrell, 2004; Silva & Casali, 2015) base their inferences mainly on feed/product size distributions, SAG sizing, bearing pressure, feed hardness, water addition and grinding charge level, and commonly assume steady-state and work isolated from up and downstream processes. While those techniques provide adequate design guidelines, they are not suitable to predict hourly, daily or even weekly energy consumptions on interconnected comminution circuits where upstream/downstream bottlenecks lead SAGs to operate below designed regimes. Forecasting energy consumption is required by short-term energy management, medium and long-term planning energy consumption, designing the nominal capacity of renewable energy sources, among other. Also, when models are input-sensitive and some of those input measurements are expensive and/or time consuming, model robustness suffers when real-time predictions are required.

Jan 1, 2019

By S. U. Baltuch, E. G. Baltuch

"Ventilation in process buildings is key to proper mill function. Correctly engineered systems to evacuate surplus thermal energy from process areas allow optimized rates of air change, thus assuring the good functioning for the lifecycle of the process while demonstrating conformity with occupational hygiene standards. Computational fluid dynamic simulations, coupled with traditional calculations and physical modeling, can demonstrate to end users and assist engineers in the optimization of mill ventilation, reducing total installation costs while assuring that the proper solution is in place for the complete lifecycle of the process equipment. Results have been fully implemented on a number of steel mill and aluminium smelter applications and we continue to study, optimize, and innovate as new tools become available to provide the best possible engineered solutions for particular applications. INTRODUCTIONThe objective of this research project is the development and implementation of modern approaches and computational fluid dynamics (CFD) simulation in the engineering of green ventilation of hot process buildings. This will assure the predictive performance and improve the quality and ease of construction of industrial gravity ventilation equipment, along with the adjunct hot process buildings, while lowering the overall project costs and time to completion.In order for a hot process building, such as a steel mill, to properly function, heat must be extracted from within. This is accomplished by having air inlets at the bottom of the building and outlets at its apex. The reason for this is to maximize the potential chimney effect. When using stack (buoyancy) effect ventilation, the process heat becomes the driver. Therefore, increasing this distance (height) improves the ability of the heated airstream to utilize basic gravity for acceleration of the heat/air flow, allowing a regular number of air changes per hour while ensuring that the process environment remains weather resistant under normal operating conditions.This process has been understood since the time of King Charles I of England, who decreed in 1600 that buildings should have 10 foot ceilings and that windows should be made taller rather than wider to allow better smoke extraction.Figure 1 is a painting of the Bethlehem Steel Works in the 1860s, where the concept of air inlets and penthouses on the roofs for air outlet was already being put into practice. Figure 2 is an early photograph of the Pittsburgh Steel Works."

Jan 1, 2012

By N. Aslin, G. Heferen, H. DeWaal

"Mount Isa Mines (MIM) acquired a reputation for the successful application of R&D to develop break-through technologies for the mining industry starting in the 1978’s through until the early 2000’s. The ISAPROCESSTM tank-house technology has been licensed to copper refineries throughout the world, and a significant per cent of the world’s copper is refined using this technology. Since development in the late 1980’s more than 20 ISASMELTTM copper and lead smelting furnaces are now installed in countries around the world. Jameson Cell flotation technology developed jointly by Mount Isa Mines and Professor Graeme Jameson is widely used in the Australian coal mining industry and increasingly in the base-metal and gold industry. The IsaMillTM’s developed at Mount Isa and McArthur River made it possible to develop the McArthur River and George Fisher orebodies and has been successfully implemented into base metal fine grinding applications around the world. The most recent commercialised innovation is the atmospheric leach Albion ProcessTM with its supersonic HyperSpargeTM gas sparger, is being adopted as a solution to the increasing complexity of orebodies. MIM’s contribution to the industry was significant given the size and the remote location of its operations with Townsville Copper Refineries more than 1350 km and Mount Isa 1800 km from the nearest state capital of Brisbane. This paper will briefly discuss the development of each of these technologies and why MIM – now owned by Glencore - was so successful innovating and developing such technologies over a period of nearly 40 years.INTRODUCTION Mount Isa is located in the Gulf Country region of Queensland about 1800 kilometers North West of Brisbane (see Figure 1). It came into existence because of the world class mineral deposits found in the area. In 1923 the orebody containing lead, zinc and silver was discovered by the miner John Campbell Miles. Mount Isa Mines Limited (MIM) was founded in 1924 to develop the minerals discovered by Miles, but production did not begin until May 1931. It paid its first dividend in 1947 after 16 years of troubled production. In 1954 the 1100 copper orebody was discovered and with rapidly rising reserves during the 1950’s and 1960’s led to the construction of new concentrators to treat lead/zinc/silver ores in 1966 (#2 concentrator) and copper ore’s in 1973 (#4 concentrator). The difficult nature of the Mount Isa lead-zinc orebodies has meant that the company had always needed to be at the forefront of mining technology. In the 1970’s through to the 1990’s, it became a world leader in developing new mining techniques and processing technologies as a response to declining metal prices and rising costs. Mount Isa has been smelting copper since 1953 and lead since the early 1930’s. Copper Refining at Mount Isa’s fully owned subsidiary of Copper Refineries Proprietary Limited (CRL) had commenced operations in 1959."

Jan 1, 2018

By P. Mottahed, J. Ran

Mining practice and research have shown that the jointed roof in stratified rock behaves like a voussoir beam structure with strength greater than that determined by the continuous beam theory. Previous studies have demonstrated the voussoir beam mechanism and developed methods to estimate the crushing and buckling strength of voussoir beams. However, research on voussoir beams with multiple mid joints has not been suffICient and problems such as the voussoir beam support and applications of the voussoir beam mechanism to the mining environment have not been addressed. In this paper, mechanism of voussoir beams containing multiple mid joints and truss support are studied and applications of the voussoir beam mechanism to underground mine openings are discussed based on the numerical and experimental results.

Jan 1, 1995

By Jinsuo Zhang

Investment in coal resource development is affected by a variety of uncertain factors. Investors can make a flexible, strategic decision to achieve the value of risk implicated in those uncertain factors. Therefore, based on real-option theory, we identified key uncertain factors that affect a coal resource investment project, and revealed the formation mechanism of option value in coal resource developing investment project. Then, a multi-factor decision making model was established for a coal resource development investment project with random changes of coal price, interest rate, convenience yield and production cost. Finally, we tested the model and analyzed relevant parameters by applying living data. Our results indicate this model reflects the value of risk implicated in uncertain factors for coal resource development investment, and is able to determine a critical point of decision making change when coal price and production cost varym respectively. By means of parameters analysis, the convenience yield has a positive effect on the project value. The interest rate has a negative effect.

Aug 1, 2013

By C. K. Wilton

"The Agnew Lake uranium deposits were discovered in 1953 following the discovery of the Elliot Lake deposits to the west. The original property was optioned to Kerr Addison Mines Limited who added additional claims by staking. Agnew Lake Mines Limited was incorporated in 1967 to develop the property and a shaft was sunk to 1040 metres and five levels developed before work was suspended due to low uranium prices at the end of1970.In 1974-75 the mine was dewatered and production started in 1977. By 1978 reserves were estimated at 10,000,000 tonnes averaging 0.35 kg. U10 , per tonne. Underground operations were terminated in 1980 although a uranium leaching operation was continued until early 1983.The deposits lie near the contact of Huronian metasediments with underlying Algoman granite. The sediments consist of arkose, conglomerate, argillite and quartzite with the uranium mineralogy mainly confined to oligomictic quartz pebble conglomerate. The higher uranium values are related to conglomerate with highest percentage of pebbles. The chief uranium minerals are uranothorite and monazite. It is of interest that the uranium thorium ratio differs appreciably from that of the Elliot Lake deposits. This fact along with the fact that the Elliot Lake sediments were deposited by paleocurrents from the northwest whereas the Agnew Lake sediments were deposited by paleocurrents from the northeast indicates widely separate sources for the deposits. It is suggested that the Agnew Lake uranium deposits are syngenetic placers deposited under anoxygenic atmospheric conditions."

Jan 1, 1986

By J. E. Lee

"This paper describes the current practices and experiences, and discusses design parameters concerning slurry pumping at Inco Metals Company in the Sudbury District. It deals mainly with the long tailing and concentrate lines. Subject matter is arranged under the following headings: pumps, lines, instrumentation, system design, operation.IntroductionThe Inco Metals Company is the mining and processing section of INCO LIMITED. In the Ontario Division, it operates 13 mines, 5 mills, a smelter, an iron ore plant and 3 refineries, all engaged in the mining and recovery of nickel and copper. This paper describes the slurry pumping practices in the mills of the Ontario Division.The PumpsWe have in our Sudbury area mills most of the available types of slurry pumps, in sizes from one inch up to twelve inches, a total of about 400 pumps. The rubber-lined, horizontal shaft pump is; most numerous. However, for certain applications, the hard-metal pump is essential, and is becoming more popular for general mill service. Two types of vertical shaft pumps are used. There are a few diaphragm pumps on small thickeners, but the larger thickeners have centrifugal pumps either directly connected to the under-flow or with one pump handling several gravity underflows. We have not used piston or plunger pumps in our mills."

Jan 1, 1978

By Derek H. C. Wilton

"The Nain Province (NP) of northern Labrador is a >600 km long by =100 km wide Archean craton that has undergone relatively little mineral exploration until economically signifcant concentrations of orthomagmatic nickel sulphide were discovered by Diamond Fields Resources (DFR) at Voisey’s Bay. Due to the great time span between crust formation andfnal intrusive activity (ca. 3.9 Ga to 1.27 Ga),there were, however, numerous metallogenic events within the NP.The NP was intruded by the ca. 1.3 Ga to1.2 Ga Nain Plutonic Suite (NPS) composite anorthosite-granite complex. The NPS dividesthe NP into the southern Hopedale Block (90 km by 150 km) and the northern SaglekBlock (375 km long by =50 km wide). These two blocks appear to represent two distinct Archean cratonic nuclei, each with its own distinct metallogenic history. The NPS is a coalesced assemblage of composite intrusions which include anorthosite, troctolite, norite, gabbro and granite.The Hopedale Block contains the Hunt River and Florence Lake greenstone belts, and the Weekes Amphibolite which represents remnantsf the older Hunt River greenstone belt. Geologically, these belts have some potential to host komatiitic Kambalda-style nickel, volcanogenic massive sulphide (VMS) and meso -thermal lode gold mineralization. The unconformity between Paleoproterozoic cover sequences and the trondhjemite-tonalite-granodiorite (TTG)suite which engulfed the greenstones was the locus for lead-zinc-bearing quartz-carbonate veins. Minor fracture-hosted uraninite showings are also present in the TTG.The Saglek Block is a high-grade gneissterrane with deformed Archean supracrustal sequences but no greenstone belts. Within the gneiss are variably-sized enclaves that range in composition from anorthositic to ultramafic; some of these latter xenoliths contain abun-dant fuchsite. There are also three small anorthositic to ultramafic meta-igneous complexes present in the gneiss near Okak Bay.Some Archean meta sedimentary and maficgneiss supracrustal sequences contain iron-oxide and sulphide members. The sulphide-bearing Tasiuyak parag neiss defines the cra-tonic suture between the NP and Churchill(Rae) Province. Along the cratonic suture between the NP and Churchill Province from Ramah Bay north are remnants of the Archean(or Paleoproterozoic) Hutton Anortho site Suite. Ultramafc layers within the suite contain chromite and elevated Ni values.Three ca. 2.0 Ga supracrustal sequenceswere deposited in small fault-bounded basins within the NP. The Snyder Group contains pyrrhotitiferous massive sulphide horizons. TheMugford Group contains SEDEX-like massive sulphide blocks in a debris fow and ultramafic sills with unusual PGE concentrations; alaskitic granite cutting basement gneiss to the group contains stockwork-like pyritiferous quartz veins. The Ramah Group contains numerous MVT-style zinc-lead sulphide occurrences.The Reid Brook Intrusion of the NPS contains enormous and high-grade nickel-copper-cobalt massive sulphide bodies at the Voisey’s Bay deposit. Exploration in the northern portions of the NPS in 1995 has indicated the presence of other potentially economic nickel sulphide horizons."

Jan 1, 1996

By Jaroslaw W. Drelich

Despite the success of DLVO and extended-DLVO models that have been developed for homogeneous and smooth surfaces, a vast majority of practical surfaces encountered in mineral ore beneficiation are typically rough at various scales; they are also typically heterogeneous. The interactions of gas bubbles with particles having rough and heterogeneous surfaces are much more complex than the commonly used DLVO or extended-DLVO models predict. The effects of surface roughness on flotation and colloidal interactions have been reported many times in the past, although a clear understanding of their origins has been lacking. To explain differences in colloidal interactions for spherical hydrophobic particles, a theoretical analysis of the interaction potential was carried out for a model rough particle interacting with a bubble surface in an electrolyte solution in this study. The attractive hydrophobic interaction potential was added to repulsive retarded van der Waals and repulsive electrical double layer interaction potentials. The rough microscopic particles were modeled as spheres decorated with nano-sized asperities. Parameters that reflect common flotation separation systems were selected for testing this theoretical model and computation of the energy barrier applicable to particle – flat bubble surface interactions. It was found that hydrophobic asperities with the height of only several nanometers can reduce the repulsive interaction energy by an order of magnitude. Theoretical analysis also reveals that surface coverage of microscopic particles by nano-sized asperities is important as well. The findings of this research suggest that manipulating and engineering the particle surface topography could lead to better control over flotation separation.

Jan 1, 2016

By Yvon T. Maurice

Under the auspices of the Federal-Provincial Uranium Reconnaissance Program, a geochemical orientation survey was undertaken in an area of uraniferous Lower Proterozoic (Aphebian) rocks near Cape Dorset in southwest Baffin Island. The main objective of this study was to establish a methodology for a future reconnaissance geochemical program using lake samples over a 300-mile Lower Proterozoic rock belt that occurs along the southern coast of Baffin Island. Mineralogical and chemical studies of known radioactive occurrences, combined with detailed sampling of secondary environment media in the vicinity of the showings. indicate that uranium is the most significant pathfinder, despite considerable enrichment of other metals in the uraniferous rocks, Significant geochemical patterns produced by uranium in lake waters and uranium in lake sediments have been obtained, but their relative usefulness depends on the distribution of carbonate bedrock, which in turn affect the bicarbonate content of lake waters. In southern Baffin Island, because of erratic variation in lake-water alkalinity, it is recommended that both water s and sediments be sampled on a routine basis. The need for lake-water acidification to prevent depletion of soluble metal ions in samples resulting from adsorption on the walls of the containers and/or suspended solid matter is discussed briefly. The base metal potential of the area was examined in some detail and found to be significant, particularly for a Lower Proterozoic gossanous formation that occurs throughout southern Baffin Island.

Jan 1, 1977

By Laxman M. Amaratunga

Laboratocy flarmnability tests were perfonned on dust samples from Fraser Mine in a 1.2 L Lindenburg horizontal tube furnace to detennine the percentage of sulphur oxidized during ignition. The explosion pot ential of sulphide dusts depends on their degree of spontaneous oxidat ion, which was measured by the quantitative analysis of so2 gas released during ignition. Test results indicated that dusts with low sulphur content could exhibit a higher degree of oxidation than a sample with high sulphur content. txlst characterisation using image analysis techniques suggests that the structure and the texture of dust are important factors influencing the explosibility of sulphide dust at ignition temperatures. Therefore for safe mine operations% sulphur content cannot be considered as a reliable single index that could be used to predict the potential of a sulphide dust explosion. Physical, chemical and mineralogical characterisation of dust plays an important role in the detennination of suitable indices for the prediction and prevention of sulphide ore dust explosions.

May 11, 1988

By A. J. Oliver, C. E. O’Neil, I. J. Itzkovitch, V. A. Ettel

A new solvent extraction process for the separation of cobalt, copper and zinc from nickel sulphate process streams has been developed. It involves selective extraction of these elements with a quaternary ammonium thiocyanate dissolved in an aromatic diluent. The chemical principles of this process have been investigated and are described, together with background physico-chemical data relating to the use of this solvent. Long-term testing in a continuous "mini-plant" circuit gave high-purity nickel and cobalt products (Ni/Co —200011 and Co/Ni ~1000/1 respectively).

Jan 1, 1976

By J. E. Dutrizac

Mercury balances have been obtained for the flotation circuits at Pamour Porcupine Mines, Timmins, Ontario, and at Brunswick Mining and Smelting Corporation, Bathurst, New Brunswick. The mineral form of mercury in both deposits has been ascertained. At Pamour Porcupine, the mercury is approximately evenly divided among sphalerite, native silverelectrum and tetrahedrite-tennantite; at Brunswick Mining, this element is contained mostly in the sphalerite, although tetrahedrite (and possibly pyrite) also contains minor quantities.

Jan 1, 1979

By D. J. McCulla

Mineral development and utilization affect the health of the economy and the pattern of long-term development throughout Canada. There are many diverse opinions on the contribution of minerals to the economy, but there is a dearth of adequate quantitative information. This paper discusses some recent research and provides some new information.

Jan 1, 1977

By J. D. Little

"THE SALMO PROPERTIES of Canadian Exploration, Limited comprise forty-one Crown-granted mineral claims situated on Iron mountain between Sheep creek (on the north) and Lost creek, some eight miles southward from Salmo, in the Nelson mining division (see Figure 1). On these claims there are at present four operating mines. These are, from north to south, the Dodger, Feeney, and Emerald, all tungsten mines, and the Jersey, a lead-zinc mine, about 7,000 feet south of the Dodger. About midway between the Dodger and the Jersey is a fifth mine, the Emerald lead-zinc mine, which was the first producer in the area but has been inactive since 1926. The locations of the mines are shown in Figure 2.Records of prospecting and claim staking on Iron mountain -which owes its name to the presence of large iron-stained outcrops -go back to 1895. The first recorded owner of the claims that form the old Emerald lead-zinc mine was John Waldbeser who, in 1908, did considerable work and produced 426 tons of lead ore valued, at the then price of lead, at $7,000. This ore was chiefly lead carbonate and was taken from the surface outcrops of two bands of ore that form the Emerald orebodies. In 1909, the Emerald was the largest lead producer in the Nelson mining district."

Jan 1, 1953

By Curtis Rempel, John Bartlett, Alex Holtzapple

METSIM is a powerful program capable of modelling and simulating every known metallurgical and inorganic chemical process. METSIM is used by companies throughout the world to design, simulate and control operations from mine to tailings and everything in between. At its absolute simplest, METSIM can be used to create a process flowsheet. METSIM modules and built-in unit operations cover mass and energy balances for either steady-state or dynamic simulations of mine, stockpile, heap leach, material handling, comminution, beneficiation, hydrometallurgy, pyrometallurgy, gas and steam handling, and tailings management processes. Data for the material being processed can include mineralogy, particle size analysis, grade by size or multicomponent size analysis, washability data, mechanical, physical and thermodynamic properties. METSIM is written in APL (A Programming Language). Unlike C++, APL is simple and easy to learn, allowing the user to program whatever they can imagine, without first obtaining a degree in computer science. METSIM can also interface with EXCEL and other software through dynamic data exchange (DDE), allowing data to be imported and exported for viewing, analyzing and controlling. METSIM can answer simple or complex metallurgical and process questions allowing the user to predict and engineer without the issues of clumsy and tortuous spreadsheets.

Jan 1, 2014

By P. Condori, G. Rech, J. Winnett

"Palabora Mining Copper has a unique ore body composition which unlike other copper ore bodies has three main components in significant proportions; these are copper bearing ore, magnetite and dolerite. The high content of dolerite, a hard barren material, creates a high proportion of pebbles which normally are recycled back to the mill. This action increases the mill bearing pressure and power progressively until corrective actions are taken.A logical action to solve the pebbles generation would be to incorporate a pebble crusher. This in fact was done however two fundamental issues were encountered; the high content of magnetite and existence of a cyclone classification section. Due to the high content of magnetite, metal detectors have not been able to work efficiently to separate tramp metal which causes damage to the pebble crushers. The existence of cyclones in the circuit had a detrimental effect on the final product when the pebbles crusher was online producing coarse sandy material.Due to the difficulties in treating pebbles via conventional procedures and the unique Palabora ore composition and characteristics, sorting technology was investigated at laboratory and pilot scale. It was found that a combination of optical and electromagnetic sorting could efficiently separate dolerite from the copper bearing and magnetite ores.This paper reports the findings of the laboratory and pilot scale work performed and discusses the additional benefits to the circuit."

Jan 1, 2012

The tensile test results of as-cast A356.2 grain-refined alloy castings show that the tensile strength can be improved by strontium modification (`SrM'), superheating at 900°C OM, and melt thermal treatment of the Sr-modified alloy melt (`SrMTT'). Both SrM and SrMTT processes can greatly improve the ductility (percent elongation) of the as-cast alloy. During solution heat treatment at 540°C, eutectic Si particles undergo fragmentation, spheroidization, and coarsening, thereby affecting their morphology. The effects of solution heat treatment on the tensile properties of the variously treated A356.2 alloy castings can be summed up as follows: the yield strength of the castings is significantly improved after 8 h solution heat treatment due to the precipitation of Mg2Si, after which it remains more or less the same with the further increase in solution treatment time up to 80 h; the ultimate tensile strength is also greatly improved within the first 8 h of solution heat treatment and then remains at the same level thereafter, up to 80h of solution treatment. The improvement in UTS is attributed to Mg2Si precipitation, dissolution of Si within the aluminum matrix, and changes in the Si particle morphology (spheroidization). The ductility of the as-received grain refined non-modified (`NM'), grain refined and superheated at 900°C (`SH'), and melt thermal-treated grain refined (`MTT') A356.2 alloy castings can be improved considerably with solution heat treatment e.g. from ~6% in the as-cast non-modified casting to ~10% after 80 h solution treatment.

Jan 1, 2011