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By D Anonby

The Fox Pit at EKATI Diamond Mine is designed with 11 m wide benches excavated using a double benching technique leaving 30 m high faces. Blasting tests were conducted to increase the percentage of benches that meet an 11 m catch width. The subdrill depth for the lower bench trim blasts and the blasthole diameter for the upper bench trim blasts were reduced to maintain the bench crests. Raising the lower trim blastholes by 0.5 m decreases the depth of broken rock below the final bench elevation, and consequently reduces damage to rock that forms the bench crest below. The use of smaller diameter (165 mm vs. 270 mm) blastholes in the A and B rows for the upper trim blast reduces the charge per delay during detonation, reduces the powder factor slightly, and reduces the energy affecting the final pit wall and crest.

Jan 1, 2007

By C. Anderson, Mike Michaelis

Ammonium Nitrate (AN) - based commercial explosives are non-ideal explosives. This is because the chemical and physical structure is heterogeneous on a distance scale comparable to, and in many cases larger than, the reaction zone in the detonating explosive. Such systems consist of inter-molecular fuel-oxidizer systems. Attempts have been made to minimize the heterogeneous nature (inter-molecular distances) of these explosives; emulsion systems are the latest examples of these commercialized AN-based explosives which balance cost, utility and performance. This latter factor (increased performance) is a direct result of increasing the contact between oxidizer and fuel.

Jan 1, 2003

By S Freij, P W, R Gunawan, D Zhang, B Feng

The Mt Whaleback iron ore mine is located adjacent to Newman, approximately 1200 km north of Perth, in the Pilbara District of Western Australia. Approximately 15 per cent of the waste materials are in the zones with high concentrations of sulfide and carbonaceous minerals and are referred to as æreactive shaleÆ. The reactive shale has the potential to undergo self-heating and can react with the ammonium nitrate (AN) based explosives used in mining operations, resulting in spontaneous combustion and spontaneous explosion. The sulfide-rich shales also have the potential to produce acid rock drainage (ARD). In the present study, over 200 shale samples have been collected from different locations in the Mt Whaleback iron ore mine, including blasthole drill cuttings, fresh mine faces and waste dumps. These samples have been systematically characterised for their geochemical properties. Based on the characterisation results, a pH test was developed as a cost-effective, fast and efficient tool for the assessment of reactive ground in the mining industry. This paper summarises the results of the sample characterisations and discusses the key findings arising from the interpretation of results. These results have significant implications in the safe storage of the reactive shales and the prevention of spontaneous explosion, spontaneous combustion and ARD.

Jan 1, 2005

By W. O. Philbrook, H. W. Hosking, N. B. Melcher

Rates and patterns of gas flow in an experimental blast furnace were investigated by measurements, at three levels, of gas compo-sitions and temperatures and by direct determination of gas transit time by a new method employing mercury vapor as a tracer. Infer-ences were drawn about localized reaction zones and the mechanism of the onset of' channeling. LACK of precise knowledge of the nature of gas movement in the blast furnace has always been an impediment to better understanding of the blastfurnace process as a whole. The effects upon operation of various types of charge distribution are very largely brought about by the modifications to gas flow which they occasion. Intelligent evaluation of these effects demands a better understanding of the factors influencing gas flow and the ways in which the flow pattern is altered by conditions existing in the stock column. The same knowledge is required before a fundamental approach can be made to the problem of establishing optimum lines for new furnaces. An experimental furnace is operated at the Bureau of Mines Central Experiment Station, Pittsburgh, Pa. Advantage was taken of experimental operation to conduct an investigation to develop and evaluate methods of study which could be applied later to industrial furnaces. The gas composition and temperature determinations were made as a preliminary study so far as gas flow was concerned but yielded significant information relating to other processes occurring within the furnace. The direct measurement of gas transit times by the mercury-vapor method constituted the major object of the investigation. Development of the mercury-vapor method was carried out while the data on gas composition and temperature were being collected. A complete description of the principle and development of the mercury-vapor method is beyond the scope of this paper but is available elsewhere. The results obtained and some consideration of the method's effectiveness and its potential value in the study of industrial problems will be treated here. DESCRIPTION OF FURNACE The general lines of the experimental blast furnace are shown in Fig. 1. The hearth diameter was 3 ft at the beginning of the investigation, and this was later enlarged to 3 ft 9 in. and finally to 4 ft to increase capacity. Tuyere to stockline height is 21 ft 4 in. The bosh depth is 3 ft 4 in. over which it opens to a width of 5 ft, and this diameter is carried up for 2 ft in a cylindrical section. The inwall batter of 1/2 in. per ft. is considerably less than in larger installations This may have influenced the movement of gaseous and solid materials. The furnace is inside a laboratory building and is charged from outside by a skip and hoist. Feeding into the first of three bell chambers, the stock is distributed by rotating the upper bell, the other two being used to obtain an effective gas seal. Three water-cooled tuyeres, with a nozzle dia-

Jan 1, 1960

By Sami Makni, Ahmed Bouajila

"To remain competitive in an open market, mining companies are more and more requested to optimise their complex and highly multivariate processes. The increasing amount of process data, brought about by intensive use of instrumentation and the progress in computer data acquisition, enhances the need for more and more powerful and robust tools for the analysis and modelling of the process data. Now, with the emergence of multivariate data analysis (MDA) techniques, on-line clustering of mineral process behaviour is possible and could help in the extraction of valuable process operation indicators. MDA can be used in different mineral processes such as flotation, grinding, smelting etc.In this paper, we focus on grinding process considered as the most costly and power consuming node of the mineral processing scheme. Different objective-oriented levels of data clustering will be addressed.First, the evaluation of grinding operation taking into account data and constraints from all processes before (e.g. blasting, crushing) and after (e.g. flotation, leaching, etc.) the grinding node. The second level deals with process diagnosis by differentiating operation level and identifying behaviour drifts. Control and optimisation are two other levels concerned here with the selection of optimum trajectories in the drift correct.Industrial plant data are processed in order to illustrate the feasibility and the potentiality of MDA applications in addressing the clustering and interpretation of grinding mill behaviour."

Jan 1, 2003

By A. Maréchal

It has been shown since a few years that the problem of estimating recoverable reserves should be solved by using specialized statistical techniques : whenever the selected blocks are chosen without any other constraint than a cut-off grade criterion, the problem of estimating the corresponding tonnage-grade curve is resolved by estimating the local histogram of block grades. Two major statistical techniques are currently used by geostatisticians to estimate local histograms : the "average conditional distribution" technique (Parker, Journel, Dixon 1979) and the disjunctive kriging technique. (Matheron, 1976, Jackson, Maréchal, 1979). Both have proved to be applicable in practice, with their pros and conconcerning their practibility and versatility.

Jan 1, 1982

By Marina Nicolova, Irena Spasova, Plamen Georgiev, Stoyan Groudev

Different strains of "silicate" bacteria were used to improve the quality of kaolin by different ways of treatment. All strains formed large slimy capsules consisting of exopolysaccharides and were related to different species of the genus Bacillus, mainly to B. circulans and B. mucilaginosus. It was found that even a short contact of some hours of well developed cultures of these bacteria resulted in improvement of the bending strength and the other ceramic properties of the kaolin. The improvement was connected with the action of some secreted microbial metabolites such as soluble heteropolysccharides, monosugars and organic acids. The best results were achieved by continuous cultivation of bacteria in the presence of kaolin with a high relative humidity and subjected to periodic stirring.

Jan 1, 2014

By Laila A. Guirguis

Impurities are removed from crude phosphoric acid (57.75% P2O5) with a mixture of low and high molecular weight alcohols, one of which is hydrophilic and the other is hydrophobic i.e. methanol and hexanol. In a single stage, the phosphate values segregate to the high molecular weight alcohol fraction and the impurities segregate to the low molecular weight alcohol fraction. The optimum ratio for the extraction is found to be 0.5 part methanol, one part impure acid and four parts hexanol where an extraction percent of more than 95% is achieved. Re-extraction of the phosphate value from the solvent is obtained by 6% phosphoric acid and the different factors affecting the re-extraction process have been studied. Finally, the purified acid is concentrated under reduced pressure and passed through activated carbon column, whereas the alcohols are re-circulated. The produced phosphoric acid was found to be in good match with the international specifications of food grade quality acid. A technological flow sheet is elucidated.

Jan 1, 2006

By A. D. Pelton

The evolution of thermodynamic models of molten salts and slags, starting with Temkin in 1948, has culminated in today?s sublattice models. These modern models have permitted the development of large thermodynamic databases of model parameters, which can be used to calculate and predict accurately the properties of multicomponent solutions. The model parameters are mainly obtained by the critical evaluation and optimization of available thermodynamic and phase equilibrium data for binary and ternary subsystems. The models are then used to estimate the properties of multi component slags and salts from these assessed binary and ternary parameters. When used in conjunction with thermodynamic databases for solids and solid solutions (salts, oxides, sulphides, metals, etc.), other liquid solutions (such as liquid metals),and gases, these databases permit the calculation of complex multiphase equilibria in multicomponent systems, with applications in a wide variety of industries. These calculations can be performed with general commercial software for Gibbs energy minimization, which can also be incorporated into process simulation software packages. Keywords: slags, salts, solution models, thermodynamics, phase diagrams, oxide systems, molten salts

Jan 1, 2004

By W. O. Philbrook. K M Goldman, M. M. Helzel

RADIOACTIVE calcium has been used to learn whether calcium can be detected in iron saturated with carbon after it has been melted under CaO- A12O3- SiO2 slags similar to those used in the iron blast furnace. It was hoped that the radioactive tracer technique might make possible a general study of steelmaking reactions in which calcium or calcium oxide are involved. No calcium could be found in the metal under conditions which were favorable for the reduction of calcium, and it has been concluded that the calcium content of the iron was less than 6 x 10 - pct. Some of the problems encountered have been instructive with regard to pitfalls and limitations of tracer methods. Calcium oxide occurs in almost all iron- and steelmaking slags, and it is essential to the success of all commercial basic steelmaking processes. Calcium alloys are sometimes used in the deoxidation of steel and for the innoculation of gray iron. The element calcium is therefore almost as ubiquitous in the steel industry as are carbon and oxygen, but calcium has been thought to be completely immiscible with iron in both the liquid and the solid states.' It does not seem entirely unreasonable to Suppose, however, that some low concentration of calcium might exist in liquid iron under a basic slag with other conditions being favorable, just as silicon and other elements can be introduced into iron by reduction of their oxides from slags under appropriate circumstances. The radioactive tracer technique offered a more sensitive method than chemical analysis of testing this supposition. The reasons for interest in this investigation were strong enough to justify a recognized risk of failure. On the theoretical side, information on the distribution of calcium between liquid iron and a slag and the rate at which the equilibrium distribution is approached would contribute strongly to the general theory of slag-metal interface reactions. Furthermore, any evidence on the presence of calcium in liquid iron might provide a vital clue to the mechanism of the desulphurization of iron by slags. All of the reactions which have been proposed to explain desulphurization postulate that the sulphur ultimately becomes fixed in the slag as calcium sulphide, but the mechanism by which sulphur

Jan 1, 1951

By C. L. Sainsbury

Lode and placer tin deposits of the western Seward Peninsula, Alaska, have produced more than 2200 tons of metallic tin and constitute the only known domestic deposits of economic grade and size. The lode deposits consist of quartz-topaz greisens containing cassiterite and wolframite as well as numerous base-metal sulfide minerals, and most are in or near altered biotite-granite that forms isolated stocks or in rhyolitic dikes near granite. Within the main lode-producing area in the central York Mountains, nonpegmatite beryllium deposits, consisting principally of fluorite, chrysoberyl, diaspore, tourmaline, and white mica, with minor euclase, bertrandite, phenakite, hematite, and todorokite, are distributed zonally around the tin deposits and locally are transitional with them. All the known beryllium deposits are replacement lodes in carbonate rocks. In the area discussed, both tin and beryllium deposits are localized in a structural belt striking N70° to N85°E across the central York Mountains. The belt is characterized by numerous normal faults, which cut extensive thrust sheets, and by dikes of rhyolite, rhyolite porphyry, and lamprophyre that were injected along the faults. Ore deposits are localized where the dikes intrude brecciated rocks beneath thrusts and, although complex in detail, form tabular lodes that tend to lie along the thrusts. The granites contain abnormal amounts of tin, beryllium, lithium, and boron, and the tin and beryllium lodes are believed to be genetically associated with these enriched granites

Jan 1, 1968

By I M. Platten, Y Xie

Sampling protocols that are designed to suit the mineralisation style will result in a reduction of the nugget effect and hence resource risk. The a priori need for all sampling programs is the effective characterisation of the mineralisation type(s) to support optimisation. This requires a program of sampling for sampling followed by holistic characterisation. At each end of the coarse-gold to fine-gold spectrum, the samplability of a deposit ranges from relatively simple for fine-grained disseminated gold particles, through to extremely difficult for coarse nuggety mineralisation. Many deposits contain a proportion of both particle size types. The proportion and size of coarse gold particles has a direct impact on the effectiveness of sampling, where coarser particles will require larger samples and more specialised protocols. The nature of mineralisation geology/mineralogy and associated gold particle sizing can only be determined by sampling to facilitate optimised protocols. Mineralogical studies, focusing on particle size, particle clustering and distribution in host minerals, are required as part of wider paragenetic and metallurgical investigations. This paper discusses the role of mineralogical studies in the characterisation of gold ores for sampling optimisation through a series of case studies.

Jan 1, 2008

Masjid-i-Su1aiman.—There have been no new developments in the Masjid-i-Sulaiman field during the year. Drilling, deepcning and acidizing operations for maintenance of production havc continued normally. Reservoir conditions have been unchanged, the rate of fall of dome prcssure remaining very low—at about 0.4 lb. per sq. in. per million tons net production. Drilling on the Lali structure northwest of Masjid-i-Sulaiman has continued but oil has not been encountered in commercial quantities. Haft Kel.—The progressive drilling program extending the production capacity of the Haft Kel field was completed carly in the year and the field is now on a routine maintenance basis. Drilling has continued on the white-oil springs structurc northwest of Haft Kel. Naft-i-Shah.—No developments of interest have occurred in Naft-i-Shah field. Offtake is for local markets only. A further large produeer was completed during the year. Gach Saran.—By the end of 1939, work on plant and pipe lines to put, the field on a production basis was approaching completion. Two substantial producers were also drilled in the initial production area. Pazanun and Agha Jari.—No further drilling was carried out on the Pazanun structure during the year, gas only having been obtained to depths exceeding 8000 ft. On the adjacent Agha Jari structure, however, a second satisfactory oil producer was completed.

Jan 1, 1940

Masjid-i-Su1aiman.—There have been no new developments in the Masjid-i-Sulaiman field during the year. Drilling, deepcning and acidizing operations for maintenance of production havc continued normally. Reservoir conditions have been unchanged, the rate of fall of dome prcssure remaining very low—at about 0.4 lb. per sq. in. per million tons net production. Drilling on the Lali structure northwest of Masjid-i-Sulaiman has continued but oil has not been encountered in commercial quantities. Haft Kel.—The progressive drilling program extending the production capacity of the Haft Kel field was completed carly in the year and the field is now on a routine maintenance basis. Drilling has continued on the white-oil springs structurc northwest of Haft Kel. Naft-i-Shah.—No developments of interest have occurred in Naft-i-Shah field. Offtake is for local markets only. A further large produeer was completed during the year. Gach Saran.—By the end of 1939, work on plant and pipe lines to put, the field on a production basis was approaching completion. Two substantial producers were also drilled in the initial production area. Pazanun and Agha Jari.—No further drilling was carried out on the Pazanun structure during the year, gas only having been obtained to depths exceeding 8000 ft. On the adjacent Agha Jari structure, however, a second satisfactory oil producer was completed.

Jan 1, 1940

By M. C. Udy, P. C. Rosenthal

The use of minute boron additions to steel has been given considerable attention in recent years. Comparisons made between boron-free and boron-containing heats of otherwise identical analysis have indicated, beyond a doubt, the potent effect of boron for increasing hardenability. The actual hardenability increase has been expressed as a multiplying factor, or in terms of the percentage of other alloying elements boron might replace. The present study presents the results of a systematic survey of the use of boron as an addition to two types of alloyed steels and as a replacement for various percentages of molybdenum in these steels. Both cast and wrought steels of the two basic compositions were prepared. Molybdenum, because of its scarcity at the time the investigation was started, was selected as the element to be replaced by boron. Attention was also given to the effects of boron on other properties of the steels, particularly their notched-bar toughness, to investigate other advantages or limitations of this element as an alloy addition. Experimental Work Steels Investigated The two basic compositions used in this survey of boron as a replacement for molybdenum are given in Table I. The cast steels were higher than the wrought steels in silicon content to improve the casting quality. Table i.—Nominal Composition of the Two Base Alloy Steels composition. Per Cent. steel Mn Si Ni Cr Xi-Cr-Mo Wrought 0.28-0.70-0.15-o.45—o.45-0.32 0.90 0.25 0.55 0.55 Cast 0.28-0.70-0.35-0.45-o.45- 0.32 0.90 0.45 0.55 0.55 hln-&lo Wrought 0.28-I .go-o.0.15-0.32 1.70 0.15 Cast o. 28- I.40- 0.35- 0.31 1.70 0.45 a Sulphur was 0.040 per cent maximum and phosphorus 0.030 per cent maximum. Each of these base steels, both cast and wrought, was made with molybdenum contents of o, 0.10, 0.20, 0.30, or 0.40 per cent, the total comprising 20 steels. In addition, each of these 20 compositions was prepared with boron additions in amounts of o.oo15, 0.003, and 0.006 per cent as ferroboron; and in amounts of 0.002 and 0.005 per cent as two commercial intensifier alloys, designated alloys A and B. The boron-treated steels totaled 100, and the entire series 120. Test Procedure Each steel was melted as an individual heat in a 50-lb., magnesia-lined induction furnace. Ingot iron scrap or mixtures of ingot iron and steel. scrap were used for melting stock. Deoxidation was carried out in the furnace with 0.10 per cent aluminum. The aluminum addition was

Jan 1, 1948

By M. C. Udy, P. C. Rosenthal

The use of minute boron additions to steel has been given considerable attention in recent years. Comparisons made between boron-free and boron-containing heats of otherwise identical analysis have indicated, beyond a doubt, the potent effect of boron for increasing hardenability. The actual hardenability increase has been expressed as a multiplying factor, or in terms of the percentage of other alloying elements boron might replace. The present study presents the results of a systematic survey of the use of boron as an addition to two types of alloyed steels and as a replacement for various percentages of molybdenum in these steels. Both cast and wrought steels of the two basic compositions were prepared. Molybdenum, because of its scarcity at the time the investigation was started, was selected as the element to be replaced by boron. Attention was also given to the effects of boron on other properties of the steels, particularly their notched-bar toughness, to investigate other advantages or limitations of this element as an alloy addition. Experimental Work Steels Investigated The two basic compositions used in this survey of boron as a replacement for molybdenum are given in Table I. The cast steels were higher than the wrought steels in silicon content to improve the casting quality. Table i.—Nominal Composition of the Two Base Alloy Steels composition. Per Cent. steel Mn Si Ni Cr Xi-Cr-Mo Wrought 0.28-0.70-0.15-o.45—o.45-0.32 0.90 0.25 0.55 0.55 Cast 0.28-0.70-0.35-0.45-o.45- 0.32 0.90 0.45 0.55 0.55 hln-&lo Wrought 0.28-I .go-o.0.15-0.32 1.70 0.15 Cast o. 28- I.40- 0.35- 0.31 1.70 0.45 a Sulphur was 0.040 per cent maximum and phosphorus 0.030 per cent maximum. Each of these base steels, both cast and wrought, was made with molybdenum contents of o, 0.10, 0.20, 0.30, or 0.40 per cent, the total comprising 20 steels. In addition, each of these 20 compositions was prepared with boron additions in amounts of o.oo15, 0.003, and 0.006 per cent as ferroboron; and in amounts of 0.002 and 0.005 per cent as two commercial intensifier alloys, designated alloys A and B. The boron-treated steels totaled 100, and the entire series 120. Test Procedure Each steel was melted as an individual heat in a 50-lb., magnesia-lined induction furnace. Ingot iron scrap or mixtures of ingot iron and steel. scrap were used for melting stock. Deoxidation was carried out in the furnace with 0.10 per cent aluminum. The aluminum addition was

Jan 1, 1948

The Bluebell mine of The Consolidated Mining and Smelting Company of Canada Limited extends under Kootenay lake, in southern British Columbia, and water control underground has always been a major problem. This paper gives a brief history of the operation, and then de-scribes the methods used by Cominco to keep the combination of lake seepage, ground water and thermal spring water under control. The pumping arrangements are de-scribed in considerable detail, with illustrations to show the various stages of development, and the power supply sys-tem is outlined.

Jan 1, 1966

By H. M. Giegerich

About Cominco Only the original Broken Hill zinc deposit in Australia is larger than Cominco's Red Dog deposit. Indeed, the third largest zinc deposit in the world is Cominco's own Sullivan mine in British Columbia. The production plan at Red Dog is based on mining 1.9 Mt/a (2.1 million stpy) or ore, to produce 635 kt (700,000 st) of zinc and lead concentrates. At full production, Red Dog will be the largest zinc mine in the Western world. It will also be one of the lowest cost producers in the Western world. And Red Dog will be one of the first major hardrock mines to operate in Alaska in modern times. The Red Dog project will be the third and largest of Cominco's Arctic mining developments in the past 13 years. The company's Black Angel mine in Greenland started up in 1973. And the Polaris mine, high in the Canadian Arctic, began production in 1982. Red Dog is one of the world's great mineral deposits. It is a unique combination of large size, high grade, and a waste-to-ore ratio less than 1:1. The present mineral reserve (Table 1) is estimated to be 77 Mt (85 million st), at a grade of 17.1% zinc, 5% lead, and 82 g/t (2.4 oz per st) of silver. Mine life is estimated at nearly 50 years. Cominco is the largest producer of lead and zinc in the Western world. Cominco's smelter in southern British Columbia is the largest lead and zinc plant in the west. Cominco also produces copper, steel, tin, gold and silver, along with potash, ammonia, urea, and phosphate fertilizers. But Cominco's major products are lead and zinc. At present, Cominco produces more than 10% of the Western world's needs for these metals. Background-Red Dog The Red Dog mineral deposit is located in northwestern Alaska, about 960 km (600 miles) by air from Anchorage, Alaska's largest city. The Red Dog region is home to more than 5000 people living in 11 villages. The largest village is Kotzebue, with a population of about 2500. The village is located about 144 km (90 miles) southwest of the mine. The country around Red Dog features rolling hills, leading into mountains to the north and east. The deposit, at an elevation of 305 m (1000 ft), is in permafrost. But the area is not nearly as cold as that encountered in the Canadian Arctic, or on Alaska's North Slope. At Red Dog, the permafrost is relatively fragile. It can be thawed fairly easily, a factor in engineering designs. Red Dog Creek flows through the mineral deposit. One of the natural phenomena at Red Dog is the presence of significant heavy metal contamination in the creek. This has eliminated all fish in the vicinity of the deposit. The contamination, and resulting mineral stain, led to the discovery of Red Dog. The staining is caused by rain and snowmelt. This leaches the heavy metals from the mineral zone, which comes right to the surface in many places. As mining progresses, this surface mantle will be removed. This will

Jan 12, 1986

By Fangming Liu

The key problems of current flowsheets and equipments are analyzed. A new steel slag's crushing flowsheet whose key equipments are the improved inertia cone crusher and inertia vibrating jaw crusher is proposed. An advanced two stage open-circuit crushing method is adopted in the flowsheet, with 90% of particle size crushing under 6mm. Using inertia vibrating technology and selective crushing principle the crushers can realize steel slag separating fully into steel and slag and with flexible transmission mechanism the crusher can be protected when iron lump is passing. The flowsheets can enhance the recovery of metal greatly, and expand the application range of tail slag and added value.

Sep 1, 2012

By J. O. Betterton, W. K. Noyce

I~JTI HE work on the indium-zirconium system is part A of a larger investigation of zirconium-phase diagrams with solute elements, silver, cadmium, indium, tin, and antimony, which is intended to provide information about the metallic valency of zirconium. The system is an ideal example since the sizes of indium and zirconium atoms are nearly the same, and the solute and the solvent occur in the same row of the periodic table. The only solute from Group III B which had previously been added to zirconium was aluminum' and it was of interest to determine whether indium would dissolve appreciably in alpha zirconium and stabilize this phase in the same manner. Experimental Procedure The experimental methods used in the indium-zirconium work are similar to those described earlier for the silver-zirconium system.' Reactor Grade 1 iodide zirconium of 99.95 pct purity* and indium of 99.99 pct purity were arc cast, and then annealed in silica capsules with protective foils of zirconium and molybdenum. Annealing temperatures and times varied from 1 day at 1300°C to 43 days at 550°C. The compositions of the alloys were detcrmined by an individual chemical analysis of the actual metallographic specimens after two or more sides were examined to insure the absence of solute segregation. Calibrated thermocouples were used throughout, and the uncertainty in the temperatures reported, owing to calibration error, furnace control, and measurement of the small temperature gradients near the capsules, is believed to be well within ±2°C. Typical impurities in the alloys were found by a neutron-activation analysis of four different alloys. The results are given in Table I where the ranges of values will be seen to compare favorably with the usual values for iodide zirconium. With respect to oxygen, nitrogen, and carbon the absence of any unusual amount of these elements compared to iodide zirconium was indicated by the alloy hardness values, since hardness is increased sharply by the presence of these elements. The value for 0 pct In, obtained from the alloys by extrapolation, is 58 2 7 VPN which is in the low part3 f the normal range of hardness found in iodide zirconium. Results of the Experiments The zirconium-rich portion of the indium-zirconium phase diagram from the annealing experiments is shown in Fig. 1. Indium was found to

Jan 1, 1959