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By Meifeng Zhi, Yuqing Niu, Xixin Chang, Fengqi Zhao, Weimin Qiu, Hao Wang, Zhenqian Wen, Zujun Shu

An applicable Eluex process was developed for acid in-situ leaching (ISL) uranium mine in Bayanwula. In this process, uranium was adsorbed with strong base anion resin from the pregnant solution, then the loaded resin was eluted by sulfuric acid. After D2EHPA extraction, the concentrated eluate was enriched, and the loaded organic phase was stripped by sodium carbonate. The yellow cake was obtained by sodium hydroxide precipitation at last. The uranium concentration in the loaded strip solution was 52.8 g/L. Parameters of the process were determined, and the impact of the Eluex process in underground leaching was also investigated. In industrial design, 95% of raffinate went back to elution and 5% back to in-situ leaching. No significant effect on uranium leaching or resin adsorption was found.

Jan 1, 2020

By R. Cottam

The deformation and recrystallisation of magnesium yttrium alloys containing 0.23, 0.84 and 2.71wt% yttrium and commercially pure magnesium extrusion has been investigated at temperatures between 200 and 350°C. The alloys were produced as billets 7.5 cm diameter, solution treated at 525 °C for 8 h and extruded into 3 cm diameter bar at 390°C. Channel die compression was employed to deform the samples at a strain rate of 1x10-3s-1. For the 0.23 wt% yttrium alloy and the pure magnesium, dynamic recrystallization (DRX) occurred at all temperatures and the amount of DRX increased as the temperature was raised. In the alloys containing 0.84 and 2.71 wt% yttrium DRX was almost completely suppressed at all temperatures. The absence of DRX in the 0.84 and 2.71 wt% yttrium alloys was accompanied by a decrease in the ductility, except at 350°C the highest deformation temperature. It was observed that this increase in ductility was accompanied by a reduction in deformation twinning and the initiation of pyramidal slip. This work highlights the important role that DRX plays in enhancing the ductility of magnesium alloys.

Jan 1, 2006

By S. E. Wolfe

The presence of helical ribs in smooth-bore round pipe results in the transport of granular solid particles m water at a much lower velocity than required to transport the same solids in a smooth pipe. The helical motion imparted to the flowing mixture effectively returns settled solid particles to the main stream. The flow may be stopped and restarted without difficulty. Due to the lower velocity required for satisfactory transport large power savings are realized. Also: due to lower velocity, the wear on the pipe walls is much reduced. For satisfactory performance, the ribs should have a high angle relative to the long axis of the pipe and the lineal spacing between adjacent ribs should be modest.

Jan 1, 1967

By Lin-fang Shen, Shao-jun Li, Zhi-liang Wang

"The meso-structure of real soil consists of numerous particles with different sizes, while the traditional reconstruction method of quartet structure generation set (QSGS) produce relatively uniform soil particles resulting in significant discrepancy between the actual structure and reconfiguration model. In order to remedy the deficiency, the QSGS is improved by considering the influence of porosity and autocorrelative function of soil, which make the models closer to the real soil. Based on the reconfiguration model, Lattice Boltzmann method is combined in the algorithm to conduct further simulation of fluid flow in soil pores. The D2Q9 model is applied to construct the two dimensional model for simulating mesoscopic seepage field of saturated soil by setting the non-equilibrium extrapolation scheme at the inlet and outlet boundary, and the bounce-back scheme at the soil particles boundary as well as the left and right boundary. According to the case study, the proposed program is realized to simulate mesoscopic seepage field of reconstructed soil with constant inlet seepage velocity. The results show that the seepage direction of soil is along the passage with good connectivity, therefore the permeability is controlled by these passages. The seepage velocity in such channels is faster than in bad connectivity channels. Even if the channel has larger pores, the seepage velocity is still small. INTRODUCTIONUnderstanding the seepage mechanism in porous materials is significant in both theoretical and engineering problems. As a typical porous media, soil consists of solid particles and voids, which form connected channels allowing water to flow through. Such seepage in soil exists widely among geotechnical project of slope, foundation pit, and tunnel, etc. Meanwhile, a number of engineering accidents are caused by limited knowledge of seepage characters in soil (Huang, 2006; Liu, 2013). The conventional method in describing seepage features mostly based on the parameter of permeability, which is a macro statistic mean evaluating the whole connectivity of soil. Obviously, this parameter cannot exactly reflect the details of how water flows through the inner soil structure, especially the flow velocity in local mesoscopic area, hence is unable to represent the actual seepage properties. Therefore, it is necessary to develop mesoscopic approaches to fully study the seepage mechanisms."

Jan 1, 2015

By K. Sawamukai, S. Ogasawara, D. Umenai, T. Tsuruta

"Removal of cobalt, strontium or cesium ion from the aqueous solution containing each metal ion only using microorganism was examined. Arthrobacter nicotianae which had a high ability to remove cationic metal ion was used for the removal of each metal. The removal of cobalt, strontium or cesium using A. nicotianae cells was affected by the solution pH, concentration of metal ion, and cell amount. The effects of above mentioned factors on the removal of each metal and time course of strontium from the solution containing each metal only using A. nicotianae cells were reported in this paper. INTRODUCTIONRadioactive elements, such as cesium, iodine, strontium, plutonium, barium, cobalt, lanthanum, yttrium, and tellurium, were detected around Fukushima Daiichi nuclear power plant, which was damaged by the magnitude 9.0 earthquake and the tsunami followed.The removal of radioactive elements from contaminated sources is a worthwhile subject to investigatein terms of environmental control. Research efforts have been especially concentrated on studying microorganisms that remove uranium including bacteria (Andres et al, 1993, Hu et al, 1996, Marques et al, 1991, Strandberg et al, 1981), actinomycetes (Byerley et al, 1987, Friiss and Myers-Keith, 1986, Golab et al, 1991), fungi (Byerley et al, 1987, Galun et al, 1983a, Galun et al, 1983b,Tsezos and Volesky, 1981, White and Gadds, 1990) and yeasts (Strandberg et al, 1981, Schmate II et al, 1978).We have investigated removal and recovery of uranium from aqueous systems using microorganisms isolated from uranium mines. We identified some strains of bacteria with extremely high uranium removing abilities (Sakaguchi et al, 1996), and thus, the microbial biomass may be considered as an adsorbing agent for the removal and recovery of uranium and heavy metals present in aqueous systems around Fukushima Daiichi nuclear power plant.In the present study, we screened various species and strains of bacteria, actinomycetes, fungi, and yeasts for their ability to adsorb uranium (Tsuruta, 2002). Basic features affecting uranium adsorption?co-existing cations and anions, cell amounts, pH, and the adsorption time course?by Arthrobacter nicotianae cells, which adsorbed the largest amount of uranium, were also investigated. In addition, we examined the removal of an other actinoid element, thorium ion, which may be present with uranium in refining effluents.In this paper, the removal of cobalt, strontium, or cesium from the solution containing each metal ion using A. nicotianae cells is discussed."

Jan 1, 2012

By Vishal Shukla, Prateek Singh, D. P. Chakraborty

"Continuous thickening by an operation called sedimentation is the separation of suspended solid particles from a liquid stream by gravity settling. The primary purpose of thickening is to increase the solids concentration of the feed stream. High rate thickeners are designed specifically to maximise the flocculation efficiency. A detailed investigation has been carried out to understand the influence of ore type and operating parameters such as bed level, bed mass, rake arm torque and flocculent concentration on thickening operation. Tata steel’s Noamundi plant data shows that variation in ore type, and operating parameters are major contributors to fluctuation in thickener performance. A lot of research has been done earlier on thickening operation but effect of ore type and operating variables by using plant data was never touched before.In this context, the performance of thickener was evaluated by daily data to study the influence of ore type and operating variables on thickener operation. Investigation shows that friable ore % in feed mix is proportional to slime density because friable ore is porous & brittle in nature. As a result, friable ore generates more fines/ultrafine during communition process in wash plant. Increase in flocculant concentration and bed mass is showing a positive change on high rate thickener performance Investigation shows that optimum bed mass and flocculant concentration is required to achieve desired pulp density in thickener underflow at different feed pulp density (g/cc).INTRODUCTIONOver the years, Iron Ore Beneficiation at Tata Steel, Noamundi has seen varied changes. Depletion of high grade iron and with increasing iron ore throughputs coupled with lowering of the hard ore a subsequent increase in slime generation, slime management and clear water requirement for wet Plant has thrown up myriad challenges. To overcome these challenges, many improvements initiatives were taken by Tata Steel in last decade. One of the major changes is the recent High Rate Thickener commissioning at Tata Steel Noamundi to cater the high iron ore throughput requirement. Slime reporting to Thickener has increased from 1.4 MTPA 2.5 MTPA over the last few decades. The above changes further aggravate the poor settling and dewatering characteristics of the slurry which is being feed to HRT. Considering the above mentioned constraints and stringent environmental implication proper water management has become a major challenge to reckon with. The thickener is used to increase the concentration of the suspension by sedimentation, accompanied by the formation of a clear liquid. In most cases the concentration of the suspension is high and hindered settling takes place."

Jan 1, 2016

By Gaoming Wang

Outline 1. The Gangdese porphyry Cu-Mo belt 1.1 Regional geological background 1.2 Cu-Mo-bearing porphyries 1.3 Mineralization and alteration 2. Dating methods and results 2.1 Qulong porphyry 2.2 other porphyries 3. Geodynamic implications 4. Conclusions 5. Acknowledgements

May 1, 2004

By Osvaldo A. Bascur

Business Challenges ? Many Versions of the Truth ? Lack of Enterprise Visibility (Transparency) ? Limited Communication & Collaboration ? Complex Implementation & Maintenance of software ? End user ease of use of information applications ? Responsive to change ? Access to timely information ? Secure computing ? Maturing Workforce Real time Portal - First of All ? Why Move to a Portal - Portals Recaptures the Business User - Broader Scope - Easy Navigation, World Standard - Features of a Portal - User Profile - Delegation (Secure Delegation of Admin Authority e.g. portal\pat) - Single Sign-On ? HUGE

May 1, 2004

By Fernando Canales

In the last decade a great dealt of attention has been paid to the chemistry of polynuclear gold derivatives with a central heteroatom, not only from the experimental and structural but also from the theoretical standpoint (1). Interesting hypercoordinated species of the type [C(AuPR3)5]+, [C(AuPR3)6]2+, [N(AuPR3)5]2+, [P(AuPR3)5]2+ and [P(AuPR3)6]3+ have been described (2), apart from other complexes with more conventional stoichiometry, and all have in common the presence of gold-gold interactions of ca. 3 Å. Usually, the chemistry of the first row elements of the p-block is known to follow classical rules of bonding, and only in cases of extreme electron-deficiency has the traditional electron count to be reconsidered to account for special types of molecular or solid state structures. Many of these heteroatomcentered complexes are electron-deficient and the gold-gold interactions provide a significant contribution to their stability. The attraction between these closed-shell systems has recently captured the attention in inorganic and organometallic chemistry (1). P. Pyykkö has summarized the available theoretical and experimental evidence of intra- and inter-molecular interactions between heavy metal atoms, such as Au(I) (3). In general, when heavy metals are involved in such interaction, the closed-shell attractions are of metallophilic or van der Waals type, as has been found for d8, d10 coinage-metals, and d10s2 centers. Experimental evidence for the aurophilic Au(I)???Au(I) attraction is available from crystallography, NMR and Raman spectroscopies, and optical spectroscopic measurements of the interaction strength (4). It is manifested in molecular conformations with relatively close Au???Au interactions of ca. 3 Å, whose strength has been estimated at ca. 25-50 kJ/mol (5). These attractions are weaker than most covalent or ionic bonds, but stronger than other van der Waals bonds and comparable in strength to typical hydrogen bonds. The phenomenon cannot be satisfactorily explained by classical theories such as hybridization (3). From a theoretical point of view, the attractions close to equilibrium distances are caused by dispersive interactions together with relativistic effects (6). The attractive contributions are dominated by pair-excitations from the heavy metal, such as gold, strengthened by relativistic effects. In all the cases where there are inter- or intramolecular metal-metal attractions, the correlation effects are essential; if they are omitted, at the Hartree-Fock (HF) level, repulsive interactions are obtained (6). Hence, it is necessary to use at least second-order Møller-Plesset level (MP2) methods for the dispersive forces, which are included in the electronic correlation effects (7).

Oct 1, 2003

By Floyd B. Bowen

Pumping methods are used, almost exclusively, to transport materials in the mining, beneficiation and chemical processing of phosphate rock in the Florida phosphate pebble field. Matrix pumping systems capable of pumping 15,000 g.p.m., transporting 15,000 long tons (dry) per hour, are now in use. They utilize 16-by 48 Yz -in. pumps, driven by 1.250-h.p. motors, discharging into pipelines 20 inches .in diameter .and sometimes several miles in length. As an average, it is necessary to pump 3 tons of matrix to the beneficiation plants, and to dispose of 2 tons of sand tailings and clay as waste, in order to produce 1 ton of shipping-grade rock. The washers and flotation plants, where the clay and phosphate and silica particles are separated, require the movement of large volumes of slurries with densities ranging from 2-3 per cent to 45 per cent solids, by weight. Extensive waste disposal systems require the pumping of dilute clay slurries in quantities of up to 50,000 g.p.m.,

Jan 1, 1963

By H. H. Bleakney

THIS paper presents evidence that in 3 1/2% nickel steel, the published temperature for the Ac1 transformation, l,275°F., represents the completion of that transformation, and that its inception occurs approximately 275°F. lower, at about l,000°F. The formation of austenite within this range, especially at the higher temperatures, and its subsequent decomposition to martensite, results in considerable impairment of the properties of the steel. That the solid solution found to occur below l,275°F. is austenite has been questioned, but the evidence herewith presented, while not decisive, appears to be reasonably convincing. INTRODUCTION The February, 1939, issue of Metals Technology contains a very interesting paper by I. N. Zavarine, Associate Professor of Metallurgical Engineering at the Massachusetts Institute of Technology. In that paper, Professor Zavarine presented photomicrographs illustrative of the microstructures produced by heating nickel steels to a temperature slightly below the carbon change point, and holding them at that temperature for various lengths of time. His illustrations show that the structures found after such treatment do not consist merely of ferrite and carbides, but are characterized by the presence of a third phase, which he describes as a' 'sub-critical solid solution'. The occurrence of this third phase in increasing amounts is accompanied by an increase in strength and a loss of ductility and impairment of elastic ratio of the steel. Some years ago, one of the authors encountered the above-mentioned phenomenon in treating large forgings of 3.5% nickel steel. After normalizing and then drawing at l,250°F., very poor mechanical properties were obtained. Investigation of the steel disclosed no inferiority in quality. Eventually, after considerable waste of time and money, a draw temperature of l,150°F. was tried. This treatment resulted in a very great increase in elastic ratio, over 5 per cent increase in percentage elongation, and proportionate improvement in reduction of area.

Jan 1, 1941

By J. E. Gill

"The Wasa Lake property is a block of about 1,640 acres in Beauchastel township, Quebec. Gold was discovered there first in 1936 in what is now known as the 'Southern area ( Fig. 1). Stripping and trenching were followed by 9,218 feet of diamond drilling in twenty holes. A number of good intersections were obtained, but their interpretation in terms of ore was difficult. A shaft was then sunk to 220 feet vertical depth. Thirteen hundred feet of lateral work and 543 feet of diamond drilling were completed at the 200-foot level before work was discontinued in 1938. Results up to this point had been just fair.Early in 1944, surface diamond drilling was resumed. The first hole cut material of ore grade in a strong shear zone 1,000 feet north of the old workings, and holes to the east and west showed this to be an extensive gold-bearing zone.In August 1945, a main working shaft was started. This has been sunk to 550 feet slope depth. A cross-cut at 390 feet vertical depth was driven to the ore zone and, by drifting and drilling at regular intervals, a length of 725 feet had been tested to December 31st, 1946 ( Figs. 1 and 2). The results check those from surface drilling quite closely.In the main zone, scoping widths from 8 to 40 feet and averaging about 25 feet are indicated. The grade after dilution should be about 0.15 oz. gold a ton and operation will probably start at 1,000 tons a day."

Jan 1, 1954

By Ferenc Molnár, David H. Watkinson

Abstract - Cu-Ni-PGE footwall ore deposits were studied in the McCreedy East and Whistle mines along the North Range, and the Lindsley and Little Stobie mines along the South Range of the Sudbury Igneous Complex. The footwall ores in these localities differ from typical magmatic Fe-Ni-Cu- PGE deposits in the Sudbury mining camp: they have higher Cu/Ni ratios, higher PGE content, veinlike appearance and ubiquitous association of ore with hydrous silicates. Results of comparative fluid inclusion petrography and microthermometry of footwall ores indicate that high temperatures (300°C to 480°C) and heavy-metal rich saline (up to about 40 NaCl equivalent wt% salinity) fluids were associated with the formation of the PGE-rich footwall ores at moderately high pressures (around 2 kbars). However, several, possibly independent fluid circulation stages were also found at the different localities and there also are differences in detailed characteristics for ore-forming fluids especially comparing data from the North Range and the South Range. Thus, in addition to the high temperature and salinity of fluids, there are local variations in the nature of hydrothermal processes. These differences may be related to the diverse origin of fluids (magmatic, metamorphic, and formational brines) and their differing extents of interaction with the compositionally different footwall lithologies.

Jan 1, 2001

By M. J. Latva-Kokko

This paper describes the behaviour of iron and the methods used for iron control in the nickel matte leaching process. OMG Harjavalta Nickel Oy processes approximately 10 000 t/y of iron, which enters the process with the nickel matte raw material. Iron dissolves and precipitates in several different stages of the leaching process. Compounds like ferric hydroxide, parabutlerite, goethite, hematite and jarosite are found. Iron removal is done within the leaching process, and this means that the dissolution of nickel sets the limiting conditions for iron precipitation. A leach residue consisting mainly of the iron precipitates is neutralized and stacked in the waste pond. When iron is precipitated from concentrated nickel sulphate solution, some nickel is lost by co-precipitation. Recent studies have shown that Ni-Fe ratios less than 1%, attributed to co-precipitation, can be obtained with jarosite precipitates, compared to 2-3% ratios typically found with hematite precipitates. Iron can be precipitated as jarosite under the optimal nickel leaching conditions by adding ammonium sulphate to the feed slurry of the autoclave.

Jan 1, 2006

By G. F. Warning

"THE H. B. Mine is situated on the north side of Sheep Creek valley, about six miles southeast of Salmo, B.C. It is the most northerly producer along a belt containing a number of zinc-lead deposits, including the Jersey mine of Canadian Exploration Limited, 3 miles to the south, and the Reeves MacDonald mine, 12 miles to the southwest. The important zinc-lead producing area around Metaline Falls, Washington, lies 23 miles to the south. Two prospectors, Horton and Benson, located and staked the oxidized outcrops in 1.907. The property was named the H.B. after the two discoverers. Exploration by a number of operators failed to locate any sulphide orebodies until 1946, when Cominco began a geological study followed by surface drilling which was successful in locating extensive sulphide mineralization. A program of underground exploration revealed sufficient ore to war-rant mill construction. A 1 ,000-ton mill was completed by 1953, but due to low metal prices production was deferred until May, 1955. To September 1, 1959, 1,900,000 tons of zinc-lead ore have been milled; present milling rate is about 1,250 tons per day. Concentrates are trucked to the Trail Smelter, a distance of 35 miles."

Jan 1, 1960

By D. Atkinson

"Porphyry molybdenum-tungsten mineralization on the east flank of Hudson Bay Mountain crops out over 5 km2 and is intersected to depths of 2 km. Features such as a hornblende-biotite aureole, mineralogical zoning and dike, vein and fracture geometries within lithologies of the Middle to Lower Jurassic Hazelton Group and Cretaceous Skeena Group reflect an intrusive complex, the Upper Cretaceous to Early Tertiary Hudson Bay Mountain stock which has been intersected by drill holes. The stock is believed to be the mineralizing agent. A southeast-dipping granodiorite sill has been outlined by drilling within the Hazelton Group. Molybdenite and scheelite veins cut all rock types; however, the granodiorite sill hosts a higher density of fine-grained, banded, quartz-molybdenite and pegmatitic quartz-molybdenite veins reflecting a competency contrast between the intrusive sill and other country rock. Due to the relative abundance of these veins, grade is higher within areas of the sill. Above the 15000£ cross-cut 20.6 million tonnes grading 0.401% MoS2 and 0.041% W03 have been defined. During exploration of the deposit sampling procedures had to be adjusted because of the nugget effect attributed to drill intersections of banded and pegmatitic veins.IntroductionMolybdenite was discovered in outcrop at the foot of Kathlyn Glacier on Hudson Bay Mountain and first reported by the Geological Survey of Canada in 1944. The deposit has several names: Hudson Bay Mountain or Glacier Gulch, both after its location, and Yorke-Hardy after the original staker.The deposit is on the east flank of Hudson Bay Mountain, 9 km northwest of Smithers, west-central British Columbia, within NTS area 93L/14 (54° 49' North, 127° 18' West, Fig. 1). Hudson Bay Mountain, on the southern edge of the Bulkley Valley, is a dominant topographical feature reaching 2590 m elevation. Mineralization is partly overlain by the Kathyln Glacier which is visible from Highway 16. Access to the 3100 m of underground development is from a portal at 1066 m elevation on the east slope of Hudson Bay Mountain."

Jan 1, 1995

By C. H. Sleeman

"The Iron Ore Company of Canada constructed a beneficiation complex in Sept-Iles, Quebec, to concentrate and pelletize earthy red hematite iron ores from the Knob Lake area. The plants were scheduled for initial production during the first quarter of 1973.Many problems have been experienced to date. Difficulties in controlling the process, excessive mechanical failures, design deficiencies and manpower-staffing problems have caused an extended start-up. The problems are now essentially solved and, with the completion of some additional minor modifications, it is expected that the plants will be producing premium iron ore pellets at or near rated capacity within the next immediate period."

Jan 1, 1976

By M. Takebayashi, K. Takenaka, S. Matsubara, T. Yoneyama

The cathode production of Toyo Smelter and Refinery, owned by Sumitomo Metal Mining Co., Ltd. reached 450,000 tons per year in 2016 with three tank houses. Niihama tank house commenced operations in 1919 with conventional sheet cathode technology. Approximately 100 years of operation experience and the technical development enabled that the current density of Niihama tank house and the Toyo tank house #1 increased to 320 A/m2. These operation techniques were utilized at the Toyo tank house #2 which started in 2005, and its current density reached up to 350 A/m2 with permanent cathode technology. In order to achieve high current efficiency under condition of 350 A/m2 operation at Toyo tank house #2, continued efforts had been made to verticality of anodes and permanent cathodes. To improve verticality of anodes and cathodes, reduction of short circuit ratio by changing the shape of the anode, optimizing the anode pressing machine and off-line process for rectifying the distortion of permanent cathodes was carried out. In addition, concentration control of electrolyte and expansion of Ni removing ability from the electrolyte prevented passivation. Finally, more than 96% of the current efficiency was stably confirmed. INTRODUCTION Today, Toyo Smelter and Refinery of Sumitomo Metal Mining operates three tank houses in Japan, namely, Toyo tank house #1, Toyo tank house #2, and Niihama tank house with a total capacity of 450,000 metric tons of copper cathodes. Figure 1 shows the trend of cathode copper production and the current density at three tank houses over the last 10 years. Cathode production by Toyo Smelter and Refinery reached 450,000 tons per year in 2016 with three tank houses.

Jan 1, 2019

By M. Clotilde Apua, A. F. Mulaba-Bafubiandi

"The efficiency of hydrochloric acid (HCl) leaching of gold from low grade gold-bearing material has been investigated in the presence of sodium hypochlorite (NaOCl) to produce in situ chlorine gas which is an oxidizing agent able to oxidize gold metal to its soluble forms. The effect of concentrations of HCl, NaOCl, and mixtures of HCl + NaOCl was sought. Iron and potassium present in the feed were leached and consumed all the HCl. Gold found as inclusion in pyrite was not exposed to the lixiviant. Therefore, leaching of gold from low grade gold-bearing material in aqueous chlorine solution is not an effective process for now.INTRODUCTIONHydrometallurgy of gold is commonly based on cyanide leaching solution. Due to the environmental concerns related to cyanidation and mercury processes, and inefficiency of cyanide gold leaching to dissolve refractory ores, sustainable alternative lixiviant systems, capable of generating gold (I) and gold (III) complexes must be studied. Amongst non-cyanide gold lixiviants there is the chloride/chlorine system (Hilson and Monhemius, 2006; Senanayake, 2004; Pilsniak and Trochimczuck, 2007; Wang et al., 2007; Reeves et al., 1999; Khodadad et al., 2008).In practice, the most oxidizing agents utilized for the leaching of gold as chloride, are chlorine (Cl2) or hypochlorite (HOCl) which are either generated in situ by suitable reaction or added in solution (Adamson, 1972). The dissolution of gold concentrate using hydrochloric acid, sodium chloride and sodium hypochlorite (Cl-/HOCl system) were studied (Puvada and Murthy, 2006). The effect of NaOCl and NaCl concentrations were also investigated. The leaching was performed under the following conditions; time: 4h, solid–liquid ratio = 1:4, at room temperature. It was found that the increase of the NaOCl concentration from 25 to 75 g/L did not have any meaningful effect on the recovery of gold which was about 30% (experimental conditions; S/L ratio = 1:4, NaCl concentration: 25 g/L, HCl concentration: 0.35 M). It was also found that from 25 g/L to 200 g/L NaCl, the recovery of gold rose from 30% to 40% (experimental conditions; S/L ratio: 1:4, NaOCl concentration: 25 g/L, HCl concentration: 0.35 M)."

Jan 1, 2012

By H. Clare Horwood

"Fractures and fracture zones containing veins and stringers of auriferous quartz in a quartz porphyry dyke are the principal structural features at the Howey and Hasaga gold mines. The 'break' containing the dyke was produced by a force from the northwest, the fractures in the dyke by compressive stress from the west.Both mines are in the north-central part of Heyson township, in the Red Lake area. They lie close to the southeastern side of the Dome granite stock. The Howey mine exhausted its ore reserves and ceased operations in November 1941. The Hasaga mine is producing at the present time (June, 1946).Mineralization was first discovered in the dyke in 1925 by the Howey brothers. Lorne Howey's discovery, which became the Howey mine, came into production in April, 1930; Ray Howey's find, which is now the Hasaga mine, started production in November, 1938.The total production from the Howey mine was 421,324 oz. gold and 144,253 oz. silver from 5,158,376 tons of ore hoisted ( 4,319,331 tons milled) during its 11 years of operation.The total production from the Hasaga mine from November, 1938, to December 31, 1945, was 124,434 oz. gold and 51,009 oz. silver from a total of 901,098 tons hoisted (721,361 tons milled).GENERAL GEOLOGYThe porphyry dyke containing the orebodies at the Howey and Hasaga mines lies a short distance southeast of the contact of a granite-granodiorite mass known as the Dome stock. The dyke fills a fracture trending N.65°E. in a tongue of Keewatin volcanic breccia that extends in a rather irregular manner into an elongate intrusive stock of dioritic rock known as the Howey diorite. The accompanying table presents the geological succession."

Jan 1, 1954